Imaging diagnosis of external root resorption in replanted permanent teeth

Abstract The present study aimed to evaluate the performance of cone beam computed tomography (CBCT) and digital periapical radiographs (PR) in diagnosing external root resorption (ERR) in human permanent teeth replanted after traumatic avulsion. The samples comprised 39 permanent maxillary incisors replanted after traumatic avulsion. Digital PR and CBCT images were taken from each tooth and independently examined by 2 calibrated examiners to assess the ERR activity regarding type and extension. The degrees of agreement between both imaging examinations were determined by the mean global agreement index using SPSS software. The two imaging examinations diverged greatly in the diagnosis of the type of ERR since CBCT identified more cases as inflammatory ERR and PR as replacement ERR. A discordance level of 69.2% was observed between the two methods in the diagnosis of the type of ERR when CBCT for mesial and distal (MD) surfaces was considered and 61.5% when CBCT for mesial, distal, buccal and lingual (MD/BL) was considered. Likewise, CBCT and PR differed regarding the ERR index. PR examinations classified most cases as moderate or severe (69.2%), while CBCT examinations classified more cases as mild either in the MD surfaces analysis (41.4%) or in the analysis of the MD-BL surfaces (51.3%). In conclusion, the present results highlight a discrepancy between CBCT and digital PR performance in the diagnosis of different types and extent of ERR in replanted teeth.

摘要 本研究旨在评估锥形束计算机断层扫描（cone beam computed tomography, CBCT）与数字化根尖周片（digital periapical radiographs, PR）在诊断外伤性脱位后再植恒牙牙根外吸收（external root resorption, ERR）中的应用效能。本研究纳入39颗因外伤性脱位接受再植术的上颌恒切牙作为研究样本，对每颗牙齿均采集数字化根尖周片与CBCT影像，由2名经过校准的检查者独立阅片，评估牙根外吸收的类型与累及范围。采用SPSS软件计算平均总体一致性指数，以分析两种影像检查方法的一致性水平。两种影像检查方法在ERR类型的诊断结果上差异显著：CBCT检出更多炎症性牙根外吸收（inflammatory ERR）病例，而数字化根尖周片则检出更多替代性牙根外吸收（replacement ERR）病例。当仅基于CBCT的近远中（mesial and distal, MD）面分析时，两种方法在ERR类型诊断中的不一致率达69.2%；若纳入CBCT的近远中、颊舌（mesial, distal, buccal and lingual, MD/BL）面分析，则不一致率为61.5%。此外，两种方法在ERR指数评估方面也存在差异：数字化根尖周片将多数病例归类为中重度病变（69.2%），而无论是CBCT的近远中面分析（41.4%）还是近远中-颊舌面分析（51.3%），均将更多病例归类为轻度病变。综上，本研究结果表明，CBCT与数字化根尖周片在再植牙不同类型及累及范围的ERR诊断中表现存在显著差异。