下颌角磨削去骨术前后咬肌变化

Change of masseter muscle after the angle-grinding ostectomy for the enlarged mandibular angle

目的探讨改良下颌角磨削去骨术矫治轻度下颌角肥大畸形术后咬肌形态的变化,为轻度下颌角肥大畸形矫治手术提供参考依据。方法应用改良下颌角磨削去骨术矫治200例轻度下颌角肥大畸形,采用高频浅表超声成像技术,随机抽取60例患者分别在术前、术后每隔4周,放松和用力咬合两种状态下测量双侧咬肌厚度,观察比较变化情况。结果术前及术后24周相比咬肌平均厚度变薄,萎缩明显(P<0.05);术后24周与术后32周相比咬肌平均厚度无变化(P>0.05)。结论改良下颌角磨削去骨术后,术后24周内肥大的咬肌可自行萎缩,不需处理。术后24周后咬肌不再有变化。轻度下颌角肥大者可行单纯磨削去骨术,无需切除咬肌。

Objective treatment of the mild enlarge To study the change of masseter muscle after the angle-grinding ostectomy for the d mandibular angle, and provide reference for the clinic. Methods The masseter thickness of 60 female patients were bilaterally measured under both rest and maximal contracted positions by high-frequency superficial ultrasonic imaging before operation and every 4 weeks postoperatively and compared. Results The mean thickness of masseter muscle on postoperative week 24 became thinner and more atrophied markedly than that before operation （ P 〈 0.05 ）. There was no obvious difference in the thickness of masseter muscle between postoperative week 24 and week 32 （P 〉 0.05）. Conclusion Mter the angle-grinding ostectomy, the hypertrophic masseter muscle can get atrophied itself in 24 weeks postoperatively without particular treatment, but no more changes happen thereafter. The patients with mild enlarged mandibular angle can be treated with angle-grinding ostectomy only.