口腔医学研究

口腔医学研究 ›› 2026, Vol. 42 ›› Issue (6): 487-492.DOI: 10.13701/j.cnki.kqyxyj.2026.06.005

• 口腔颌面外科学研究 • 上一篇    下一篇

基于CBCT拔除下颌阻生第三磨牙断根移位的解剖学因素分析

滕腾1,2, 宫坤2#, 栾百婷1, 王祎琛1, 梁晓雷1, 王一名1, 张武阳1, 薛洋1, 胡开进1, 邓天阁1*   

  1. 1.口颌系统重建与再生全国重点实验室,国家口腔疾病临床医学研究中心,陕西省口腔疾病临床医学研究中心,空军军医大学口腔医院口腔外科 陕西 西安 710032;
    2.滨州医学院附属烟台口腔医院口腔颌面外科 山东 烟台 264000
  • 收稿日期:2025-09-30 出版日期:2026-06-28 发布日期:2026-06-23
  • 通讯作者: *邓天阁,E-mail:dtgyszc@163.com
  • 作者简介:滕腾(1988~),女,烟台人,硕士,主治医师,研究方向:口腔颌面外科。宫坤(1984~),男,烟台人,硕士,副主任医师,研究方向:口腔颌面外科。#为共同第一作者
  • 基金资助:
    陕西省自然科学基金(编号:2024SF-YBXM-263);国家口腔疾病临床医学研究中心资助课题(编号:LCB202410);空军军医大学第三附属医院新技术新业务项目(编号LX2021-332)

Anatomical Analysis of Root Fragment Extraction in Impacted Mandibular Third Molars Based on CBCT

TENG Teng1,2, GONG Kun2#, LUAN Baiting1, WANG Yichen1, LIANG Xiaolei1, WANG Yiming1, ZHANG Wuyang1, XUE Yang1, HU Kaijin1, DENG Tiange1*   

  1. 1. State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shannxi Clinical Research Center for Oral Diseases, Department of Oral Surgery, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China;
    2. Department of Oral and Maxillofacial Surgery, The Affiliated Yantai Stomatological Hospital, Binzhou Medical University, Yantai 264000, China
  • Received:2025-09-30 Online:2026-06-28 Published:2026-06-23

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摘要： 目的:探讨基于锥形束计算机断层扫描(cone beam computed tomography,CBCT)拔除下颌阻生第三磨牙(impacted mandibular third molar,IMTM)断根的解剖学因素。方法:回顾性分析近5年空军军医大学口腔医院口腔外科接收外院转诊的未完全拔除IMTM患者52例(颗)分为移位组(16颗断根移位至舌侧间隙)和未移位组(36颗断根无明显移位,残留于牙槽窝内)。通过术前术后CBCT观察两组舌侧皮质骨壁厚度与完整性、下颌舌侧颌骨形态、IMTM轴向位置关系、下颌管与牙根位置关系以及邻牙远中牙槽骨吸收程度,比较断根移位组与未移位组的差异,分析断根移位的解剖学因素。结果:与IMTM舌侧皮质骨壁完整相比,舌侧骨皮质缺如IMTM拔除术中易发生断根移位(P＜0.001)。CBCT冠状面牙槽骨解剖形态呈倒凹型和倾斜缩窄型IMTM拔除易发生断根移位。非垂直位轴向位置关系与邻牙远中牙槽骨吸收呈Ⅲ型的IMTM断根拔除易发生移位(P＜0.05);断根移位组与未移位组舌侧骨壁平均厚度分别为(0.81±0.58) mm和(1.41±1.02) mm,两者比较差异有统计学意义(P＜0.05)。结论:CBCT冠状面牙槽骨解剖形态呈倒凹型和倾斜缩窄型,舌侧骨壁平均厚度≤0.81 mm,邻牙远中牙槽骨吸收呈Ⅲ型,IMTM非垂直位阻生均是断根舌侧移位的重要解剖学因素。

关键词: 下颌阻生第三磨牙, 舌侧骨壁, 断根, 锥形束计算机断层扫描

Abstract: Objective: To investigate the anatomical factors associated with root fragment displacement during the extraction of impacted mandibular third molars (IMTM) using CBCT. Methods: This retrospective study included 52 patients (52 IMTMs) who were referred to the Department of Oral Surgery, School of Stomatology, The Fourth Military Medical University, due to incomplete IMTM extraction over the past five years. These cases were divided into the displaced group (16 root fragments displaced into the lingual space) and the non-displaced group (36 root fragments with no significant displacement, remaining in the alveolar socket). Preoperative and postoperative CBCT were used to assess the thickness and integrity of the lingual cortical bone wall, the anatomical morphology of the lingual side of mandible, the axial positional relationship of IMTMs, the positional relationship between the mandibular canal and tooth roots, and the degree of alveolar bone resorption in the distal aspect of adjacent teeth in both groups. The displaced and non-displaced groups were compared to analyze the anatomical factors contributing to root fragment displacement. Results: Those with missing lingual cortical bone were more prone to root fragment displacement during extraction (P<0.001). IMTMs with alveolar bone anatomical morphologies showing "undercut type" or "inclined narrowing type" on CBCT coronal sections were susceptible to root fragment displacement. IMTMs with non-vertical axial positions and type Ⅲ alveolar bone resorption in the distal aspect of adjacent teeth were more likely to have root fragment displacement during extraction (P<0.05). The average thickness of the lingual bone wall in the displaced group and the non-displaced group was (0.81±0.58) mm and (1.41±1.02) mm, respectively (P<0.05). Conclusion: Alveolar bone anatomical morphologies of "undercut type" and "inclined narrowing type" on CBCT coronal sections, an average lingual bone wall thickness ≤0.81 mm, type Ⅲ alveolar bone resorption in the distal aspect of adjacent teeth, and non-vertical impaction of IMTMs are all significant anatomical factors contributing to lingual displacement of root fragments.

Key words: impacted mandibular third molar, lingual bone wall, root fragment, CBCT