Orthodontic finishing proffit chapter17.pptx

Chapter 17 of Proffit, discussion in details.

1. Finishing By\ Sahar Emad

2. contents Introduction. Adjustment Of Individual Tooth. Midline Discrepancies. Tooth Size Discrepancies. Excessive Overbite & Anterior Open Bite. Settling Of Teeth. Special Finishing Procedures To Avoid Relapse Micro-esthetic Procedures In Finishing

3. Introduction Finishing is the last phase of “active” treatment Levelling and aligning Overbite correction Spaces are closure The final stage of treatment is to get the details correct. Heavily dependent upon the previous stages of treatment. It is extremely difficult to achieve an acceptable result when the treatment objectives and proper mechanics have not been met

4. 2- Adjustment of Individual Tooth Positions At the finishing stage , Unnecessary if appliance prescription and bracket positioning were perfect But due to the variations in ( tooth anatomy and bracket placement ) some tooth position adjustment may be needed

5. If bracket is poorly positioned Rebond the bracket Placing compensating bends in arch wires 1- Rebond the bracket after bracket rebonding, a flexible wire must be placed to bring the tooth to the correct position.

6. Arch wires for tooth positioning in finishing stage:

7. 2- Step Bends The first order ( in-out / rotation ) Tight interproximal contacts No rotations. Allowing the perfect arch form. Typical first-order bends are : - - lateral incisors (insets), - canines (offsets) and - first molars (bayonet bends, toe in).

8. The upper first molar Mesiobuccal cusp makes mesial out rotation is considered to be ideal. the buccal surface of the upper first molar should be parallel to the palatal suture

9. The second order ( mesio -distal / tipping) evaluate the root parallelism and marginal ridges. (Clinically) The marginal ridges should be at the same level especially buccal segments. (Radiograph)root parallelism important for retention and stability.  

10. Radiographic Objectives Panoramic Radiograph Recommended before starting the finishing stage To evaluate root position and root parallelism . Evaluating root resorption If observed, that might dictate ending treatment early or taking a break from the final active treatment for 3 to 4 months to allow cementum to heal.

11. Problems of second-order angulation are commonly found in the upper lateral incisors lower premolars teeth adjacent to the extraction sites. Problems might be related to abnormal tooth morphology bracketing errors

12. Applications of second order bend: During space closure phase the goal is to achieve bodily tooth movement and preventing the crowns from tipping toward each other. In case of a small amount of tipping will occur after space closure some degree of root paralleling at extraction sites often will be necessary. In case of improper bracket positioning root separation or paralleling may be needed in non extraction cases (this is most likely on maxillary lateral incisors and premolars).

13. In standard edgewise brackets Similar to begg and tip edge technique That use springs For controlling root tipping

14. In standard edgewise brackets may includes a vertical slot behind the edgewise bracket allows root tipping using springs that inserted and hooked beneath the main st.st. arch wire.

15. In preadjusted edgewise brackets No Uprighting springs and vertical slots Angulated bracket slots that allow proper root paralleling when a flexible full-dimension rectangular wire is placed.

16. With the 18-slot appliance To correct mild tipping finishing arch wire is (17 × 22 or 17 × 25) st.st. which is produce the necessary root paralleling moments. To correct greater degree of tipping more flexible rectangular arch wire is needed. To correct more severe tipping 17 × 25 beta- Ti (TMA) 17 × 25 nickel–titanium (M- NiTi )

17. With 22-slot brackets if teeth have tipped even slightly into an extraction space or if other root-positioning is needed Under most circumstances 21 × 25 beta- Ti wire if significant root position­ing is needed 21 × 25 M- NiTi should be used first. If greater range of action is needed (severely tipped tooth) A- NiTi wire initially, then M- NiTi . We can’t use for tipping 19 × 25 st.st. ( too stiff )

18. Root parallelism is important for three reasons: To transmit occlusal load of the forces across the longitudinal axis of the tooth. A greater potential for relapse If only the crown has been tipped and the root is not in its proper position. A greater potential for periodontal problems due to root proximity.

