下颌前导后髁突骨形态学指标变化的动物实验

Expression of bone histomorphometry parameters in rabbit condyle during mandibular forward positioning

目的观察免下颌持续功能能前导后骨形态学指标的变化特征，以期为临床更好地应用功能性矫治器提供实验依据。方法40只8周龄日本大耳门兔，州随机数字表法分成前导组（24只）和对照组（16只）．前导组动物24h戴用咬合前导矫治器，对照组不进行处理．．分别于实验2、4、8、12周时处死6只前导组和4只对照组动物，取有侧颞下颌关节标本进行硬组织切片，甲苯胺兰和Masson染色，进行骨形态计量学测量。结果8周时前导组髁突软骨F区骨体积分数[（75．83±1．10）％]、骨小梁厚度[（103．28±2．89）μm]、骨小梁数[（2．86±0．06）mm2]、矿化沉积率[（2．23±0．02）μm/d]和成骨细胞指数[（30．20±0．47）个／mm2]均较埘照组[分别为（64．00±1．54）％、（87．00±1．13）LLm、（1．84±0．08）mm2、（1．69±0．02）μm／d和（21．07±0．59）个／mm2]湿著增高，12周时骨小梁骨间距[（170．00±2．25）μm]则比对照组[（241．50±1．57）μm]显著减低，两组差异均有统计学意义（P〈0．05）；晒髁突中心区骨静态学和动态学指标的两组差异均无统计学意义（P〉0．05）。结论下颌持续前导后髁突软骨下区’胃’形态学指标的动态变化与髁突改建关系密切。

Objective To observe the changes of bone histomorplmmetry parameters in eondyle of rat）bits during mandibular forward positioning. Methods Forty rabhits with eight weeks of age were simple randomly divided into the experimental gruup （n =24） and control group （n = 16）. Mandibles of rabhits in the experimental groups were induced to forward position by a functional appliance. The experimental group and control group were sacrificed after 2 and 4, 8, 12 weeks. The specimens from right tempromanditmlar joints were processed for undemineralised sections. These sections were used for [luoreseent mieroseopy observation and the measurement of bone histomorphometry. Results At 8 week bone-volume fraction [（75.83 ±1. 10）%1, traheeular thickness [（ 103.28± 2.89） μm], trabeeular number [（2.86±0.06） mm ^-1, mineral apposition rate [（2.32 ±0.02） ] and index of osteoblast [（30.20± 0.47） N/mm-1] in subchondral region of the cartilage in the experimental group were siguitieantly increased compared with the age-matched controls [ respectively （64. 00 ± 1. 54 ） % , （ 87.00 ± 1.13 ） Ixm, （ 1.84 ± 0. 08） mm ], （1.69±0.02） μm/d and （21.07 ±0.59） N/mm2] （P 〈0.05）. However, trabeeular separation [（170.00 ±2.25） μm] was lower than those in the controls[（241.50± 1.57）μm] with signifiean! difference （P 〈 0. 05 ）. There was no significant difference in the bone histomorphometry parameters of the eentral region between the experimental group and the age-matched control group （ P 〉 O. 05 ）. Conclusions The pattern of bone histomorphome parameters expression in subchondml region has a high correlation with the adaptive remodeling of the eondyle after functional appliance.