Cone-beam computed tomography ; Endodontics ; Korean population ; Mandibular premolars ; Radicular groove ; Root canal morphology
Abstract
The aim of this study was to investigate canal morphology and analyze the radicular groove on mandibular
premolars using cone-beam computed tomography (CBCT) images in large Korean population. CBCT scans including
mandibular premolars for the purpose of dental planning and treatment was selected to evaluate the root canal
morphology. The canal anatomy of premolar was evaluated in three different directions of image slides. Mandibular
premolars were categorized into five types according to the classification of Vertucci et al. In addition, the presence
and location of radicular groove were evaluated. The location of groove was assessed as buccal, lingual, mesial,
and distal in horizontally and upper and lower in vertically. The prevalence of radicular groove was analyzed by sex
and tooth. Total of 496 patients (271 males, 225 females, average age: 38.74 years) with 992 first and 987 second
premolars were evaluated. In canal morphology analysis, the most frequent type, type Ⅰ was accounted for 89.3% and
99.5% on first and second premolars, respectively. In first premolars, type Ⅴ and Ⅲ were followed at 6.5% and 3.7%,
separately. In second premolars, type Ⅲ and Ⅴ were followed at 0.3% and 0.2 %. Radicular grooves were significantly
more presented in the first premolar (10.3%) than in the second premolar (0.5%). Radicular groove of the first molar
was 2.4 times more frequent in male patient compared to female patient with significance. Both first and second premolars, radicular grooves were most commonly detected on the mesial and the lower area. Clinicians should
consider the possibility of anatomical variations of canal and root morphology, including radicular groove in the
mandibular premolar, especially the mandibular first premolar root canal treatment, periodontal treatment. Information
on these anatomical variations will play a key role in successful non-surgical endodontic treatment.