Tay Wan Zhi, Sklavos Anton, Mian Mustafa, Delpachitra Seth, Chandu Arun
Resident, Department of Oral and Maxillofacial Surgery, Royal Dental Hospital Melbourne, Carlton, Victoria, Australia.
Registrar, Department of Oral and Maxillofacial Surgery, Royal Melbourne Hospital, Carlton, Victoria, Australia.
J Oral Maxillofac Surg. 2025 Jan;83(1):54-61. doi: 10.1016/j.joms.2024.10.004. Epub 2024 Oct 16.
Cone-beam computed tomography (CBCT) provides additional 3-dimensional information on the relationship between the mandibular third molar (M3M) and the inferior alveolar nerve (IAN). As such, CBCT is being increasingly utilized in preoperative M3M assessment.
The purpose of the study was to compare the radiographic findings on panoramic and CBCT and their association with postoperative IAN paresthesia.
STUDY DESIGN, SETTING, SAMPLE: We conducted a retrospective cohort study in a sample of patients referred to the Department of Oral and Maxillofacial Surgery at the Royal Dental Hospital of Melbourne, for management of impacted M3Ms. Patients were included in this study if they had 1 or more high-risk findings on orthopantomogram (OPG), had both OPG and CBCT imaging taken and if at least 1 M3M had been extracted. Subjects were excluded from this study if their M3Ms were not extracted or if a CBCT was not indicated.
The independent variable was radiographic features identified on OPG (Rood and Shehab's radiographic signs, root morphology, impaction type, Pell and Gregory classification) and CBCT (number and location of roots, severity of IAN compression and the presence of ankylosis).
The outcome variable was postoperative neurosensory function defined as any reported paresthesia at 2-week postprocedural review.
The covariates were patient demographic information (age, sex).
Variables were initially assessed with univariate logistic regression analysis to determine factors related to developing postoperative paresthesia. Multivariate logistic regression analysis was then used to assess the association between positive univariate study variables and postoperative paresthesia, while adjusting for potential confounders. Covariates were assessed using an omnibus likelihood ratio test and included if they were statistically significant at the P < .05 level.
The study sample consisted of 257 subjects who underwent surgical removal of n = 386 M3Ms. The mean age was 25.9 (standard deviation = 7.05). The panoramic features of narrowing of canal, diversion of canal and dark and bifid roots were identified as statistically significant associations of postoperative paresthesia. No CBCT features were significantly associated of postoperative paresthesia.
Certain panoramic features, along with patient age, are significant predictors of IAN paresthesia. CBCT findings were not significant predictors upon multivariate analysis, thus additional CBCT imaging did not significantly improve ability to predict paresthesia.
锥形束计算机断层扫描（CBCT）可提供有关下颌第三磨牙（M3M）与下牙槽神经（IAN）之间关系的额外三维信息。因此，CBCT在术前M3M评估中的应用越来越广泛。
本研究旨在比较全景片和CBCT的影像学表现及其与术后IAN感觉异常的相关性。
研究设计、地点、样本：我们对墨尔本皇家牙科医院口腔颌面外科转诊来处理阻生M3M的患者样本进行了一项回顾性队列研究。如果患者在全景片（OPG）上有1项或多项高风险表现，同时有OPG和CBCT影像，且至少拔除了1颗M3M，则纳入本研究。如果患者的M3M未拔除或未行CBCT检查，则排除在本研究之外。
自变量为在OPG上识别出的影像学特征（Rood和Shehab影像学征象、牙根形态、阻生类型、Pell和Gregory分类）以及CBCT上的特征（牙根数量和位置、IAN受压程度和骨粘连情况）。
观察变量为术后神经感觉功能，定义为术后2周复查时报告的任何感觉异常。
协变量为患者人口统计学信息（年龄、性别）。
首先用单因素逻辑回归分析评估变量，以确定与术后感觉异常发生相关的因素。然后用多因素逻辑回归分析评估单因素研究阳性变量与术后感觉异常之间的关联，同时对潜在混杂因素进行校正。协变量用综合似然比检验进行评估，如果在P <.05水平具有统计学意义则纳入分析。
研究样本包括257名接受了n = 386颗M3M手术拔除的受试者。平均年龄为25.9岁（标准差 = 7.05）。发现根管狭窄、根管移位以及牙根暗黑和双根等全景片特征与术后感觉异常存在统计学意义的关联。没有CBCT特征与术后感觉异常有显著关联。
某些全景片特征以及患者年龄是IAN感觉异常的重要预测因素。多因素分析时CBCT表现不是显著的预测因素，因此额外的CBCT影像并未显著提高预测感觉异常的能力。
