Avaliação anatômica de molares inferiores por microtomografia computadorizada: estudo ex vivo

Abstract

The internal anatomy of mandibular molars presents considerable morphological variability, representing one of the main challenges to successful endodontic treatment. The present study aimed to evaluate, by means of micro-computed tomography (micro-CT), the internal morphology of mandibular molars, further investigating possible associations between Vertucci's classification and other morphological characteristics of the root canal system. A total of 97 micro-CT acquisitions of mandibular molars were analyzed, of which 90 teeth were included in the statistical analysis after exclusion of specimens with C-shaped canals and supernumerary roots (radix). Two calibrated examiners evaluated, using CTAn and DataViewer software, the canal configuration according to Vertucci's classification, the classification of root isthmuses according to Hsu and Kim, and the presence of intercanal (cavo-interradicular) canal, apical delta, accessory foramina, middle mesial canal, recurrent canal, and other accessory canals. The association between Vertucci's classification and the remaining variables was verified using Fisher's exact test and Cramér's V coefficient, complemented by univariate binary logistic regression models. The results demonstrated marked morphological asymmetry between the roots: the distal root predominantly presented Vertucci Type I configuration and a single canal, whereas the mesial root exhibited high anatomical complexity, with a balanced prevalence between Vertucci Types II and IV, and near-universal presence of two main canals (96.6%) and root isthmuses (98.8%). Roots with Type IV configuration showed a greater likelihood of exhibiting lateral canals and, notably, intercanal communications (OR = 6.25; p = 0.001) compared to Type II roots, in addition to greater diversity of isthmus configurations. It is concluded that the mesial root of mandibular molars concentrates the greatest anatomical complexity of the root canal system, and that Vertucci's classification may serve as a relevant indicator of the presence of accessory structures, aiding the clinical planning of endodontic treatment.