Full mouth rehabilitation FINAL PRESENTATION

FULL MOUTH REHABILITATION AND VARIOUS PHILOSOPHIES ARE EXPLAINED IN DETAIL

1. FULL MOUTH REHABILITATION Presented by Dr.Namitha AP 3rd MDS 1

2. CONTENTS INTRODUCTION DEFFINITIONS EVOLUTION OF OCCLUSION GOALS OF FMR INDICATIONS OF FMR REASONS FOR FMR LIMITATIONS OF FMR MASTICATORY SYSTEM DISORDER INSTRUMENTS USED FOR OCLLUSAL ANALYSIS AND TREATMENT DIAGNOSTIC WAX UP OCCLUSAL EQUILIBERATION/PRINCIPLES OF OCCLUSAL CORRECETION ROLE OF OCCLUSAL SPLINT IN FMR EXAMINATION, DIAGNOSIS AND TREATMENT PLANNING IN FMR PREPARING THE MOUTH FOR FMR TREATMENT PROCEDURES AND TECHNIQUES IN FMR FINAL RESTORATIONS FOR FMR COMMON PROBLEMS AND DIFFICULTIES IN FMR POST OP CARE TECH FUTURE IN FMR CONCLUSION REFERENCES 2

3. Ultimate goal - Optimum oral health Introduction The term ‘full mouth rehabilitation’ is used to indicate extensive and intensive restorative procedures in which the occlusal plane is modified in many aspects in order to accomplish “equilibration”. Multidisciplinary Approach Both function and health can be restored in badly detiorated , diseased mouths by utilizing modern techniques of oral rehabilitation 3

4. Definition (GPT9) Full mouth rehabilitation is defined as the restoration of the form and function of the masticatory apparatus to as nearly a normal condition as possible The word rehabilitate implies ‘ To restore to good condition or to restore to former privilege’. Reynolds JM. Modern gnathological concepts—Updated: By Victor O. Lucia, DDS, FACD Chicago, 1983, Quintessence Publishing Co., Inc. 439 pages, illustrated, indexed . All the procedures necessary to produce healthy, esthetic , well functioning, and self-maintaining masticatory mechanism. 4

5. Objectives of FMR A static centric occlusion in harmony with centric relation. Even distribution of stresses in centric occlusion and on eccentric functional inclines. Equalization of forces directed against supporting structures Restoration of normal healthy function of the masticating apparatus Irving Goldman: The goal of full mouth rehabilitation, J PROSTHET DENT 1951, vol 2, 246-251 5

6. Reasons for full mouth rehabilitation   O btain and maintain the health of periodontal tissues .   Temperomandibular joint disturbance   Need for extensive dentistry as in case of missing teeth, worn down teeth and old fillings that need replacement .   Esthetics as in case of multiple anterior worn down teeth and missing teeth. Reynolds JM. Modern gnathological concepts—Updated: By Victor O. Lucia, DDS, FACD Chicago, 1983, Quintessence Publishing Co., Inc. 439 pages, illustrated, indexed . 6

7. INDICATIONS   Restore impaired occlusal function Preserve longevity of remaining teeth Maintain healthy periodontium Improve objectionable esthetics pain and discomfort of teeth and surrounding structures CONTRAINDICATIONS Malfunctioning mouths that do not need extensive dentistry and have no joint symptoms should be best left alone. Prescribing a full mouth rehabilitation should not be taken as a preventive measure unless there is a definite evidence of tissue breakdown. No pathology- No treatment. Reynolds JM. Modern gnathological concepts—Updated: By Victor O. Lucia, DDS, FACD Chicago, 1983, Quintessence Publishing Co., Inc. 439 pages, illustrated, indexed . 7

8. Classification of patients requiring occlusal rehabilitation   Classification by Turner and Missirlain (1984) The patients were classified into three categories – Category 1 - Excessive wear with loss of vertical dimension. Category 2 - Excessive wear without loss of vertical dimension of occlusion but with space available. Category 3 - Excessive wear without loss of vertical dimension of occlusion but with limited space available Turner KA, Missirlian DM. Restoration of the extremely worn dentition. Journal of Prosthetic Dentistry. 1984 Oct 1;52(4):467-74. 8

9. Restoring vertical dimension at occlusion loss of occlusal vertical dimension due to unstable posterior occlusion or congenital disease and exhibit excessive wear of anterior teeth. method to confirm loss of vertical dimension is with trial restorations A removable occlusal overlay splint or a treatment partial denture that restores the occlusal vertical dimension is given for 6-8 weeks and the patient is evaluated for comfort and function. teeth are prepared and provisional fixed restoration are given 2-3 months . Then the final restorations can be given Category 1 J PROSTHET DENT 1984, vol 52, 467-474 9

10. A long history of gradual tooth wear caused by bruxism or moderate oral habits Anterior slide is present from centric relation to centric occlusion. Equilibration or stability of posterior teeth for stability in centric relation, in combination with enameloplasty of opposing teeth can provide sufficient space for restorative materials. gingivoplasty and gingivectomy , 2-3mm of supporting bone can usually be removed without jeopardizing periodontal support, dynamic recordings of mandibular movement ,are recommended for this type of rehabilitation . Category 2 10

11.   exhibit minimum posterior wear but excessive gradual wear of anterior teeth over many years. Centric relation and centric occlusion are coincidental. Restoring this patient is most difficult because vertical space must be obtained for restorative materials Increasing the occlusal vertical dimension to achieve space for restorative materials where there has apparently been no loss of occlusal vertical dimension is seldom advisable; but if deemed necessary , the increase should be minimal and for restorative needs only. Trial restorations are crucial and must be evaluated for longer period of time to ensure patient accommodation to the altered occlusal vertical dimension Category 3 11

12. Classification by Brecker Group I Class I – Patients with collapse of vertical dimension of occlusion because of shifting of existing teeth caused by failure to replace missing teeth.   Class II – Patients with collapse of vertical dimension of occlusion because of loss of all posterior teeth in one or both jaws with remaining teeth in unsatisfactory occlusal relationship.    Class III – Patients with collapse of vertical dimension of occlusion because of excessive attritional wear of occlusal surfaces. Brecker SC. Clinical procedures in occlusal rehabilitation. WB Saunders; 1966. 12

13. Group II   Class I – Patients with all or sufficient natural teeth present, with satisfactory occlusal relationship . Class II – Patients with limited teeth present but in satisfactory occlusal relationship r equiring aid in the form of occlusal rims. Group III – Patients requiring maxillofacial surgery or orthodontic treatment as an aid in restoring the lost vertical dimension. Group IV – Patients in whom sectional treatment is required over extended periods of time because of status of health of the patient, age or economic factor .   Clinical procedures in occlusal rehabilitation .W.B Saunders,Philidelphia 1958 13

14. Etiology of extremely worn dentition Congenital abnormalities Amelogenesis imperfecta Dentinogenesis imperfecta Parafunctional occlusal habit Chronic bruxism and other habits Abrasion Erosion Loss of posterior support Bernard smith :Tooth wear : Etiology and diagnosis Gerodontology Text Book 1994, 88-102 46/400 14

15. Advanced occlusal disease Anterior guidance attrition Sensitive teeth Sore teeth H ypermobility Spilt teeth and fractured cusps Painful musculature Examples of occlusal disease Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 21-26 15

16. D iagnosis Ist appointment Listen to p atient’s opinion and expectations Make diagnostic casts Radiographs Bite records and facebow transfer IInd appointment Individual tooth is meticulously examined Extracted or restored Serve as abutments for RPDs or fixed prosthesis Tentative treatment plan done EXAMINATION DIAGNOSIS AND TREATMENT PLANNING IN FMR Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 360-363 16

17. Diagnostic aids Medical history Dental history Behaviour evaluation Radiographs – Complete mouth periapical radiographs and orthopentamograph Photographs – to remind previous state of mouth prior to restorative therapy Clinical examination Diagnostic wax-up Computer imaging CBCT Bowley JF, Stockstill JW, Attanasio R. A preliminary diagnostic and treatment protocol. Dental Clinics of North America. 1992 Jul;36(3):551-68. 17

18. DIAGNOSTIC WAX UP The process of converting the programmed treatment plan into a three dimensional visualisation Before diagnostic wax-up, the occlusal discrepancies in centric and eccentric occlusion should be eliminated Thus planning of subgingival margins or surgical crown lengthening required can be done Then wax is used to appropriately shape all crowns and final prosthesis is planned c an be used to prepare an elastomeric putty mould and used for temporization or sectioned through long axis of tooth to act as reduction guide intra-orally. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 365-366 18

19. Steps in the diagnostic wax up Step 1: Mount upper and lower casts with centric relation bite record and facebow. Duplicate the casts to preserve the original conditions. Step 2: Verify the accuracy of the mounting. Step 3: Examine the occlusal relationship on the casts. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 365-366 19

20. Step 4: Lock the centric latch when observing the casts. Step 5: Determine the correct vertical dimension. Step 6: Return the condyles to centric relation and lock the centric lock. Occlusal interferences should be eliminated by selective grinding on the casts until the incisal pin contacts the guide plate. At that point, the original vertical dimension will have been re-established in centric relation. If a change in VDO is needed to fulfil requirements for stability, it can be determined now. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 368 20

21. Step 7: Observe the teeth that were reshaped. Step 8: Remove unsavable teeth from the casts. From the clinical exam, all teeth that cannot be saved are marked with an X. Step 9: Mark decisions that have been made to use certain types of restorations. For example, in the figure the two upper molars have been predetermined to need crowns (C). Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 368,369 21

22. Step 10 : Equilibration is the first treatment option to explore. The jaw-to-jaw relationship at the first point of tooth contact in centric relation. Equilibration of the casts clearly shows that reshaping the teeth is a good choice of treatment because contact with the canines is achievable by selective grinding away of the deflective interferences . Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 369 22

23. Step 11: Examine the plane of occlusion. If the casts were mounted with a facebow that was parallel with the eyes, the incisal plane and the occlusal plane will relate to the bench top. If the occlusal plane is slanted in the mouth (yellow line), it will be slanted on the articulator (red line) Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 370 23

24. The occlusal plane established by the simplified occlusal plane analyzer. Model is trimmed back to the established new occlusal plane. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 370,371 24

25. Note how the buccal surfaces have been contoured to move the cusp tip more in line with the upper teeth. The wax-up has been started. The completed wax-up. These corrected casts are now used to form a putty matrix for fabrication of provisional restorations. They are also the perfect visual aid when presenting the treatment plan to the patient . Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 371 25

26. Step 12: Establish stable holding contacts on the anterior teeth. Step 13: Correct lower incisal edges if needed. This refers to both position and contour. Unmounted casts do not provide the information needed to fulfill this objective Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 371,372 26

27. Step 14: Start with the lower anterior teeth. Step 15: Re-evaluate the total occlusion with the upper cast to see it can be adapted to occlude with the lower arch. simplifies the whole wax-up. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 371,372 27

28. Step 16: Establish holding contacts on the upper anterior teeth This diagnostic wax-up positioned the incisal edges forward and also made the teeth longer. Casts of a patient with a tight neutral zone that positioned the upper anterior teeth with a lingual inclination . Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 374 28

29. A digital photograph of this patient shows the incisal edges in line with the inner vermillion border of the lower lip. It also shows a lingual inclination of the upper anterior teeth. This photograph shows how the provisional restorations made from the wax-up had to be recontoured back to achieve a comfortable lip closure path and phonetics. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 375 29

30. Cast of poorly contoured anterior restorations. Note the contour of the pontics where they meet the ridge. Cast showing defect of lost labial plate of bone that makes it impossible to establish gingival contours on pontics that are esthetically pleasing. Fill-in of area with pink wax will be used to communicate desired result to the surgeon. A bone augmentation was needed to achieve the planned contour. All guesswork was eliminated. Recontouring of the anterior teeth on the cast will be used to form provisional restorations, as well as explain the treatment goal to the patient and the surgeon. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 376,377 30

