Complete Denture Occlusion Introduction
Occlusion means “contact”. Occlusion in prosthesis is required to achieve esthetic, stability, and chewing ability. This chapter focuses on different concepts and types of complete denture occlusion.
Table of Contents
Complete Denture Occlusion Definition
Occlusion: The relationship between the occlusal surfaces of the maxillary and mandibular teeth when they are in contact.
Read and Learn More: Preclinical Prosthodontics Notes
Complete Denture Occlusion Objectives
- It should provide maximum intercuspation of the maxillary and mandibular teeth in centric relation
- Should minimize harmful lateral forces
- Should be designed to provide stability to complete denture
- Should maintain comfort and well-being of the patient
- Should be designed such a way that it can guide jaw closure
- Occlusion should not cause any trauma to underlying soft and hard tissue.
Differences Between Natural And Artificial Occlusion
The teeth in natural dentitions are retained by periodontal tissues. In complete denture all the teeth are on denture bases seated on denture foundation. In natural dentitions the teeth receive individual occlusal load and can move independently to adjust to occlusal load. The artificial teeth move as a whole unit on denture foundation.
Malocclusion of natural teeth may not be harmful for years. Malocclusion of artificial teeth induces an instant response and involves all of the teeth and the denture base. Horizontal or rotational forces on natural teeth during function affect only the teeth involved and are usually well tolerated, whereas in artificial occlusion, the effect involves all of the teeth on the denture bases and is traumatic.
In natural teeth, the second molar is the favored area for masticating hard foods. Heavy pressures of mastication in the second molar region with artificial dentition will tilt the prosthesis. In natural teeth, prematurities are avoided due to neuromuscular system control. In artificial occlusion any prematurely causes instability due to lack of feedback.
Complete Denture Occlusion Classification
Angle classified occlusion in three classes based on relationship of opposing posterior teeth.
Theories Of Occlusion
Bonwill’s Theory of Occlusion:
According to this theory of occlusion, the teeth move in relation with each other as guided by the condylar and incisal guidance. This theory is also known as “Theory of equilateral triangle”. According to this, distance between two condyles is equal to distance between condyle and midincisor point of mandible. Each side of this triangle measures 4 inch (all sides measure equal distance of 4 inch, so called as equilateral triangle).
Conical Theory of Occlusion:
This theory was proposed by RE Hall. According to this theory mandibular teeth move over the surface of the maxillary teeth as if they are moving over the surface of a cone, generating an angle of 45° with the central axis of the cone tipped at 45° to the occlusal plane.
Spherical Theory of Occlusion:
This theory was proposed by Monson. According to this theory, mandibular teeth move over the surface of the maxillary teeth,as over a surface of sphere with a diameter of 8 inch. The center of the sphere located in the region of glabella. The surface of sphere passes through the glenoid fossa and articulating eminences.
Types/Concepts Of The Complete Denture Occlusion
Balanced Occlusion:
Definition:
The bilateral, simultaneous, anterior, and posterior occlusal contact of teeth in centric and eccentric positions. In this type of occlusion there is bilateral, simultaneous, anterior, and posterior occlusal contact of teeth in centric and eccentric positions. This type of occlusion provides good stability of denture due to simultaneous contacts.
In most cases anatomical teeth are used for arrangement. Dificult and time consuming to get balanced occlusion. It enhances retention and stability of complete denture. Balanced occlusion distributes forces equally all over the denture-bearing area resulting in reduced resorption of alveolar bone.
Factors Influencing Balanced Occlusion:
Condylar guidance: It is angle generated by condyle and the articular disk traversing the contour of glenoid fossa.
Incisal guidance: The influence of contacting surfaces of maxillary and mandibular anterior teeth.
Plane of occlusion: It is average plane established by the incisal and occlusal surfaces of teeth.
Cuspal inclination: Cuspal inclination is slope of a cusp with the occlusal plane.
Compensating curve: Anteroposterior and mediolateral curves in alignment of artificial teeth are used to develop balanced occlusion.
Lingualized Occlusion:
Definition:
This form of denture occlusion articulated the maxillary lingual cusps with the mandibular occlusal surfaces in centric, working, and nonworking mandibular positions (the term is attributed to Earl Pound and was first describes by S Howard Payne, in 1941).
This form of denture occlusion articulates the maxillary lingual cusps with the mandibular occlusal surfaces in centric, working, and nonworking mandibular positions. Carry advantages of both anatomical and nonanatomical teeth.
Monoplane Occlusion:
Definition:
An occlusal arrangement wherein the posterior teeth have masticatory surfaces that lack any cuspal height. This type of occlusion arrangement is achieved using nonanatomic or monoplane teeth.
Philosophy behind this type of arrangement is to elimination of cusps and so minimizing the lateral forces which ultimately enhance the denture stability. Anterior teeth are arranged with 2 mm overjet and zero overbite. Easy to arrange teeth according to this scheme but chewing efficiency is less due to monoplane/nonanatomic teeth.
Neutrocentric Concept Of Occlusion
This concept was proposed by Devan. It expresses the centralization of occlusion forces that act on the basal seal when mandible is in centric relation with maxilla. Teeth are arranged flat with no medial or lateral inclination. No compensating curves are incorporated.
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