The relationship between radiologic interpretation and root tip fracture during tooth extraction performed by junior clinicians

Objectives. The purpose of this study was to analyze the relationship betwe en root tip fracture and radiologic interpretation of root morphology on pe riapical radiographs during third molar extraction performed by junior clin icians, Methods. Before tooth extraction, periapical radiographs of 107 patients wi th 116 third molars were evaluated by junior clinicians, all with less than 5 years of clinical experience. Radiologic interpretations of root morphol ogy-including number, curvature, fusion, and accessory root-were recorded b efore each extraction. The clinicians were also asked to estimate the possi bility of root fracture on a Visual Analogue Scale before the procedure. Th e exact morphology of the extracted teeth was recorded after the extraction for the Purpose of comparison. Results. Twenty-nine of 116 teeth extracted were not correctly interpreted in at least 1 of the morphologic categories surveyed. The average expected fracture rate of nonfractured teeth was 23.1%, whereas the average expected fracture rate of fractured teeth was a significantly higher 50.3%. Misinte rpretation of root morphology on radiographs decreased with increased clini cal experience. Senior residents had the lowest misinterpretation and fract ure rate. Logistic regression analysis showed that fracture is most closely related to the estimated fracture rate (4.95) and is also significantly re lated to underestimation of root curvature (0.95; 24.56 with 2 df of chi-sq uare, P = .0001). Conclusions. Misinterpretation of root morphology on radiographs occurred i n 25% of the teeth. Root curvature was the most misinterpreted item studied . Fracture was most closely related to the estimated fracture rate. junior clinicians in this study expected that only 50% of the fractured teeth woul d fracture, reflecting a general underestimation of root tip fracture. Furt her study should be performed to evaluate how to increase the accuracy of r oot curvature interpretation.