19. The third order (labiolingual – torque) Affect The esthetics of the smile (an extraoral category). The inter-arch objectives (the occlusal relationship) Are difficult and time consuming as it need extensive bone remodeling

20. The third order Controlling third order can be done by Maintaining a proper moment/force ratio during the retraction phase in extraction cases. To allow only root correction and prevent incisors from flaring. 3 rd order bend for anterior teeth cinching the arch wires lacing the entire arch. Mesial migration of upper molar (rowboat effect) can be generated So use of Class II elastics is recommended to prevent it.

21. Auxiliary torquing springs a mild bowing of the anterior segment is expected

22. Root Torque of Incisors If incisors tipped lingually more than desired while retraction, Lingual root torque may be required as a finishing procedure. In the Begg technique an auxiliary appliance “piggyback arch” over the main or base arch wire.

23. The torquing auxiliary is a “piggyback arch” contacts the labial surface of the incisors near the gingival margin creating the necessary couple with a moment arm of 4 to 5 mm . can be used in edgewise technique in the same way the basic principle of torquing auxiliary : the auxiliary arch Initially shaped into a tight circle when it is partially straightened out to normal arch form It exerts a force against the roots of the teeth

24. With a modern edgewise appliance only moderate additional incisor torque may be needed during the finishing stage. With the 18-slot appliance a 17 × 25 st.st. arch wire Built-in torque in the bracket slot There is no need to place torquing bends in the arch wire making the accomplishment of torque as a finishing procedure relatively straight forward.

25. With 22-slot brackets with built-in torque full-dimension M- NiTi or beta- Ti arch wires can be used (torque built in) reduce the need for auxiliary arches. Not effective For correcting ligually tipped incisors to place a rectangular steel arch wire only depending on bracket torque-prescription because the wire creates too much torsional force and has a very limited range . for 22-slot edgewise torquing auxiliaries have almost disappeared from contemporary use except when upright incisors are to be corrected by tipping the crowns facially The auxiliaries are probably the best way to do this.

26. IN Class II division 2 malocclusion If maxillary central incisors are severely tipped lingually require torquing movement while the lateral incisors need little torque. Burstone torquing arch is the most effective torquing auxiliary Because of the long lever arm, It is equally effective with the 18- or 22-slot appliance.

27. Three factors determine the amount of torque that will be expressed by any rectangular arch wire in a rectangular slot: the torsional stiffness of the wire the inclination of the bracket slot relative to the arch wire the tightness of the fit between the arch wire and the bracket.

28. Buccal Root Torque of Premolars and Molars Can affect smile esthetics It is common that at the end of fixed appliance treatment, maxillary canines and premolars Roots are tipped facially and crowns lingually because the prescription in many modern brackets provides negative torque

29. To obtain a broader and more pleasing smile , the solution is not to expand across the premolars but to use buccal crown torque so that the crowns are up righted This gives the appearance of a broader smile without the risk of relapse that accompanies arch expansion.

30. Midline Discrepancies The midline objectives should be evaluated in the intraoral and extraoral finishing category ( specially the upper arch ). Midlines should be coincident. >2 mm discrepancy should be treated in the early phases of treatment.

31. Midline Discrepancies This can result from 1- Improper planning or mechanics a preexisting midline discrepancy that was not completely resolved at an earlier stage of treatment asymmetric closure of spaces within the arch. 2- Skeletal Cause Skeletal asymmetry the treatment should be camouflage or surgical correction

32. 3- Dental Cause caused only by lateral displacements of maxillary or mandibular teeth that accompanied by a mild Class II or Class III relationship on one side. Tipping is the major type of tooth movement that can be used to correct midlines Treated by anterior cross elastics. Or a combination of Class II elastics on one side and Class III on the other can be used.

