渐进性咬合垂直距离降低对大鼠咬肌微观结构和线粒体Ca^(2+)含量的影响  

The effects of progressive decrease of the occlusal vertical dimension on the microstructure and the mitochondria Ca^(2+) content of rat masseter muscle

作　　者：李甜[1] 于世宾[1] 何惠明[1] 党薇[1] 

机构地区：[1]第四军医大学口腔医学院,陕西西安710032

出　　处：《牙体牙髓牙周病学杂志》2013年第2期95-99,共5页Chinese Journal of Conservative Dentistry

基　　金：全军后勤科研计划面上项目(CWS12J101)

摘　　要：目的:观察渐进性咬合垂直距离(occlusal vertical dimension,OVD)降低对大鼠咬肌显微、超微结构和线粒体Ca2+含量的影响。方法:8周龄雄性SD大鼠50只,随机分为两组(每组25只)。实验组采用人工逐次磨低大鼠上颌后牙牙冠高度的方法建立渐进性OVD降低动物模型,对照组模拟所有操作过程但不磨低牙齿。分别于建模后3、7、14、28、42 d时每组各处死5只大鼠,取深层咬肌分别进行HE染色观察和透射电镜观察;同时测定咬肌线粒体Ca2+含量。结果:渐进性OVD降低可引起大鼠显微和超微结构的改变。其中以超微结构的损伤为主,表现为线粒体结构破坏,并伴随有线粒体Ca2+含量明显增加(P<0.05)。但上述损伤表现仅出现在早期,且散在、局限,并未造成广泛性的损伤,至实验第42天时,肌纤维结构已趋于正常,同时线粒体Ca2+含量也恢复正常。而对照组显微及超微结构未观察到明显改变,线粒体Ca2+含量未见明显增加(P>0.05)。结论:渐进性OVD降低可导致大鼠咬肌损伤,主要表现为超微结构异常和线粒体Ca2+含量增加,但这种损伤是可逆的。AIM： To observe the effects of progressive decrease of occlusal vertical dimension （OVD） on the mierostructure, ultrastructure and mitochondria Ca2＋ content of rat masseter muscle. METHODS ： Fifty 8-week- old male SD rats were randomly divided into experimental group and control group （ n = 25 ）. For the experimental group, the crown height of the upper molars and the lower incisors was shortened by 0.3mm each time for 4 times with the interval of 5 days in between to establish the animal models of progressive decrease of OVD. For control group, all operations were imitated, except for reducing the crown height. 5 rats in experimental group and 5 age-matched con- trols were sacrificed at 3, 7, 14, 28 and 42 d respectively after establishment of the models. The deep masseter mus- cles were excised, then were observed by HE staining and transmission electron microscope （TEM）, the mitochondria Ca2＋ in masseter muscles was measured by atomic absorption spectrophotometer. RESULTS： Disorganization of mitochon- dria and mitochondria Ca2＋ increase（P 〈0.05） in the masseter muscles were observed in the rats with the progressive de- crease of OVD. However, 42 days after decrease of OVD the microstructure, the uhrastructure and mitochondria Ca2＋ con-tents showed no significant changes（P 〉 0. 05）. CONCLUSION： Progressive decrease of OVD may lead to reversible injury of the rat masseter muscle, with ultrastructural changes and Ca2＋ overload in mitochondria as the main manifestation.

关 键 词：渐进性咬合垂直距离降低 咬肌 微观结构 线粒体 CA2+ 

分 类 号：R782.6[医药卫生—口腔医学]