山羊下颌角截骨术后咬肌再附着过程中胶原变化的观察

The reattachment of the masseter muscle following mandibular angle ostectomy: a histological study in goats

目的:观察不同术式下颌角截骨术后山羊咬肌再附着过程,并与正常咬肌附着进行比较,探讨下颌角截骨术后咬肌-下颌骨再愈合过程对口腔咀嚼功能恢复的影响。方法:以16只成年山羊为研究对象,随机分入A、B、C、D四组,每组4只。A组:随机取一侧行下颌角弧形截骨术;B组:随机取一侧行下颌角弧形截骨术+咬肌部分切除术;C组:随机取一侧行下颌骨外板取出术;D组:随机取一侧行下颌骨嚼肌剥离术。分别于术后1月、2月、3月、6月于各组咬肌再附着区行组织学观察及骨膜厚度测量。结果:术后3个月前,各实验组界面愈合有一定差别,恢复程度依次为咬肌剥离组,去下颌骨外板组,去下颌角组,去下颌角及咬肌组,术后3个月后各实验组肌骨界面恢复情况无明显差别,术后6月各组肌-骨界面结构类似于正常咬肌附着。骨膜厚度测量结果,咬肌剥离组在术后2月时基本恢复正常厚度,其余实验组在术后6月时恢复正常厚度。结论:下颌角截骨术后2个月,咬肌-下颌骨附着初步重建,术后3个月,建立较牢固的肌骨附着,术后6个月,肌骨附着基本恢复正常。间接说明下颌角截骨术后3月,患者可逐渐恢复正常的咀嚼活动。

Objective To investigate the reattachment process of masseter muscle following different methods of mandibular angle ostectomy with comparing to the normal insertion and discuss the influence to the mastication function. Methods Classifying sixteen goats into A,B,C and D group. In group A we performed unilateral curved osteotomy of the mandibular angle, in group B we performed unilateral curved ostectomy with partially masseter excision, in group C we performed unilateral angle splitting ostectomy, while in group D we performed unilateral dissection of the masseter muscle. We examined the histologic changes in the interface and measured the thickness of periosteum. Results The histological examination showed that the reattachment of masseter muscle to the mandibular in each group were distinguishable before 3 months after operation, the recovery degree of the periosteum was dissection group, angle splitting ostectomy group, curved ostectomy group, curved ostectomy with partially masseter excision group by turns, after 3 months, their recovery process were indistinguishable,the interface between mandibular angle and masseter in each group was similar to the normal after 6 months, the periosteum thickness of masseter disscection group was similar to the normal after 2 months and other groups returned normal after 6 mouths. Conclusion This study shows that the attachment of the masseter muscle to the mandibular rebuilt preliminary after 2 months, the reattachment became stronger after 3 months, the attachment nearly recovered after 6 months. All these findings imply that patient could return to the normal mastication activity gradually 3 months after mandibular angle ostectomy.