The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedical Engineering of Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, P.R. China.
Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, Wuhan, P.R. China.
Sci Rep. 2017 Oct 26;7(1):14154. doi: 10.1038/s41598-017-14144-y.
This study aims to investigate the characteristics of adjacent anatomy of mandibular third molar germs (MTMGs). Three hundred Chinese patients aged 12 to 17 years old who received cone-beam computed tomography (CBCT) were enrolled. The continuity of cortical outline of inferior alveolar canals (IACs) in the region of MTMGs, the integrity of lingual bone cortex and the relationship between hard tissue part of MTMGs and IACs were investigated by observing CBCT data via the NNT viewer software. The age, degree of dental development, gender and location were recorded as variables. The associations between different variables and the observed data were analysed. The possibilities of disrupted cortical outline of IACs or the hard tissue part of MTMGs contacting IACs were significantly lower in 12 or 13 age groups, lower in Nolla stage ≤ 6. Males were significantly less than females in the incidence of disrupted cortical outline of IACs. As to the perforation of lingual bone cortex, no significant differences were observed in gender, ages, location or development stages. According to the CBCT images, anatomical factors contributed the lest to the risk of inferior alveolar nerve and lingual nerve injury in the 12 to 13 age group during removing the MTMG removal.
本研究旨在探讨下颌第三磨牙牙胚（MTMGs）毗邻解剖结构的特征。共纳入 300 名年龄在 12 至 17 岁之间接受锥形束 CT（CBCT）检查的中国患者。通过 NNT 查看器软件观察 CBCT 数据，研究了 MTMGs 区域下牙槽神经管（IAC）皮质连续、舌骨皮质完整以及 MTMGs 硬组织部分与 IACs 之间的关系。记录年龄、牙齿发育程度、性别和位置等变量。分析了不同变量与观察数据之间的关系。IACs 皮质轮廓中断或 MTMGs 硬组织部分与 IACs 接触的可能性在 12 或 13 岁组中显著降低，在 Nolla 分期≤6 时也显著降低。男性 IACs 皮质轮廓中断的发生率显著低于女性。至于舌骨皮质穿孔，在性别、年龄、位置或发育阶段方面没有观察到显著差异。根据 CBCT 图像，在 12 至 13 岁年龄组中，在去除 MTMG 时，解剖因素对下牙槽神经和舌神经损伤的风险影响最小。
