Balanced occlusion

balanced occlusion in complete dentures

1. BALANCED OCCLUSION DELLA S INDRAN II MDS

2. CONTENTS INTRODUCTION CENTRIC ,ECCENTRIC OCCLUSION REQUIREMENTS IN COMPLETE DENTURE OCCLUSION THEORIES IN COMPLETE DENTURE OCCLUSION CONCEPTS IN OCCLUSION STEPS INVOLVED IN BALANCING TEETH ARRANGEMENT SELECTIVE GRINDING ERRORS IN OCCLUSION CONCLUSION REVIEW OF LITERATURE REFERENCES

3. INTRODUCTION Occlusion is the term to describe the contact between upper and lower teeth. Teeth whether natural or artificial are not immobile, so occlusion can never be a static relationship. Natural teeth move in the socket under load and returns back to position when load is removed. In artificial occlusion, teeth moves as in group on a common base because of nature of supporting structures. Hence its difficult to obtain purely static artificial occlusion.

4. BALANCE When forces act on a body in such a way that no motion results; there is balance or equilibrium. OCCLUSION Relationship between the occlusal surface of the maxillary and mandibular teeth when they are in contact. ARTICULATION The contact relationship between the occlusal surfaces of the teeth during function . MAXIMUM INTERCUSPAL POSITION MIP is the patients maxillomandibular relationship where the teeth are in maximum occlusal contact irrespective of the position of the condyle disk assemblies.

5. Balanced occlusion: T he bilateral, simultaneous, anterior, and posterior occlusal contact of teeth in centric and eccentric positions. Centric occlusion: The occlusion of opposing teeth when the mandible is in centric relation. This may or may not coincide with the maximal intercuspal position.(GPT 8) Centric occlusion the tooth-to-tooth relation whereas centric relation is a static position and a bone-to-bone relation.

6. Eccentric occlusion Eccentric occlusion refers to contact of teeth that occurs during movement of the mandible. It is of two types:- 1. Functional occlusion 2. Non fucntional occlusion

7. 1.Functional occlusion Functional occlusion (also called working side occlusion) refers to tooth contacts that occur in the segment of the arch towards which the mandible moves. Two types : a. Lateral functional occlusion b. Protrusive functional occlusion

8. LATERAL FUNCTIONAL OCCLUSION: It includes tooth contacts that occur on canines and posterior teeth on the side towards which the mandible moves. Two types : Canine guided occlusion Grouped lateral occlusion

9. i ) Canine guided occlusion: During lateral mandibular movement, the opposing upper & lower canines of the working side contact thereby causing disclusion of all posterior teeth on the working & balancing sides. Canine guided occlusion is usually seen in young individuals with unworn dentition.

10. ii) Grouped lateral occlusion : In addition to canine guidance, certain other posterior teeth on the working side also contact during lateral movement of the mandible. Such a type of contact during lateral movement is called grouped lateral occlusion.

11. B) PROTRUSIVE FUNCTIONAL OCCLUSION: It includes eccentric contacts that occur when the mandible moves forward. Ideally the six mandibular anterior teeth contact along the lingual inclines of the maxillary anterior teeth while the posteriors disocclude . CHRISTENSENS PHENOMENA   A gap occurring in the natural dentition or between the opposing posterior flat occlusal rims when the mandible is protruded (posterior open bite). It can lead to instability in full dentures unless compensating curves are incorporated into the dentures .

12. Requirement of Complete Denture Occlusion (Winkler) Stability of occlusion in centric relation and in areas forward and lateral to it. Balanced occlusal contacts bilaterally for all eccentric mandibular movements. Unlocking the cusp mesiodistally to allow for gradual but inevitable settling of the bases due to tissue deformation and bone resorption . Control of horizontal forces by buccoligual cusp height reduction according to the residual ridge resistance .

13. Functional lever balance by favorable tooth to-ridge crest position

14. Cutting, penetrating and shearing efficiency of the occlusal surface (sharp cusps or ridges) Anterior clearance of teeth during mastication. Minimum occlusal contact between the upper and lower teeth to reduce pressure during function.(lingual occlusion). Sharp ridges or cusps and generous sluiceways to shear and shred food with minimum of force.

