concept of occlusion

COMPLETE DENTURE OCCLUSION

Concepts of OCCLUSION

Balanced Occlusion Monoplane (nonbalanced) Occlusion Lingualized Occlusion

Balanced Occlusion is defined as the bilateral, simultaneous, anterior, and posterior occlusal contact of teeth in centric and eccentric positions. Balanced occlusion in complete dentures is unique, as it does not occur with natural teeth. If it occurs in natural teeth, it is considered as a premature contact on the nonworking side and is considered to be pathologic.
1. Balanced Occlusion

Positioning artificial anatomic posterior teeth to simulate natural occlusion. The teeth, must be arranged with a compensating curve running anteroposteriorly and mediolaterally
Anatomic or semi anatomic teeth are arranged in point centric occlusion.

Max. arch alignments of cusped posterior teeth and the mand. Residual ridge as a landmark for setting teeth

The position Of the tooth in relation to the ridge is the important factor in controlling the force and its effect on stability of the base

Teeth make contact in lateral excursion on the working and balancing sides

Excursive Movements

Protrusive movement

Excursive Movements

Laterotrusive and Mediotrusive
Non-working Side (Mediotrusive)
Working Side (Laterotrusive)
LEFT MANDIBULAR EXCURSION

2- The Lingualized Occlusion

A method to achieve bilateral balanced occlusion with an attempt to maintain the esthetic and food penetration advantages of the anatomic form while maintaining the mechanical freedom of the non-anatomic form

Advantages of lingualized occlusion:

1. Esthetics is maintained. 2. Efficiency is maintained. 3. Mechanical freedom of occlusion from the non-anatomic teeth form. 4. Mechanical stability due to centralized forces. 5. Bilateral balanced occlusion is readily obtained for a region around centric relation. 6. No lateral forces due to one contact point. 7. Lingualized occlusion can be used with all morphologic ridge contours. 8. Buccal cusp tilt allows escape way for the bolus of food.


The maxillary buccal cusps are not in contact, leaving only the maxillary lingual cusps as the centric holding cusps,
which helps to stabilize the upper and lower dentures and minimizes the number of tooth contacts



Reducing the efficiency of the lower buccal cusps, Vertical forces are centralized on the mandibular teeth. thus directing the forces to the lingual side of the lower ridge crest to encourage lever stability of the lower denture.

The maxillary cusps act also as the centric holding cusps. This give mortar and pestle type contact that lingualizes the resultant force without moving the teeth in relation to the ridge.
Maxillary lingual cusp make a point of contact somewhere along the mandibular central fossa.

Eliminate anterior interferences

In Centric occlusion (A) when considerable horizontal overlap is present between the anterior teeth. Esthetic vertical overlap of the teeth can be accommodated. (B) When little horizontal overlap then the vertical overlap must be reduced to approach

In Protrusive movement is possible while maintaining balanced occlusion with minimal vertical overlap of anterior teeth. Selective grinding of mandibular tooth forms is needed to create a slight concavity in the occlusal surface.: Left. Shallow cusp form: right. 0 degree cusp form

In lateral excursive movements clearance between the maxillary and mandibular buccal cusps to increase lever stability to the lower denture.
In Bilateral eccentric equilibration

Maintaining teeth on the ridge preserves lever balance

Lingualized occlusion helps centralization of force
Lingual bone resorption prevents placing teeth within the neutral zone



In this concept, a nonanatomic occlusal scheme is used with a few specific modifications. The amount of horizontal overlap is determined by the jaw relationships. The maxillary posterior teeth are arranged first, and the occlusal plane must fulfill certain requirements: 1. The occlusal plane should evenly divide the space between the upper and lower ridges 2. The occlusal plane should be parallel to the mean denture base foundation 3. Finally, the plane should fall at the junction of the upper and middle thirds of the retromolar pads.

Non- anatomic teeth with flat occlusal surfaces set to a flat occlusal plane

The decision as to whether to locate the linear ridge of contacts in the maxillary or mandibular arch depends on the factors of denture stability and esthetics


The idea is to minimize the force penetrating food by sharp linear contact between the upper and lower posterior teeth. A line of occlusal contact in one dental arch occluding with a flat occlusal table in the other dental arch,

Posterior horizontal overlap of flat plane teeth

The posterior limit of the lower posterior teeth is the point at which the mandibular ridge begins to curve upward, with elimination of contact between the upper and lower second molars.
The patients should avoid incising with their anterior teeth

Advantages of monoplane occlusion:

Non-Balanced Does not require precision with records. By removing any inclines, destructive forces on residual ridges is reduced. Easier to adjust. Freedom in CR Cross-bite patients



Disadvantages Flat premolars may appear less esthetic Reported as less efficient in chewing tests Anterior esthetics needs more overjet and no overbite.


We forced to such concept because: The character of the supp. foundation & mucosa resiliency make it almost impossible to harmonize tooth arrangement with mand. movements in the eccentric relations.
4. Unalanced Occlusion
To minimize horizontal forces that are unstabilizing and potentially destructive to the supp. tissue.
When the jaws are in CR and the contact of the teeth produces no discomfort to the supp. tissues or the joints

Advantages of unbalanced Occlusion

Simple technique. No lateral forces. Freedom of occlusion. Used with compromised ridges. Necessitates minimum adjustments.


Poor esthetics. Poor masticatory efficiency. No balancing contacts. Restricted penetration and incision. Lateral chewing cycle.
Disadvantages of unbalanced Occlusion