Abstract: Objective: To analyse the features of mandibular movement trace in patients with unilateral chewing. Methods: During the maximum mouth opening and closing movement, the trace of mandibular incisor point was recorded both in the bilateral chewing group and unilateral chewing group. Data collected were used for statistical analysis. Results: 1)The jaw tangent point trace was separate in unilateral chewing group. There was statistical significance for the opening type between bilateral chewing group and unilateral chewing group (P<0.05). 2) The vertical and sagittal displacements in the unilateral chewing group were significantly lower than those in bilateral chewing group (P<0.01). Conclusion: Patients with unilateral chewing would deflect mandible to the working side during maximal mouth opening and closing. 50% of them exhibited a separated jaw tangent point trace and limited mouth opening. Unilateral chewing might lead to abnormity of mandibular movement trace.

Key words: Unilateral chewing, Opening and closing movement, Trace of mandibular incisor point