15. Requirements of Incising units These units: Should be sharp in order to cut efficiently Should not contact during mastication Should contact only during protrusive incising function Should have as flat incisal guidance as possible considering esthetics and phonetics Should have horizontal overlap to allow for base settling without interference

16. Requirements of Working occlusal units Should be efficient in cutting and grinding. Should have less bucco -lingual width – to minimize the workload. Should function as a group with simultaneous harmonious contacts at end of the chewing cycle and eccentric excursions. Should be over the ridge crest in the masticating area for lever balance. Should have surface to receive and transmit force of occlusion essentially vertically. Should center the work load near the anteroposterior center of the denture. Present plane of occlusion as parallel as possible to mean foundation plane.

17. Requirements of Balancing occlusal units Should contact on the second molars when the incising units contact in function Should contact at end of the chewing cycle when the working units contact Should have smooth gliding contacts for lateral and protrusive excursions

18. AXIOMS FOR ARTIFICIAL OCCLUSION –SEARS (1952) The smaller the area of occlusal surface acting on food, smaller will be the crushing force on food transmitted to the supporting structures. Vertical force applied to an inclined occlusal surface causes non-vertical forces on the denture base. Vertical force applied to an inclined supporting tissue causes non-vertical force on the denture base. Vertical forces applied to a denture base supported by yielding tissue causes the base to teeter when the force is not centered on the base. Vertical force applied outside (lateral) to the ridge crest creates tipping forces on the base .

19. Theories of complete denture occlusion BONEWILL Theory Bonewill theory (1858) E quilateral triangle T eeth move in relation to each other as guided by the condylar controls and incisal point

20. CONICAL THEORY CONICAL THEORY(1915) The lower teeth move over the surfaces of the upper teeth as over the surfaces of a cone and with a central axis of cone tipped at 45 degree angle to the occlusal plane.

21. Spherical theory Proposed by G S MONSON in 1918. Lower teeth move over the surface of upper teeth as over the surface of sphere with a diameter of 8 inches. Centre of sphere – glabella Sphere passed through glenoid fossa along through articulating eminences.

22. Various concepts of occlusion In pertinence to occlusion the concept of occlusion for complete denture falls in to two broad disciplines Balanced occlusion. ( Heartwell 5th ed ) Non-balanced occlusion . Concepts of occlusion acc. to Boucher (13th ed ) • Balanced • Monoplane • Lingualized

23. Balanced Occlusion Reported by Brewer . “Stable simultaneous contact of the opposing upper and lower teeth in centric relation position and a continuous smooth bilateral gliding from this position to any eccentric position within normal range of mandibular function.”- Winkler

24. OBJECTIVES OF BALANCED OCCLUSION To improve the stability of denture. To reduce resorption of the residual ridge and soreness . To improve oral comfort & well being of the patient.

25. CHARACTERISTIC REQUIREMENTS OF BALANCED OCCLUSION All the teeth of working side should glide evenly against opposing teeth No single tooth should produce any interference or disocclusion of other teeth There should be contacts in balancing side but they shouldn’t interfere with smooth gliding movements of working side There should be simultaneous contact during protrusion

26. GENERAL CONSIDERATIONS FOR BALANCED OCCLUSION : The wider and larger the ridge & the teeth closer to the ridge, the greater the lever balance. Wider the ridge & narrower the teeth buccolingually , greater the balance . The more lingual the teeth are placed in relation to the ridge crest, the greater the balance. The more centered the force of occlusion anterioposteriorly , the greater the stability of the base.

27. TYPES OF BALANCED OCCLUSION: Balance may be: Unilateral, bilateral, or protrusive . UNILATERAL LEVER BALANCE This is present when there is equilibrium of the base on its supporting structures when bolus of food is interposed between the teeth on one side and a space exits between the teeth on the opposite side. Following points encourages the lever balance a) Placing the tooth so that the resultant direction of force on the functional side is over the ridge or slightly lingual to it. b ) Having the denture base cover as wide an area on the ridge as possible . c ) Placing the teeth as close to the ridge as other factors will permit . d ) Using as narrow a buccolingual width occlusal food table as practical .

28. 1.Unilateral ooclusal balance : It is present when occlusal surface of teeth on one side articulate simultaneously, as a group, with smooth uninterupted glide . This is not followed during complete denture construction. It is more pertained to fixed partial dentures. 2.Bilateral occlusal balance: This is present when there is equilibrium on both sides of denture due to simultaneous contact of teeth in centric and eccentric occlusion . It requires a minimum of three contacts. The more the contacts the more assured the balance.