31. Treatment plan Comprehensive treatment plan must be established prior to start of the treatment . Communication and patient education are essential in order to match the dentist’s and patient’s definition of success 31

32. Preprosthetic phase To develop proficiency in diagnosing the need of occlusal rehabilitation, periodontist , orthodontist , endodontist , oral surgeon and prosthodontist must all be integrated in establishing an environment conducive to oral health. Minor orthodontic tooth movement-tooth can be uprighted, rotated, moved laterally, intruded or extruded to improve axial alignment, create favorable pontic space and direct occlusal forces along the long axis of teeth. Scaling and root surface curettage bring back the gingival health. Surgical crown lengthening - to improve esthetics and provide adequate retention when clinical crown is short. Free autogeneous gingival graft - increase width of inadequate attached gingiva caries, decalcification, erosion, attrition, abrasion, exposed root surface or fractures - restore where required. Elective endodontic treatment may be necessary for supraerupted or malaligned teeth post and core Infected root pieces, hopelessly mobile teeth and impacted or unerupted supernumerary teeth are removed. Block resection and movement of both maxillary and mandibular segments Elective soft tissue surgery ,alteration of muscle attachments and alveoplasty 32

33. Prosthetic phase Prosthetic full mouth rehabilitation is divided into- Immediate treatment Definitive treatment 33

34. Postponing treatment until adulthood IMPORTANCE OF IMMEDIATE TREATMENT 34

35. Vertical Dimension : The distance between two selected anatomic or marked points, one on a fixed and the other on a movable member. Vertical Dimension of Rest : The postural position of the mandible when an individual is resting comfortably in an upright position and the associated muscles are in a state of minimal contractual activity. Vertical Dimension of Occlusion : The distance between two selected anatomic or marked points when in maximal intercuspal position.

36. Dawson P E. Evaluation, diagnosis and treatment of occlusal problems. pp 280-285. St Louis, MO: CV Mosby, 1989. UNDERSTANDING VERTICAL DIMENSION You cannot determine vertical dimension based on whether the patient is comfortable. Measuring the freeway space is not an accurate way to determine the correct vertical dimension of occlusion. Determining the rest position of the mandible is not a key to determining vertical dimension. Lost vertical dimension is not a cause of temporomandibular disorders.

37. The mandible-to-maxilla relationship, established by the repetitive contracted length of the elevator muscles, determines the VDO. Dawson P E. Evaluation, diagnosis and treatment of occlusal problems. pp 280-285. St Louis, MO: CV Mosby, 1989 page number 115 The teeth continue to erupt until they meet an opposite force of equal intensity to the eruptive force. The jaw-to-jaw dimension is maintained with such consistent muscle contraction length that even rapid abrasive wear does not cause a loss of vertical dimension (A). The alveolar process lengthens in an amount equal to the wear.

38. METHODS OF DETERMINING VERTICAL RELATION Abduo J, Lyons K. Clinical considerations for increasing occlusal vertical dimension: a review. Australian dental journal. 2012 Mar;57(1):2-10.

39. Calliper Method Willis gauge Boley gauge Geerts GA, Stuhlinger ME, Nel DG. A comparison of the accuracy of two methods used by pre-doctoral students to measure vertical dimension. The Journal of prosthetic dentistry. 2004 Jan 1;91(1):59-66.

40. Phonetic methods Silverman’s closest speaking space Patient is encouraged to relax his jaws so that it goes into physiologic rest position . Swallowing and pronounciation of ‘M’ sounds have been used. Then the interocclusal distance should be measured. 40 Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.128

41. Facial appearance Diminished facial contours, thin lips with narrow vermillion borders and drooping of commisure are associated with overclosure where as increased vertical dimension gives a stretched out appearance Neuromuscular perception Robert Lytle used centre bearing device to permit the patient the experience different comfort levels during use of different vertical relations for comparison. 41

42. Can vertical dimension be altered? 42

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45. When Must The Vertical Dimension Be Changed? Extremely worn dentition Crown lengthening vs. increasing the VD Restoring severe arch mal-relationships Extreme occlusal plane problems Anterior open bite Why Not Increase The VD? Any disharmony in the system provokes adaptive responses designed to return the system to equilibrium. Adaptive process is not always predictable. No benefit over time to the patient whatsoever. The goal of occlusal therapy is to minimise the requirements for adaptation. Segmental - instability of the entire occlusal harmony. 45

46. Methods of obtaining space for restoring worn teeth Selective grinding Badly worn anterior teeth that have drifted into anterior wear end to end relationship Posterior teeth that interfere, deflect the mandible forward and cause excessive wear on upper anterior lingual incline. Interferences should be eliminated by selective grinding so that mandible can close at centric relation 46 Bloom DR, Padayachy JN. Increasing occlusal vertical dimension—Why, when and how. British dental journal. 2006 Mar;200(5):251-6.

47. Periodontal surgery I ncludes gingivoplasty , osteoectomy to gain clinical crown length is sometimes required for retention and esthetics. 2-3mm of supporting bone can usually be removed without jeopardizing periodontal support. 47

48. There are occasionally situations where restoration of a worn dentition can be accomplished only by increasing occlusal vertical dimension, even though a loss of vertical dimension is not diagnosed Splints and provisional restorations If deemed absolutely necessary, modification of vertical dimension should be accomplished through cautious trials with removable occlusal splints 48

49. Occlusal splints Permissive occlusal splints have a smooth surface on one side that allows the muscles to move the mandible without interference from deflective tooth inclines into centric relation. Directive occlusal splints D irect the lower arch into a specific occlusal relationship that in turn directs the condyles to a predetermined position . very limited use reserved for specific conditions involving intracapsular TMDs. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 380 49

50. When occlusal splints are not necessary? No history of problems in the TMJs, including no history of clicking, discomfort in the joints, restriction or deviation of jaw movement, No intracapsular disorder. No sign of tenderness or tension on load testing Not necessary to fabricate an occlusal splint prior to restorative dentistry orthodontics, or equilibration. Occlusal splint is appropriate: If there is doubt about complete seating of the TMJ Long-standing intracapsular disorder that has been resolved. To stabilize hypermobile teeth and distribute the loading forces over more teeth. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 382 50

51. Fabrication of occlusal splints Three very common errors are: The splint does not fit the teeth properly, so it is uncomfortable or loose, or it rocks in place. The occlusal contacts on the splint are not in harmony with centric relation. An intracapsular structural disorder was not diagnosed, so centric relation was not achievable. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 383 51

52. Procedure Take a verified centric relation bite record. Mount the casts in centric relation with a facebow Outline the coverage area of the base. Fabricate a Biostar vinyl base on the cast. (An acrylic or light-cured composite base will also work.) Remove the excess from the base, but do not remove it from the cast . Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 384,385 Place it back on the articulator. Open the pin enough separate all posterior teeth from any contact with the base 52

53. Mix resin and position it on the base just behind the upper anterior teeth to contact and be slightly indented by lower anterior teeth in centric relation. Remove the base and smooth the edges. Remove undercuts into interproximal areas. The completed splint should fit perfectly and require almost no adjustment. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 385,386 53

54. The splint in place may contact all of the anterior teeth in centric relation, but there should be no contact on posterior teeth. Slight adjustment is often needed on the anterior contact area. It should be smooth and flat to permit the condyles to seat into centric relation with no back teeth contact. This is an ideal permissive anterior deprogramming device to use. If all tension or tenderness disappears after placement of the splint and there is verification that no posterior teeth are contacting the splint, it is a good indication that the TMJs are in either centric relation or adapted centric posture. It also indicates that the TMJs are not the source of pain. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 386 54

55. Principles of full occlusal splint design The design must incorporate four main principles: The splint should allow uniform, equal-intensity contacts of all teeth against a smooth splint surface when the joints are completely seated in centric relation. The splint should have an anterior guidance ramp angled as shallow as possible for horizontal freedom of mandibular movement. Occlusal splints for therapy must be worn 24 hours a day except to eat and brush until the occlusion and the TMJs become stable. Stability is determined by three verifications: Elimination of painful symptoms Verification of centric relation by load testing Stability of the bite on the splint over the course of a few days (or weeks if joint damage has occurred) Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.page no. 387 55

56. If injury or inflammation has occurred within the capsule of the TMJ, muscle will attempt to protect the joint from compressing the edematous retrodiskal tissue Anterior deprogramming splint is contraindicated increases compressive loading and also activates lateral pterygoid activity to more intense protective contraction. A full-coverage occlusal splint decreases compressive loading of the joint, reduces loading of the joint, and reduces compression of the retrodiskal tissue Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31.389 56

57. Dahl appliance P artial coverage splint, 2-4 mm thick, designed to depress the opposing teeth against which it contacts and to allow the unopposed teeth to overerupt . It contacts anterior teeth and allows posterior teeth to erupt. Alveolar remodeling ensures that anterior teeth are not intruded into the bone, with a resulting loss of crown height Poyser , N., Porter, R., Briggs, P.  et al.  The Dahl Concept: past, present and future.  Br Dent J   198,  669–676 (2005 ). https ://doi.org/10.1038/sj.bdj.4812371 57

58. Dahl described the use of cobalt chromium appliance but its modifications of acrylic and bonded composite have been used satisfactorily. Most space is created between 2-4 months of continuous wear Irish Dentist July 2011 58

59. Centric Relation It is defined as “ the maxillo -mandibular relationship in which the condyles articulate with the thinnest avascular portion of their respective discs with the complex in the anterior-superior position against the slopes of articular eminences. This position is independent of tooth contact.” 59

60. Methods available to guide the mandible into centric relation 1.Chinpoint Guidance method or one handed technique Guichet It places the condyles in most posterior and superior position which can result in trauma to TMJ. not advocated . 2. Unguided method Brill introduced a muscular position which allows patient’s natural muscle functions to position the mandible into centric relation position. 3 . Bilateral manipulation method Dawson introduced this method in which the condyles are in their most superior position in the gleoid fossa. Firmness of upwardly directed pressure at or near the angle of the mandible to ensure that the condyles are seated seated againt the eminence Brit Dent J.1959, vol 106, pg 391-400 60

61. Method for taking centric bite records Factors considered while making interocclusal records Purpose:to capture ,in some stable material ,the relationship of the mandible to the maxilla when the condyles are in their terminal axis position 61

62. 4 basic techniques for making centric relation interocclusal record: 1.Wax bite procedures 2.Anterior stop techniques 3.Use of preadapted bases 4.Central bearing point techniques 62

63. Wax bite procedure M ost popular procedure (simple) Extra hard baseplate wax is an excellent bite material When it is warm it becomes soft enough not to cause movement of teeth . I t should be brittle and not bend to mould itself to fit the models as it will mask the errors if not rigid. This method is not suitable for patients having extremely mobile teeth or large edentulous area. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.93 63

64. Anterior stop technique Extremely accurate Allows the condyles to seat up without any possible deviation from posterior teeth. When mandible is closed the lower incisors strike against a stop that is precisely adapted to fit against the upper incisors thin enough so that the first point of posterior contact just barely misses Anterior stop may be made from acrylic or hard compound 64

65. Mandibular deprogramming Ask the patient to bite on these with anterior teeth for 5 -10 minutes. The memory position of teeth intercuspation is lost 1) Cotton role 2) Anterior Jig 3) Leaf Guage 65

