Lingualized occlusion (cusp to fossae) develops a mortar and pestle occlusal configuration. This arrangement enables excellent penetration of the food bolus. Bilateral balance is primarily accomplished by the maxillary lingual cusps maintaining contact during excursions with the inclines and central fossae of the mandibular cusps. This program illustrates in great detail the positioning of the posterior denture teeth so as to create bilateral balanced occlusion.

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Complete Dentures»

Complete Dentures – Occlusal Schemes – Lingualized Occlusion — Course Transcript

  • 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
  • 3. Balanced occlusion Our objective with this tooth form (Ivoclar Ortholingual) is to create a balanced occlusion. We wish to insure that all the posterior teeth as well as the anterior teeth, contact in excursions. To ensure bilateral balance we place an anterior-posterior curve in the arch, called a compensating curve, which is analogous to the curve of Spee in natural dentition. In addition , we develop a slight curve from side to side, the so called curve of Wilson, with the posterior tooth arrangement. 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
  • 6. Clinical Determinants of Anterior Tooth Placement Clinically determined by Phonetics Esthetics Lip support Utilizing Wax Occlusion Rims Wax Trial Denture Set Up
  • 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.
  • 8. Clinically determined by Assessment of dynamic position of “teeth” during speech Functional Phonetic Determinants of Anterior Tooth Position Utilizing Wax Occlusion Rims Wax Trial Denture Set-up “ F” and “V” position “ S” position
  • 9. Note the relationship between the incisal edge to the wet line of the lower lip when the patient makes a fricative sound. Functional Phonetic Determinants of Anterior Tooth Position “ F” and “V” position
  • 10. Note the maxillary to mandibular anterior tooth relationship during sibilant sounds. Functional Phonetic Determinants of Anterior Tooth Position “ S” position The mandible travels down and forward to create a small space between the maxillary and mandibular incisors during the production of sibilant sounds.
  • 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
  • 12. Materials and Preparation Setting the Maxillary Anterior Denture Teeth
  • 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
  • 16. When the wax rim is ideally contoured and mounted and the lower cast mounted on the on the articulator with a centric relation record, the plane of occlusion is readily seen. The three landmarks used to determine the plane of occlusion are: The midpoint of the retromolar pads bilaterally as previously marked on the mandibular cast. The incisal edge of the maxillary central incisors Setting the Anterior Teeth
  • 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.
  • 30. Setting Mandibular Anterior Teeth Determinants of Mandibular Anterior Tooth Position Phonetics Jaw relations Occlusal schemes with bilateral balance
  • 31. Vertical overlap (1-2 mm)** Horizontal overlap (1-2 mm )* No contact is centric occlusion * When using occlusal schemes with bilateral balance, the amount of vertical and horizontal overlap will vary depending on condylar inclination, occlusal plane orientation and esthetic needs. Setting Mandibular Anterior Teeth Patients with skeletal Class I relationships ** It is generally advisable to keep the vertical overlap to a minimum in complete dentures .
  • 32. Why horizontal and vertical overlap ? We desire to minimize the forces applied to the mandibular and maxillary anterior ridges in centric occlusion . Create the appropriate relationship of the maxillary and mandibular anterior teeth during the production of sibilant speech sounds. Setting Mandibular Anterior Teeth
  • 33. Magnitude of horizontal overlap ? In Class II patients the mandible tends to travel farther anteriorly in function than the typical Class I patient and consequently more horizontal overlap is necessary to allow for this functional movement . Setting Mandibular Anterior Teeth In contrast Class III patients often demonstrate little or no anterior movement of the mandible during function. Consequently, little or no horizontal overlap is developed in the set up. Class I Class II Class III
  • 34. Setting Mandibular Anterior Teeth As noted previously, during the production of sibilant sounds the mandible travels down and forward and a space of about 1 mm is created between the maxillary and mandibular incisors. “ S” position
  • 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.
  • 50. Setting the Maxillary Posteriors All of the maxillary teeth have been positioned. Note that the maxillary lingual cusps all firmly contact the central fossae of the mandibular teeth.
  • 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
  • 52. Lingualized Occlusion Verify working, balancing and protrusive. Make adjustments as necessary. This is the working position. Note that the anterior teeth are in contact during lateral excursions. If adjustments are necessary to achieve appropriate contact they should be done at this stage.
  • 53. Lingualized Occlusion Verify working, balancing and protrusive. Make adjustments as necessary. This is the balancing position.
  • 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.