Root Canal Anatomy of Maxillary First Premolar by Microscopic Computed Tomography in a Chinese Adolescent Subpopulation.

Objectives. To investigate the root morphology and root canal anatomy of maxillary first premolar using microscopic computed tomography (micro-CT). Methods. 324 maxillary first premolars were collected and scanned. -e root and canal diameter, canal wall thickness, root taper, and cross-sectional shapes were determined in the single root with 1 canal (SR1C), single root with 2 canals (SR2C), and 2 roots with 2 canals (2R2C) by micro-CT. Results. -e results showed that single-rooted maxillary premolars were more common than other types. -e incidence of SR1C, SR2C, and 2R2C reached 25%, 26.39%, and 26.39%, respectively. Root and canal diameters and canal wall thickness were decreased from coronal third to apical foramen. -e three parameters and canal taper showed increases from buccal and palatal (BP) to mesiodistal (MD) aspects.-eroot canal tapers were smallest of the middle third level.-efindings showed the different variations in 2R2C teeth.-eroot canal cross-sectional morphology in maxillary first premolars is complicated, including round, oval, long oval, flat canal, and irregular canal shapes. -e distribution varied in different aspects. Conclusion. Root canal morphology showed a wide variation and complicated structure. -e single-rooted teeth were more common in the Chinese adolescent population, and the majority of maxillary first premolars have two canals. [ABSTRACT FROM AUTHOR]