66. Anterior bite stops/ Jig Anterior jig prevents posterior teeth from occluding and thus disrupts the proprioceotive memory. As the anterior stop is rigid on contact with lower incisor teeth, anterior resistance is created and a mandibular leverage is created with naturally braced tripod effect along with two condyles. Jig breaks the patient’s habitual closure pattern and acts as the third leg of the tripod by creating resistance while stopping the closure. Principle Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.81 66

67. Fabrication of anterior jig C ompound is softened and added to upper incisors so that their lingual surfaces are completely covered The patient closes into the compound until the posterior teeth barely miss the contact while in supine position the lower central incisors contact the smooth lingual incline of the jig at only one point . The jig incline must stop the mandible before posterior tooth contact and should be angled 45-60 degrees posteriorly and superiorly from the occlusal plane. The jig can also be made of autopolymerizing acrylic resin on mounted casts and then adjusted intraorally . After the jig is made posterior bite record is taken Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.81 67

68. Leaf Gauge – Dr James.H.Long (1973) Previously they were made of unexposed X- ray films after developing to remove the emulsion coating. Clear film was then cut into 1 cm X 5 cm sections . Recently , leaf gauges of uniform 0.1mm thickness which are sequentially numbered are described convenient and measure the exact vertical opening between the incisors Centric relation interocclusal records Occlusal equilibration Relieve painful spasms of lateral pterygoid muscle. Most useful and practical alternative to anterior jig Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.82 68

69. P rocedure Arbitary number of leaves are placed at the maxillary anterior midline parallel to the lingual plane of central incisors. Patient is instructed to close on back teeth until lower incisors touch on back side of leaf guage . Leaves are added or subtracted until patient can barely feel a posterior tooth touch while closing firmly on leaf guage . Often the patient can feel a posterior tooth contact in 15- 52 seconds after the jaw is closed with a ‘half hard’ closing force. This procedure is repeated after adding a leaf guage until the patient can close for 2-5 minutes without feeling a posterior tooth contact. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.82 69

70. Power Bite Proper use requires precise location of centric relation before closing power from the elevator muscles is applied. starts with a bite record made between the upper and lower anterior teeth. a softened compound that hardens after the indentations have been made between the upper and lower anterior teeth . Closure of the jaw must stop short of any posterior tooth contact . patient is then instructed to clench tightly to seat the condyles up into centric relation. The problem is that if the anterior segment of the bite is made with the mandible displaced from centric relation, the hardened material locks the jaw into that relationship and prevents the condyles from moving back and up 70

71. Use of preadapted bases I ndicated whenever there is a danger that teeth will move or soft tissues be compressed by the bite record Heated strip of dead soft wax should be added over it in edentulous region to indent the lower teeth in centric occlusion without tooth to tooth contact It is made with triple layer of extra hard baseplate wax adapted on an accurate model, usually of the upper arch to avoid dislodgement by the tongue 71

72. Manipulated centric relation closure can bring the lower anterior teeth into contact with the wax. While holding the TMJs firmly on their centric relation axis, ask the patient to lightly bite into the wax to form shallow indentations. Then chill the wax to harden it and add the putty silicone to the preformed wax base. Manipulate a verified centric relation and close into the indentations . The soft putty silicone will adapt to the opposing ridge 72

73. Central bearing point technique It enables free movement of the mandible without influence of teeth proprioceptives . Drawback is that vertical dimension must be increased considerably to accommodate the clutches and bearing point apparatus. If the terminal axis is not recorded precisely it will result in mounting error. If a central bearing point apparatus is adapted to well-fitted upper and lower clutches, all occlusal contact can be disengaged. The bite record is made between the clutches rather than directly between opposing teeth. 73

74. Long centric / Freedom in centri c D efined as ‘ freedom to close the mandible either into centric relation or slightly anterior to it without varying the vertical dimension of occlusion. When interference in centric relation is eliminated by equilibration ‘long centric will usually be provided automatically . The most important aspect is that the vertical dimension of occlusion must be the same from back to front of each long centric contact area. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.190 74

75. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.192,193,195 Contact in centric relation Clearance for long centric 75

76. Providing long centric by equilibration When Interferences to CR are eliminated by equilibration Long centric is automatically acquired Equilibrated patient is free to move into centric or into his original convenience position or any where in between Freedom to do so the mandible will close directly into centric or a few mm anterior to it , depends on the anatomy and the musculature . Length of the long centric is determined by the anatomy of the condyle disk relationship. Equilibration should not cause extensive flattening of the cusps and reduce the efficiency of chewing for that careful use of small stones on the interfering inclines only has to be used 76

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78. P rocedure To determine the patient’s long centric two different colours of marking ribbon are used green or blue - centric relation points Red ribbon - closure from postural rest position knife edge inverted cone carborundum stone is used for accurate grinding There are no contraindications for providing the freedom. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.196 78

79. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.197 79

80. Reading the marks 1 . Red mark covered by Green Indicate that terminal hinge closure and light closure from rest are identical A Long Centric is not essential in these cases 2. red mark extend forward from green centric mark Shows a need for long centric Should not grind the green centric marks equilibration complete when there are no red marks on the inclines In perfected occlusion the red marks will still extend forward from green but at the same VD VD will slightly open posteriorly but very minimally Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.196,197 80

81. 3.Red mark extend forward from green Only reason that the dentist has not correctly manipulated the CR 4.Green centric marks missing from red marks The equilibration is incomplete Teeth with some degree of mobility are being move when patient taps To check mobility different color ribbon should be used for comparing light contacts from firm contacts Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.196,197 81

82. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.197 82

83. Long centric when occlusion is to be restored By preparing all posterior teeth all possibilities of interferences are eliminated then all that is needed is to correct any inclines on the anterior teeth that cause a deviation from deviation from terminal hinge closure. Properly adjusted centric stops on anterior teeth should be stable enough that not one of the teeth is jarred when the teeth are firmly tapped together in a terminal hinge closure. If the patient requires the freedom of Long Centric red marks will extend from the green marks. Occlusal inclines restricting mandibular movement are potential stress producers Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.193 83

84. Symptoms indicating requirement of long centric Patient says they are comfortable when lying down but interfere while sitting up Patient says teeth fit fine when dentist pushes the jaw back but hit only on front teeth if close it themselves Advantage of long centric Freedom of movement in centric occlusion provides patient comfort and reduces the tendency to bruxism and other traumatogenic influence on the supporting structures. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.191 84

85. CUSTOMIZING THE ANTERIOR GUIDANCE Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.196,197 85

86. 86 The centric relation contacts The most critical tooth contour in the entire occlusal scheme is also the most universally mismanaged. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.164

87. Upper half of labial surface second most important determination is upper incisal edge position . will not be precise until the upper half of the labial contour has been determined. There is no bulge in nature from the alveolus to upper labial surface ie the upper half of the labial surface is continuous with the labial surface of the alveolar process Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.164 87

88. Lower half of labial surface two planes - for incisal position and to allow the lip closure path to slide along the labial surface hence the need to roll in the incisal tip. very important step in determining horizontal position of the incisal edges lower lip can easily slide by the incisal third to seal contact with the upper lip - lip-closure path. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.165 88

89. Incisal edge This should rest along the inner vermillion border of the lower lip and is best determined by observing the patient to counting from 50 to 55 ie 'F' sound. This needs to be in harmony with the neutral zone, lip closure path, phonetics, envelope of function and aesthetics . Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.167 89

90. Anterior guidance Contour of the lingual surface from the centric stop to the gingival margin: There should be no interferences with the 'T', 'D' or 'S' sounds. This is determined by the protrusive path but should include a 'long centric' that allows a little freedom before this path is engaged and so the lower incisors are not bound in Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.167 90

91. Restoring lower anterior teeth Lower incisal edges are the starting point for anterior guidance and “the view” when speaking. The arrangement of the entire occlusal scheme starts with the lower anterior teeth 5 important goals 1. E sthetics 2. Phonetics 3. O cclusal plane 4. Anterior guidance 5. Stability 91 Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.179

92. 92 The height of the incisal plane In ideal instances, the lower incisal edges form a continuous gentle curve that is an extension of the posterior occlusal plane ( Lips sealed The lower incisal edge is at the height of the juncture of the upper and lower lips when the teeth are together. On a lateral cephalometric radiograph, this usually positions the incisal edge slightly above the functional occlusal plane. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.183,184

93. 93 Speaking Smiling Lips slightly parted “The view” when speaking is of the incisal edges of the lower anterior teeth. A varying amount of labial contour may also be on display. The upper teeth are usually hidden during speech. Only the upper anterior teeth are typically on display during smiling. The lower incisors are usually hidden during a big smile. When the jaw is at rest and the lips are slightly parted in a half smile, both upper and lower labial surfaces are about equally on display.

94. 94 Lower incisal edge contours The most important contour on the lower incisal edges is the labio-incisal line angle. The “leading edge” is important for natural appearance but also to achieve a stable holding contact against the upper lingual stop. Use of the Esthetic Checklist reminds the technician to do this on every lower anterior restoration

95. 95 The entire occlusion can be compromised by instability if lower incisal edges are not correct. It is a critical point for analysis and treatment of anterior teeth

96. Determining plane of occlusion 2 basic requirement Permit anterior guidance to disocclude posterior teeth when mandible is protruded Permit disclusion of all the teeth on balancing side when mandible is moved laterally Curvature of anterior teeth determined by- Establishing correct smile line proper phonetics Anterior guidance 96

97. CURVATURE OF POSTERIOR TEETH Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.401 97

98. Establishing plane of occlusion 3 practical methods Analysis on natural teeth through selective grinding Analysis of models with fully adjustable instrumentation Use of Pankey - Mann –Schuyler methods of occlusal plane analysis. 98

99. SOPA-simplified occlusal plane analyzer Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.401 99

100. Broadrick occlusal plane analuser The Broadrick flag accomplishes the same occlusal analysis on almost all types of semiadjustable articulators. (1) Card Index 142-101, (1) Bow Compass 142-1001 with graphite leads, an extra center point and a needle point, (1) Scribing Knife 142-3201 and (12) Plastic Record Cards 142- 3401 Card index 142-101 Bow compass 142-1001 with graphite leads 100

101. . M axillary cast mounted by Facebow transfer mandibular cast mounted in centric relation The accessory Hanau-Mount Split-Cast Mounting Plate- This split cast allows rapid cast removal and accurate replacement during the survey. visual guide for adjustment of the Articulator to protrusive or lateral interocclusal relation records Place the Card Index onto the Upper Member with the open end around the incisal pin and the slot on the side around the mounting plate thumbscrew. Orbitale Indicator be mounted to the articulator, it must me removed in order to mount the Card Index Tighten the thumbscrew to hold the Card Index in place Press a Plastic Record Card over the dowels on the right side of the Card Index. The Cards are matte finished on both sides and readily accept pencil or ink markings. 101

102. An average of a 4 " radius may be used in the majority of surveyed cases. Variation is necessary only when pronounced Curve of Spee - 3-3/4" radius flat Curve of Spee may require - 5" radius. The relatively small divergence between arcs of 3-3/4", 4" and 5" radii over the functional occlusal surfaces on the lower posterior teeth 102

103. T his point must be selected as the most desirable to “Beam” the line and plane of occlusion posteriorly. Once selected, it is marked on the cuspid and NOT CHANGED Position the center point of the Bow Compass on the anterior survey point (A.S.P.) which is usually the disto-incisal of the cuspid , If the cuspid is worn flat, the A.S.P. may be at the incisal edge With the center point of the Compass positioned on the A.S.P ., apply a long arc (about 3”) on the Plastic Record Card . The occlusal plane survey center (O.P.S.C.) will ultimately be located on some point on this arc 103

104. . Select the posterior survey point (P.S.P.) at the distobuccal cusp of the last lower molar No molars in the mandibular arch Remove the upper cast and select a P.S.P. on the modelling compound in the same manner as the P.S.P. was selected on the last molar Position the center point of the Bow Compass on the P.S.P. and apply an arc to intersect the arc from the A.S.P. as illustrated. 104