33. Class II or Class III and anterior cross elastic should be reserved for small discrepancies long term use side effect occur in the vertical and transverse planes the vertical component of the anterior cross elastic force cause canting of the occlusal planes In The Transverse plane, rotation of the dental arches around the y axis with the use of Class II/Class III elastics may result in a crossbite tendency on one buccal segment and a Brodie bite tendency on the other

34. Tooth Size Discrepancies A significant tooth size discrepancy exists between the dental arches (i.e. a Bolton discrepancy). Example: upper lateral incisors lower second premolars

35. As a general guideline from Bolton analysis the threshold for clinical significance of tooth size discrepancy is 2 mm. So more than 2mm discrepancy will necessitate steps to deal with it during treatment. And not be delayed at the finishing stage Discrepancies due to excess tooth size Interproximal enamel reduction (IPR). is the usual strategy to compensate for discrepancies caused by excess tooth size. A topical fluoride treatment recommended immediately after IPR.

36. Discrepancies due to tooth size deficiency leave space between the diffident teeth Finally, will be closed by restorations. composite buildup Laminate veneer Delaying restoration Leaving the space

37. 1- composite buildup The best plan, Should be done during the finishing stage for easier and Precise finishing The lateral incisor root should be close to ideal position before buildup because change in root position after buildup will change contact points and embrasure relationships leading to bad esthetics . 2- Laminate veneers should be delayed because bonding and debonding may damage the it’s surface. 3- Delaying restoration The main reason for waiting until after the orthodontic appliance has been removed would be to allow any gingival inflam­mation to resolve itself. So, the restoration should be done during retention phase. initial retainer to hold the space and new retainer immediately after the restoration is completed. 4- Leaving the space distal to the lateral incisor can be esthetically and functionally acceptable

38. Excessive Overbite evaluate two things: 1- The vertical relationship between the upper lip and maxillary incisors If Appropriate maxillary incisors display of the on smile Maintain this relationship Make any overbite correction by repositioning the lower incisors. If Excessive maxillary incisors display of the on smile intrusion of the upper incisors would be indicated. 2- Anterior face height. With Short facial height elongating the posterior teeth slightly (the lower posterior teeth) would be acceptable With Long facial height intrusion of incisors would be needed.

39. For example: for incisors intrusion: a stabilizing trans-palatal arch needed cutting the rectangular finishing arch wire distal to the lateral incisors Making two segment anterior segment and buccal segment install an auxiliary intrusion arch That is tied to this Anterior segment in the appropriate place

40. if slight elongation of the posterior teeth is indicated step bends in a flexible arch wire would be satisfactory. The arch wire before the final finishing arch wire is used for these step bends ( 17 × 25 TMA with the 18-slot appliance, 21 × 25 M- NiTi with the 22-slot appliance).

41. Anterior Open Bite why the problem exists ? excessive eruption of posterior teeth a poor growth pattern excessive use of inter arch elastics can be very difficult to correct Evaluate two things: The vertical relationship between the upper lip and maxillary incisors Anterior face height.

42. With severe long face growth pattern. intrusion of posterior teeth By Using skeletal anchorage to be more effective. Or Placing miniplates or palatal anchors A mild open bite with no facial growth pattern problems This may be due to an excessively leveled lower arch. This is managed by elongating the lower incisors creating a slight curve of Spee in the lower arch ,use vertical elastics to deepen the bite -flexible lower arch wire, a stabilizing stiffer upper wire

43. Final “Settling” of Teeth Methods for Settling the Teeth Into Ideal Occlusion Control of Rebound and Posturing Removal of Bands and Bonded Attachments

44. A. Methods for Settling the Teeth Into Ideal Occlusion There are three ways to settle the occlusion: Replacing the rectangular arch wires with light round arches and using light vertical elastics to bring the teeth together Removing the posterior segments of the arch wires And Using laced posterior vertical elastics Using a tooth positioner after the bands and brackets have been removed

45. Replacing full-dimension rectangular wires with light round wires the original method for settling recommended by Tweed. the patient wear light posterior vertical elastics, with light arches wires ( 16 mil in the 18-slot appliance, 16 or 18 mil in the 22-slot appliance ) light arches wires Allowing some freedom for settling movement of posterior teeth and This will quickly settle the teeth into final occlusion Elastics and light wires should used only a few weeks at most. Disadvantage precise control of anterior teeth is lost.

