Related Experiment Video
Updated: Jun 3, 2026
Systematic Assessment of Mammalian Skull Specimens for Dental and Temporomandibular Joint Pathology
Published on: August 22, 2022
Root canal morphology of permanent three-rooted mandibular first molars: Part III--An odontometric analysis
Yongchun Gu1, Peigang Zhou, Yuefeng Ding
1Dental Department, First Hospital of Wujiang City, Wujiang, China.
Introduction:
The purpose of this study was to quantitatively analyze the root canal morphology of three-rooted mandibular first molars by micro-computed tomography (micro-CT) scans.
Methods:
Twenty three-rooted mandibular first molars were scanned by micro-CT scans. The teeth were reconstructed three-dimensionally by software Mimics 10.01 (Materialise, Leuven, Belgium). The levels of the root apexes and furcations; the diameters; wall thicknesses; and tapers of the mesiobuccal (MB), mesiodistal (ML), distobuccal (DB) and distolingual (DL) canals were determined. The buccolingual/mesiodiatal (BL/MD) diameter ratios (ΔC) and the prevalence of long oval canals (ΔC > 2) at different levels were calculated.
Results:
The level of distal furcations was significantly (P < .01) lower than that of MD furcations with an average of 1.09 mm. The buccal and lingual walls were significantly (P < .05) thicker than the mesial and distal for the MB, ML, and DB canals. Among four canals, the DL canal had the smallest mean value of ΔC at each level. The average BL taper was greater than the MD for each canal except the middle portion of the DL canal.
Conclusion:
The vertical length, width, BL/MD diameter ratio, wall thickness, and BL taper of the DB canals are on average greater than the DL canals. The MB, ML, and DB canals are more oval, whereas the DL canals are relatively rounder. The geometric data of root canals are useful for endodontic treatment on three-rooted mandibular first molars.
Related Concept Videos
01:21Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or grinding food.
01:15Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...