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Abstract：
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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).
UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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).
UNASSIGNED: 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.
摘要：
■这项研究的目的是确定进行牙根发育的有限元分析（FEA）模型所需的上颌中切牙（MCI）的平均牙本质壁厚（DWT）。
■共检查了137张7至11岁儿童MCI的口内根尖周X光片，然后根据根发育阶段分为5组，其中包括1/2的根系发育（S1），根系发育的3/4（S2），超过3/4的根系发育（S3），以开放的顶点完成发育（S4），以封闭的顶点完成发育（S5）。在三条参考（水平）线处测量DWT：距顶点1mm（M），4毫米的顶点（L）和子宫颈线（K）。牙本质远端壁厚（M1，L1和K1），纸浆厚度(M2、L2和K2)，近中牙本质壁厚(M3、L3和K3)，使用诊断软件SoredexScanora5.1.2.4测量顶点厚度(N)。统计分析比较了参数K的值，L,发育阶段之间的M(多变量方差分析)和参数之间的线性相关性(皮尔逊相关性分析)。所有分析均在显著性水平α=0.05下进行。
■参数L和M的发育阶段之间存在统计学上的显着差异，而参数K没有发现显着差异。参数之间的大多数相关性具有统计学意义，皮尔逊相关系数R>0.6的值被认为是实际显著的。同一参考线上的远端和近端牙本质壁厚以及牙髓厚度的所有参数相互关联良好（R=0.46-0.68），但是在同一参考线上与总根厚度没有统计学上的显着相关性（参数K，L,或M)，除了参数K3(R=0.42)。
■尽管本研究有局限性，上颌中切牙5组发育阶段选定参数的平均值可用于有限元分析模拟牙本质壁厚。
■共检查了137张7至11岁儿童MCI的口内根尖周X光片，然后根据根发育阶段分为5组，其中包括1/2的根系发育（S1），根系发育的3/4（S2），超过3/4的根系发育（S3），以开放的顶点完成发育（S4），以封闭的顶点完成发育（S5）。在三条参考（水平）线处测量DWT：距顶点1mm（M），4毫米的顶点（L）和子宫颈线（K）。牙本质远端壁厚（M1，L1和K1），纸浆厚度(M2、L2和K2)，近中牙本质壁厚(M3、L3和K3)，使用诊断软件SoredexScanora5.1.2.4测量顶点厚度(N)。统计分析比较了参数K的值，L,发育阶段之间的M(多变量方差分析)和参数之间的线性相关性(皮尔逊相关性分析)。所有分析均在显著性水平α=0.05下进行。
■参数L和M的发育阶段之间存在统计学上的显着差异，而参数K没有发现显着差异。参数之间的大多数相关性具有统计学意义，皮尔逊相关系数R>0.6的值被认为是实际显著的。同一参考线上的远端和近端牙本质壁厚以及牙髓厚度的所有参数相互关联良好（R=0.46-0.68），但是在同一参考线上与总根厚度没有统计学上的显着相关性（参数K，L,或M)，除了参数K3(R=0.42)。
■尽管本研究有局限性，上颌中切牙5组发育阶段选定参数的平均值可用于有限元分析模拟牙本质壁厚。