46. Removing only the posterior part of the rectangular finishing wire leaving the anterior segment (typically canine-to-canine) and using laced elastics to bring the posterior teeth into tight occlusion Light, not heavy, force is needed. Disadvantage This sacrifices a large degree of control of the posterior teeth . Contraindicated with should not be used in patients who had major rotations or posterior crossbite Indicated for patients who had well-aligned posterior teeth from the beginning simple and effective way to settle the teeth into occlusion.

47. 3- Positioners for Finishing an elastic device was used to assist in finishing in the pre–straight-wire era ,now almost disappeared from routine use. Now modified aligners are replacement for conventional positioners

48. B- Control of Rebound and Posturing We should not be confused between Rebound & Posturing Posturing: With using Class II elastic force or its equivalent ,patients begin to posture the mandible forward ,so that the occlusion looks more corrected than it really is. if the appliances are removed at that point The patient slip back toward a Class II molar relationship and increased overjet. This can lead to 4 to 5 mm of relapse. it is important to detect it and continue treatment to a true correction

49. Rebound which is only due to tooth movement. is a 1 to 2 mm phenomenon Control of rebound patient with Class II anterior deep bite before we stop Class II elastics or another type of Class II corrector. The teeth should be taken to an end-to-end incisor relationship both overjet and overbite totally eliminated This provides some latitude for the teeth to rebound before final settling is accomplished.

50. Guidelines for using inter arch elastics during finishing treatment When overcorrection has been achieved Elastics force should be decreased, Or the wear interval reduced ( 8 to 12 hours per day ) and continued for another appointment interval. At that point, inter-arch elastics should be discontinued 4 to 8 weeks before removal of the orthodontic appliances To observe changes due to rebound or posturing If changes do occur, another period of elastics is needed. Using elastics to achieve stable occlusion as a final step in treatment the teeth should be brought into a solid occlusal relationship without heavy arch wires present by using one of the methods described earlier.

51. C- Removal of Bands and Bonded Attachments Removal of bands For upper molar and premolar teeth , a band-removing instrument is placed so that first the lingual then the buccal surfaces are elevated . A welded lingual bar is needed on these bands to provide a point of attachment for the pliers if lingual hooks or cleats are not a part of the appliance. For the lower posterior teeth the sequence of force is just the reverse

52. Bonded brackets must be removed as possible without damaging the enamel surface Done by creating a fracture within the resin bonding material Or between the bracket and the resin and then removing the residual resin from the enamel surface. Removal of metal brackets applying special pliers to the base of the bracket so that the bracket bends is the safest method. Disadvantage Is destroying the bracket so cannot be reused Advantage protecting the enamel.

53. Removal of ceramic brackets there were reports of enamel fractures and removal of chunks of enamel During debonding ceramic brackets Enamel damage more likely with ceramic than metal brackets. There are three approaches for debonding ceramic brackets: Modify the interface between the bracket and the bonding resin to allow the failure to occur between the bracket and the bonding material. Avoiding Chemical bonds between the bonding resin and the bracket And Using ceramic brackets designed for mechanical bonding.

54. Use heat to soften the bonding resin so that the bracket can be removed with lower force. By using Electrothermal and laser instru­ments So less force is needed when the bracket is heated, there is little patient discomfort and minimal risk of pulpal damage. Modify the bracket so that it breaks predictably when debonding force is applied. One advantage of a metal slot in a ceramic bracket is that the bracket can be engineered to fracture in the slot area which makes it much easier to remove.

