四川地区人离体上颌恒中切牙及其唇面发育沟的形态学观测

Morphology and developmental groove of maxillary permanent central incisors in Sichuan people

目的观察四川地区人上颌恒中切牙发育沟的表面结构特征,以指导固定修复体的仿真制作。方法采用一定纳入标准选择58颗四川地区人离体上颌恒中切牙,测量其解剖牙冠长度、宽度,近远中发育沟长度、宽度,以及近远中发育沟两边界之夹角。结果四川地区人上颌恒中切牙的解剖牙冠冠长和冠宽分别为(11.9±1.3)mm和(8.7±0.8)mm,发育沟长和沟宽分别为(5.7±0.9)mm和(2.1±0.5)mm,近远中发育沟长度和宽度的差异均无统计学意义。冠长与发育沟长的比值为2.1,冠宽与发育沟宽的比值为4.2。近中发育沟两边界之夹角为23°±4.7°,远中发育沟两边界之夹角为23°±5.7°。结论四川地区人上颌恒中切牙解剖牙冠的长、宽平均值与中国人的平均值接近;冠长与发育沟长之比、冠宽与发育沟宽之比恒定,发育沟所成角度的大小较确定;其数值为固定修复体的仿真制作提供了参考。

Objective To investigate the morphology of maxillary permanent central incisors of people in Sichuan so as to provide some guidance for emulational restoration of fixed prosthesis. Methods Fifty-eight extracted maxillary permanent central incisors were selected from people in Sichuan. All of the teeth involved in this study were selected according to certain criterions. The length and width of the anatomical crowns, the length and the width of the developmental grooves and the angles formed by the two sides of the developmental grooves were measured. Results The average length and width of anatomical crowns in Sichuan people were （11.9±1.3） mm and （8.7± 0.8） mm respectively. And the average length and width of the developmental grooves were （5.7±0.9） mm and （2.1± 0.5） mm respectively. There were no statistical differences between the length of the mesial and distal developmental grooves and so were the width. The ratio of the length of crowns to that of the developmental grooves was 2.1, while for the width, it was 4.2. The angles of the mesial and distal developmental grooves formed by its two sides were 23°±4.7° and 23°±5.7° respectively. Conclusion The average length and width of maxillary permanent incisors were close to Wang＇s report, which means the length and width of the maxillary permanent incisors of people in Sichuan were quite close to those of Chinese people. The ratio of the length of anatomical dental crowns to that of the developmental grooves was steady, and so was the ratio of the width of them. The angles of the developmental grooves were quite steady too. These may help us in making fixed prosthesis.