29. Advantages: Better stability of denture base Reduced trauma, improved comfort The functional movements are possible Disadvantages: Time consuming Cannot be used in all patients

30. ADVANTAGES OF BILATERALLY BALANCED OCCLUSION Sheppard gave the concept of “ ENTER BOLUS EXIT BALANCE” which implies that introduction of food on one side will prevent the teeth of opposite side from contacting and hence occlusal balance is impossible during mastication.

31. However Sheppard (1964) later gave the concept of ENTER BOLUS ENTER BALANCE according to which even while chewing, the teeth cut through the bolus and come in contact with each other, for few fractions of a second. Hence the stability of the denture is maintained during various movements of mandible during chewing.

32. Brewer and hudson (1963) found in a 24 hour test that : Normal individual makes masticatory tooth contact only for 10 mins in one day compared to 4hrs of total tooth contact during other functions . So, for these 4hrs of tooth contact, balanced occlusion is important to maintain denture stability It improves the stability of denture, reduce resorption of the residual ridge and soreness and improve oral comfort & well-being of the patient .

33. Pros (as stated in winkler ) If this contact is interruptive and deflective; and not bilateral, the denture base will not be stable. Hence, bilateral balanced contacts during the terminal arc of closure help to seat the denture in a stable position. Also bilateral balanced occlusion is important during activities such as swallowing saliva, closing to reseat the dentures and bruxism of teeth during times of stress. Patient with a balanced design do not upset the normal static, stable and retentive position of their dentures. In bilateral balance the bases are stable during bruxing activity and they are tight when the patient separate the teeth.

34. Cons: There are some possible disadvantages of bilateral balanced articulation: It may tend to encourage lateral and protrusive grinding, although this habit may be confined to those people who are subjected to irrelevant muscle activity . It is difficult to achieve in mouths where an increased vertical incisor overlap is indicated, and is better to retain the vertical overlap, than to sacrifice it in order to achieve articular balance. A semi-adjustable or fully adjustable articulator is required.

35. 3.Protrusive occlusal balance: This is present when the mandible moves essentially forward and occlusal contacts are smooth and simultaneously in posterior region both on right and left sides as well as anterior teeth. It is slightly different from bilateral balanced occlusion as it requires a minimum of three contacts, one on each side posteriorly and one anteriorly .

36. Factors influencing balanced occlusion ( 1) Inclination of the condylar path ( 2) Incisal guidance ( 3) Orientation of the plane of occlusion ( 4) Cuspal angulation ( 5) Compensating curve

37. 1. CONDYLAR GUIDANCE Condylar guidance is due to path followed by condyle in temporomandibular joint. Obtained by protrusive registration record.

38. HANAU states that inclination of condylar guidance is definite anatomical conception. This path is precise & constant and it guides mandible so precisely that it is primary dictator of occlusion. KURTH claims that condylar path is not same for varying incisal guidances . WEINBERG showed that condylar path varies owing to variable pressures of function . Significance Increase in condylar guidance will increase jaw separation during protrusion. In patients with steep condylar guidance, incisal guidance should be decreased to reduce amount of jaw separation produced during protrusion. As this factor cannot be modified, all other 4 factors should be modified to compensate effects of this factor.

39. 2. INCISAL GUIDANCE It is the effect of contact of upper and lower anterior tooth on the movement of mandible. Expressed in degrees of angulation from the horizondal by a line drawn from sagittal plane between the incisal edges of upper and lower incisor teeth when closed in centric relation. If incisal guidance is steep, it requires steep cusp, a steep occlusal plane or a steep compensatory curve for a balanced occlusion.

40. Angle of incisal guidance is largely under influence of dentist This factor is influenced by amount of horizontal, vertical overlap • Greater horizontal overlap = lesser angle of inclination Lesser the vertical overlap = lesser angle of inclination

41. During protrusive movements mandibular teeth move downward & forward as per incisal guidance . For complete dentures the incisal guidance should be as flat as esthetics and phonetics will permit. When the arrangement of the anterior teeth necessitates vertical overlap, a compensating horizontal overlap should be set to prevent dominant incisal guidance, from upsetting the occlusal balance on the posterior teeth.

42. 3.PLANE OF OCCLUSION OR OCCLUSAL PLANE Defined as “An imaginary surface which is related anatomically to the cranium and which theoretically touches the incisal edges of the incisors & the tips of the occluding surfaces of posterior teeth . It represents the mean curvature of the surface . Established anteriorly by height of lower canine and posteriorly by height of retromolar pad. ( winkler ).