55. Special Finishing Procedures to Avoid Relapse Control of Unfavorable Growth Control of Rebound After Tooth Movement Overtreatment Adjunctive Periodontal Surgery: Sectioning Elastic Gingival Fibers

56. Control of Unfavorable Growth Changes resulting from continued growth in Class II Class III deep bite open bite the pattern of skeletal growth contribute to a return of the original malocclusion and relapse not just to tooth movement. Controlling this type of relapse requires a continuation of active treatment after the fixed appliances have been removed.

57. This “active retention” takes one of two forms. continue extraoral force in conjunction with orthodontic retainers (high-pull headgear at night, like in a patient with a Class II open bite growth pattern). using of a modified functional appliance rather than a conventional retainer which is much more acceptable to the patient

58. Control of Rebound After Tooth Movement A major reason for retention is to hold the teeth until soft tissue remodeling can take place. some rebound occurs Even with the best remodeling There are two ways to deal with this phenomenon: Overtreatment so that any rebound will only bring the teeth back to their proper position, adjunctive periodontal surgery to reduce rebound from elastic fibers in the gingiva.

59. Overtreatment Positioning the teeth at the end of treatment in a slightly overtreated position. Because the teeth will rebound slightly toward their previous position after orthodontic correction Only a small degree of overtreatment is compatible with precise finishing Consider four specific situations: Correction of Class II or Class III malocclusion Crossbite correction. Crowded and irregular teeth. Rotation correction.

60. Adjunctive Periodontal Surgery: Sectioning Elastic Gingival Fibers the network of elastic supra crestal gingival fibers. As teeth are moved to a new position, these fibers are stretched, and they remodel very slowly. If the pull of these elastic fibers could be eliminated, a major cause of relapse of previously irregular and rotated teeth should be eliminated. relapse caused by gingival elasticity is greatly reduced if the supra crestal fibers are sectioned and allowed to heal while the teeth are held in the proper position,.

61. It can be carried out by either of two approaches. The first method , originally developed by Edwards, is called circumferential supra crestal fibrotomy (CSF). After infiltration with a local anesthetic, the procedure consists of inserting the sharp point of a fine blade into the gingival sulcus down to the crest of alveolar bone. Cuts are made inter proximally on each side of a rotated tooth and along the labial and lingual gingival margins

62. An alternative method is to make an incision in the center of each gingival papilla, sparing the margin but separating the papilla from just below the margin to 1 to 2 mm below the height of the bone buccally and lingually. This is said to reduce the possibility of gingival recession after the surgery and indicated for esthetically sensitive areas (e.g., the maxillary incisor region).

63. CSF or the papilla-dividing procedure the surgery should be done a few weeks before removal of the orthodontic appliance or, if it is performed at the same time the appliance is removed, a retainer must be inserted almost immediately. full-time retention is needed until the soft tissues heal, and this is accomplished best by still having the fixed appliance in place.

64. Micro-Esthetic Procedures in Finishing Recontouring the Gingiva to Improve Tooth Proportions and Display Reshaping the Teeth for Enhanced Esthetics As a general rule , the soft tissue considerations should be dealt with first, Enameloplasty should be deferred until initial alignment has been achieved and rotations have been corrected.

65. Soft tissue recontouring The first step in treatment. This allows ideal vertical placement of brackets at the beginning of treatment so that gingival margins and placement of incisal edges can be optimized and provides time for healing so that the apparent proportions of the teeth will not be affected by soft tissue changes.

66. Enamel recontouring should not be done until after the initial phase of orthodontic alignment because if a tooth rotation is corrected, the perception of its width is changed while the height is not, giving a misleading height–width ratio. After alignment, reshaping of the teeth can be carried out as desired but should be completed before the end of the finishing stage of treatment.

67. References: Contemporary Orthodontics ,6ed (2019) Biomechanics and Esthetic Strategies in Clinical Orthodontics ,1ed (2005) Andrews, L. F. The Six Keys to Normal Occlusion, Sept. 1972, AJO. Roth, R. H.: Temporomandibular Pain-Dysfunction and Occlusal Relationships, The Angle Orthodontist, April 1973. A Gnathologic Approach to Orthodontic Finishing, JCO 1975 Jul (405-417)