Complete Dentures – Occlusal Schemes – Monoplane with Balancing Ramps
Monoplane posterior teeth are generally used in bruxers, and patients with arch discrepancies, poor neuromuscular control and with poor residual ridges. This program describes the arrangement of monoplane posterior teeth to achieve bilateral balanced occlusion. The separation of the posterior teeth during excursive movements is overcome with balancing ramps.
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Complete Dentures – Occlusal Schemes – Monoplane with Balancing Ramps — Course Transcript
- 1. 18. Occlusal Schemes – Monoplane with Balancing Ramps 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. Lateral or tipping forces tend to have an unfavorable effect on denture stability and on structures comprising the denture foundation area. As such denture occlusion differs from organic occlusion (bilateral balance vs anterior guidance) in order to compensate for the lack of retention, stability and support when compared with natural dentition. Bilateral balance decreases the transmission of lateral tipping forces. Monoplane occlusion attempts to further decrease tipping forces by minimizing the effect of incline plane contact between the maxillary and mandibular denture. Bilateral balanced occlusion is obtained by using balancing ramps. Monoplane with Balancing Ramps Background
- 3. Background Sources of inclined plane contact a)The cuspal inclines of the maxillary and mandibular denture teeth b)The vertical overlap of the maxillary and mandibular anterior teeth Monoplane with Balancing Ramps Monoplane occlusion attempts to minimize both these sources of inclined plane contacts in order to minimize tipping forces. Balancing ramps are added to counteract Christiansen’s phenomenon.
- 4. Monoplane with Balancing Ramps
- 5. Monoplane with Balancing Ramps Begin by positioning the appropriate protrusive insert. Check to ensure that the incisal guide pin is set at zero and in contact with the incisal guide table. Protrusive inserts Protrusive insert Zero setting
- 6. Mark the casts indicating midline, crest of the ridge, and the retromolar pad . These landmarks will be used to check your denture setup. Maxilla Midline Anterior land Mandible Ridge Retromolar pad Cast Landmarks
- 7. Anterior land Cast Landmarks – Maxilla Midline Incisive papilla
- 8. 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
- 9. As previously mentioned (13c, 1a), the wax rim is ideally contoured on the patient and used to mount the upper cast with a facebow transfer record. When the lower cast is mounted on the articulator with a centric relation record the plane of occlusion is readily seen. The three landmarks used to identify 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 Maxillary Anterior Teeth
- 10. 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 Maxillary Anterior Teeth Mark indicating midpoint of the retromolar pad
- 11. Setting the Maxillary Anterior Teeth Soften some baseplate wax and attach some to the ridge lap portion of the other maxillary central incisor and attach it to the record base as shown. Set the lateral incisors and cuspids as shown previously. For details see Section 13c, 1a, Lingualized occlusion.
- 12. Setting the Maxillary Anterior Teeth Note the angulations of the anterior teeth in relation to the occlusal plane when viewed in profile. Occlusal plane
- 13. Setting the Maxillary Anterior Teeth “ 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). The centrals and laterals are inclined slightly towards the distal.
- 14. Vertical overlap (0-1mm)* Horizontal overlap (1-2 mm ) No contact is centric occlusion *When using monoplane teeth with balancing ramps the vertical overlap is kept to a minimum. Setting Mandibular Anterior Teeth Patients with skeletal Class I relationships
- 15. 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
- 16. Setting the Mandibular Anterior Teeth The horizontal overlap should be consistent throughout the anterior region. In this setup it is about 1.5 mm.
- 17. Setting the Mandibular Anterior Teeth Positions of the anterior teeth. The lateral incisors should be placed similar in angulation to the central incisors. Note that the cuspids are towed out at the cervical.
- 18. The number and combination of the denture teeth utilized varies depending on the arch length of the patient. The mandibular occlusal table should end prior to the ascending ramus. The distal surface of most posterior maxillary denture tooth should extend one half 1-2mm distal to the most posterior mandibular denture teeth. Monoplane with Balancing Ramps Background – Setting the posterior teeth
- 19. Monoplane with Balancing Ramps Position the posterior mandibular teeth over the crest of the ridge. Check to ensure they are set to a flat plane and on the plane of occlusion. Make corrections as necessary. Because of the vertical overlap of anterior teeth, only the posterior teeth are on the plane of occlusion.
- 20. Monoplane with Balancing Ramps Position the maxillary posterior teeth.
- 21. Monoplane with Balancing Ramps Note that the distal surface of the most posterior maxillary tooth extends 1-2mm distal to the distal surface of the most posterior mandibular tooth.
- 22. Monoplane with Balancing Ramps Check the horizontal overlap of the posterior teeth. The overlap should be at least one third of the width of the occlusal surface and be sufficient to prevent biting of the cheek and corner of the mouth. Horizontal overlap
- 23. Monoplane with Balancing Ramps Note that the premolar of the Ivoclar Orthoplane is of sufficient length to harmonize with the cuspid. In addition the the marginal ridges of the premolars have been lowered. This change provides the esthetics usually associated with anatomic teeth. Monoplane with balancing ramps
- 24. Monoplane with Balancing Ramps The flatness of the maxillary premolars is provided by the flat buccal and lingual cusps. Note that in this set up both lingual and buccal cusps contact the plane of occlusion.
- 25. Monoplane with Balancing Ramps Verify again that all the maxillary teeth, with the exception of the lateral incisors and perhaps the cuspids, are on the plane of occlusion. Make corrections by manipulating the maxillary teeth. When you have completed this step, thoroughly cool the wax before proceeding to the next step.
- 26. Monoplane with Balancing Ramps Reestablish centric contacts as necessary by manipulating the mandibular posterior teeth. Make sure that the incisal guide pin maintains contact with the incisal guide table when you have completed this step. While performing this step make sure you do not alter the horizontal overlap of the posterior teeth.
- 27. Monoplane with Balancing Ramps Add the balancing ramp as shown. In all lateral excursions you should observe at least three points of contact bilaterally if bilateral balance is to be achieved. Protrusive
- 28. Monoplane with Balancing Ramps Working Balancing