43. It is related to ala -tragus line or camper’s line . The plane of occlusion can be altered to a maximum of 10°

44. HANAU states plane of orientation is purely geometrical factor and pass through central incisal point & summits of mesiobuccal cusps of molars . According to Sharry , plane of orientation established intially can be altered subsequently to serve purposes. Its existence is temporary as it is lost in establishing compensating curves.

45. If soft tissues surrounding dentures are to work around them as they did around natural teeth, occlusal plane should be oriented exactly as it was when natural teeth are present By positioning anterior teeth correctly for esthetic appearance & locating posterior end of occlusal plane approximately level with top of retromolar pad-factor of orientation of occlusal plane is fixed.

46. 4.Cuspal Inclination It is an important factor that modify the effect of plane of occlusion & the compensating curves . The angulation of the cusp is more important than the height of the cusps . It is advocated that all mesiodistal cusp heights are eliminated in anatomic type teeth, only the buccolingual inclines need to be considered as determinants of balanced occlusion . In shallow bite cases - cuspal angle should be reduced to balance the incisal guidance . Deep bite cases with steep incisal guidance , the jaw separation is more during protrusion .Teeth with high cuspal inclines are required.

47. 5.COMPENSATING CURVE “ The anterioposterior and lateral curvatures in the alignment of the occluding surfaces and incisal edges of artificial teeth which are used to develop balanced occlusion”(GPT -8 ) Determined by inclination of posterior teeth and their vertical relationship to occlusal plane . The primary function thus of compensating curve is to provide balancing contacts for protrusive mandibular movements. Steep condylar path requires steep compensating curve to produce balanced occlusion. In case lesser compensating curve given for same condylar path ,anterior interference can occur.

48. With compensating curve it is possible to produce eccentric balance in monoplane occlusal scheme, which is otherwise said to be deficient in this . The compensating curve incorporated in a properly oriented plane of occlusion starts with the first replacemental tooth by raising it at distal and continuing this initiated curve with further rise in the 2nd molar with distal surface located at or above the top of retromolar pad . Anteroposteriorly it should not exceed 20 degree and mediolateraly it should not exceed 10 degree .

49. TYPES OF COMPENSATING CURVES in natural dentition Curve of spee Monson’s curve Wilson’s curve

50. Curve of spee Von Spees or Spee’s curve. Defined as the curvature of the mandibular occlusal plane beginning at the canine and following the buccal cusps of the posterior teeth, continuing to the terminal molar.

51. Curve of wilson GEORGE.H.WILSON eponym for mediolateral curve contacts buccal and lingual cusp tips of molars on each side of arch.

52. In mandibular arch results from inward inclination of lower posterior teeth-making lingual cusps lower than buccal cusps – curve being concave. In maxillary arch-results from outward inclination of posterior teeth-making buccal cusp higher than lingual cusps-curve being convex. Teeth set on this curve will have lateral balance of occlusion.

53. CURVE OF MONSON : GEORGE S. MONSON eponym for proposed ideal curve of occlusion in which each cusp and incisal edge touches or conforms to segment of surface of sphere 8 inches in diameter with its center in region of glabella .

54. Compensatory curves in complete denture Defined as “The antero -posterior and lateral curvatures in the alignment of the occluding surfaces and incisal edges of artificial teeth which are used to develop balanced occlusion” – GPT U sed to develop balanced occlusion. Determined by inclination of posterior teeth and their vertical relationship to occlusal plane and there are two curve : 1- Anteroposterior compensating curve 2- Mediolateral compensating curve

55. Anteroposterior Compensating Curves: These are compensatory curves running in an anteroposterior direction. They compensate for the curve of Spee seen in natural dentition

56. Lateral Compensating Curves These curves run transversely from one side of the arch to the other.

57. Interaction of the five factor Condylar guidance cannot be changed,as it’s anatomic factor. The incisal guidance and the plane of occlusion can be altered only a slight amount because of esthetic and physiologic factors . The important working factors for the dentist to manipulate are the compensating curve and the inclinations of cusp on the occlusal surfaces of the teeth.

58. CONTACTS IN BALANCED OCCLUSION Working side : The mandibular buccal cusp ridges makes articular contact with the maxillary buccal cusp ridges as the mandibular lingual cusp ridges are making contacts with the maxillary lingual cusp ridges . Balancing side : The mandibular buccal cusps & their occlusal facing ridge, contacts maxillary lingual cusps & ridge. Protrusion : Incisal edges of the mandibular anterior teeth contact with the lingual surface of the maxillary anterior teeth. The mesiobuccal & lingual cusp ridges of the mandibular teeth contact the distobuccal & lingual cusp ridges of the maxillary teeth.