105. Alternate to the molar P.S.P. is a position on the Condylar Element of the Articulator , at its anterior intersection with the Condylar Shaft Position the center point of the Compass on this condylar posterior survey point (C.P.S.P.) and apply an arc to intersect the arc formed from the A.S.P Continue with by substituting the needle point for the graphite lead. 105

106. Place the center point of the Bow Compass, still adjusted to the 4” radius, at the intersection of arcs on the Plastic Record Card (initial occlusal plane survey center). Sweep the the needle point over the occlusal surfaces of the lower posterior teeth to see how the arc conforms to the existing occlusal plane. Shift this occlusal plane survey center (O.P.S.C.) on the long arc on Plastic Record Card, the A.S.P. line, until the most acceptable line and plane of occlusion is found. 106

107. By trial and retrial, in ideal survey center forming the most acceptable line and plane of occlusion will be located The center point of the Bow Compass is now pierced into this ideal O.P.S.C. on the Plastic Record Card and circled with pencil or ink for subsequent relocation. It may be advantageous to mark “R” (right) in the upper corner of the Plastic Record Card for identification A Plastic Record Card is then place over the dowels on the left side of the Card Index and marked “L”. Repeat the survey procedure 107

108. Measurement of difference between survey lines of different radii of curvature Various survey lines obtained from different radii of curvature 108

109. Posterior occlusion Posterior teeth should have equal intensity contacts that do not interfere with either the temporomandibular joints (TMJs) in the back or the anterior guidance in the front . The requirements for perfected posterior occlusions start with the lower posterior teeth. Three key determinants Plane of occlusion Location of each lower buccal cusp tip Position and contour of each lower fossa 109

110. Placement of Lower Buccal Cusps determined on the basis of providing the optimum effect for buccolingual stability, mesiodistal stability, and noninterfering excursions. Upper central groove position is analyzed . On each upper occlusal surface, a line is drawn from mesial tdistal in the central groove. The ideal contact point for each lower buccal cusp tip is usually located somewhere on this line . In some tilted teeth, it is advantageous to move the central groove to gain better direction of forces through the long axis. If moving the central groove will enable the stresses to be directed more nearly through the long axis of any upper tooth, the improved central groove position should be so noted on the upper cast by drawing a new line. 110 Buccal cusp placement for buccolingual stability

111. 111 A mark is made on each lower tooth to indicate the position of the buccal cusp that would be optimum for buccolingual stability and direction of force Alignment of the optimum lower buccal cusp position against optimum upper central groove position is evaluated. The basic rule to follow regarding the buccolingual position of the lower buccal cusp is: The lower buccal cusp must be positioned so that its contact directs the stresses through the long axis of both upper and lower teeth.

112. Mesiodistal placement of lower buccal cusps The best mesiodistal stability is attained by placement of the lower buccal cusps in upper fossae. Placement in the fossae directs the stresses properly through the long axis, eliminates any possibility of plunger cusp food impaction at contact, and is stable. There is no tendency for cusp tips to migrate out of properly contoured fossae 112

113. Locating the lower buccal cusps for noninterfering excursions Determining which fossa the lower buccal cusp should contact depends on where the cusp travels when it leaves centric relation . The mesiodistal placement of each lower buccal cusp is determined when one locates it in the fossa that permits excursions from centric relation without interference Contouring cusp tips 113

114. 114 Placement of lower lingual cusps In normal tooth-to-tooth relationships, the tip of the lower lingual cusp never comes in contact with the upper tooth . Even though the buccal incline of the lower lingual cusp can be made to contact in working excursions act as a gripper and a grinder by passing close enough to the upper lingual cusps to aid in tearing, crushing, and shearing the food that is caught between the opposing surfaces. The position of the tip should have enough lingual overjet to hold the tongue out of the way, but it should always be located over the root, within the long axis . The measurement between buccal cusp tip and lingual cusp tip should not be much greater than half of the total buccolingual width of the tooth at its widest part . lower lingual cusp height should be about a millimeter shorter than the buccal cusp. Cusp height can be lowered further in the first premolar

115. 115 Countouring the lower fossae As the mandible moves right or left from centric relation, its front end should be guided down the lingual incline of the upper canine. When it serves as the lateral anterior guidance, the lingual incline of each upper canine dictates the fossa contour of each lower incline that faces it

116. If Only Lower Posterior Teeth Are to Be Restored Cusp tip position and fossa contours for lower posterior restorations are aligned and contoured in relation to the existing upper teeth on the opposing cast . Lower fossa contours will be established to conform to the upper lingual cusps. Fossa walls can be carved to be discluded by the anterior guidance without complication. If Both Upper and Lower Posterior Teeth Are to Be Restored If posterior disclusion is the goal, it is easily achieved by making fossa walls flatter than the lateral anterior guidance, and establishing an acceptable occlusal plane that permits the anterior guidance to disclude the posterior teeth in all excursions. After the anterior guidance has been finalized, the simplest method for ensuring that fossa walls will be discluded in lateral excursions is through the use of a fabricated fossa contour guide. 116

117. Determining and Carving Lower Fossa Contours Purpose to ensure a noninterfering accommodation for the upper lingual cusps. It will provide a fossa contour that is compatible with the lateral anterior guidance regardless of the contour of the anterior guidance. It can be easily modified to provide extra freedom. Fossa contour guide can be used in any stage of wax-up or even porcelain application . used only if both upper and lower posterior teeth are to be restored The anterior guidance must be correct before the guide is fabricated or before occlusal contours can be determined for lower posterior restorations 117

118. 118 Making the fossa contour guide The anterior guidance may be corrected in provisional restorations, and a centrically mounted cast of the provisional restorations in place may be used to determine the allowable fossa-wall angulation for the posterior restorations. The guide is usually made when the casts are mounted, but it is not used until the posterior wax-up is done or the porcelain is being applied and contoured. Step 1 The regular incisal guide pin is removed and replaced with the special fossa-contour pin. The blade of the pin is indented into a mound of wax on a flat plastic guide table

119. 119 The upper bow is moved into left and right excursions, allowing the contours of the lateral anterior guidance to determine the path that the guide pin cuts into the wax. When the lateral guidance paths have been cut sharply into the wax, the special pin is raised. It is then used to hold a handle for the fossa guide. Make the handle by cutting off the tip of a plastic protector for a disposable needle. The large end fits snugly onto the raised special pin.

120. 120 Resin is wiped into the hollow end of the handle, and the pin is lowered so that the two portions flow together. The resin is allowed to set hard. The guide can then be removed. The wax on the guide table is then no longer needed, and so it can be cleaned off after the guide is removed. A creamy mix of self-curing acrylic resin is flowed into the indentation in the wax. Because of the design of the special wax-cutter pin, the lateral anterior guidance angle will be evident as a sharp line running along the bottom edge of the acrylic guide. The edge is marked with a pencil, and any excess acrylic resin may be ground off in front of the line.

121. 121 One may actually hollow-grind the front surface down to the line to make a scoop-shaped guide, which is excellent for shaving out wax from the fossae. To ensure posterior disclusion , the fossa walls must be flatter than the lateral anterior guidance, so the fossa guide angle is flattened on the sides and the tip is rounded to a more opened-out fossa. The fossa guide can be used to contour the wax patterns or as a guide for shaping occlusal surfaces in porcelain. The tip of the guide should be able to touch the base of the fossa without interference from the walls of the fossa.

122. Carving the marginal ridges The ridges should be contoured to reflect food away from the contact, which means directing it into the fossae. Sluiceways should provide an escape route for the bolus out of the fossae toward the lingual as the stamp cusps crush the food against the fossae walls. Countouring ridges and grooves work out the fossae contours first and then functionalize and beautify the anatomy by placing the appropriate grooves at the working, protrusive, and balancing excursion . There can be no entanglement of cusps in grooves that have been made into inclines that are already out of reach. Other grooves may be added as desired to improve esthetics or to provide more ridges for better masticatory function 122

123. 123 Upper posterior teeth last segment to be restored . It is the fixed posterior segment, and its cusps, inclines, grooves , and ridges are placed and contoured to accommodate the many border movements of the lower posterior teeth . If the upper contours are determined by the paths of the lower posterior teeth, both the form and the paths of the lower teeth should be finalized before the upper teeth are restored

124. LENGTH OF GROUP FUNCTION CONTACT IN WORKING EXCURSION If we elect to provide group function on the working side, we should be aware that all teeth do not stay in excursive contact for the same length of stroke. As the mandible starts its move to the working side, all of the posterior teeth may contact in harmony with the anterior guidance and the condyle. As the mandible moves further to the side, the first teeth to disengage from contact are the most posterior molars. The disengagement is progressive, starting with the back molar, which has the shortest contact stroke, forward to the canine, which has the longest contact stroke 124 Balancing inclines must be relieved on all natural teeth regardless of the method used to record the border movements.

125. Types of posterior occlusal contours There are three basic decisions to make regarding the design of posterior occlusal contours: 1. Selection of the type of centric relation contacts 2. Determination of the type and distribution of contact in lateral excursions 3. Determination of how to provide stability to the occlusal form 125

126.   Occlusal considerations in full mouth rehabilitation There is no one type of occlusion that is optimum for all patients. The starting point in designing occlusal contours is to shape and locate the centric contacts so that the forces are directed parallel to the long axes of the teeth. Ideal occlusion can be defined as an occlusion compatible with the stomatognathic system, providing efficient mastication and good esthetics without creating physiologic abnormalities ( Hobo) 126

127. 127 Types of centric holding contacts Centric relation contact is usually established on restorations in one of three ways :

128. Types of centric holding contacts 128

129. Determinants of occlusal morphology Posterior controlling factor The steeper the articular eminence, the steeper path will the condyles follow during protrusion. It is a fixed factor. Anterior controlling factor The steeper the lingual surfaces of the maxillary anterior teeth, the steeper and more vertical will be the movement of the mandible. It is a variable factor and can be altered by the dental procedures. 129

130. Vertical determinants of occlusal morphology Anterior Guidance Condylar Guidance Distance of cusps from these controlling factors Plane of occlusion Curve of Spee Bennett movement – Amount, Direction and Timing Horizontal determinants of occlusal morphology It includes the relationship that influence the direction of ridges and grooves on the occlusal surface. Since the cusps pass between the ridges over grooves, the horizontal determinants also influence the placement of cusps Ridge and groove direction has the influence of the following factors Distance of tooth from axis of rotation Distance from mid-sagittal plane Bennett movement Intercondylar distance 130

131. Occlusal scheme Removable – distal extension Patient presents with Occlusal scheme Natural canine protected Canine protected Natural group function Group function Canine missing or periodontally weak Group function Opposing complete denture Balanced or monoplane Where no posterior tooth remaining Canine protected 131

132. Variations of posterior contact in lateral excursions 132 contacting inclines must be perfectly harmonized to border movements of the condyles and the anterior guidance . Convex-to-convex contacts cannot be used to accomplish this.

