Facial Asymmetry and Unilateral Chewing in the TMJ Internal Derangement Patient

For the research, thirty patients complained about unilateral TMJ sound and pain and been diagnosed having TMD were selected for study group. In control thirty people who had healthy TMJ were selected. After we selected some reference points in thePA cephalo radiograph, we measured the difference of both left and right measurement value using the referenc points and the degree of deflection of midline between maxilla and mandible. So we investigated the possible relationship of disc derangement and facial asymmetry and unilateral chewing pattern. the following results were obtained: 1. In comparing the measurement value of P-A cephalo radiographs in study and control group, the location of Me, FCP and FJP to MS is deflected to the left side. the distance of Ag to Ms is longer in left side comparing with control group. The other measurement value had no significant difference with control group. 2. In comparing the absolute value of P-A cephalo radiographs in study and control group. the deflection degree of Me to MS and the vertical location of Co have significant asymmetry with the controls. The angle of FOP to MS, the distance of Oc to MS, and the vertical locational difference of Oc are greater than controls. And the length between Co and Ag, Ag and Me, Co and Me which reveals the volume of mandible have significant bilateral asymmetry than controls. (P<0.05) 3. Some of the patient groups, the patient who complained about their right side, their measurement value has changed to that of left side and compared with the controls. In controls FCP to MS have slight deflection tendency to right side but in study group to left side. And in study group the distance of J and AG to MS, vertical location of Co to MS and the length between Co and Ag have more value in left side but in controls in Right side. (P<0.05) 4. In midline discrepancy between maxilla and mandible there is no significant difference between study and control groups. But for absolute value there is significant difference. (P<0.05) 5. Study group and control group have been divided into two groups , who have unilateral chewing pattern or not. In study group there is more patient have unilateral chewing tendency. (P<0.01). When divided into three groups who have not unilateral chewing pattern, have right side chewing pattern and left side, in all cases there have more unilateral chewing pattern in study group. (P<0.01) And when changing measurement value of right side to that of left side the result are same of that. (P