Root-level vulnerability and lingual plate fracture risk in mandibular third molars: A retrospective CBCT-based cross-sectional study

Q1 Medicine

Journal of oral biology and craniofacial research Pub Date : 2026-05-01 Epub Date: 2026-04-27 DOI:10.1016/j.jobcr.2026.101461

Son Hoang Le , Bich-Ly Thi Nguyen

{"title":"Root-level vulnerability and lingual plate fracture risk in mandibular third molars: A retrospective CBCT-based cross-sectional study","authors":"Son Hoang Le , Bich-Ly Thi Nguyen","doi":"10.1016/j.jobcr.2026.101461","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><div>Prior studies investigating the relationship between lingual plate (LP) fracture risk and mandibular third molar (M3M) anatomy have produced inconsistent findings. Factors such as age, sex, impaction depth, and buccolingual angulation have shown variable associations with fracture risk. Importantly, M3M rotational angulation has rarely been evaluated. While most research has focused on the middle and apical thirds of the root, one clinical study suggested the cemento-enamel junction may represent a structurally vulnerable site.</div></div><div><h3>Objectives</h3><div>This study aimed to identify anatomical and demographic risk factors associated with LP fracture across the coronal, middle, and apical thirds of the M3M root.</div></div><div><h3>Methods</h3><div>Cone beam computed tomography (CBCT) images of 300 mandibular third molars were retrospectively reviewed. Data collected included patient sex, age, tooth side, and spatial alignment. M3M root length was measured and divided into coronal, middle, and apical thirds. The thinnest LP region at each level was recorded, and fracture risk was classified into three categories: low, moderate, and high. Ordinal logistic regression was used to determine significant risk factors.</div></div><div><h3>Results</h3><div>Fracture risk was significantly lower in the coronal third compared to the middle and apical thirds. Younger patients exhibited higher fracture risk at all levels. Greater root length increased risk at the apical third. Horizontal impaction level II, mesial and horizontal angulations, and buccal inclination were associated with elevated risk, while lingual inclination and rotational angulation reduced risk.</div></div><div><h3>Conclusion</h3><div>Age, root morphology, impaction depth, and three-dimensional M3M angulations are key predictors of LP fracture risk at distinct root levels.</div></div>","PeriodicalId":16609,"journal":{"name":"Journal of oral biology and craniofacial research","volume":"16 3","pages":"Article 101461"},"PeriodicalIF":0.0000,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of oral biology and craniofacial research","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2212426826000734","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/4/27 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"Medicine","Score":null,"Total":0}

引用次数: 0

Abstract

Background

Prior studies investigating the relationship between lingual plate (LP) fracture risk and mandibular third molar (M3M) anatomy have produced inconsistent findings. Factors such as age, sex, impaction depth, and buccolingual angulation have shown variable associations with fracture risk. Importantly, M3M rotational angulation has rarely been evaluated. While most research has focused on the middle and apical thirds of the root, one clinical study suggested the cemento-enamel junction may represent a structurally vulnerable site.

Objectives

This study aimed to identify anatomical and demographic risk factors associated with LP fracture across the coronal, middle, and apical thirds of the M3M root.

Methods

Cone beam computed tomography (CBCT) images of 300 mandibular third molars were retrospectively reviewed. Data collected included patient sex, age, tooth side, and spatial alignment. M3M root length was measured and divided into coronal, middle, and apical thirds. The thinnest LP region at each level was recorded, and fracture risk was classified into three categories: low, moderate, and high. Ordinal logistic regression was used to determine significant risk factors.

Results

Fracture risk was significantly lower in the coronal third compared to the middle and apical thirds. Younger patients exhibited higher fracture risk at all levels. Greater root length increased risk at the apical third. Horizontal impaction level II, mesial and horizontal angulations, and buccal inclination were associated with elevated risk, while lingual inclination and rotational angulation reduced risk.

Conclusion

Age, root morphology, impaction depth, and three-dimensional M3M angulations are key predictors of LP fracture risk at distinct root levels.

查看原文本刊更多论文

下颌第三磨牙牙根脆弱和舌板骨折风险：一项基于cbct的回顾性横断面研究

背景先前研究舌板（LP）骨折风险与下颌第三磨牙（M3M）解剖结构之间的关系产生了不一致的结果。年龄、性别、嵌塞深度和颊舌角度等因素与骨折风险有不同的相关性。重要的是，M3M旋转成角很少被评估。虽然大多数研究都集中在牙根的中间和根尖的三分之一，但一项临床研究表明，牙骨质-牙釉质交界处可能是一个结构上脆弱的部位。目的：本研究旨在确定横跨M3M根冠状、中、尖三分之一的LP骨折的解剖学和人口学危险因素。方法对300颗下颌第三磨牙的ct图像进行回顾性分析。收集的数据包括患者的性别、年龄、牙齿侧面和空间排列。测量M3M根长，并将其分为冠状、中间和根尖三分之一。记录每个级别最薄的LP区域，并将骨折风险分为低、中、高三类。采用有序逻辑回归确定显著危险因素。结果冠状三分之一骨折风险明显低于中、根尖三分之一。年轻患者在所有级别均表现出较高的骨折风险。根长增加了根尖三分之一的风险。水平嵌塞II级、中位和水平角度以及颊倾斜与风险升高相关，而舌倾斜和旋转角度降低风险。结论年龄、牙根形态、嵌塞深度和三维M3M角度是不同牙根水平LP骨折风险的关键预测因素。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of oral biology and craniofacial research Medicine-Otorhinolaryngology

CiteScore

4.90

自引率

0.00%

发文量

133

审稿时长

167 days

期刊介绍： Journal of Oral Biology and Craniofacial Research (JOBCR)is the official journal of the Craniofacial Research Foundation (CRF). The journal aims to provide a common platform for both clinical and translational research and to promote interdisciplinary sciences in craniofacial region. JOBCR publishes content that includes diseases, injuries and defects in the head, neck, face, jaws and the hard and soft tissues of the mouth and jaws and face region; diagnosis and medical management of diseases specific to the orofacial tissues and of oral manifestations of systemic diseases; studies on identifying populations at risk of oral disease or in need of specific care, and comparing regional, environmental, social, and access similarities and differences in dental care between populations; diseases of the mouth and related structures like salivary glands, temporomandibular joints, facial muscles and perioral skin; biomedical engineering, tissue engineering and stem cells. The journal publishes reviews, commentaries, peer-reviewed original research articles, short communication, and case reports.