Anatomical morphology of the root and root canal system of the second permanent molar in the Uygur people

• Main Author: SHEN Yifen
• Format: Article
• Language: zho
• Published: Editorial Department of Journal of Prevention and Treatment for Stomatological Diseases 2019-08-01
• Series: 口腔疾病防治
• Subjects: Uygur people; permanent mandibular second molar; root canal system; C-shaped canal; micro-CT
• Online Access: http://manu45.magtech.com.cn/Jwk3_kqjbfz/EN/10.12016/j.issn.2096-1456.2019.08.009

Objective To study the anatomical characteristics of the root and root canal system of the mandibular second permanent molar in the Uygur people and provide a reference for clinical practice.Methods A total of 125 mandibular second permanent molars were extracted from Uygur patients in hospitals in the Xinjiang Uygur Autonomous Region. Three-dimensional reconstruction was performed after micro-CT scanning. The number of root canals, the root canal type (Weine classification and Fan′s C-shaped canal classification) and the occurrence of lateral accessory canals were observed.Results A sex difference was not detected in the root number or root form (χ2 = 1.277, P = 0.259). The incidence of 2-rooted molars was 70.4% (n = 88); type 2-1 canals were most common in the mesial root, with an incidence of 29.5%, followed by type 1-1 and 2-2 canals (each with an incidence of 26.1%), and the distal root mostly had a type 1-1 canal (96.6%). The incidence of single-rooted molars was 28.8%, and the frequency of C-shaped (n = 28) and non-C-shaped (n = 8) single-rooted molars was 22.4% and 6.4%, respectively. A three-rooted molar was detected in one case. The incidence of accessory canals was 65.2%.Conclusion Uygur mandibular second molars are mainly composed of two roots, and the incidence of a single root and root canal fusion is low (including C-shaped canals). Two-rooted molars frequently have two mesial canals and one distal canal.