16.occlusal schemes lingualized occlusion

16. Occlusal Schemes - Lingualized 16. Occlusal Schemes - Lingualized OcclusionOcclusion

John Beumer III, DDS, MSJohn Beumer III, DDS, MSandand

Michael Hamada DDSMichael Hamada DDSDivision of Advanced Prosthodontics, Division of Advanced Prosthodontics, Biomaterials and Hospital DentistryBiomaterials and Hospital Dentistry

UCLA School of DentistryUCLA School of Dentistry

This program of instruction is protected by copyright ©. No portion of This program of instruction is protected by copyright ©. No portion of this program of instruction may be reproduced, recorded or transferred this program of instruction may be reproduced, recorded or transferred by any means electronic, digital, photographic, mechanical etc., or by by any means electronic, digital, photographic, mechanical etc., or by any information storage or retrieval system, without prior permission.any information storage or retrieval system, without prior permission.

13c. Occlusal Schemes13c. Occlusal Schemes1. Bilateral Balance1. Bilateral Balance

(a) Lingualized Occlusion(a) Lingualized Occlusion

Lingualized OcclusionLingualized Occlusion

Balanced occlusionOur 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.

Begin by positioning the appropriate protrusive insert, and Begin by positioning the appropriate protrusive insert, and check to ensure that the incisal guide pin is set at zero and check to ensure that the incisal guide pin is set at zero and in contact with the incisal guide table.in contact with the incisal guide table.


Protrusive insertsProtrusive inserts

Protrusive Protrusive insertinsert

Zero Zero settingsetting

Setting Maxillary Anterior Denture TeethSetting Maxillary Anterior Denture Teeth

Clinical Determinants of Anterior Clinical Determinants of Anterior Tooth PlacementTooth Placement

Clinically determined by• Phonetics• Esthetics• Lip support

Utilizing• Wax Occlusion Rims• Wax Trial Denture Set Up

Lip SupportLip 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.

Functional Phonetic Determinants of Functional Phonetic Determinants of Anterior Tooth PositionAnterior Tooth Position

Clinically determined byClinically determined by• Assessment of dynamic position of “teeth” during Assessment of dynamic position of “teeth” during

speechspeech

UtilizingUtilizing• Wax Occlusion RimsWax Occlusion Rims

• Wax Trial Denture Set-upWax Trial Denture Set-up

““F” and “V” positionF” and “V” position ““S” positionS” position

Functional Phonetic Determinants of Functional Phonetic Determinants of Anterior Tooth PositionAnterior Tooth Position

Note the relationship between the Note the relationship between the incisal edge to the wet line of the incisal edge to the wet line of the lower lip when the patient makes a lower lip when the patient makes a fricative sound.fricative sound.

““F” and “V” positionF” and “V” position

Functional Phonetic Determinants of Functional Phonetic Determinants of

Anterior Tooth PositionAnterior Tooth Position Note the maxillary to mandibular Note the maxillary to mandibular

anterior tooth relationship during anterior tooth relationship during sibilant sounds.sibilant sounds.

““S” positionS” position

The mandible travels down and forward to create a small space between the maxillary and mandibular incisors during the production of sibilant sounds.

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

Esthetic Determinants of Anterior Tooth PlacementEsthetic Determinants of Anterior Tooth Placement

Materials and PreparationMaterials and Preparation

Setting the Maxillary Anterior Denture Teeth

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.

MaxillaMidlineAnterior landIncisive papilla

MandibleRidge Retromolar pad

Cast LandmarksCast Landmarks

Anterior land

Cast Landmarks - MaxillaCast Landmarks - Maxilla

Midline

Incisive papilla

Lines indicating the crest of the ridge

Cast Landmarks -MandibleCast Landmarks -MandibleMidpoint of

retromolar pad

Land Mark on land indicating the midpoint of the retromolar pad

When the wax rim is ideally contoured and mounted and the lower cast 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 mounted on the on the articulator with a centric relation record, the plane of occlusion is readily seen.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 TeethSetting the Anterior Teeth

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.


Mark indicating midpoint of the retromolar pad

Setting the Maxillary Central IncisorsSetting 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


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.