133. Anterior group function 1. It distributes wear over more teeth. 2. It distributes the stresses to more teeth. 3. It distributes stress to teeth that are progressively farther from the condyle fulcrum . convex lateral guidances make it difficult to accomplish. Canine-protected occlusion all lateral stresses must be resisted solely by the canine. capability of the canine to withstand the entire lateral stress load without any help from other teeth . Exquisitely sensitive nerve endings protect the canines against too much lateral stress by redirecting the muscles to more vertical function. 133

134. 134 Selecting occlusal form for stability

135. Occlusal equilibration in natural dentition The term ‘ occlusal equilibtation ’ refers to the correction of stressful occlusal contacts through selective grinding . It is a phase of treatment that eliminates only that part of tooth structure that is in the way of harmonious jaw function . Objectives Centric relation occlusion Acceptable disclusion of anterior teeth in harmony with condylar movement. Stability of occlusion Resolution of temperomandibular joint symptoms. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.394 135

136. Equilibration procedures Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.395 136

137. Interference to Centric Relation Centric interference can be differentiated into two types- Interference to arc of closure Interference to line of closure Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.396 137

138. Note the freedom to close either in centric relation or in maximal intercuspation at the most closed vertical Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.397,398 Interferences to the arc of closure 138

139. Interference to the line of closure Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.398,399 139

140. A balancing incline interference that would be easily missed if the condyles are not held firmly up on the centric relation axis during closure When the condyles are seated, the right molar is the only contact during closure. Squeezing the teeth together shifts the jaw to the right and causes the left condyle to displace. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.399 140

141. Grinding Rules Rule 1: Narrow stamp cusps before reshaping fossae Rule 2: Don’t shorten a stamp cusp 141

142. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.401 142

143. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.401 Tilted teeth Tilted teeth or wide cusp tips can be adjusted to improve stability as well as to eliminate interferences. If the mark on the upper tooth is buccal to the central fossa, the buccal surface of the lower tooth is ground to move the cusp tip lingually if the shaping can be accomplished without shortening the cusp tip out of centric contact. Grinding on the upper teeth only may mutilate upper cusps unnecessarily 143

144. Rule 3: Adjust centric interferences first 1. By adjusting centric interferences first, you have the option of improving cusp-tip position . 2. When cusp-tip position is given first priority, occlusal grinding is more evenly distributed to both arches . 3. If cusp-tip contours and position are improved first in centric relation, eccentric interferences can be eliminated with speed and simplicity. Rule 4: Eliminate all posterior incline contacts. Preserve cusp tips only. If all eccentric contacts on posterior teeth are to be eliminated, any posterior incline that marks in any excursion can be reduced. Centric stops must be preserved, but all other contacts can be shaped so that they are discluded by the anterior guidance. 144

145. Lateral excursion interferences The path that is followed by the lower posterior teeth as they leave centric relation and travel laterally is dictated by two determinants : 1. The border movements of the condyles, which act as the posterior determinant 2. The anterior guidance, which acts as the anterior determinant determine type of occlusion Group Function - posterior disclusion Cusp tips are centric holding stops hence adjustings to be done on fossa inclines 145

146. PROTRUSIVE INTERFERENCES Correction done in case of steep anterior guidance Grinding rule- DUML Materials for marking interference Ribbons Marking paper Joffe -marker waxes 146

147. Works with Denar articulators It is preset to 4” line drawn on the cast represent an acceptable coclusal plane This process is used only if the posterior teeth are to be restored . It is never used to determine whether or not teeth must be prepared Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.401 147

148. Schuyler’s principles 1. A static co-ordinated occlusal contact of the maximum number of teeth when the mandible is in centric relation . 2 . An anterior guidance that is in harmony with function in lateral eccentric position on the working side . 3 . Disclusion by the anterior guidance of all posterior teeth in protrusion 4 . Disclusion of all non-working inclines in lateral excursions. 5 . Group function of the working side inclines in lateral excursions 148

149. 149 Sequence is advocated by the PMS philosophy: The functionally generated path technique is so closely allied with this part of the reconstruction.

150. Advantages of the Pankey Mann Schuyler technique: 1. It is possible to diagnose and plan the treatment for entire rehabilitation before preparing a single tooth. 2 . It is a well- organized logical procedure 3. never a need for preparing or building more than 8 teeth at a time 4. It is neither necessary nor desirable to do the entire case at one time . 5 . The operator always has an idea where he is at all times . 150

151. 6. The functionally generated path and centric relation are taken on the occlusal surface of the teeth to be rebuilt at the exact vertical dimension to which the case will be reconstructed. 7 . All posterior occlusal contours are programmed by and are in harmony with both condylar border movements and a perfected anterior guidance . 8 . no need for time consuming techniques and complicated equipment . 9 . Laboratory procedures are simple 10 . The PMS philosophy of occlusal rehabilitation can fulfill the most exacting and sophisticated demands if the operator understands the goals of optimum occlusion. 151

152. Purpose of PM Instrument 1.to engineer the entire oral rehabilitation before a single tooth is prepared 2.Determine the occlusal plane on the lower cast 3.Study and plan the preparations of the lower and upper teeth 4.Orient both the relationship of both arches in centric position with maximum esthetics and conservation of tooth structure 5.To establish and carve the occclusal plane and curvature in wax patterns 6. to check finished restoratons 152

153. P-M instrument ( Mann and Pankey ) 6.Platform base Mann AW, Pankey LD. Oral rehabilitation: Part I. Use of the PM instrument in treatment planning and in restoring the lower posterior teeth. Journal of Prosthetic Dentistry. 1960 Jan 1;10(1):135-50. 1. Main base from which extends an upright rod 2.upright rod holding two assemblies. 3.Horizontal rod 4.Facebow frame 5.Upper cast mounting assembly 8 A and 8 B Diagnostic dividers and cutting dividers 9.Bite fork joined to a crossbar and two face-bow rods attached to the crossbar . 10. screwdriver wrench 11. Allen wrench Auxiliary parts of the P-M instrument . 153

154. P-M face-bow (9) is seated in position on the lower plaster cast (7) with the ends of the face-bow rods (9) approximating the pins in the ends of the horizontal tube of the face-bow frame (4). jackscrews support the cast on the platform base (6), enabling each corner of the cast to be raised or lowered to facilitate adjustment. Moldine in the center of the platform base to facilitate the preliminary cast adjustment. 154

155. cast (7) is in the same position Note that the booked end of the dividers (8A) is placed in position in the divider seat on the horizontal rod (3) and the straight end describes an arc of a sphere, establishing the occlusal plane (curvature). 155

156. 156

157. The occlusal plane (OP.) is the plane passing through the tips of all major cusps of the lower posterior teeth. In the mouth, the preparation plane (PP) guides are used to facilitate tooth removal down to this plane. After this, additional tooth substance is removed to complete the occlusal preparations (F.P .) Diagram showing the amount of study cast and tooth substance to be removed. 157

158. master cast is mounted in the same manner as the study casts were mounted, except the diagnostic dividers (8A), set at their original settings, now sweep l/l6 inch above tips of the cusps of the prepared teeth. optimal functional occlusal curvature has been established, and the deformity has been eliminated. Note the improved cusp-to-fossae patterns providing optimal functional efilciency . (The right third molar was disregarded because it was not in occlusion.) Casts before and after complete lower posterior rehabilitation Before treatment there was a “swayback” functional occlusal curvature caused by a premature loss of the lower first molar and a perpetuation of the deformity in the original fixed partial denture 158

159. Functionally generated path It is a method of rehabilitating the upper posterior teeth using ‘ functionally generated path ’ record based on a modification of the principles outlined by Meyer and Brenner in 1933 Functionally generated path relies on recording in a simple, yet precise manner the pathways traveled by the cusps in the border movements of the mandible. Pankey LD, Mann AW. Oral rehabilitation: Part II. Reconstruction of the upper teeth using a functionally generated path technique. Journal of Prosthetic Dentistry. 1960 Jan 1;10(1):151-62. Meyer FS. The generated path technique in reconstruction dentistry: Part II. Fixed partial dentures. Journal of Prosthetic Dentistry. 1959 May 1;9(3):432-40 . Meyer FS. The generated path technique in reconstruction dentistry: Part I: Complete dentures. The Journal of Prosthetic Dentistry. 1959 May 1;9(3):354-66. 159

160. Tooth is ready for the functional tracing when the occlusal reduction is completed A square of tacky wax is positioned over tooth being prepared Tracing is begun by having the patient close in the retruded position Paths of the cusps in working excursion are recorded. The area and direction of these excursive movements are demonstrated by fine lines in the inset 160

161. Path of cusps in non working excursions are recorded next Protrusive paths are recorded last Paths of the cusps in working excursion are recorded. 161

162. Unneeded portion of the functional index tray is broken off The functional core is begun by brushing mounting stone on the functional tracing The tray is held in position while the stone sets Excess mounting stone is trimmed from the functional core The bite registration frame is held while the bite registration paste sets Cast is placed in wet stone in Dilok tray Cast with prepared tooth is mounted on the lower member of the twin stage occlude. Anatomic cast is seen on upper left member and functional core on the upper right member 162

163. Axial contours and proximal contacts are checked before preceding to the occlusal surface. The wax added technique is used to form the occlusal morphology. Now the occlusal portion of the wax pattern cab be completed by waxing against the functional core. The functional core is painted with white liquid shoe polish To mark the wax pattern, the freshly painted functional core is closed against it Restoration is adjusted to fit against the functional core Occlusal contacts on the wax pattern for mutually protected occlusion A, and unilaterally balanced occlusion B. 163

164. Hobo’s Philosophy They believed in posterior disclusion in eccentric movements Posterior disclusion is dependent on the angle of hinge rotation created by the angular difference between anterior guidance and condylar path, and on inclination and shape of posterior cusps, which helps in controlling harmful lateral forces. 164

165. 165 In this case, during the protrusive movement the mandible does not rotate around the intercondylar axis but only translates. Translation as defined means "parallel displacement of a body" (the mandible). Since maxillary and mandibular molars slide in contact during eccentric movement, disocclusion does not occur

166. 166 In this case , the mandible translates and rotates around the intercondylar axis; the maxillary and mandibular molars dlsocclude . McHorris (1979) I ncisal path should be 5 degrees steeper than the condytar path. However , when setting the sagittal lncisal path inclination 5 degrees steeper than the condylar path, the amount of disocclusion during protrusive movement is only 0.2 mm, about one-fifth the standard value (1.0 mm). If the incisal path is steeper than 5 degrees, the patient will complain of discomfort. Anterior guide component

167. 167 In this case, the mandible does not rotate around the intercondylar axis, it only translates . However , since the cusp angle is shallower than the condylar path, the maxillary and mandibular molars disocclude . Thus , the component influencing the amount of disocclusion when the cusp angle is shallower than the condylar path is referred to as the cusp shape component as a mechanism of disocclusion .

168. 168 This shows the case when the sagittal inclination of the condylar path is 40 degrees, the incisal path is steeper than the condylar path and the cusp angle is shallower than the condylar path. In this case, the mandible translates and rotates simultaneously around the intercondylar axis.

