维吾尔族人下颌第一恒磨牙的牙体测量及根管形态

目的：掌握维吾尔族人下颌第一恒磨牙的解剖特点。方法采集维吾尔族人离体下颌第一恒磨牙105颗，锥形束 CT（cone-beam，CT）法观测牙根变异及根管分类（Weine 分类）；挑选出牙体完整的离体牙标本63颗，游标卡尺法测量8项牙体形态参数。结果维吾尔族人下颌第一恒磨牙牙齿总长度均值为18．9 mm，近中根长度均值为13．9 mm，远中根长度均值为12．8 mm；以双根型最多见（94．3％），三根型发生率较少（5．7％），未检出单根型；近中根根管多为2-2型（83．8％），远中根多为1-1型（84．8％）。结论维吾尔族人下颌第一恒磨牙牙根及根管形态的变异度较低。

The odontometric measures and root canal morphology of permanent mandibular first molars in the Uyghur people

Objective To investigate the anatomic features of the permanent mandibular first molars in the Uyghur people.Methods A total of 105 extracted permanent mandibular first molars in Uyghur people were collected and scanned by CBCT.The variations of the roots and canals were determined by the num-ber of the roots and the Weine′s root canal classification respectively.63 molars without defections were chosen and 8 odontometric parameters were measured with a digital caliper.Results The mean value of the complete teeth length of the permanent mandibular first molars was 18.9 mm,and the mean length of the mesial and distal roots were 13.9 mm and 12.8 mm;the permanent mandibular first molars were usual-ly two-rooted （94.3%）,and the incidence of the three-rooted form was only 5.7%.Single-rooted molar was not observed;the mesial root usually contained a type 2-2 canal,with an incidence of 83.8%,whereas the distal root more frequently had a type 1-1 canal （84.8%）.Conclusions The root and canal variations of the permanent mandibular first molars in the Uyghur people were less frequent than those in the Han Chi-nese people.Understanding the anatomic features of the teeth in different ethnic groups can be useful for clinical dental treatments.