上颌全口义齿支持组织的三维有限元分析

目的研究三种腭穹隆形状(适中、高、低平)时,人工牙排列位置、牙尖斜度对上无牙颌牙槽骨应力分布状况的影响.方法应用三维有限元应力分析法,研究在三种腭穹隆形状时,人工牙排列位置、牙尖斜度对上无牙颌牙槽骨应力分布状况的影响.结果三种腭穹隆形状牙槽骨应力分布状况相似,但应力强度不同,应力强度由高到低依次为:高腭穹隆、腭穹隆适中、腭穹隆低平;各种载荷条件下,随着牙尖斜度的增加,牙槽骨的应力减小;前牙唇向偏离牙槽嵴较后牙颊向偏离牙槽嵴顶对前牙区牙槽嵴及其唇侧牙槽骨应力状况影响明显.结论腭穹隆形状、牙尖斜度和人工牙的排列位置对上颌全口义齿牙槽骨的应力集中状况有明显的影响作用.高腭穹隆者牙槽骨应力集中区的强度明显大于腭穹隆适中和低平者.提示临床行全口义齿修复时,应考虑患者腭穹隆形状,选择适当牙尖斜度的人工牙,因修复需要上前牙排列必须唇向偏离牙槽嵴时,其偏离距离应适度,特别是高腭穹隆患者.

A 3-dimensional finite element analysis (3-D FEA) of the stress distribution of the alveoli dentales maxillae

Objective To study the relationship between the stress distribution on the alveoli dentales maxillae and the different palatal vault, cusp inclination and position of artificial teeth.Methods 3-D FEA was used to study the effects of the stress distribution on the alveoli dentales maxillae with palatal vault, cusp inclination and position of artificial teeth.Results The stress distribution on the alveoli dentales was not different among the three kinds of palatal vaults .The stress concentration of the alveoli dentales maxillae of deep palatal vault was stronger than that of medium vault, which was stronger than that of flat vault. As the cusp inclination increased, the stress concentration of the alveoli dentales maxillae decreased in different loading conditions. The stress influenced by artificial incisors away from alveolar ridge was much more than that by artificial molars away from alveolar ridge.Conclusion The palatal vault, cusp inclination and the position of artificial teeth have apparent influence upon the stress concentration on the alveoli dentales maxillae. Special attention should be paid to palatal vault and cusp inclination. The position of the artificial incisors should not be far away from the alveolar ridge, especially for deep palatal vault.