A Clinical Study on Mandibular Movement after Orthognathic Surgery

The purpose of this study is to evaluate the relationship of the factors which could be influenced by orthognathic surgery especillay SSRO. We measured the amounts of the maximum opening, lateral movements, maximum velocity and pattern of mandibular path during the opening and closing of mandible at the following times ; preoperative, 1 month after operation, 6 months after operation respectively using MKG. And the results were compared according to the categorized subgroups. Following results were obtained : 1. The change of the amounts of mandibular lateral movement and maximum opening velocity were statistically different between male and female (p0.05). 3. According to the amounts of mandibular movement, the recovery of left lateral movement of the group of 6~10mm was better than the other groups (p0.05). 6. There was not a statistical difference in the change of the mandibular movement between repositioning device applied group and non-applied group (p>0.05). 7. Sixty three percents of the patients who had preoperative TMJ symptoms were improved after surgery and preoperative TMJ symptoms were more improved after operation in the repositioning device non-applied group statistically (p<0.05).

Astudy of the effect of posterior teeth with reverse cross-bite on chewing mov ement / 实用口腔医学杂志

Objective:To investigate the effect of partial p osterior teeth with reverse cross-bite at one side of mandible on the chewing m ovement. Methods: 16 university students with partial posterior teeth reverse cross-bite and 12 with normal occlusion were included, 5 cycles o f gum chewing movement with left and right side separately were recorded with K6 -Ⅰmandibular kinesiograph (MKG) for the trace and velocity. Results: ①The chewing movement recorded in frontal plane was with a typical cycl e in controls while that in reverse cross-bite individuals was vertically in an d/or out type (59.38%), as well as in and out in same direction type (21.88%). ②Chewing movement in reverse cross-bite patients was in posterior direction, together with a larger angle of closing trace to horizontal plane and higher che wing terminal velocity. Conclusion: Partial posterior teeth with reverse cross-bite at one side have significant effect on both direction and v elocity of chewing movement.