Changes of collagen fiber during reattaching of the musseter muscle following different curved osteotomies of prominent mandibular angle: a study in goats / 中华医学美学美容杂志

ABSTRACT

Objective To investigate the changes of the constitution and its ratio of collagen fiber in the process of masseter reattachment following different osteotomies of the prominent mandibular angle so as to offer guidance for the resection of mandibular angle. Methods Sixteen adult goats were randomized into four groups. In group A we performed unilateral curved osteotomy of the mandibular angle. In group B unilateral curved ostectomy was performed with partial masseter resection. In group C unilateral angle splitting ostectomy, while in group D unilateral dissection of the masseter muscle was conducted. The constitution and its ratio of collagen fiber in the interface were observed at 1-month, 2-month, 3-month, and 6-month after operation. Results On the changes of collagen fiber in the process of muscular reattachment, at 1-month post-operation, the constitution of collagen fiber (types Ⅰ and Ⅲ) in groups A and B were significantly different from that of control group (P<0.05). However, both groups C and D had no statistic difference from control group (P>0.05). At 2-month, 3-month and 6-month post-operation, those of all experimental groups had no statistic difference from control group. And with time, the percentage of collagen fiber type Ⅰ increased and type Ⅲ decreased gradually. Conclusion The recovery sequences of masseter muscle reattachment in this study are firstly group C, secondly group A and finally group B. It suggests that the recoveries of mastication and other oral activities are different. Group B turns out to be with a slow muscle reattachment. Thus, we recommend treating different kinds of mandibular hypertrophy with different ostectomies.