Evaluation of root canal morphology of premolar teeth using cone beam computed tomography: a retrospective study

This study aimed to evaluate the root and canal morphology of maxillary and mandibular premolars using cone-beam computed tomography (CBCT) and to assess bilateral anatomical symmetry between contralateral teeth. A total of 157 CBCT scans from patients aged 18–60 years were retrospectively analyzed. Root number, canal number, Vertucci classification types, and bilateral symmetry of premolars in the maxilla and mandible were recorded. Maxillary first premolars most commonly exhibited two roots and two canals (70.70%), with Vertucci Type IV being the dominant configuration (78.02%). Maxillary second premolars most frequently presented one root with two canals (48.40%), and Vertucci Type I was the most prevalent morphology (28.66%). Mandibular first and second premolars predominantly exhibited one root and one canal (72.29% and 93.63%), with Vertucci Type I being the most frequent configuration (71.65% and 93.63%). Bilateral root and canal symmetry was high for all premolars: 89.15% in maxillary first premolars, 89.78% in maxillary second premolars, 87.26% in mandibular first premolars, and 94.90% in mandibular second premolars. Root and canal morphology differed by sex and by jaw (p < 0.001). CBCT enables accurate visualization of premolar root canal anatomy and assists clinicians in identifying anatomical variations. The high degree of bilateral symmetry suggests that contralateral teeth may serve as useful anatomical references during endodontic procedures.