Objective:To study character mandibular movement tracings during mandibular protrusion in patients with unilateral posterior crossbite and compare the difference with normal occlusion.

Mandibular movement is a kind of complex spacial three dimensional movement which is the result of contractions of active masticatory muscles and guided by the occlusion and temporomandibular joints.

This paper presents the studies of tapping movement and centric occlusion of 32 normal individuals and 37 patients with TMJ dysfunction syndrome by the Mandibular Kinesiograph (MKG).