Anatomical Evaluation of Mandibular Premolars in Saudi Population: An In Vivo Cone-beam Computed Tomography Study

Cone-beam computed tomography (CBCT) offers a three-dimensional (3D) image of the anatomical structures in the maxillofacial region. CBCT can provide images with sufficient spatial resolution and low radiation dose in endodontic diagnosis and treatment planning.

This study aimed to evaluate the root canal morphology of mandibular premolars in a Saudi sub-population by showing the importance of cone-beam computed tomography radiographic analysis in detecting varieties of the root canal system.

A total of 776 mandibular first and second premolars were analyzed. Teeth that have completed root development and apical closure were included. To accurately evaluate the external and internal morphologies of the teeth, three sections (i.e., the serial axial, coronal, and sagittal sections) were acquired for each tooth. Data are presented in terms of frequencies and percentages. The chi-squared test was used to determine the differences between two sides (right and left). A p-value of less than 0.05 was considered statistically significant.

Among the 397 mandibular first premolars, 99.5% had one root, 69.5% had one canal, and 29.5% had two canals. In terms of root canal configuration, 69.5%, 6.3%, 22.2%, and 0.3% of the teeth had Vertucci type I, type III, type V, and type VII canal configurations, respectively. Similarly, among the mandibular second premolars, 100% had one root, 96.8% had one canal, and 2.1% of teeth had two canals. Most of the samples (96.8%) had Vertucci type I canal configuration, and 1.6% and 0.8% of the teeth had Vertucci type III and type V canal configurations, respectively. In both groups of teeth, no statistically significant differences were observed between the right and left sides (P> 0.05).

Mandibular premolars could have challenged internal morphology, and CBCT small field of view is advised in case periapical x-ray is inconclusive.