Department of Clinical Medicine, Nanjing Medical University, Nanjing, China.
Department of Dentistry & Central Lab, First People's Hospital of Wujiang Dist., Nantong University, Suzhou, China.
Arch Oral Biol. 2018 Nov;95:134-140. doi: 10.1016/j.archoralbio.2018.07.020. Epub 2018 Aug 8.
To investigate the anatomical variations of the root and root canal configuration of the human third molars.
A total of 130 maxillary and 130 mandibular third molars were collected from a native Chinese population. All teeth were scanned by micro-computed tomography. After 3D reconstruction, the root and canal morphology of each tooth was examined both qualitatively and quantitatively.
For maxillary molars, a single fused root (67 cases, 51.5%) and a single root canal system (64 cases, 49.2%) was most common root/canal form; the typical three-rooted molars were detected only in 33 cases (25.4%), and the secondary MB canals were detected only in 9 molars (6.9%). For mandibular molars, 62 teeth were single-rooted (47.7%) and 42 had a single root canal system (32.3%); 20 singled-rooted and 60 double-rooted molars exhibited independent mesial and distal root canal systems (61.5%), and the type 1-1 canal was the most common configuration for mesial (57 cases) and distal (81 cases) root canal systems. C-shaped canals were detected in 11 maxillary and 36 mandibular single-rooted molars. The mean root surface area, root and crown volume of mandibular third molars were significantly higher than the maxillary third molars (P < 0.01).
The root canal system of the third molars may exhibit several anatomic variations. Whereas in most of cases, the degree of the canal differentiation was at a low level, and the canal form was not complicate.
研究人第三磨牙的牙根和根管形态的解剖变异。
从中国人群中收集了 130 颗上颌第三磨牙和 130 颗下颌第三磨牙。所有牙齿均通过微计算机断层扫描进行扫描。三维重建后，对每颗牙齿的牙根和根管形态进行定性和定量检查。
上颌磨牙中，最常见的牙根/根管形态为单融合根（67 例，51.5%）和单根管系统（64 例，49.2%）；典型的三牙根磨牙仅在 33 例（25.4%）中检测到，仅在 9 颗磨牙（6.9%）中检测到第二 MB 根管。下颌磨牙中，62 颗为单根（47.7%），42 颗有单根管系统（32.3%）；20 颗单根和 60 颗双根磨牙具有独立的近中和远中根管系统（61.5%），1-1 型根管是近中（57 例）和远中（81 例）根管系统最常见的形态。11 颗上颌单根磨牙和 36 颗下颌单根磨牙中检测到 C 形根管。下颌第三磨牙的牙根表面面积、牙根和牙冠体积均明显高于上颌第三磨牙（P<0.01）。
第三磨牙的根管系统可能存在多种解剖变异。尽管在大多数情况下，根管分化程度较低，且根管形态并不复杂。
