中文摘要：

下颌前突是最常见的颌面畸形,其下颌骨的力学环境不同于正常人。基于一位下颌前突患者的头部CT片,建立下颌骨的三维有限元模型,关节盘和关节软骨层间考虑接触,对其施加模拟正中咬合的载荷,分析下颌骨不同部位的应力分布特点,为下颌前突的治疗提供参考。结果表明：下颌骨的高应力区出现在乙状切迹和下颌角,分别为13.337MPa和13.850MPa;下颌骨的最大变形发生在颞下颌关节（TMJ）区域。通过与正常人下颌骨的比较,发现下颌骨大部分区域的应力分布较为吻合,但TMJ内的应力分布存在较大的差异,表明下颌前突可能导致TMJ内紊乱症,甚至髁突吸收、关节盘穿孔。可见,除了必要的矫形或手术治疗外,有时还需要针对TMJ进行治疗。

英文摘要：

Mandibular prognathism is the most familiar cranialfacial malformation.The mechanical environment in prognathic mandibles is different from that in normal human beings.In this paper,a 3D finitl element（FE） model based on CT slices of a female with mandibular prognathism was established.Contact surfaces were defined to represent the interaction between the articular disks and the cartilages of the condyles,the fossa-eminence complexs.The stress and deformation distributions in the model were analyzed under the load corresponding to centric clenching.The results showed that the stresses in sigmoid notch and gonial were 13.337MPa and 13.850MPa,respectively,which were the highest in the mandible;and the maximum deformation located at the temporomandibular joint（TMJ）.Although the stress distributions in most regions of the model were consistent with normal mandibles,the stress distributions within the TMJ had signifucant differences.It indicates that mandibular prognathism may induce TMJ internal derangement,condylar resorption and disk perforation.Therefore as well as orthodontic or orthopedic therapies,the TMJ of prognathic mandible should be treated in time.