With the loss of the alveolar height, the maximum equivalent stress and the principle stress of the upper central incisor periodontium increased. 随着牙槽骨高度的降低，上中切牙牙周膜最大等效应力和主应力逐渐增大。
There is no significant stress difference in the dentin for glass ionomer restoration when compared with that of an opening incisor. 凡以玻璃水门汀为补缀材料之门齿，在应力分布的表现上皆与根管治疗后尚未补缀之门齿相同没有差异。
Cusp-like structure projects from the cingulum area or cementoenamel junction on the palatal surfaces of the maxillary anterior teeth. 这如牙阜般的结构是出现在上颚正中门齿颚侧，由舌面隆凸向牙骨质牙釉质交接处延伸。
