Radiographic detectability of bone loss in the bifurcation of mandibular molars: an experimental study.

The aim of this study was to evaluate observer performance in the diagnosis of bone loss in the bifurcation of mandibular molars on conventional radiographs. Standardized radiographs were obtained of the first and second molars in 10 dry hemimandibles at baseline and after preparation of bony defects corresponding to degree I and degree II buccal furcation involvements. The radiographs were randomly presented to 12 observers who were asked to determine the presence or absence of bone loss. Receiver operating characteristic (ROC) curve analysis was used for evaluation. The mean AZ-value of all observers was 81% for the first molar and 80% for the second. As the degree of furcation involvement increased, the mean AZ-value of the observers also improved from 68% (furcation involvement degree I) to 86% (degree II). Multiple regression analysis revealed that lesion depth was the factor which most strongly influenced the observers' diagnostic performance.