1. 16. Occlusal Schemes - Lingualized Occlusion John Beumer III, DDS, MS and Michael Hamada DDS Division of Advanced Prosthodontics, Biomaterials and Hospital Dentistry UCLA School of Dentistry This program of instruction is protected by copyright ©. No portion of this program of instruction may be reproduced, recorded or transferred by any means electronic, digital, photographic, mechanical etc., or by any information storage or retrieval system, without prior permission.

2. 13c. Occlusal Schemes 1. Bilateral Balance (a) Lingualized Occlusion

4. Begin by positioning the appropriate protrusive insert, and check to ensure that the incisal guide pin is set at zero and in contact with the incisal guide table. Lingualized Occlusion Protrusive inserts Protrusive insert Zero setting

5. Setting Maxillary Anterior Denture Teeth

7. Lip Support The need for lip support from the teeth and denture flange varies depending upon the degree of ridge resorption. The amount required is determined by both the wax rim and the trial denture.

11. A typical esthetic display of the maxillary anterior teeth. The central incisors are aligned with the midline and the laterals and cuspids are elevated off the occlusal plane. Esthetic Determinants of Anterior Tooth Placement

13. Mark the casts indicating midline, crest of the ridge, and the midpoint of the retromolar pad . These landmarks will be used to check your denture setup. Maxilla Midline Anterior land Incisive papilla Mandible Ridge Retromolar pad Cast Landmarks

14. Anterior land Cast Landmarks - Maxilla Midline Incisive papilla

15. Lines indicating the crest of the ridge Cast Landmarks -Mandible Midpoint of retromolar pad Land Mark on land indicating the midpoint of the retromolar pad

17. To set the remaining maxillary anterior teeth a clear glass or plastic slab is positioned on the mandibular record base to represent the plane of occlusion. Setting the Anterior Teeth Mark indicating midpoint of the retromolar pad

18. Setting the Maxillary Central Incisors Soften some baseplate wax and attach the other central incisor to the ridge lap portion of the maxillary central incisors and attach it to the record base

19. Setting the Maxillary Central Incisors The mesial of each tooth should be on the midline (arrow) and the incisal edge should be parallel to and in contact with the occlusal plane.

20. Setting the Maxillary Central Incisors Viewed from the facial perspective, the maxillary central incisor is placed so that the long axis shows a slight distal inclination to the perpendicular.

21. Setting the Maxillary Central Incisors When viewed from profile the cervical aspect of the tooth should be slightly depressed. Note that the incisal 2/3 of the central incisors are perpendicular to the plane of occlusion In this particular patient, appropriate lip support was achieved by placing the labial surface of the central incisors on a curve coinciding with the inner edge of the land of the cast (red line). This may vary, and in many patients the incisors project more anteriorly, particularly in those with severe resorption of the premaxilla. Inner edge of the land Occlusal plane

22. Setting the Maxillary Lateral Incisors The maxillary lateral incisor is should be positioned with a slight distal inclination and is usually ½ to 1 mm above the plane of occlusion.

23. Setting the Maxillary Lateral Incisors When viewed in profile note that the lateral incisor is positioned with a slight distal inclination in relationship with the central incisor. Note again that the lateral incisor is positioned slightly above the plane of occlusion.

24. Setting the Maxillary Lateral Incisors When viewed from the occlusal, the incisors should follow the same curvature as the internal aspect of the land.

25. Setting the Maxillary Cuspids When viewed in profile the cuspid has a slight distal inclination from the perpendicular and the incisal tip touches the occlusal plane (arrow).

26. Setting the Maxillary Cuspids “ Toed-in” Position Note how the cervical and incisal edges of the cuspid are aligned vertically (yellow line). The facial surface of the cuspid however, is canted inward and appears “toed in” (red line) due to the prominence of the cervical area of the tooth (yellow arrow).

27. Setting the Maxillary Cuspids The cuspid has two planes on the labial surface – a mesial plane (yellow line) and a distal plane (red line). When viewed from the anterior only the mesial plane should be visible.

