Previous research has shown a relationship between head posture and rest position of the mandible. Should this relationship really be an interrelationship? Does a change in mandibular posture alone also alter head and neck posture? The purpose of this article is to demonstrate how a change in mandibular posture, specifically an increase in vertical dimension, contributes to craniovertical extension leading to suboccipital compression and upsetting the postural balance between the head and neck. A model of physiologic equilibrium is presented for the craniomandibular articulation.