CHEWING PATTERN-ANALYSIS IN TMD PATIENTS WITH AND WITHOUT INTERNAL DERANGEMENT .1.

In order to investigate the chewing movement of temporomandibular diso rders (TMD) patients with and without internal derangement of the temp oromandibular joint (TMJ), analysis of the envelope of motion during c hewing was performed in 103 TMD patients with unilateral internal dera ngement (ID group), 94 TMD patients without internal derangement (NID group) and 10 normal subjects (normal group). The analysis of numeric parameters revealed that the ID group demonstrated a significantly res tricted range of motion compared to the NID or normal groups, and the NID group demonstrated significant irregularity of chewing compared to the ID or normal groups. The analysis of chewing also demonstrated th at the chewing pattern for the ID group demonstrated more frequent dev iation of the turning point to the nonchewing side in the frontal plan e and a narrow anteroposterior pattern in the sagittal plane compared to the other groups. No characteristic chewing patterns were identifie d for the NID group.