Lingualised occlusion revisited

lingualized occlusion in cd

1. LINGUALISED OCCLUSION Presented by: Dr. Aarti Kochhar MDS 1 st year Department of Prosthodontics Including Crown & Bridge, Maxillofacial Prosthodontics & Oral Implantology

2. “ Lingualized occlusion should not be confused with placement of the mandibular teeth lingual to the ridge crest, as suggested by several authors.” Winter, C. M., Woelfel , J. B., and Igarashi, T.: Five Year Changes in the Edentulous Mandible as Determined on Oblique Cephalometric Radiographs, J. Dent. Res. 1974;53: 1455- 67

3. INTRODUCTION The search for the ideal denture occlusion has been going on for almost two centuries in an effort to find the tooth form which provides maximum denture stability and masticatory efficiency without compromising the health of the underlying bone. Concern about ridge resorption started a trend toward use of nonanatomic occlusal forms in the 1920’s. Sears, V. H. : Chewing Members, J. PROSTHET. DENT. 1951; 1: 761-3

4. OCCLUSAL FORMS Today, the available occlusal forms can be classified into three major groups : Anatomic-30 degree Cusps Semianatomic - 20 degree cusps Nonanatomic or cuspless - 0 degree cusps. Becker C, Swoope C, Guckes A, Linguatizd occlusion for removable prosthdontics . J. Prosthet . Dent, 1977:601-8

5. A monoplane occlusal scheme limits esthetic results in the premolar region. Becker C, Swoope C, Guckes A, Linguatizd occlusion for removable prosthdontics . J. Prosthet . Dent, 1977:601-8

6. A lingualized occlusion provides improved esthetics in the premolar region. Becker C, Swoope C, Guckes A, Linguatizd occlusion for removable prosthdontics . J. Prosthet . Dent, 1977:601-8

7. IDEOLOGY Lingualized occlusion is an attempt to maintain the esthetic and food-penetration advantages of the anatomic form while maintaining the mechanical freedom of the nonanatomic form. Becker C, Swoope C, Guckes A, Linguatizd occlusion for removable prosthdontics . J. Prosthet . Dent, 1977:601-8

8. EVOLUTION Gysi was first to report the biomechanical advantages of lingualized tooth forms (1927). The basic concepts of lingualized occlusion were first suggested by Payne (1941). Pound discussed a similar occlusal concept and used the term “ lingualized occlusion” (1973). Ortman , Murrell, Becker, and Kelly provided additional support for this occlusal concept (1977). Parr GR, Loft GH. The occlusal spectrum and complete dentures. Compend Contin Educ Dent 1982; 3:241-50 Parr GR, Ivanhoe JR. Lingualized occlusion:an occlusion for all reasons. Dent Clin North Am 1996;40:103-12

9. RATIONALE In the early 1900s, Gysi noted that 60% of his denture patients had developed reverse articulations due to common resorptive patterns. He also recognized the advantages associated with balanced occlusions, but encountered difficulties while attempting to create such occlusions with the prosthetic teeth of the era. Phoenix R, Engelmeier R, Lingualized occlusion revisited. J Prosthet Dent 2010;104:342-6

10. OBJECTIVE

11. In a lingualized occlusion scheme, the objective is the elimination of buccal cusp contacts in order to alleviate lateral stresses or lateral dislodging forces.

12. The lingual cusps of the upper posteriors make contact in centric relation in the central fossae of the lower posteriors. The buccal cusps are out of contact; however the lingual cusps are in contact in centric, working and balancing movements.

13. For this reason, all the stresses created during working and balancing motions are of a downward nature, thus creating stability.

14. HISTORY Gysi designed and patented “Cross-Bite Posterior Teeth” in 1927. Each maxillary tooth featured a single, linear cusp that fit into a shallow mandibular depression. These teeth were reasonably esthetic, easy to arrange, and encouraged vertical force transmission via their mortar-and-pestle anatomy. Gysi A. Special teeth for cross-bite cases.Dent Digest 1927;33:167-71

15. By 1935, French had patented his “Modified Posterior Teeth ”. The maxillary teeth featured shallow fossae , while the mandibular teeth displayed narrow, planar occlusal surfaces. French FA. The problem of building satisfactory dentures. J Prosthet Dent 1954;4:769-81

16. The shallow mortar-and-pestle anatomy encouraged vertical force transmission . The facial contours of the maxillary teeth yielded desirable facial support and esthetics . Despite the designs of Gysi and French , early embodiments of lingualized occlusion failed to gain a significant following .

