Bučević Sojčić Petra, Horina Jasna Leder, Jurčević Lulić Tanja, Bočkaj Nina, Jurić Hrvoje
Department of Pediatric and Preventive Dentistry, School of Dental Medicine University of Zagreb.
Department of Mechanical Engineering, University North, University Centre Varaždin.
Acta Stomatol Croat. 2023 Sep;57(3):206-215. doi: 10.15644/asc57/3/1.
The aim of this study was to determine the average dentin wall thickness (DWT) of the maxillary central incisor (MCI) required for performing finite element analysis (FEA) models of root development.
A total of 137 intraoral periapical radiographs of MCI in children aged 7 to 11 years were examined and then classified into 5 groups according to root development stages, which included 1/2 of root development (S1), 3/4 of root development (S2), more than 3/4 of root development (S3), complete development with wide-open apex (S4) and complete development with closed apex (S5). DWT was measured at three reference (horizontal) lines: at a distance of 1 mm from the apex (M), 4 mm from the apex (L) and at the cervical line (K). The distal dentin wall thickness (M1, L1, and K1), the pulp thickness (M2, L2, and K2), the mesial dentin wall thickness (M3, L3, and K3), and the apex thickness (N) were measured using the diagnostic software Soredex Scanora 5.1.2.4. Statistical analysis compared the values of the parameters K, L, and M between developmental stages (multivariate ANOVA) and the linear correlations between the parameters (Pearson's correlation analysis). All analyses were performed at significance level α = 0.05.
There were statistically significant differences between the developmental stages for parameters L and M, while no significant differences were found for parameter K. Most of the correlations between the parameters were statistically significant, with the values of the Pearson correlation coefficient R > 0.6 considered practically significant. All parameters on the same reference line for distal and mesial dentin wall thickness and for pulp thickness correlated well with each other (R = 0.46 - 0.68), but there was no statistically significant correlation with total root thickness on the same reference line (parameters K, L, or M), except for parameter K3 (R = 0.42).
Despite the limitations of this study, the mean values of the selected parameters for the 5 groups of developmental stages of the maxillary central incisor could be used to model dentin wall thickness using finite element analysis.
本研究旨在确定进行上颌中切牙牙根发育有限元分析（FEA）模型所需的平均牙本质壁厚度（DWT）。
共检查了137张7至11岁儿童上颌中切牙的口腔内根尖片，然后根据牙根发育阶段分为5组，包括牙根发育1/2（S1）、牙根发育3/4（S2）、牙根发育超过3/4（S3）、根尖孔敞开的完全发育（S4）和根尖孔闭合的完全发育（S5）。在三条参考（水平）线上测量DWT：距根尖1mm处（M）、距根尖4mm处（L）和颈缘线处（K）。使用诊断软件Soredex Scanora 5.1.2.4测量远中牙本质壁厚度（M1、L1和K1）、牙髓厚度（M2、L2和K2）、近中牙本质壁厚度（M3、L3和K3）以及根尖厚度（N）。统计分析比较了发育阶段之间参数K、L和M的值（多因素方差分析）以及参数之间的线性相关性（Pearson相关分析）。所有分析均在显著性水平α = 0.05下进行。
参数L和M在发育阶段之间存在统计学显著差异，而参数K未发现显著差异。参数之间的大多数相关性具有统计学显著性，Pearson相关系数R的值> 0.6被认为具有实际显著性。远中牙本质壁厚度、近中牙本质壁厚度和牙髓厚度在同一条参考线上的所有参数彼此之间相关性良好（R = 0.46 - 0.68），但与同一条参考线上的总牙根厚度（参数K、L或M）没有统计学显著相关性，除了参数K3（R = 0.42）。
尽管本研究存在局限性，但上颌中切牙5组发育阶段所选参数的平均值可用于通过有限元分析建立牙本质壁厚度模型。
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