28. Setting the Maxillary Cuspids When viewed from the occlusal the anterior teeth follow the curvature of the internal portion of the land.

29. Setting the Maxillary Cuspids Note the inclination of the anterior teeth.

35. Setting the Mandibular Central Incisors In most patients the labial surface of the mandibular incisors should be roughly perpendicular to the occlusal plane. Occlusal plane

36. Setting the Mandibular Central Incisors In the setup shown here, the initial vertical overlap chosen was 1.0 mm and the amount of horizontal overlap was 1.5 mm. Vertical overlap 1 mm Horizontal overlap 1.5 mm

37. Setting the Mandibular Central Incisors Horizontal overlap 1 mm Horizontal overlap is measured from the tip of the maxillary central incisor to the labial surface of the mandibular central incisor. Horizontal overlap 1.5 mm

38. Setting the Mandibular Central Incisors Incisal angle Occlusal plane The incisal angle varies depending on the magnitude of the vertical and horizontal overlap, the arrangement of the occlusal plane and the condylar inclination. It is generally advisable to keep the incisal angle to a minimum in complete dentures. Vertical overlap

39. Setting the Lateral Incisors and Cuspids Position the remaining mandibular anterior teeth. The lateral incisors should be placed similar in angulation and position to the central incisors. Note that the cuspids are towed out at the cervical. The vertical overlap can be easily appreciated from frontal perspective.

40. Setting the Lateral Incisors and Cuspids The vertical overlap should be 1.0 mm throughout the anterior region at this stage of the setup. Note that the cuspid is slightly inclined to the distal whereas the lateral incisor is relatively vertical. Occlusal plane

41. Setting the Lateral Incisors and Cuspids The horizontal overlap should be consistent throughout the anterior region. At this stage it should be about 1.5 mm.

42. Setting the Lateral Incisors and Cuspids From the anterior perspective the angulation of the mandibular anterior teeth should be as indicated. Note that the cervical of the cuspids are in the towed out position.

43. Setting the Anterior Teeth The anterior teeth have now been positioned. The final positions will be determined during the trial denture appointment.

44. Setting the Mandibular Posteriors Set the mandibular premolars and the 1 st molar. Make sure these teeth are on plane and on ridge. Use the marks on your cast to help you visualize the occlusal plane and crest of the ridge. Occlusal plane Line indicating the crest of the ridge

45. Setting the Mandibular Posteriors When using this lingualized posterior tooth form (Ivoclar Ortholingual) there should be little or no curve of Wilson. In this set up both the lingual and buccal cusp tips of the premolars and the 1 st molar were on the plane of occlusion.

46. Setting the Mandibular Posteriors Position the 2 nd molar. The curve of Spee is created by slightly elevating the distal half of the 1 st molar and by elevating the the 2 nd molar by about 15 degrees up from the occlusal plane. 15 degrees

47. Setting the Mandibular Posteriors Both sides have now been set. Before setting the maxillary posterior teeth make sure the posterior mandibular teeth are centered over the ridges and on plane.

48. Setting the Maxillary Posteriors Position the maxillary posterior teeth. There should be about a 1mm space between the lingual inclines of the buccal cusps of the maxillary teeth and the the buccal slopes of the buccal cusps of the mandibular teeth.

49. Setting the Maxillary Posteriors The lingual cusp tips should be in contact with the central fossae of the opposing mandibular teeth. However, as opposed to anatomic teeth set to bilateral balance, they need not be arranged in a cusp – embrasure relation ship.

51. Verify centric and make adjustments as necessary. The lingual cusps of the maxillary posterior teeth must rest in the central fossa of the opposing mandibular teeth. There should be no buccal cusp contacts of posterior teeth in centric or in lateral excursion. Completed Denture Setup

54. Lingualized Occlusion Protrusive Develop protrusive contacts as shown. Light contact of the anterior teeth in protrusion enhances stability. Note the contacts in the 2 nd molar region.