Investigation of canal variations and morphometric structures of lower premolar teeth with cone-beam computed tomography imaging

Aim of this study is to examine the root canal variations and morphometric structures of the mandibular first and second premolars. In our study, analyzes were made in the light of data obtained from tomography images of 75 female and 75 male patients. In total, 600 teeth were examined considering the presence of symmetrical premolars from 150 patients. The 3D Endo™ (Dentsply Sirona) program was used to analyze the images obtained from the patients. Root canal variation analyzes were also recorded by calculating the three-dimensional lengths of crowns and roots in the program. It was tried to determine the similarity with the lower molars in terms of root number. Curvature analyzes were handled in the MATLAB (MathWorks) program. In the study, it is aimed to obtain a three-dimensional image of the canal path by using image processing methods on the data obtained from sagittal and coronal angles. Related to the results in our study, 98.16% single-rooted and 1.84% two-rooted were observed, with more multi-rooted teeth in first premolars. While the presence of two canals was 34.4% in the first premolars, it was 6.17% in the second premolars. Vertucci Type 1 was detected as 60.7%, Type II 4%, Type III 21.4%, Type V 8.7% in first premolars in males. Type I 82%, Type II 8%, Type III 3.4%, Type V 2% in lower second premolars; Type I 70.16%, Type II 2%, Type III 17.4%, Type V 6% in first premolars in women; Type I was 93.4%, Type II was 4%, and Type V was 2% in lower second premolars. While the incidence of C-shaped canal was 2.7%, it was found in 0.6% of the teeth in total. While the average crown length was 6.18 mm in the lower first premolars, it was 6.04 mm in the second premolars; root lengths were determined as 15.68 mm and 15.82 mm, respectively. The first curvature angle is 11.38° in men and 9.45° in women in the lower first premolars. In the lower second premolars, it is 9.6° and 10.79°, respectively. As conlusion, in symmetrical teeth in lower premolars; similar root canal morphologies and structures are observed in men and women.