西安地区人上颌中切牙牙冠三维结构的研究

The 3-D study of the human maxillary central incisor crown in Xi'an area

目的:探索人上颌恒中切牙牙冠三维结构的建模方法,精确测量其釉质和牙本质解剖学参数。方法:选取牙冠形态、冠根比正常,无磨耗的西安地区人上颌恒中切牙30个,Micro CT扫描后,用Mimics和Geomagic Studio逆向工程软件重建上颌中切牙釉质帽、牙本质核和髓室三维模型,精确测量牙冠不同部位釉质和牙本质核的厚度以及近、远中髓角至各自切端和邻面的距离。结果:建立了人上颌中切牙釉质帽和牙本质核的三维模型,其厚度(mm)分别为:唇侧釉质(0.47±0.12)^(1.08±0.19),舌侧釉质(0.39±0.07)^(0.71±0.15);唇侧牙本质(0.46±0.09)^(2.17±0.48),舌侧牙本质(0.33±0.06)^(2.82±0.36),P﹤0.05;近中髓角至切端4.24±1.04,远中髓角至切端4.71±0.98;近中髓角至近中邻面2.09±0.26,远中髓角至远中邻面2.53±0.30,差异均有统计学意义(P﹤0.05)。结论:西安地区人上颌中切牙牙冠不同部位釉质帽和牙本质核厚度存在差异。

AIM：To establish a 3-D structure model of human maxillary central incisor crown and to inves-tigate its anatomical parameters.METHODS：30 human maxillary central incisors from Xi＆#39;an area were elected at ran-dom,which had normal crown shape and no severe abrasion.All the teeth were scanned by Micro CT,and then recon-structed into the 3-D models,each 3-D model included 3 sub-models of the enamel cap,dentin core and pulp cham-ber.The reverse engineering software of Mimics and Geomagic Studio was applied to measure the thickness of different sites of sub-models.RESULTS：The fine 3-Dmodel of human maxillary central incisor crowns was acquired.The thickness（mm）of the enamel cap and dentin core were as below：labial enamel,0.47 ±0.12-1.08 ±0.19;lingual en-amel,0.39 ±0.07-0.71 ±0.15;labial dentin,0.46 ±0.09 -2.17 ±0.48;lingual dentin,0.33 ±0.06 -2.82 ± 0.36,P〈0.05.The distances（mm）between the pulp chamber and enamel surface were as following：from mesial medullary angle to incisal edge,4.24 ±1.04;distal medullary angle to incisal,4.71 ±0.98;mesial medullary angle to mesial adjacent surface,2.09 ±0.26;distal medullary angle to distal adjacent surface,2.53 ±0.30,P〈0.05. CONCLUSION：This study proved the obvious variances in the thickness of enamel cap and dentin core in different sites of the human maxillary central incisor crowns in Xi＆#39;an area.