Department of Biomaterials, Institute of Clinical Dentistry, Faculty of Dentistry, University of Oslo, Oslo, Norway.
Department of Biomaterials, Institute of Clinical Dentistry, Faculty of Dentistry, University of Oslo, Oslo, Norway.
Int Dent J. 2023 Feb;73(1):71-78. doi: 10.1016/j.identj.2022.04.003. Epub 2022 Jun 10.
The purpose of this study was to determine the degree of similarity between contralateral mandibular incisors utilising 3-dimensional (3D) models obtained from micro-computed tomographic (micro-CT) scans of extracted human teeth. The null hypothesis was that contralateral mandibular incisors do not exhibit matching symmetry.
Sixty pairs (n = 120) of extracted mandibular incisors were obtained from 30 patients and scanned with micro-CT with a voxel size of 15.0 μm. 3D virtual models of the pulpal cavities were rendered. Geometric morphometric deviation analysis was performed after mirroring, automatic alignment, and co-registration of the models of contralateral teeth root mean square (RMS) errors were calculated. The quantitative analysis of the 3D models included 6 different geometric parameters. Data sets were examined with a 2-sample Kolmogorov-Smirnov test. Post hoc retrospective power analysis was performed to find statistical power (α = 0.05).
Contralateral pairs had a narrower distribution in deviation than random pairs. Also, contralateral pairs showed a statistically higher similarity coefficient (5 out of 6 geometric parameters) compared to random pairs (P < .001); no difference was found when comparing central to lateral pairs or between Vertucci type I configurations compared to non-type I. RMS errors had significantly lower Contralateral premolars (CPs) values than random pairs (P < .001).
A high degree of similarity was demonstrated for pairing contralateral mandibular incisors using 3D models. The similarity between contralateral central and lateral incisors suggests that when screened and matched, these 4 teeth might be used in endodontic research where similar root canal anatomy is crucial.
本研究旨在通过对从人类拔牙中获得的微计算机断层扫描（micro-CT）扫描的 3 维（3D）模型，确定双侧下颌切牙的相似程度。零假设是双侧下颌切牙没有表现出匹配的对称性。
从 30 名患者中获得 60 对（n=120）下颌切牙，并使用微 CT 以 15.0 μm 的体素大小进行扫描。对牙髓腔的 3D 虚拟模型进行渲染。对模型进行镜像、自动对准和配准后，进行几何形态偏差分析，计算双侧牙齿根均方根（RMS）误差的偏差分析。对 3D 模型的定量分析包括 6 个不同的几何参数。使用 2 样本 Kolmogorov-Smirnov 检验检查数据集。进行事后回顾性功效分析以找到统计功效（α=0.05）。
与随机对相比，双侧对的偏差分布更窄。此外，与随机对相比，双侧对的相似系数（6 个几何参数中的 5 个）更高（P<0.001）；中央对与侧对之间或Vertucci 1 型构型与非 1 型构型之间没有差异。RMS 误差的 CP 值明显低于随机对（P<0.001）。
使用 3D 模型对双侧下颌切牙进行配对显示出高度的相似性。双侧中央和侧切牙之间的相似性表明，在筛选和匹配时，这 4 颗牙齿可能用于根管解剖结构至关重要的牙髓研究。