59. Concepts proposed to attain balanced occlusion GYSI’S CONCEPT FRENCH’S CONCEPT SEARS’S CONCEPT PLEASURE’S CONCEPT FRUSH’S CONCEPT HANAU’S QUINT TRAPAZZANO’S CONCEPT LOTT’S CONCEPT BOUCHER’S CONCEPT LEVIN’S CONCEPT

60. GYSI’S CONCEPT He proposed the 1 st concept towards balanced occlusion in 1914 . He suggested arranging 33 degree anatomic teeth could be used under various movements of the articulator to enhance the stability of the denture.

61. FRENCH’S CONCEPT (1954) Proposed that lowering lower occlusal plane to increase the stability of the denture along with balanced occlusion. He arranged upper first premolars with 5 degree ,upper second premolar with 10 degree and upper molars with 15 degree inclinations. He used modified French teeth to obtain balanced occlusion .

62. SEARS’S CONCEPT(1920) He proposed the balanced occlusion for non-anatomic teeth using posterior balancing ramps or an occlusal plane which curves anteroposteriorly & laterally.

63. Pleasure’s concept In 1937, Dr. Max Pleasure presented an occlusal scheme called the “pleasure curve” Buccal tilt is given at the premolars , no tilt or flat occlusal surface at first molars and a lingual tilt to second molars The curve is created to direct forces of occlusion lingually to favor stability of lower denture Lingual tilt of the second molar provides a buccal rise for a lateral balancing contact.

64. FRUSH’S CONCEPT(1966) He advised arranging teeth in a one – dimensional contact relationship, which should be reshaped during try – in to obtain balanced occlusion . Intent of this occlusion was to remove occlusal deflective contacts and provides greater stabilization of dentures . Buccal blades of the lower posterior teeth should form a perfect straight blade. This blade should be perfectly straight to support one-dimensional contact against the opposing occlusion.

65. “ Hanau’s Laws of articulation ” RUDOLPH L. HANAU Nine factors governing the articulation are- Horizontal condylar guidance Compensating curve Protrusive incisal guidance Plane of orientation Buccolingual inclination of the tooth axis Sagittal condylar pathway Sagittal incisal guidance Tooth alignment Relative cusp height

66. Later Hanau combined the original nine factors and reduced them to five. The five factors are (HANAU QUINT) Condylar guidance Compensating curve Relative cusp height Incisal guidance Plane of orientation

67. Trapozzano concept He simplified Hanau’s quint. 3 factors necessary for determining plane of occlusion 1. Condylar guidance 2. Incisal guidance 3 . Cuspal angle He stated occlusal plane could be shifted at various heights to favor weaker ridge. He also stated that by arranging cusped teeth-these curves are produced automatically.

68. Boucher’s concept 3 fixed factors : The orientation of the occlusal plane, the incisal guidance, and the condylar guidance . The angulation of the cusp is more important than the height of the cusp . The compensating curve enables one to increase the effective height of the cusps without changing the form of the teeth.

69. He recommended that the occlusal plane should be orientated exactly as where natural teeth were present . “The value of the compensating curve is that it permits alteration of cusp height without changing the form of the manufactured teeth… If the teeth themselves do not have any cusps, the equivalence of a cusp can be produced by a compensating curve”.

70. The Lott concept He clarified the laws of occlusion by relating them to the posterior separation that is the resultant of the guiding factor.

71. Levin’s concept : Levin’s concepts are similar to that of Lott’s, but he eliminates the plane of occlusion. Levin has put forth the four factors in the form of a Quad . The essentials of a Quad are :- The condylar guidance is fixed & is recorded from the patient. The incisal guidance is usually obtained from patient’s esthetic & phonetic requirements. However it can be modified for special requirements. E.g., the incisal guidance is decreased for flat ridges .

72. The compensating curve is the most important factor in obtaining occlusal balance. Monoplane or low cusp teeth must employ the use of compensating curve. Cusp teeth have the inclines necessary for balanced occlusion but nearly always are used with a compensating curve.

