实验性兔下颌骨骨折愈合过程的影像学及组织学观察

目的：研究在不同应力条件下骨折愈合过程中骨痂内的组织学变化。方法：选用成年新西兰大白兔16只，随机分为2组。通过截骨方法，在兔下颌骨的相同部位造成斜行和垂直2种不同类型的骨折，用小型接骨板进行固定。对骨切开线下方、骨折间隙、牙槽嵴3个骨痂的不同部位，用影像学和组织学方法对不同愈合时期的骨痂内的组织进行观察和比较。结果：2组骨折在骨折愈合方式、愈合顺序上基本类似。垂直骨折组在愈合速度上略快于斜行骨折组，骨痂内分化组织的时间分布在垂直骨折组和斜行骨折组略有差异。结论：由于2组动物实验的生物条件基本相同，造成2组骨折愈合过程中组织学变化的不同源于其不同的生物力学条件。

The histological and radiological investigation of mandibular fracture healing in rabbits

PURPOSE: This study aimed to investigate the difference of tissue differentiation of mandibular fracture callus under two different biomechanical environments in rabbits. METHODS: 16 male New Zealand rabbits were divided into 2 groups by vertical and angulated direction of fracture line manually made in the mandible with a 2 mm fracture gap. All fractures were fixed using titanium plates. The histological changes of the fracture callus were observed every week. The callus center, bottom fringe and top fringe (alveolus) were selected as the three sites, where the tissue would be changed in the healing process. X-ray photography was used to evaluate the healing of fracture,too. RESULTS: The fracture healing type and order in the two groups were similar; the healing velocity of vertical fracture was higher than angulated fracture; the spatio-temporal sequence of tissue differentiation was different in the two groups at the three sites. CONCLUSIONS: Under the same biological condition, the difference of the spatio-temporal sequence of tissue differentiation of the two groups was resulted from the different mechanical conditions. Supported by Shanghai Leading Academic Discipline Project (Grant No.Y0203).