Individual morphological variability canalroot systems of teeth according to microfocus computer tomography (Part I)
The morphological features of the canal-root systems of the mandibular premolars among the indigenous inhabitants of the Russian Federation have been studied by the method of high-resolution microfocus computed tomography on the “Skyscan 1176” (“Bruker”) apparatus. Coherence between specialist radiologist and dentist was assessed using Cohen's kappa (k). Analysis of coronal, axial and sagittal sections of 209 permanent mandibular premolars removed for medical reasons revealed the presence of various variations in the structure of the canal-root systems of the teeth. The first premolars of the lower jaw, in comparison with the second mandibular premolars, predominantly have a non-standard morphology of the canal-root system of the teeth. The most common are single-rooted, single-canal first and second premolars of the lower jaw. Type I of the configuration of root canals in the first lower premolars (Vertucci FJ, 1974) was recorded in 63,9% of cases, while type II-VIII accounted for 29,2% of cases, while V, III and IV types (10,8%, 5,9% and 4,9%, respectively). In the second lower premolars, type I structure with a single-channel system of teeth was detected in 94,9% of cases, type II of structure with a two-channel system of teeth - in 3,4% of cases. The incidence of additional types of root canal configuration among the first lower premolars is 6,9%, among the second mandibular premolars - 1,7%. The agreement between the radiologist and the dentist endodontist for the estimation of the number of roots corresponds to “exact” (k = 0,83-1,00; p<0,001), for the estimation of the number of root canals and types of structure configurations - “significant” and “exact” (k = 0,76-1,00, p<0,05).