建立大鼠颞下颌关节骨关节炎动物模型的2种方法比较

Comparison of Two Induction Methods of Temporomandibular Joint Osteoarthritis in Rat Models

目的 通过被动张口和咬合紊乱2种方法建立大鼠颞下颌关节骨关节炎的模型,观察软骨和软骨下骨的病理变化来比较2种建模方法并评价其实用性。方法 21只8周龄雄性SD大鼠随机分为4组,对照组(Control组)3只大鼠常规饲养。剩余18只大鼠随机分成3组:被动张口组(OP组),每天保持张口度20 mm,持续1 min;咬合紊乱组(OD组),0.25 mm的结扎丝包绕第一磨牙,结扎在第一磨牙的面;咬合紊乱对照组(ODS组)采用同样的手术方法,结扎结在第一磨牙的近中。4周后处死所有大鼠,解剖下颌骨后,通过MicroCT,番红-O-固绿染色,HE染色来评估颞下颌关节的变化。结果 OD组和OP组均出现了颞下颌关节骨关节炎样组织学改变,Micro CT分析都表现出骨体积分数的下降,骨体积比和骨小梁厚度在OD组与OP组的差异无统计学意义(P> 0.05)。OD组和OP组的改良Mankin评分均增高,但差异无统计学意义(P> 0.05),且OP组中有2个样本未出现颞下颌关节骨关节炎样组织学改变。结论 咬合紊乱为较为稳定的大鼠颞下颌关节骨关节炎的建模方法,被动张口能造成大鼠颞下颌关节骨关节炎的组织病理学表现,但不稳定且效率较低。

Objective To establish TMJ-OA rat models by occlusal disorder and forced open mouth,compare two TMJ-OA induction methods and assess their applicability by pathological changes in the cartilage,subchondral bone. Methods Twenty-one 8-week-old Sprague-Dawley( SD) male rats were divided into four groups,namely control group,and three rats were conventional feeding. eighteen SD rats were randomly allocated to three groups using the randomization table;each group had the same number of SD rats. The Forced open mouth(OP),steady mouth opening was imposed to 20 mm daily(1 minute/day for 16 days). the occlusal disorder group(OD),an orthodontic ligation silk(0.25 mm diameter) revolved around the first molar,and a ligation knot was created on the first molar of the maxillary. The control group of occlusal disorder(ODS) use the same method,a ligation knot in the mesial of the first molar. Rat models were employed and followed for 4 weeks after experimental procedures,and TMJ joints in each group were harvested. The TMJ changes were evaluated by micro-CT,HE staining,and Safranin-O/Fast green staining. Results We found apparent histological phenotypes of TMJ-OA in the OP and OD groups,and observed a pronounced drop in bone volume fraction,BV/TV and Tb.Th between OD and OP groups had no significant difference(P > 0.05),and a substantial increase in the modified Mankin score was found,there was no significant difference in the two groups(P > 0.05),but two samples of OP group didn’t present apparent histological phenotypes of TMJ-OA. Conclusions Osteoarthritis-like pathological changes in the cartilage and subchondral bone can be observed in both of the two methods. The occlusal disorder is a stable TMJOA model,forced open mouth caused osteoarthritis-like changes,but it’s unstable and inefficient.