169. 169 Influence of the amount of disclusion Dependent factors NON WORKING SIDE WORKING ISDE

170. Twin-tables technique -Hobo ( 1991) Posterior teeth are restored using two customized incisal tables: without disclusion; and with disclusion They did not include freedom in centric. Limitations The cusp angle was fabricated parallel to the measured condylar path, and the cusp angle became too steep To obtain a standard amount of disclusion with steep cusp angle, the incisal path has to be set at an angle that is extremely steep The customized guide tables were fabricated by means of resin molding . Was technique sensitive 170

171. Standard values of effective cusp angles on molars The cusp angle was then considered more reliable ( value of cusp angle at the time of eruption was used as a reference for occlusion) The value of cusp angle was then found by trigonometry. The standard cusp values were summarized as standard values of effective cusp angles on molars- Cusp angle Cusp angle on molars ( deg ) Protrusive effective cusp angle 25 Working side effective cusp angle 15 Non working side effective cusp angle 20 171 a standard value for cusp angle was determined such that it may compensate for wear of natural dentition due to caries, abrasion and restorative works. By using the standard cusp angle, it was possible to establish the standard amount of disclusion

172. Twin – Stage Procedure Hobo and Takayama 1989 A dvanced version of the Twin-Table technique A kinematic formula to calculate anterior guidance from condylar path I ncorporated easily with commonly used clinical techniques such as facebow transfer, various centric recording methods, and cusp-fossa waxing INDICATIONS single crowns fixed prosthodontics Implants complete-mouth reconstructions, complete dentures Contraindicated for malocclusion cases 172 Hobo S (1991) Twin-tables technique for occlusal rehabilitation.Part I: mechanism of anterior guidance. J Prosthet Dent 66:299–303

173. 173 In order to provide disocclusion , the cusp angle should be shallower than the condylar path. Since anterior teeth help produce disocclusion , when waxing of the occlusal morphology is done, to produce shallow cusp angle, the anterior portion of the working cast becomes an obstacle - cast with a removable anterior segment is fabricated. Different adjustment values of an articulator were determined for each occlusal scheme to reproduce the standard amount of disclusion

174. Condition 1 The occlusal morphology of the posterior teeth without anterior segment is produced so that the cusp angle is coincident with the standard value of effective cusp angle. This is referred to as ‘condition 1 ’ Condition 2 Secondly, the anterior morphology of the anterior segment is produced to provide anterior guidance with standard amount of disocclusion . This is referred to as ‘ condition 2’ The application of the two conditions described to fabricate the cusp angle and anterior guidance are termed as ‘ twin stage procedure 174

175. Factors that determine disclusion Angle of hinge rotation Cusp shape factor A nterior guidance is steeper than condylar guidance. The mandible rotates around the intercondylar axis . The fact that compensates for the difference in steepness is the angle of hinge rotation Cusp shape factor P osterior teeth disclude only when the cusp inclination of the molar is parallel to the condylar path and anterior guidance is steeper than condylar path. 175

176. During protrusive movements, condyle rotates along horizontal axis if anterior guidance (/?) is steeper than condylar path ((Y). Angle of hinge rotation compensates for this angular difference. During protrusive movement, condyle translates without rotation when anterior guidance (~3) and condylar path (fi) are parallel. Hobo S (1991) Twin-tables technique for occlusal rehabilitation.Part I: mechanism of anterior guidance. J Prosthet Dent 66:299–303 176

177. When cusp inclination of molars is parallel to anterior guidance, there is no posterior disclusion despite steeper anterior guidance (fi) than condylar path ((Y). Posterior disclusion is evident when cusp inclination of molars is parallel to condylar path and anterior guidance (8) is steeper than condylar path ((Y). Hobo S (1991) Twin-tables technique for occlusal rehabilitation.Part I: mechanism of anterior guidance. J Prosthet Dent 66:299–303 177

178. Contraindications In the above contraindicated cases, the vertical axis of the posterior teeth may have inclined abnormally. As a result, the effective cusp angle may vary to some extent even though the cusp angle of a n atural tooth varies minimally. In such condition The standard effective cusp angle presented in the twin-stage procedure may not be applicable - occlusion of a restoration may be inaccurate 178 Abnormal curve of Spee Abnormal curve of Wilson Abnormally rotated tooth Abnormally inclined tooth

179. Evaluation of twin stage procedures The articulator test In the articulator test, after completion of the posterior occlusal wax-up on casts mounted on an articulator (under Condition 1 ), and adjusting the articulator (under Condition 2), the specific amount of disocclusion occurring during various eccentric movements was determined . This is an in vitro test . The intra oral test In the intraoral test, when the results of test 1 were completed and satisfactory, the restoration made on the articulator was cemented in the patient's mouth. Then it was tested to determine if the amount of disocclusion was reproduced as occurred in test 1 . This is an in vivo test. 179

180. 180

181. 181

182. 182

183. Solving deep overbite problems Care must be taken to maintain neutral zone relationship of upper anterior teeth. Deep overbites are almost always related to strong lip pressures and a tight neutral zone . Phonetic relationship of incisal edges is critical for deep overbite patients. Supraeruption of lower incisors often requires correction. If lower incisors are shortened, stops must be provided. If stops cannot be provided, a removable substitution may be needed to prevent supraeruption , or splinting may be considered. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.453,454 183

184. Applying the principles A poorly made anterior fixed bridge with no holding contacts. The lower incisors erupted up to impinge on gingival tissues. The lower lip position is behind the upper incisors because the tight neutral zone prevented the lip from fitting in front for a normal lip seal. The result was very unaesthetic as well as unstable. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.455 184

185. The first treatment option: Reshape It is often necessary to reshape the lingual of upper restorations to provide a holding contour and shorten the lower incisors if they have erupted up too far to make contact. The second treatment option: Reposition If the upper incisors have been wedged forward, they can be moved back so lower incisor contact can be achieved. Changes the neutral zone as the lower lip will be able to slide in front of the labial surfaces to hold them back as the lips seal. The first goal of treatment is to achieve stable holding contacts on all anterior teeth. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.456,457 185

186. A simple but effective appliance for moving the anterior teeth back into a predetermined position against contoured slots in the palatal part of the appliance. A rubber band directs the teeth into the slots. The complete lack of holding contacts on the straight lingual contours of the original restoration. The anterior teeth are brought lingually, their lingual contours has to be recontoured to permit anterior teeth contact into a stop. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.456,457 186

187. Teeth are prepared and provisional restorations are used refine the anterior guidance and esthetic concerns. The third treatment option: Restore After the teeth have been brought into an acceptable alignment by reshaping and repositioning. To achieve contact on all lower anterior teeth, it is often necessary to move one or more teeth forward. Any tooth that is not in contact will supraerupt . Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.456,457 187

188. After the teeth have been repositioned for centric relation contact , the final details are worked out in provisional restorations. The patient may wear the provisionals as long as necessary to determine that they are comfortable, functional, and esthetically acceptable. After approval, the details must be communicated precisely to the technician via casts of the approved provisional mounted in centric relation. A putty silicone index communicates the exact incisal edge positions. A customized anterior guide table communicates the lingual contours, leaving nothing to chance for fabrication of the finished restorations. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.456,457 188

189. Deep overbite with tissue contact Lower incisors erupt up into soft tissue lingual to the upper anterior teeth. It is not a problem if: The upper lingual tissue has been unaffected by the contact. The contacted tissue is dense, firm, flat, and shows no sign of inflammation. The lower incisor tissue contact is simultaneous with contact against the lingual surface of the cingulums of the upper incisors. The incisal edges of the lower incisors are smooth with no sharp edges. The incisal plane of the lower anterior teeth is acceptable esthetically and must be in conformity with the rest of the occlusal plane. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.456,457 189

190. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.459 190

191. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.460 191

192. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.460,461 192

193. Deep overbite problems associated with an anterior slide Such a problem calls for a three-step solution: We must equilibrate to permit the mandible to close without deflection from posterior teeth. We must shorten the lower incisors to position the incisal edges in an optimum relationship to previsualized centric stops on the upper incisors. We must restore the upper lingual contours to establish stable centric stops Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.456,457 193

194. Solving deep overbite problems by splinting Teeth that have supraerupted into the palatal tissue can be shortened to relieve the pressure against the soft tissues. Splinting is often the most practical method of stabilizing such lower anterior teeth. Includes Full coverage Resin bonded lingual restorations Modifications in partial denture e.g. continuous clasp splinting and Swing-lock design. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.464 194

195. Bite planes to solve deep overbite problems Discomfort from tissue impingement and if future problems are imminent. Least complicated way of preventing supraeruption of the lower anterior teeth. Fabrication is carried out on centrically mounted models. The appliance is most esthetically acceptable when it is made of clear acrylic resin. It must provide stable centric contacts for all lower teeth, and it should be equilibrated so that there is no interference to any excursive movement. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.464,465 195

196. Partial dentures to solve deep overbite problems When an upper partial denture is required, it can sometimes fulfill a double purpose by serving as a contact for the lower anterior teeth. Palatal bar is designed to cover the tissues behind the upper anterior teeth, the lower anterior teeth may be permitted to contact the palatal bar to prevent supraeruption. The contour of the palatal coverage may be designed to permit protrusive excursions of the lower anterior teeth to slide smoothly from the palatal coverage onto the lingual inclines of the upper anterior teeth. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.465 196

197. Solving anterior overjet problems Overjet patients present the greatest difficulty for providing centric stops on all the teeth. Careful observation is important to make sure the overjet relationship is not stable before attempting to correct it. The tongue is a common substitute for holding contacts. Evaluate to see if it effectively stabilizes the lower incisors Evaluate the horizontal component of jaw function before arbitrarily moving anterior teeth. Problems with posterior teeth stability are common with anterior overjet because of the difficulty of providing anterior guidance with posterior disclusion . Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.467 197

198. It is essential to determine whether the overjet is caused by maxillary protrusion, or by mandibular insufficiency before a treatment plan is selected. Overjet problems are common in children with airway problems because the tongue must posture forward to permit mouth breathing. Correction of the airway problem is critical to correction of the overjet problem. Note the A point is forward of the nasion perpendicular while Po is in correct alignment with the cranial base. The maxilla is the problem. Use the nasion perpendicular analysis 198

199. Extreme anterior overjet treatment choices Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.468 199

200. The problems of anterior overjet Problem 1 Lower teeth with no stabilizing contact with the upper teeth either in centric relation or near centric relation have tendency to supraerupt, drift out of alignment, and frequently impinge on the palatal tissues. Problem 2 Problem 3 Excessive overjet relationships make it difficult or impossible for the anterior guidance to do its job of posterior disclusion. associated with excessive anterior overjet is esthetics . The classic bucktooth appearance has long been used by cartoonists to depict stupidity. It is not a pleasant appearance, and it is often the real reason why patients seek treatment. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.469 200

201. The resolution of anterior overjet problems involves four considerations: Stabilization of the lower anterior teeth Providing the best possible anterior guidance for posterior disclusion in protrusion Providing the best possible relationship for disclusion of the balancing inclines Improving the position, alignment, or shape of the upper anterior teeth for better esthetics Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.469 201

202. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.469 Applying the principles Overjet with lower incisor contact on palatal tissue with esthetic concerns. The lower lip locks behind the upper anterior teeth, affecting speech and causing exposure to unesthetic drying of the incisors" labial surfaces. Option 1 Analysis on mounted casts showed the need to narrow the incisors to make room for moving the incisor segment lingually . Option 2 After narrowing the incisors to a predetermined width, an appliance is made with a lingual plate contoured to receive the teeth into their predetermined position as they are moved lingually . Reposition Reshape 202

203. A rubber band attaches to the appliance to move the teeth into the contoured slots in the lingual plate. Use of such appliances is a simple way to achieve dramatic results, but alternative methods using bands or brackets must always be considered if final positioning requires horizontal bodily movement of roots. Results of repositioning show an improved incisal plane as incisal edges move down as they are pulled back into a position that permits contact with the lower incisors. Note: The appliance increases the VDO to allow room to move the upper teeth back. The lingual contours are then reshaped to ideal contact with lower incisors. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.474 203

204. Option 3 Restore Teeth are prepared, and a provisional restoration is made as a copy of the diagnostic wax-up. The provisional restorations are refined in the mouth The restorations are tested for a smooth functioning anterior guidance, making sure that immediate disclusion of the posterior teeth is achieved. This may require some reshaping of posterior surfaces. The putty silicone index communicates incisal edge position and contour. The custom anterior guide table communicates the exact lingual contours . The mounted cast of approved provisionals provides exact details to the technician Final restorations copy all of the details. Nothing is left to chance . Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.474,475 204

205. Post-op stabilization. Because teeth were repositioned, a period of post-op stabilization is indicated. This can be easily accomplished with a simple Biostar appliance made of flexible vinyl. It requires no clasps because it snaps over the teeth and engages the undercuts for retention. Finished restorations (far right) showing improved relationship to smile line. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.475 205

