中国组织工程研究 ›› 2026, Vol. 30 ›› Issue (16): 4030-4037.doi: 10.12307/2026.700

• 口腔组织构建 oral tissue construction • 上一篇    下一篇

下颌第二磨牙根尖与下颌神经管距离及位置的锥形束计算机断层扫描

翁志荣1,2,格根塔娜1,2   

  1. 1内蒙古医科大学附属医院,内蒙古自治区呼和浩特市  010050;2内蒙古医科大学口腔医学院,内蒙古自治区呼和浩特市  010059

  • 收稿日期:2025-06-16 接受日期:2025-08-20 出版日期:2026-06-08 发布日期:2025-11-25
  • 通讯作者: 格根塔娜,博士,教授,主任医师,内蒙古医科大学附属医院,内蒙古自治区呼和浩特市 010050;内蒙古医科大学口腔医学院,内蒙古自治区呼和浩特市 010059
  • 作者简介:翁志荣,女,1998年生,内蒙古自治区乌兰察布市人,汉族,内蒙古医科大学在读硕士,医师,主要从事牙体牙髓病学的研究。

Cone beam computed tomography of the distance and position of the root apex of the mandibular second molar relative to the mandibular canal

Weng Zhirong1, 2, Gegentana1, 2    

  1. 1 Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010050, Inner Mongolia Autonomous Region, China; 2 School of Stomatology, Inner Mongolia Medical University, Hohhot 010059, Inner Mongolia Autonomous Region, China
  • Received:2025-06-16 Accepted:2025-08-20 Online:2026-06-08 Published:2025-11-25
  • Contact: Gegentana, MD, Professor, Chief physician, Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010050, Inner Mongolia Autonomous Region, China; School of Stomatology, Inner Mongolia Medical University, Hohhot 010059, Inner Mongolia Autonomous Region, China ​
  • About author:Weng Zhirong, MS candidate, Physician, Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010050, Inner Mongolia Autonomous Region, China; School of Stomatology, Inner Mongolia Medical University, Hohhot 010059, Inner Mongolia Autonomous Region, China

摘要:

文题释义:
下颌神经管:又称下牙槽神经管,是位于下颌骨的骨密质管道,下牙槽神经位于管内,下牙槽动静脉与其伴行。下牙槽神经支配下颌牙的牙髓及其牙周膜和牙槽骨,终末分支颏神经支配唇颊侧部分牙龈、下唇黏膜皮肤及颏部皮肤。
锥形束计算机断层扫描:是一种三维成像的方式,可以清楚地可视化解剖标志,其图像具有空间分辨率高、三维立体成像、无失真变形等优点。

背景:下颌第二磨牙牙根形态复杂多样,根管治疗难度大。除下颌第三磨牙外,下颌第二磨牙根尖是距离下颌神经管最近的下颌后牙。在行下颌第二磨牙根管治疗、根尖手术时易导致下牙槽神经意外受损,引起该神经支配区域温度、疼痛和机械感觉的变化,影响患者的口腔生理功能。
目的:研究不同分型的下颌第二磨牙根尖与下颌神经管的距离及位置关系,探究性别、侧别、年龄对其影响,提升下颌第二磨牙治疗的安全性。
方法:筛选符合纳排标准的330例患者的锥形束CT资料,左右侧共660颗下颌第二磨牙,其中男性164例,女性166例;青年组200例,中年组103例,老年组27例。测量不同分型(主要统计了锥形融合根型、双根型及C形根型)下的下颌第二磨牙根尖与下颌神经管的距离和位置关系,运用SPSS 24.0软件对比分析以上研究内容在性别、侧别、年龄上的差异性。
结果与结论:①双根型最常见,多见于男性,女性和青年人牙根形态较复杂,其锥形融合根和C形根检出率较高。②锥形融合根的根尖距神经管的距离最近,其次是C形根,最后是双根。双根型的远中根比近中根更接近神经管。男性双根型近远中根根尖距神经管的距离大于女性;下颌第二磨牙根尖与下颌神经管的距离有随着年龄增大而增加的趋势。③下颌神经管与下颌第二磨牙的位置关系依次为颊侧位、根尖正下方、舌侧位、与根尖紧贴、穿过根尖;女性的锥形融合根及C形根比男性更容易分布在神经管的正上方。④结果显示:锥形融合根和C形根在女性和青年人常见,且两者根尖距离神经管距离较近,位置关系密切,根管治疗术中损伤下牙槽神经风险较高。
https://orcid.org/0009-0009-0864-4605(翁志荣)

中国组织工程研究杂志出版内容重点:干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程

关键词: 下颌第二磨牙, 根, 下颌神经管, 距离, 位置, CBCT, 下牙槽神经, 根管治疗

Abstract: BACKGROUND: The root morphology of the mandibular second molar is complex and diverse, making root canal treatment challenging. In addition to the mandibular third molar, the root apex of the mandibular second molar is the closest to the mandibular canal among the mandibular posterior teeth. During root canal treatment and apical surgery on the mandibular second molar, the inferior alveolar nerve is at risk of accidental damage, which can lead to changes in temperature sensation, pain, and mechanical sensitivity in the affected area, ultimately impacting the oral physiological functions of patients.
OBJECTIVE: To investigate the distance and positional relationship between the root apex of the mandibular second molar and the mandibular canal across various anatomical types, and to evaluate the influence of sex, side, and age on this relationship with the purpose of enhancing the safety of mandibular second molar treatments.
METHODS: The cone beam computed tomography data of 330 eligible patients were included in the final analysis. A total of 660 mandibular second molars from 164 males and 166 females were analyzed. The cohort included 200 cases in the youth group, 103 cases in the middle-aged group, and 27 cases in the older adult group. The distance and positional relationship between the root apex of the mandibular second molar and the mandibular canal were measured across different subtypes, including conical fused root type, double-rooted type, and C-shaped root type. SPSS 24.0 software was used to compare and analyze the differences across genders, sides, and ages.
RESULTS AND CONCLUSION: (1) The most common type of double-rooted type was often found in males. This root morphology in female and young individuals was more complex, and the detection rates for conical fused roots and C-shaped roots were higher. (2) The apex of the conical fused root was closest to the mandibular canal, followed by the C-shaped root and then the double-rooted type. The distal root of the double-rooted type was closer to the mandibular canal than the mesial root. In males, the distance from the mandibular canal to the proximal and distal roots of the double-rooted type was greater than in females. Additionally, the distance between the mandibular canal and the root apex of the mandibular second molar increased with age. (3) The positional relationship between the mandibular canal and the mandibular second molar can be classified as buccal lateral, directly below the root apex, lingual lateral, close to the root apex, or through the root tip. Conical fused roots and C-shaped roots in females are more likely to be located directly above the mandibular canal than in males. (4) The results indicated that conical fused roots and C-shaped roots were more common in female and young individuals, with a shorter distance between the root apex and the mandibular canal. Furthermore, the positions of these two root types were closely related, which increases the risk of damage to the inferior alveolar nerve during root canal treatment.

Key words: mandibular second molar, root apex, mandibular neural tube, distance, location, CBCT, inferior alveolar nerve, root canal therapy

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