上颌窦底不同位置冲顶对上颌窦内提升术影响的三维有限元分析

Three dimensional finite element analysis of different positions of maxillary sinus floor on internal sinus floor elevation

目的通过建立冲顶器顶端在上颌窦底不同位置进行冲顶的上颌窦区域及冲顶器的三维有限元模型,动态模拟研究行窦底冲顶时窦底提升的安全性和有效性。方法通过逆向工程建立在上颌窦底部、与上颌窦侧壁成30°角、成60°角及上颌窦纵隔底部等不同位置进行冲顶的上颌窦区域三维有限元模型,施加动态冲击载荷进行窦底提升,研究窦底冲顶时冲顶器、窦底骨质及黏膜的应力和位移情况。结果应用三维有限元法,通过建立在上颌窦底部、与上颌窦侧壁成30°角、成60°角及上颌窦纵隔底部等不同位置进行冲顶的上颌窦区域模型,动态模拟了行窦底冲顶时冲顶器、窦底骨质及黏膜的应力和位移情况;上颌窦内提升术在纵隔底部进行冲顶时存在上颌窦黏膜撕裂的风险,临床上应慎重开展,在上颌窦侧壁进行提升时,如果接触角过小,应有意识控制防止冲顶器的侧滑造成不利的影响。结论上颌窦内提升术前应明确提升的部位,防止纵隔底部进行冲顶及与窦侧壁接触角过小冲顶造成的风险。

Objective To study the influence of different positions of maxillary sinus floor on internal sinus floor elevation （ISFE） by establishing three dimensional （3-D） finite element model of maxillary sinus and bone condenser. Methods Establishing 3-D finite element model of maxillary sinus with shallow concave floor by RP software. The operation of ISFE was simulated by accomplishing the dynamic loading process of osteotome technique under different positions of maxillary sinus floor conditions. The lifting area located at the sinus floor, the lateral wall of sinus with the contact angle of 30 degrees and 60 degrees, the sinus floor with septa. The stress and displacement of bone condenser, bone and mucosa of maxillary sinus were investigated. Results Stress and displacement of bone condenser, bone and mucosa of maxillary sinus were studied by accomplishing the dynamic loading process of osteotome technique. There were some risks of maxillary sinus mucosa perforation in lifting the floor of maxillary sinus septa, so this surgical type must be adopted cautiously. When the lifting area located at the lateral wall of maxillary sinus, operator should keep bone condenser from sideslip if the contact angle was too small. Conclusion The lifting area of sinus must be determined before internal sinus floor elevation. It can decrease the risks when the lifting area was located at the steep lateral wall of maxillary sinus and the sinus septa.