206. Solving anterior open bite problems The most important determination is what caused the open bite. Always evaluate the condition of the temporomandibular joints (TMJs). Loss of condylar height usually causes progressive anterior separation. If a habit pattern caused the open bite, correction will be unsuccessful unless the habit is eliminated. Skeletal malrelationships can usually be successfully treated. There are many degrees of open bite depending on tongue or lip habits that intrude teeth or prevent their eruption. Many anterior open bites are stable. A major problem of anterior open bite is trauma to posterior teeth. A second major problem is lack of an anterior guidance for posterior disclusion Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.475 206

207. Treatment objectives 1. Maximize the number of equal-intensity occlusal contacts on both sides of the arch. 2. Correct a "reverse smile line" on upper anteriors for esthetic improvement. 3. If only one arch is malaligned , close the anterior relationship by correcting the arch that is wrong. 4. If a habit pattern cannot be broken, the occlusion must conform to the habit. 5. Achieve posterior disclusion in protrusive by determining the anterior guidance as far forward as possible. 6. If anterior guidance cannot be achieved for disclusion of the balancing side, use group function of the working side posterior teeth. 7. If condylar breakdown is progressive, correction of the occlusion must keep up with it. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.475 207

208. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.482 Anterior open bite in a patient with occluso -muscle pain. Deflective interferences on molars created a slide to maximal intercuspation . At maximal intercuspation , no contact was possible for the anterior teeth. Tongue posture at maximal intercuspation 208

209. Maximal intercuspation after occlusal correction by equilibration. Anterior teeth still could not contact opposing teeth. Position of teeth after 10 months. No orthodontic treatment or any other attempt was made to close the anterior open bite . The teeth erupted to contact because the tongue no longer maintained a posture to cushion the bite for protection of the deflective premature contact. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.483 209

210. Severe anterior open bites Solving the problem of achieving a stable anterior relationship may require a three-pronged attack: 1. Orthodontic correction of anterior tooth relationships 2. Occlusal equilibration to eliminate the need for protective tongue or lip habits 3. Use of a retainer at night Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.483 210

211. Applying the principles Anterior open bite. Contact in centric relation is only on second molars. Esthetics is a major concern of the patient. First treatment option: Reshape. Contour of space indicates that the tongue will not be a problem if the space is closed. The question to ask: How much closure can we get by reduction of the posterior teeth? This can be determined on the mounted casts. it is practical to shorten the molars to gain anterior contact. Adjustment on the casts shows that contact in the canines could be achieved by judicious reshaping of the molars to close the bite This overlay can then be shaped in the mouth to show the patient in advance what a change in the incisal plane would do for the smile. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.483 211

212. Surgical option Inclination of opening toward the front suggests that a successful result can be achieved by closing the vertical space between the anterior teeth. The first treatment option of reshaping could only achieve this much closure without mutilating the molar teeth. This leads to evaluation of repositioning the teeth but it would have to involve the dento -alveolar process to achieve an acceptable esthetic result . Important rule: Don’t change what is right to fit what is wrong. Analysis shows that the height of the lower incisal plane is correct. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.483 212

213. The upper dento -alveolar segment should be repositioned down to close the space and gain contact with the lower teeth. Final result achieves a pleasant esthetic result as well as a functional anterior guidance. The steep guidance was acceptable because the envelope of function was very vertical (as it is on most anterior open bites). Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.483 213

214. Treating end to end occlusions Important considerations: Anterior end-to-end relationships may be very stable if they are in harmony with centric relation. Lateral anterior guidance is achieved by sliding sideways against ,the flat incisal edges. Condylar guidance can usually combine with flat anterior guidance to disclude all posterior teeth. The principal problem is failure to disclude the posterior teeth in excursions, so care must be taken to make sure the occlusal plane and fossae contours are correctly related for disclusion by the condylar path on the balancing side. This typically requires flatter occlusal contours for disclusion on the working side because working side disclusion is achieved solely by the lateral anterior guidance. Anterior end-to-end relationships Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.483 214

215. Changing an anterior end-to-end occlusion to an overlap relationship steepens the anterior guidance and will probably cause a bruxing wear problem on the anterior teeth. A nighttime bruxing appliance is in order whenever the envelope of function is restricted. Even though restriction of the anterior guidance causes wear, etc., it is not usually uncomfortable for the patient as long as there are no interferences to centric relation closure. The ideal solution is to maintain the anterior guidance as flat as possible if esthetic goals can be met without an anterior overbite relationship Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.483 215

216. Restoring end- to-end anterior teeth Minimal changes in incisal edge position can effect gross improvements in anterior function. Moving the upper incisal edges forward and the lower incisal edges inward can extend the protrusive contact by a couple millimeters or more. Even a horizontal zero-degree guidance can fulfill all the disclusive needs of the posterior teeth if occlusal contours are also kept flat enough and the occlusal plane is correct . Restorative recontouring of teeth in an end-to-end bite an cause special problems if the stresses are moved off the direction of the long axis. The stresses are so confined to the long axis that the periodontal fibers and the bone trabeculae are not aligned to resist lateral stress. Suddenly changing a tooth's contour to subject it to lateral forces may produce unwanted effects of tenderness or hypermobility until the fibers realign and the bone becomes more resistant to the lateral forces . Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.483 216

217. The choice that must be made is between increasing the vertical dimension of occlusion (VDO) or endodontically treating the teeth and maintaining the VDO. The VDO should be increased no more than is necessary to provide room for the restorative materials on the incisal edges. 1.5 mm increase should usually provide the needed space. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.483 217

218. Special considerations Stability Whether an end-to-end occlusion is stable depends principally on two factors: 1. Harmony with the neutral zone 2. Noninterference with the envelope of function Skeletofacial profile R equires cephalometric analysis as well as mounted diagnostic casts. The purpose of the cephalometric evaluation is to determine whether the end-to-end relationship is caused by an underdeveloped maxilla or an overdeveloped mandible, or some combination of both. The decision to alter the occlusal relationship should be based on a careful evaluation of the following factors: Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.495,496 218

219. Function It is rare for a patient with a stable end-to-end relationship to complain of inadequate function. Esthetics The irony of an anterior end-to-end occlusion is that although many dentists believe it should be "corrected," most patients believe it is the ideal relationship. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.496 219

220. If an end-to-end relationship occurs posterior to the facial plane, it results in a "pushed-in" appearance as a manifestation of bimaxillary deficiency This type of occlusal relationship should be treated with caution because it is usually accompanied by a very strong buccinator- orbicularis oris limitation on arch size. Neutral zone Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.496 220

221. Posterior end-to-end relationships 1. Are all teeth stable or unstable? (Look for wear or hypermobility.) 2. Can the anterior guidance disclude the posteriors? If so, an end-to-end occlusion is not a problem. 3. If anterior guidance cannot disclude the posterior teeth in lateral excursions, correct the posterior relationship by the best choice of : • reshaping • repositioning • restoring (with centralized cusps) • surgery Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.497 221

222. Evaluate each method and select the most practical way to fulfill the requirements for stability. The goal is posterior disclusion of the balancing side either by the anterior guidance or by the posterior teeth on the working side. 4. Anterior guidance can sometimes be steepened if it is not steeper than the lateral path originally found during excursions dictated by posterior teeth Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.498 222

223. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.498 Restoring end-to-end posterior teeth Lower Cusp Tip to Upper Flat Surface Provide almost normal lower posterior occlusal form, with slight modifications to flatten and broaden upper cusp tips to serve as stops for the more rounded lower cusps. Overjet can be provided to hold the cheek away from the contacts. Adequate as long as the teeth are positioned in harmony with the cheeks and tongue. The goal is to provide as much stability as possible in centric relation and as much relief as possible in excursions. 223

224. By converging the lower buccal and lingual cusps into single centralized cusps, it is practical to place them in the central fossae of the upper teeth. Stress direction is ideal for both upper and lower teeth, and function is excellent. With centralized lower cusps, the upper working inclines can be used to disclude the balancing inclines on the opposite side, and it can be accomplished within the limits of the normal neutral zone. Centralization of the Lower Cusps Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.498 224

225. Treating splayed or separated teeth Some splayed anterior teeth with spaces are healthy and have stable holding contacts. If the teeth are stable and the supporting structures are healthy, the decision is based on the patient's esthetic desires. Splayed anterior teeth are usually in a definite neutral zone corridor. They can be moved or reshaped within that corridor, but movement toward either the tongue or the lips usually results in interference with the musculature and eventual instability. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.501,502 225

226. Applying the principles The patient presented with the primary concern of improving the esthetics of his smile. The teeth were splayed, separated, and inclined forward. All teeth were firm with no sign of wear or fremitus . Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.504 226

227. Maximal intercuspation There is a long slide from the first contact at the most closed position. Centric relation The true arc of closure to anterior contact in centric relation can then be determined on mounted casts. EQULIBRATION OF CASTS ANTERIOR GUIDANCE Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.505 227

228. DIAGNOSTIC WAX UP NEUTRAL ZONE CONSIDERATIONS Splayed anterior teeth are usually in the most balanced relationship between tongue and lip pressures. THE DIAGNOSTIC WAX-UP COMPLETED Prepared teeth. Note centric relation contact on centrals and canines. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.506 228

229. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.501,502 Matrix used as reduction guide and for direct fabrication of provisional restorations Provisional restorations in place Patient can test the provisionals to be sure that appearance, phonetics, and function are all acceptable. Functional esthetics . Mounted cast of the approved provisional restorations eliminates all guesswork for the technician. The putty silicone index precisely communicates the incisal edge position and contour that can then be copied in the wax-up on the master die model. A customized anterior guide table dictates the exact configuration of the lingual contours. 229

230. Precise doctor/technician communication yields precise results. The finished restorations follow the exact guidelines that were worked out in the mouth and tested in function. The putty matrix simplifies communication in a way that is verifiable by both the technician and the dentist Lingual contours on the restorations match what was worked out in the mouth and communicated via the customized anterior guide table. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.508 230

231. Treating the cross bite patient first analyze the tooth-to-tooth relationships at the selected vertical dimension in centric relation . Is the anterior crossbite the result of mandibular prognathism or maxillary deficiency ? What is the anterior relationship in centric relation? If it is end to end in centric relation, how much vertical displacement of the condyles is there in maximal intercuspation ? Do the anterior teeth need to be restored because of wear or appearance? Is the crossbite an esthetic problem? Can the anterior teeth be restored end to end? Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.513 231

232. Problems with anterior crossbites Esthetics Elimination of the "bulldog look" of prognathism surgery seems to be the only practical method if the prognathism is severe. No centric contact on anterior teeth In more severe malrelationships , there is no anterior contact. The usual problem associated with lack of centric contact is supraeruption of the teeth. This is rarely a problem with anterior crossbites because the upper lip substitutes for the contact and holds the lower anterior teeth in place. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.514 232

233. No Anterior Guidance Most prognathic patients limit their function to vertical "chop chop" movements Provide balancing incline disclusion. The necessary lift can usually be provided by the working-side inclines. Group function of the working inclines is usually the occlusion of choice. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.515 233

234. Why increasing the VDO works ? If the increased VDO at the anterior teeth is offset by upward movement of the condyles from maximal intercuspation to centric relation, the interference with elevator muscle contracted length may be minimal or none. Even if increasing the VDO cannot be offset completely by upward condylar repositioning, the increased VDO can be well tolerated as the muscles return it to their original contracted length. If all teeth are in contact in centric relation , the corrected occlusion will be maintained with minimal adjustments required Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.516 234

235. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.517 235

236. Applying the principles Anterior crossbite at maximal closure. At this most closed position, the condyles are displaced down and forward The end-to-end relationship occurs in centric relation when the condyles have moved up their eminentiae. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.518 236

