Development of a Preoperative Assessment Table for Predicting the Difficulty of Mandibular Third Molar Extraction Based on CBCT Images

Song Xinlei; Wang Ligang; Ding Yubao

doi:10.3969/j.issn.1004-5775.2025.17.020

Abstract：Objective:To develop and validate a preoperative assessment table for evaluating the difficulty of impacted lower third molar extractions based on cone-beam computed tomography(CBCT)images.Methods:In the first phase of the study,a retrospective analysis was conducted on 585 impacted lower third molars extracted at Xuancheng People's Hospital from June 2021 to June 2023.Univariate logistic regression methods were used to identify relevant difficulty indicators and establish the preoperative assessment table.The reliability of the table was verified by calculating Cronbach's alpha,its content validity was assessed through Pearson's correlation coefficient,and its structural validity was confirmed using the Kaiser-Meyer-Olkin(KMO)measure of sampling adequacy.In the second phase,the assessment table was employed for preoperative difficulty prediction in 200 impacted lower third molars extracted in Xuancheng People's Hospital from June 2023 to June 2024.The agreement between predicted and actual difficulty levels was evaluated by calculating Cohen's Kappa coefficient.Results:In the first phase,a preoperative assessment table for the difficulty of impacted lower third molar extraction was developed by selecting 10 influencing factors.The reliability,content validity and structural validity of the table were confirmed with Cronbach's alpha,Pearson's correlation coefficient,and KMO values of 0.796,0.853 and 0.803,respectively.In the second phase,the agreement between predicted and actual difficulty levels was 0.752.Conclusion:The preoperative assessment table for the difficulty of impacted lower third molar extraction based on CBCT images demonstrates high reliability and practicality,making it suitable for clinical use in preoperative difficulty assessment.