Some physiologic considerations of centric and other jaw relations

Abstract

The postural position of the mandible is the only reflex determining mandibular position present at birth. Centric relation is learned after the teeth errupt: it is the first learned reflex determining the occlusal position of the mandible after the primary dentition is complete. Eccentric mandibular positions are learned as expedient mechanisms for avoiding occlusal disharmonies. They are forgotten when the source of the afferent impulses prompting them is removed. Centric relation in the edentulous adult is determined by muscle proprioceptors largely, and thus presents slightly different problems in registration.