237. An existing removable partial denture was used to increase the VDO at the anterior end-to-end relationship. Based on the analysis on the mounted casts, the anterior teeth were narrowed a predetermined amount to facilitate moving them into a better alignment that was pre-established on the diagnostic wax-up. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.518 237

238. A continuous clasp was cast to fit the repositioned teeth on the diagnostic wax-up. The clasp is bonded to the canines on each side. The canines and central incisors are in the neutral zone and will not be moved. 238

239. Small rubber bands are used to pull the lateral incisors into the slots designed to receive them Alignment of the teeth progresses After the lateral incisors are aligned, direct composite buildup is used to develop contacts and contours. It is copied in provisional restorations that serve as a retainer until final preparation and completion. 1. Selective shaping and occlusal equilibration 2. Orthodontic repositioning of the teeth within the present bone framework 3. Restorative reshaping 4. A combination of the above procedures The conservative approaches for resolving anterior cross bite problems can be summarized as follows: Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.518 239

240. Surgical Correction of Anterior Crossbite 1. Resection through the ramus so that the body of the mandible can be moved distally into alignment with the maxilla. 2. Horizontal resection of the maxilla so that it can be moved forward into alignment with the mandible. 3. Sectional osteotomies so that an anterior segment can be repositioned. This is not ideal if there is a severe skeletal discrepancy. Dawson PE. Functional occlusion-e-book: from TMJ to smile design. Elsevier Health Sciences; 2006 Jul 31 . PAGE NO.522 There are three methods for correcting an anterior crossbite surgically: 240

241. Determining the best treatment choice for posterior crossbite. In most instances, it is "leave it alone" unless there are interferences to centric relation or excursions. Analyzing cusp/fossae relationships in crossbite cases. The lower lingual cusp and the upper buccal cusp become the stamp cusps. Treatment objective Cross bite occlusions follow the same rules as normal occlusions with regard to the requirements for stability. They just use different cusps for holding contacts. 241

242. Restoring Posterior Crossbite The most common treatment mistake in crossbites: Upper inclines that face the cheek or lower inclines that face the tongue should never contact in lateral excursions. This rule should be followed regardless of the arch relationship. All inclines should disclude when the lower teeth move toward the tongue. When posterior crossbites are being restored, the lower lingual cusps become the functioning cusps. They fit into the same upper fossae and function against the same inclines as the lower buccal cusps do in a normal relationship. 242

243. If posterior group function is desired, the lower lingual cusps contact the lingual inclines of the upper buccal cusps in working excursions ( laterotrusion ). This working incline contact can be used very effectively to disclude the opposite-side balancing inclines. The lower buccal cusp is a nonfunctioning cusp in crossbite relationship, and its lingual inclines should never contact; so it should be shortened slightly from the normal contours so that it does not interfere in balancing excursions ( mediotrusion ). 243

244. Treating crowded, irregular, or interlocking anterior teeth 1. We can narrow the teeth so that they will fit into the available space. 2. We can widen the space by reshaping the adjacent teeth. 3. We can reduce the number of teeth that must fit into a given space. 4. We can increase the space by changing the shape 0f the arch. 5. We can change the axial inclination of the anterior teeth. Five possible ways of solving the space problem: 244

245. Narrowing crowded teeth Several techniques that can be used for moving teeth into their predetermined correct position in the arch: Finger pressure Ligatures and rubber bands Removable appliances Bands Cemented brackets Vinyl repositioners Invisible retainers Flexible ethylene vinyl acetate (EVA) polymer joined to a semi rigid polycarbonate material. Invisalign It utilizes a series of computer-generated sequences for tooth movement to achieve an ideal alignment of teeth in both arches. 245

246. Applying the principles The upper-left central incisor was locked behind the lower incisors . Because the incisal third of the tooth was fractured, it was just shortened further so it could be moved forward without having to open the bite temporarily to move it past the lower incisal edges. 246

247. A simple removable appliance was used with a finger spring to push the tooth forward until it was positioned in alignment with the other upper anterior teeth. After the tooth was in position, it was prepared for provisional restorations. The anterior guidance was refined so a cast could be made and mounted in centric relation to fabricate a custom anterior guide table. Preparations were then completed. A provisional restoration was copied from the diagnostic wax-up. This will serve as a retainer until the bone stabilizes. After approval, permanent restorations will copy it. 247

248. Producing acceptable occlusal relationship using Invisalign ® Patient with upper-left lateral and canine locked behind lower teeth. The upper-right lateral and canine are lingually inclined to create a poor esthetic alignment. A centric relation bite is made using bilateral manipulation with load testing to verify centric relation. 248

249. Casts are mounted in centric relation with an earbow for location of centric relation condylar axis. A silicone index is made to relate the casts to centric relation at first point of tooth contact. The index is used in the computer-generated jaw relationship to which the teeth will be aligned. This corrects for discrepancies inherent in unmounted casts related to maximum intercuspation. Series of Invisalign® overlays to be used in sequence. 249

250. Computer-generated image of starting point. Image of projected treatment goal. The treatment goal for this patient includes the use of laminates for the initial determination of where the teeth needed to be positioned to facilitate an esthetic and functional result. Teeth after movement to the predetermined treatment goal. Planning included use of laminates for final esthetic position and contour on right and left laterals and canines. Teeth prepared for laminates. Finished result of very conservative treatment. Central incisors were bleached to lighten color , avoiding any need for restorations on them. Note the uniform occlusal contact in centric relation, made possible by aligning the teeth to a correct maxillo -mandibular relationship. 250

251. Crowded anterior teeth with severe posterior interferences 251

252. 252

253. 253

254. SUMMARY Procedural steps in full mouth rehabilitation 254

255. Shade selection Prepare lower anterior teeth Provisionalization Prepare upper anterior teeth Provisionalization Evaluation of anterior guidance, plane of occlusion, and occlusal scheme on provisional restorations Recording and transferring anterior guidance record of provisional Final impression of upper and lower anteriors Evaluate anterior plane for occlusion, phonetics, esthetics and function Interocclusal record to mount on articulator Final impression of upper and lower posteriors Temporary cementation of final anterior restorations Bisque tryin Metal tryin Metal tryin Bisque tryin 255

256.   Evaluate for function, esthetics and comfort Remounting Maintenance phase Final cementation of restorations Temporaty cementation of upper and lower final posterior restorations Follow up 256

257. C ASE R EPORTS – Bruxism 45-year-old male patient with a habit of bruxism Attrition : Marginally less in the posteriors as compared to the anterior teeth Total collapse of the vertical dimension Lower anterior teeth were totally razed to the gingival level Upper lateral incisors & canines were also very badly destroyed 257

258. C ASE R EPORTS Second molars : Intercuspating occlusion First molars : > 40% attrition on the occlusal surfaces with no intercuspation Upper right lateral incisor & canine : attrided to the gingival level Lower Anterior : Right f irst premolar - left canine were totally razed to gingival level Remaining teeth : > 40% of loss of crown structure 258

259. C ASE R EPORTS Phase I Endontic Reestablishment of Vertical dimension Occlusal equilibration Phase II CLP Upper and lower incisors Endodontics Glass fiber posts + Adhesive restorations Post & core on upper right canine & lower canine 259

260. C ASE R EPORTS 260

261. Amelogenesis Imperfecta Incisal aspects …completely worn away exposing the pulp chambers Occlusal aspects of all the posterior teeth were also severely worn Cervical & proximal enamel was found to be normal Attrition of the molars resulted in a decrease of the vertical dimension of occlusion Interocclusal distance : At physiologic rest position = 7.3 mm Centric Occlusion = Maximum intercuspal position Gingival status: Good and well maintained Oral hygiene : satisfactory 261

262. C ASE R EPORTS Panoramic Radiographic Examination Enamel of the teeth appeared to have the same radiodensity as dentin Morphology of the roots were normal Pulp chambers were normal with no evidence of calcification Cementum , lamina dura , & bony trabeculations were within normal limits 262

263. C ASE R EPORTS Inadequate crown height for the fabrication of the prosthesis Apically positioned flap Crown lengthening Increase of crown height by approximately 2 mm was achieved Caries excavation was done for all carious teeth Endodontic therapy was carried out as required Bite registration using Type II modeling wax Increased vertical dimension of 5 mm with 3 mm of freeway space Splint fabricated with heat-cured Polymethyl methacrylate acrylic resin Patient used the splint for three months 263

264. C ASE R EPORTS Full-mouth, heat-cured provisional restorations were fabricated at the desired vertical dimension (with 3 mm freeway space) using methyl methacrylate acrylic resin & were temporarily cemented 264

265. C ASE R EPORTS Maxillary anterior teeth: cast post cores Mandibular anterior teeth : prefabricated posts Premolars & right first molar : Composite core build-ups to increase the crown height Crown preparation: Porcelain-fused-to-metal (PFM) : Maxillary & mandibular anteriors , premolars, and maxillary first molars All-metal restorations: remaining teeth 265

266. C ASE R EPORTS 266

267. Failure and success in full mouth rehabilitation dependent on technical and biophysical factors. Technical failures may be loss of restorations and retainers or fracture of metal or porcelain components. Caries , fracture of abutments, periodontal disease and extractions are classified as biological failures . Health of periodontium is influenced by the oral hygiene practice of the patient, crown position and margin, contour and occlusion of the restoration. Hygiene instructions combined with repeated prophylaxis every six months prove successful in maintaining oral health. Adequate plaque control program to prevent secondary caries is essential 267

268. Conclusion The patient needing extensive restorations is often neglected and overlooked by a general practitioner due to lack of specialized training . Its important to know that achieving success in full mouth rehabilitation requires a multidisciplinary approach. The ultimate goal of any dental treatment is to provide optimum oral health 1 . to attain this ooral health it is important to have properly scheduled recall visits and oral hygiene maintenance . R estorations must be meticulously fabricated considering mechanical and biological factors,which will ultimately lead to long term success of full mouth rehabilitation 268

269. R eferences Evaluation.Diagnosis , and treatment of occlusal problems Peter E Dawson 2 nd edition The freeway space and its influence in the rehabilitation of masticatory apparatus vol 2 no 6 J pros dent 1952 A Three-Stage Approach to Full-Mouth Rehabilitation Compendium—Volume 29 (Special Issue 1 ) A Three-Stage Approach to Full-Mouth Rehabilitation Pract Proced Aesthet Dent 2008;20(2): 81-87 An analysis of current practices in mouth rehabilitation J pros dent 1955 Full Mouth Rehabilitation with Group Function Occlusal scheme in a patient with severe Dental Fluorosis INDIAN JOURNAL OF DENTAL ADVANCEMENTS vol 3 issue 3 Custom Made Occlusal Plane Analyzer : Fabrication and Technique International Journal of Advanced Dental Science and Technology 2013, Volume 1, Issue 1, pp. 17-24 269

270. PHILOSOPHIES IN FULL MOUTH REHABILITATION – A SYSTEMATIC REVIEW Int J Dent Case Reports 2013; 3(3): 30-39 The Dahl principle revisited Irish Dentist July 2011 ORAL REHABILITATION Part I. Use of the P-M Instrument in Treatment Planning and in Restoring the Lower Posterior Teeth J. Pros. Den. Jan .-Feb., 1960 Increasing occlusal vertical dimension — Why, when and how D R Bloom & J N Padayachy British Dental Journal 200, 251 - 256 (2006) Broadrick occlusal plane analyzer 2008 whipmix corporation Twin – tables technique for occlusal rehabilitation : part 1 – Mechanism of anterior guidance J PROSTHET DENT 1991, vol 66 pg 299-303 Functionally generated paths for Ceramometal restorations J PROSTHET DENT 1999, vol 81 pg 33-36 270