73. STEPS INVOLVED IN BALANCING: To develop a balanced occlusion one needs an adjustable articulator which should -Receive a face-bow transfer. -Adjust to individual condylar guidance. -Have an adjustable incisal guide table. The teeth have to be inclined to develop a balanced occlusion. The upper and lower incisal units meet only when the mandibular teeth are protruded and protrusive balancing unit functions only when upper and lower units contact.

74. To adjust the articulator, it requires: A centric relation record. Eccentric protrusive record. Right and left lateral relation records are desirable if the articulator is capable of accepting the records. If the articulator will not receive the lateral records (Hanau type) then lateral condylar guidance is calculated as: L = H/8 + 12

75. ARRANGEMENT OF TEETH

76. Position of lower teeth should be guided by following factors: ANTERIORLY The position and height of first bicuspid is determined by the setting of anterior teeth to the proper phonetic and incisial guidance position. POSTERIORLY The last tooth should be over foundation tissue that is firm and not be set on a steep lower molar slope and never extend distally to the apex of the retromolar pad

77. BUCCALY The tooth should be out of occlusal contact for centric and mandibular working positions. LINGUALLY The tooth should not crowd the tongue or project lingually inside the mylohyoid ridge

78. OCCLUSAL PLANE Anteriorly by the esthetic and function of anterior teeth. Posteriorly by a height projected from the occlusal surface to the middle third of retromolar pad. COMPENSATING CURVE Is set to provide harmony between incisal guidance and inclination of condylar path. HORIZONTAL PLANE The cusp teeth are set with the lower buccal and lingual cusps on the same horizontal plane.

79. SETTING THE UPPER POSTERIOR TEETH The upper posterior teeth are set so that in centric occlusion only the lingual cusp occludes with the central fossa of lower teeth. Check and refined for dynamic cusp contacts in working, balancing and protrusive movements

80. Balancing the occlusion in Class Ⅱ and Class Ⅲ relation CLASS Ⅱ OCCLUSION In Orthognathic the lower denture foundation is small and weak especially in anterior and bicuspid area . In class ii there is large buccal horizontal overlap in the first bicuspid area so the lingual tip of the upper and buccal tip of the lower first bicuspid is flattened to a horizontal table to provide a stable centric contact . Usually non-anatomic teeth with pleasure curve is given. A reverse occlusal curve is set in bicuspid region to favour the stability of lower denture. Molar is set to flat scheme of occlusion and Second molar is set to spherical scheme.

81. CLASS Ⅲ OCCLUSION In Prognathic relationships the lower arch is located too far bucally . To control the tipping force on upper denture base the teeth are set in Cross bite relationship. Non-anatomic teeth is indicated because with this type of teeth the buccolingual and mesio –distal relation is not as critical.

82. SELECTIVE GRINDING Selective grinding is defined as the, “intentional alteration of the occlusal surfaces of the teeth to change their form’’ – GPT 9 Rational : 1) Eliminate occlusal interferences and to achieve occlusal harmony. 2) Contacts in harmony with TMJ and neuromuscular system Failure to achieve it - soreness -loss of supporting bone -TMJ problems

83. Occlusion indicators

84. -“BULL’S LAW- Reduce the inner inclines of the Buccal cusps of the maxillay teeth Lingual cusps of the mandibular teeth.

85. Final result should be smooth gliding lateral excursion with fine working and fine balancing contacts .

86. SELECTIVE GRINDING FOR CENTRIC CONTACTS: After the complete arrangement of teeth, place an articulating paper and tap the articulator. Only the lower central fossa or marginal ridges should be ground not the upper lingual cusps. If any upper buccal cusps or inclines are in contact, they should be ground out of contact. “The final result should be upper lingual cusp in lower central fossa

87. SELECTIVE GRINDING FOR WORKING AND BALANCING CONTACTS: There should be working and balancing contacts that are in harmony with condylar inclination and incisal guidance. If the mandible moves to left, the upper left lingual cusps should contact lower left lingual cusps (on working side) and the upper right lingual cusps contact lower buccal cusps (balancing side). WORKING SIDE BALANCING SIDE

88. Grind the marked premature balancing contacts, heavily marked working side contacts on the lower teeth Do not grind the upper lingual cusps Do not grind the lower buccal cusps No upper buccal cusp contact in any excursion The lingual of the upper anterior incisal edges and the labial of the lower anteriors are ground to eliminate any interference

89. Selective grinding for the protrusive contacts Maxillary lingual cusp gliding over the distal lingual cusp of the mandibular teeth. The upper second molars riding up the distal inclines of the lower second molars created by the compensating curves .