17. PAYNE’S CONCEPT This changed in 1941, when Payne introduced a more cogent form of lingualized occlusion. According to Payne’ article, a mortar-and-pestle arrangement was created via judicious recontouring of 30-degree teeth. Payne SH. A posterior set-up to meet individual requirements. Dent Digest 1941;47:20-2

18. The maxillary lingual cusps maintained contact with the mandibular teeth in eccentric movements. In contrast, the maxillary buccal cusps did no contact to the opposing teeth during mandibular movements. Payne SH. A posterior set-up to meet individual requirements. Dent Digest1941;47:20-2

19. POUND’S CONCEPT Pound also championed lingualized occlusion in his articles and presentations . Pound used maxillary teeth having cusp angles greater than 30 degrees in conjunction with mandibular teeth having cusp angles of 20 degrees or less. He carefully reshaped mandibular fossae to produce cross-arch balance. Pound E. Utilizing speech to simplify a personalize denture service. J Prosthet Den1970;24:586-600

20. Pound ensured that maxillary buccal cusps did not contact mandibular teeth during eccentric mandibular movements . He accomplished this by reducing the facial surfaces of the mandibular posterior teeth rather than elevating the buccal cusps of the maxillary teeth. Though the method for eliminating maxillary buccal contact was dissimilar , the mechanical results were nearly identical to those described by Payne.

21. Authors such as Ortman , Murrell, Becker, and Kelly provided additional support for this occlusal concept. Proponents of lingualized occlusion reported additional advantages including 1. Simplified tooth arrangement 2. Simplified occlusal adjustment 3. Reduced lateral forces 4. Efficient bolus penetration 5. Good esthetics.

22. Tooth arrangement was characterized by articulation of the maxillary lingual cusps with the opposing mandibular occlusal surfaces in centric and eccentric positions. Maxillary buccal cusps were not permitted to contact the mandibular teeth in centric or eccentric positions. Phoenix R, Engelmeier R, Lingualized occlusion revisited. J Prosthet Dent 2010;104:342-6

23. ADVANTAGES L ingualized occlusion yielded cross-arch balance . This resulted in improved denture stability and enhanced patient comfort. L ateral forces were reduced because maxillary lingual cusps provided the sole contact with mandibular posterior teeth. As a result, potentially damaging lateral forces were minimized . V ertical forces could be centered upon the mandibular residual ridges. The application of vertical forces was considered advantageous for denture stability and maintenance of the supporting hard and soft tissues. Becker C, Swoope C, Guckes A, Linguatizd occlusion for removable prosthdontics . J. Prosthet . Dent, 1977:601-8

24. 4. Cusp form is more natural in appearance compared to nonanatomic tooth form. 5. Good penetration of the food bolus is possible. Becker C, Swoope C, Guckes A, Linguatizd occlusion for removable prosthdontics . J. Prosthet . Dent, 1977:601-8

25. INDICATIONS 1. Severe alveolar bone resorption resulting in little or no ridge, or resulting in a discrepancy between the size of the narrowing and receding upper ridge compared with the widening and receding lower jaw. Becker C, Swoope C, Guckes A, Linguatizd occlusion for removable prosthdontics . J. Prosthet . Dent, 1977:601-8

26. 2. Implant-supported overdentures to eliminate lateral forces that can rock abutments loose over time.

27. 3. Lingualized occlusion is appropriate for free-end attachment cases to reduce stress on distal extension.

28. 4. Intra-coronal attachments to avoid breakage. Becker C, Swoope C, Guckes A, Linguatizd occlusion for removable prosthdontics . J. Prosthet . Dent, 1977:601-8

29. PRINCIPLES 1. Anatomic posterior (30 or 33 degree) teeth are used for the maxillary denture. Tooth forms with prominent lingual cusps are helpful. 2. Nonanatomic or semianatomic teeth are used for the mandibular denture. Becker C, Swoope C, Guckes A, Linguatizd occlusion for removable prosthdontics . J. Prosthet . Dent, 1977:601-8

30. Either a shallow or flat cusp form is used. A narrow occlusal table is preferred when severe resorption of the residual ridges has occurred. 3. Maxillary lingual cusps should contact mandibular teeth in centric occlusion.

31. The mandibular buccal cusps should not contact the upper teeth in centric occlusion, as is customary with usual anatomic tooth placement.

32. It is helpful to slightly rotate the maxillary posterior teeth buccally to allow for slight clearance of the buccal cusps in the working position and to reduce the need for extensive grinding

33. 4. Balancing and working contacts should occur only on the maxillary lingual cusps.

34. The maxillary lingual cusps remain in contact on the working side . This helps to reduce lateral movement of the lower denture by placing occlusal forces more lingual to and toward the center of the mandibular teeth. On the balancing side the maxillary lingual cusps contact the mandibular buccal cusps as is customary with anatomic occlusal arrangements

35. 5. Protrusive balancing contacts should occur only between the maxillary lingual cusps and the lower teeth.

36. DENTAL TECHNIQUE 1. Determine and set horizontal condylar guidance elements using a protrusive jaw relation record . 2. Establish and set lateral condylar guidance values using Hanau’s formula (L = H/8 + 12). Javid NS, Porter MR. The importance of the Hanau formula in construction of complete dentures . J Prosthet Dent 1975;34:397-404

37. 3. Determine the incisal guidance by subtracting 20 degrees from the average horizontal condylar guidance value. 4. Set lateral components of incisal guidance at 5 degrees on each side. 5. Establish appropriate soft tissue support , as well as acceptable esthetics and phonetics.

