The term disclusion is used to describe dis-occlusion or separation of nonfunctional posterior teeth during eccentric motions of the jaw.
Disclusion of posterior teeth is brought about by condylar guidance and incisal guidance
Condylar guidance refers to the downward movement of both the condyles along the slopes of the articular eminence during protrusive movements leading to separation of the posteriors.
In case of lateral movements, the condyle on the non- functioning side translates forward along the eminence while the condyle on the functioning side pivots in its fossa leading to disclusion of posteriors on the nonfunctional side.
Anterior guidance refers to anterior tooth functions which separate the posterior teeth during eccentric motions of the Jaw.
During protrusive and lateral movements of the mandible, the lower anterior teeth track downward from their area of centric contact towards the incisal edges of maxillary teeth while dis-occluding the non—functional posterior teeth.
Condylar guidance has its greatest influence on the discluding the most distal posterior teeth, while the incisal guidance provides disclusion effect on the more mesial teeth.
The condylar guidance is a fixed anatomic factor that cannot be controlled by dentist while the incisal guidance can be controlled by modifying the form and arrangement of the anterior teeth.