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


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 Inner edge of the landof the land

Occlusal Occlusal planeplane

Setting the Maxillary Lateral IncisorsSetting 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.


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.


When viewed from the occlusal, the incisors should follow the same curvature as the internal aspect of the land.

Setting the Maxillary CuspidsSetting 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).


““Toed-in” PositionToed-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 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.


When viewed from the occlusal the anterior teeth follow the curvature of the internal portion of the land.


Note the inclination of the anterior teeth.

Setting Mandibular Anterior TeethSetting Mandibular Anterior Teeth

Determinants of Mandibular Anterior Tooth Position

• Phonetics• Jaw relations• Occlusal schemes with bilateral balance

• Vertical overlap (1-2 mm)**• Horizontal overlap (1-2 mm)*• No contact is centric occlusion

* When using occlusal schemes When using occlusal schemes with bilateral balance, the amount with bilateral balance, the amount of vertical and horizontal overlap of vertical and horizontal overlap will vary depending on condylar will vary depending on condylar inclination, occlusal plane inclination, occlusal plane orientation and esthetic needs. orientation and esthetic needs.


Patients with skeletal Class I relationships

** It is generally advisable ** It is generally advisable to keep the vertical overlap to keep the vertical overlap to a minimum in complete to a minimum in complete denturesdentures..

Why horizontal and vertical overlapWhy horizontal and vertical overlap??

1. We desire to minimize the forces applied to the mandibular and maxillary anterior ridges in centric occlusion.

2. Create the appropriate relationship of the maxillary and mandibular anterior teeth during the production of sibilant speech sounds.


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.

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 IClass I Class IIClass II

Class IIIClass III

Setting Mandibular Anterior Teeth 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” positionS” position

Setting the Mandibular Central IncisorsSetting the Mandibular Central Incisors

In most patients the labial surface of the mandibular incisors should be roughly perpendicular to the occlusal plane.

Occlusal planeOcclusal plane


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 Vertical overlap overlap 1 mm1 mm

Horizontal Horizontal overlap overlap 1.5 mm1.5 mm


Horizontal Horizontal overlap overlap

1 mm1 mm

Horizontal overlap is measured from the tip of the maxillary central incisor to Horizontal overlap is measured from the tip of the maxillary central incisor to the labial surface of the mandibular central incisor.the labial surface of the mandibular central incisor.

Horizontal Horizontal overlap overlap 1.5 mm1.5 mm


Incisal Incisal angleangle


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 Vertical overlapoverlap

Setting the Lateral Incisors and CuspidsSetting 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.


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.



The horizontal overlap should be consistent throughout the anterior region. At this stage it should be about 1.5 mm.


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.


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

Setting the Mandibular PosteriorsSetting the Mandibular Posteriors

Set the mandibular premolars and the 1st 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 planeOcclusal plane

Line indicating the Line indicating the crest of the ridgecrest of the ridge


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 1st molar were on the plane of occlusion.


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

15 degrees


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

Setting the Maxillary PosteriorsSetting 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.


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.


All of the maxillary teeth have been positioned. Note that the maxillary lingual cusps all firmly contact the central fossae of the mandibular teeth.

Verify centric and make adjustments as necessary. The lingual cusps of the 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 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 teeth. There should be no buccal cusp contacts of posterior teeth in centric or in lateral excursion. lateral excursion.

Completed Denture SetupCompleted Denture Setup


Verify working, balancing Verify working, balancing and protrusive. Make and protrusive. Make adjustments as necessary. adjustments as necessary. This is the working position. This is the working position. Note that the anterior teeth Note that the anterior teeth are in contact during lateral are in contact during lateral excursions. If adjustments excursions. If adjustments are necessary to achieve are necessary to achieve appropriate contact they appropriate contact they should be done at this should be done at this stage.stage.


Verify working, balancing and protrusive. Make adjustments Verify working, balancing and protrusive. Make adjustments as necessary. This is the balancing position.as necessary. This is the balancing position.


ProtrusiveProtrusive

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

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16.occlusal schemes lingualized occlusion