38. 6. Arrange the maxillary anterior teeth in accordance with rim contours . 7. Arrange mandibular anterior teeth to harmonize with maxillary anterior teeth.

39. 8. Clearly identify the positions of the retromolar pads . Identify the medial and lateral extensions of the pads with distinct lines on the posterior land area of the mandibular cast. 9. Identify one half the height of each retromolar pad with a distinct line on the land area of the mandibular cast.

40. 10. Arrange the mandibular posterior teeth determine the mediolateral placement of the mandibular posterior teeth by ensuring that mandibular lingual cusps fall within Pound’s triangle. Pound E. Utilizing speech to simplify a personalized denture service. J Prosthet Dent 1970;24:586-600

41. If they are set too far lingually , they will impinge on the tongue. If they are too far to the buccal , the denture will be unstable.

42. 11. Modify the vertical dimension of the articulator to accommodate corrective adjustment procedures. 12. To accomplish this, create a 0.5-mm increase in occlusal vertical dimension at the incisal pin.

43. 13. Arrange the maxillary posterior teeth , ensuring that the maxillary lingual cusps are placed in the opposing central grooves. 14. Position the maxillary buccal cusps 1 mm superior to the maxillary lingual cusps

44. Nonworking side contact is limited to maxillary lingual cusps.

45. Working side contact is limited to maxillary lingual cusps. Maxillary buccal cusps do not contact mandibular teeth in centric or eccentric positions.

46. 15. Return the incisal pin to its neutral (zero ) position . 16. Using articulating instrumentation , perform corrective adjustment procedures .

47. 17. Restrict adjustment to the mandibular teeth. 18. Stop the procedure when the incisal pin is in contact with the incisal table.

48. 19. Perform corrective adjustment procedures to ensure appropriate contact in centric relation position . 20. Be certain that bilateral posterior contact is present when anterior teeth are in an edge-to edge relationship .

49. 21. Accomplish corrective adjustment procedures for right lateral and left lateral excursions.

50. 22. Ensure sustained, bilateral contact of the teeth as the articulator is moved into right lateral and left lateral positions.

51. REFERENCES 1. Lang BR, Razzoog ME. Lingualized integration: Tooth molds and an occlusal scheme for edentulous implant patients. Implant Dent 1992;1:204-11 2. Ortman HR. Complete denture occlusion. In: Winkler S, editor. Essentials of complete denture prosthodontics , vol 1. 2nd ed. St. Louis:Ishiyaku EuroAmerica ; 1994L217-29 3. Hanau RL. Full denture technique for Hanau Articulator Model H. 4th ed. Buffalo:Hanau Engineering; 1930 4. Ortman HR. The role of occlusion in preservation and prevention in completed denture prosthodontics . J Prosthet Dent 1971;25:121-38

52. 5. Murrell GA. The management of difficult lower dentures. J Prosthet Dent 1974;32:243-50 6. Becker CM, Swoope CC, Guckes AD. Lingualized occlusion for removable prosthodontics . J Prosthet Dent 1977;38:601-8 7. Winter, C. M., Woelfel , J. B., And Igarashi, T.: Five Year Changes In The Edentulous 8. Mandible As Determined On Oblique Cephalometric Radiographs, J. Dent. Res.1974;53: 1455-67 9. Boswell, J. V.: Practical Occlusion In Relation To Complete Dentures, J. Prosthet . Dent. 1951;1: 307-21

53. 10. Sears, V. H.: Specifications For Artificial Posterior Teeth, J. Prosthet . Dent. 1952;2: 353-61 11. Porter, C. G.: The Cuspless Centralized Occlusal Pattern, J. Prosthet . Dent. 1955;5: 313-8 12. Mcmillian , H. W.: Unilateral Vs. Bilateral Balanced Occlusion, J. Am. Dent. Assoc. 1930;17:1207-21 13. Sears, V. H. : Chewing Members, J. Prosthet . Dent. 1951;1: 761-3 14. Hall, R. E.: The Inverted Cusp Tooth, J. Am. Dent. Assoc. 1931;18: 2366-8 15. Hardy, I. R.: The Development In The Occlusal Patterns Of Artificial Teeth, J. Prosthet . Dent. 1951;1: 14-28

54. 16. Sears, V. H.: Thirty Years Of Non Anatomic Teeth, J. Prosthet . Dent.1953; 3: 596-617 17. Rapp, R.: The Occlusion And Occlusal Patterns Of Artificial Posterior Teeth, J. Prosthet . Dent. 1954;4: 461-80 18. French, F.: The Problem Of Building Satisfactory Dentures, J. Prosthet . Dent.1954; 4: 769-81