90. All the premature contacts are gently ground off . Anterior teeth prematurities - anterior mandibular teeth are being modified keeping aesthetics in mind

91. HOW TO FIX ERRORS IN OCCLUSION?

92. Contact in the posterior region with the cast in a protrusive relation Prominence of antero posterior curve Cusp height Plane of orientation in posterior region Absence of contact P remature contact

93. Premature contact of the anterior teeth with the casts in the protrusive relation Rearrange the lower anterior teeth closer to the lower ridge. Use shorter lower anterior teeth Shorten them by grinding

94. LINGUALIZED OCCLUSION It was first proposed by Gysi (1927) Acc . to GPT-9, lingualized occlusion is defined as the form of denture occlusion in which the maxillary palatal cusps articulate with the mandibular occlusal surfaces in centric, working and balancing mandibular positions.

95. GYSI in 1927 introduced this type of concept. POUND used it for non balanced articulation. PAYNE in 1941 used it for balance articulation.

96. INDICATIONS When the patient places high priority on esthetics but non-anatomic occlusal scheme is indicated because oral conditions such as severe alveolar resorption , a Class II jaw relationship, or displaceable supporting tissue. Patients having parafunctional habits, so that reduced amount of horizontal forces are transmitted to supporting tissues.

97. Principles of lingualized occlusions (Becker)- Anatomic posterior (30-33 degree) teeth are used for maxillary denture. Tooth forms with prominent palatal cusps are useful. Non anatomic or semi anatomic teeth are used for mandibular denture . Either a shallow or a flat cusp form is used. Narrow occlusal form is preferred where resorption of residual ridge has occurred. Lingualized Occlusion: An Emerging Treatment Paradigm - Journal of Medical and Dental Science Research (2015)

98. Modification of mandibular posterior teeth is accomplished by selective grinding which is always necessary regardless of the material used . Maxillary palatal cusp contact mandibular teeth in centric occlusion Balancing and working contacts should occur only on the maxillary palatal cusps. Protrusive contacts only between upper palatal cusps and lower teeth.

99. Advantages- 1. Improved denture stability and enhanced patient comfort. 2. Reduced lateral forces because only the palatal cusp of the maxillary teeth provides the sole contact with the mandibular posterior teeth.

100. 3. Vertical forces are centered upon the mandibular residual ridges 4. Simplified tooth arrangements , simplified occlusal adjustments, good esthetics. 5. Provides mortar and pestle type of occlusion with cusp teeth to provide a smaller occlusal contact for more efficiency and control of resultant forces.

101. MONOPLANE OCCLUSION Non anatomic tooth form may be occlusion of choice for given situation. Like poor neuro -muscular control, highly resorbed residual ridge. ADVANTAGES Preservation of structure of basal seat. Efficient occlusal form. Simplicity of technique involved

102. MAIN FEATURES Anterior teeth primarily set for length and proper lip support. Elimination of cuspal inclines and teeth must be set in flat monoplane arrangement, Zero incisal guidance should be established

103. BALANCING IN MONOPLANE OCCLUSAL SCHEME In this occlusal scheme problem arises because flat teeth occlude in two dimension but the mandible moves in three dimension because of this there will be cuspal rise and loss of contact. This problem can be resolved by Flat incisal guidence Inclined occlusal plane and compensating curve Balancing ramp Reverse curve and pleasure curve

104. ADVANTAGES The patient has sense of freedom because they do not lock the mandible in one position only. They are more adaptable to unusual jaw relations such as Class II and Class III malocclusions Minimal horizontal pressures are created because of elimination of inclined planes. Simplified and less time consuming technique and offer greater comfort

105. Disadvantages Poor esthetics Decreased masticatory efficiency More difficult to obtain balanced occlusion

106. The occlusal spectrum and complete dentures

107. The occlusal spectrum-collection of occlusal schemes (tooth form and arrangement) arranged to match patients need and requirement. Anatomic (Balanced) Occlusion Semi-anatomic (balanced ) Lingualized Occlusion Non-anatomic (balanced) Neutrocentric Occlusion Concluded- L ingualized occlusion is an outstanding occlusal scheme with maximum advantages .

108. CONCLUSION Many investigations on a scientific level have not proved conclusively that any one scheme of occlusion is ♦ superior in function, ♦ safer to the supporting oral structures, or ♦ more acceptable to patients. Thus the prosthodontist should provide an occlusion, which is compatible with the stomatognathic system and provides efficient mastication and esthetics , without any physiologic abnormality.

