Considerations of Occlusion in Fixed Partial Dentures

Abstract

Centric occlusion of the teeth of the fixed partial prosthesis should coincide with centric relation of the mandible to the maxilla. The functional significance of centric relation and centric occlusion is explained. An existing occlusion that is within acceptable vertical limits should be adjusted to coincide with centric relation before beginning the prosthesis. The prosthesis is then built in harmony with the corrected occlusion. If, on the other hand, the vertical position of occlusion is to be changed, involving the entire dentition (full mouth reconstruction), this may be done with maximum accuracy and minimum complexity if the vertical position is first determined and centric relation is recorded and maintained at that vertical. Conventional hinge-axis procedures will then be unnecessary. An expeditious and effective method for detection of traumatogenic areas is given. In the adjustment of occlusion little or no attention per se need be given to eccentric “balance.” The overwidened mandibular buccal and maxillary lingual surfaces that interfere with full closure to centric occlusion are the same areas that cause lateral interference. When these specific areas are narrowed to allow full entry to centric occlusion, it will be found that the source of lateral interference during function has also been removed. Effort should be concentrated on providing free unimpeded entry of the cusps into the sulci, terminating in a stable centric occlusion that coincides with centric relation. Movement of prepared teeth must be prevented in the interim that the fixed partial denture is being fabricated. Suitable temporary covering is described. Checking the occlusion in the mouth after insertion is imperative to avoid development of sensitivity and soreness of the teeth, bruxism, erosion and temporomandibular joint disturbances.