全颞下颌关节置换稳定性的实验研究

EXPERIMENTAL STUDY ON STABILITY OF TEMPOROMANDIBULAR JOINT REPLACEMENT

目的通过建立山羊全颞下颌关节置换模型,探讨采用人工全颞下颌关节假体进行关节置换的稳定性及可行性。方法取健康成年山羊6只,雌雄各半,体重35.3～37.0 kg。根据山羊颞下颌关节正侧位X线片测量所得参数,结合同种山羊头骨形状制备人工全颞下颌关节假体;随机取山羊一侧颞下颌关节进行全关节置换,作为实验组(n=6);并根据假体放置部位不同(关节窝及髁突)进行观察。另一侧颞下颌关节植入钛板,作为对照组(n=6)。术后观察实验动物一般情况,并于4、8、12周取材行大体、组织学及扫描电镜观察钉-骨界面结构变化;并行剪切力及ALP活性检测,观察钉-骨界面的结合程度及成骨细胞活性。结果实验动物均存活至实验完成,开口度正常,咀嚼功能恢复良好,能够正常进食。术后4、8、12周,实验组假体与对照组钛板均固位良好,固位钛钉无松动脱落。组织学及扫描电镜观察提示随着时间延长两组钉-骨界面成骨细胞逐渐增多。除术后4周实验组关节窝部位固位钛钉剪切力及ALP活性与对照组比较,差异有统计学意义(P<0.05)外;其余各时间点组间比较,差异均无统计学意义(P>0.05)。结论采用人工全颞下颌关节假体对山羊行关节置换后能获得较好的稳定性。

Objective To discuss the stabil ity and practical ity of temporomandibular joint replacement by establ ishing goats artificial temporomandibular joint replacement model. Methods Six healthy mature goats were selected, the male and female being half and weighing 35.3-37.0 kg. According to the parameters from X-ray films of goat’ s temporomandibular joint and the shape of the same kind goat’s skull, the total temporomandibular joint prosthesis was prepared. The one side temporomandibular joints of six goats were replaced by prosthesis randomly as the experimental group （n=6, fossa and condyle according to replacement location） and the other side by titanium plate as the control group （n=6）. At 4, 8, and 12 weeks, the histological observation, scanning electron microscope （SEM） observation were carried out for observing structural changes in the interface. The mechanical test and histochemistry test were used for observing the combination degree of interface and the alkal ine phosphatase （ALP） activity. Results All animals were al ive to the end of experiment with normal open mouth, good recovery of masticatory function, and normal eating. At 4, 8, and 12 weeks, implants were stable in 2 groups without loosening. The histological observation and SEM observation showed the amount of osteoblasts in interface increased over times. There were significant differences in the shearing force and the ALP activity between fossa in experimental group and control group at 4 weeks （P 〈 0.05）, but there was no significant difference between other groups （P 〉 0.05）. Conclusion The total temporomandibular prosthesis has good stabil ity in temporomandibular joint reconstruction of goat after replacement.