109. Review of literature

110. Influence of the Occlusal Concept of Complete Dentures on Patient Satisfaction in the Initial Phase After Fitting: Bilateral Balanced Occlusion vs Canine Guidance. Rehmann P, Int J Prosthodont . 2008 Jan-Feb;21(1):60-1 OBJECTIVE To evaluate the impact of the occlusal concept on patient satisfaction in the initial phase after fitting new CDs . Materials and methods One maxillary and 2 nearly identical mandibular CDs were fabricated for 38 edentulous patients. The inclusion criteria were patients wearing CDs for at least 6 months with insufficient occlusion. The exclusion criteria were CD cases with adequate bbO or cG .

111. After 2 weeks, the patients' satisfaction was evaluated and the OC was changed. Two weeks later, the patients' satisfaction was reevaluated.After 2 nd and 4 th week, 63% and 47% of the patients preferred bilateral balanced occlusion and 5% and 11% preferred canine guidance, respectively . conclusion Thus, a bilateral balanced occlusion primarily facilitates the adaptation of a new CD

112. Comparison of patient satisfaction in complete denture patients with different occlusal schemes International Journal of Applied Dental Sciences 2017; 3(4): 51-52 AIM The aim of this study was to evaluate effect of Bilateral Balanced Occlusion (BBO) & Canine guided occlusion (CGO) on patient satisfaction in complete denture patients . Materials and Methodology Twenty completely edentulous patient’s (12 males and 8 females) with an average age of 65 years were included in the study . Exclusion criteria being dysfunctional disorders of masticatory system.

113. 10 patient’s received dentures with bilateral balanced occlusion scheme and other 10 with canine guided occlusal scheme . patient satisfaction was evaluated with a standard 5 point Likert scale questionnaire, which included subjective parameters such as initial adaptability, post insertion problems, aesthetics, masticatory ability, speech, retention. RESULT OCCLUSION MEAN BBO 19.33 CGO 18.33

114. Conclusion Bilateral balanced occlusion is not the only occlusal concept recommended for the success of complete dentures. Even, canine guided occlusion can be used with success . However, results suggest that initial patient’s adaptation is better with balanced dentures when compared to canine guided dentures

115. Masticatory Efficiency in Denture Wearers with Bilateral Balanced Occlusion and Canine Guidance Braz Dent J (2010) 21(2): 165-169 AIM The aim of this study was to evaluate the masticatory efficiency in complete dentures wearers with bilateral balanced occlusion and canine guidance. MATERIALSAND METHODS Sample composed of 24 patients with mean age of 59.7 years . All patients had previously worn CD. After giving informed consent, patients were randomized to one of the 2 treatment groups (BBO-CG or CG-BBO) with different treatment sequences .

116. Three months after insertion of the new dentures, the occlusal concept was changed . Thus , patients were subjected to both occlusal concepts for the same period of 3 months . Data were collected by the masticatory efficiency test and questionnaires at 3 and 6 months after denture insertion. Result

117. Patient response to variations in denture techniques. Part VI: Mastication of peanuts and carrots. Westly RC, J Prosthet Dent,1984, 51:467-469 Materials and method Sixty-four patients who had been edentulous for at least 1 year were selected for this study and divided into two equal groups to test two different denture techniques . The techniques were designated “complex” and “standard .”

118. The complex technique involved location of the hinge axis to mount the maxillary cast on a semiadjustable articulator. In the standard technique a face-bow transfer was not used. The maxillary cast was mounted arbitrarily, and the mandibular cast was mounted in centric relation. RESULT N o significant statistical differences in masticatory ability existed between the two groups.

119. LIST OF REFERENCES ESSENTIALS OF COMPLETE DENTURE PROSTHODOTICS , SECOND EDITION, by Sheldon Winkler BOUCHER’S PROSTHODONTIC TREATMENT FOR EDENTULOUS PATIENTS, ELEVENTH EDITION, by Hickey , Zarb and Bolender . SYLLABUS OF COMPLETE DENTURES, by Charles M. Heartwell and Arthur O. Rahn Beck H.O.: Occlusion as related to complete removable prosthodontics. JPD,1972;27:246-256 . Trappozano V.R.: An experimental study of the testing of occlusal patterns on the same denture bases. JPD.;1952; 440-457 .

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