Evaluation of palatal dimensions in different facial patterns by using digital dental casts

ABSTRACT Objective: To analyze the variations of hard palate volume in adults with normal occlusion and different facial types and patterns, by using a three-dimensional analysis on digital casts. Methods: The dental casts of 70 Caucasian adults (28 men, 42 women), mean age of 16.4 years (SD 1.3 years), were scanned by using a tridimensional scanner (Delcam PowerSHAPE™, 2010, Birmingham, UK). Close points were selected in the gingival and cervical regions on the lingual surface of the maxillary teeth, to analyze palatal morphology. The facial patterns and types, and the measurements (width, length, height, volume) of the space on the hard palate were compared using analysis of covariance (ANCOVA), with age as the covariate, and sex as the independent variable. The significance level of 5% (p < 0.05) was adopted. Results: This study showed that the measurements of the width and length were similar among the mesofacial, dolichofacial and brachyfacial facial types, although the height and volume of the space on the hard palate were slightly smaller in dolichofacial individuals, and both Pattern I and Pattern II individuals showed no significant changes for the four measurements. The mean values among facial patterns were: Pattern I - width 38.31±2.59 mm; length 37.44±2.42 mm; height 17.03±2.42 mm and volume 10.52±1.72 mm3; Pattern II - width 37.48±2.44 mm; length 37.48±2.44 mm; height 16.79±2.42 mm and volume 10.41±1.65 mm3 (p>0.05 for all variables). Conclusion: There were no significant differences for the facial patterns and facial types of the individuals compared in the analyzed sample.

摘要
目的：本研究借助数字化模型三维分析手段，探究正常咬合且具有不同面型及面型分型的成人硬腭体积变化特征。
方法：选取70名高加索成人（男28名、女42名）作为研究对象，其平均年龄为16.4岁（标准差（standard deviation, SD）=1.3岁）；采用三维扫描仪（Delcam PowerSHAPE™ 2010，英国伯明翰）对所有受试者的牙颌模型进行扫描。在上颌牙齿舌侧的龈缘与颈缘区域选取密集测点，以分析腭部形态。以年龄为协变量、性别为自变量，采用协方差分析（analysis of covariance, ANCOVA）比较不同面型组及面型分型组的硬腭间隙测量指标（宽度、长度、高度及体积），检验水准设定为5%（p<0.05）。
结果：本研究结果显示，均面型（mesofacial）、长面型（dolichofacial）与短面型（brachyfacial）三组受试者的硬腭宽度及长度测量值无显著差异；但长面型个体的硬腭间隙高度与体积略低于其他两组。而面型分型I型与II型受试者的四项测量指标均无显著变化。不同面型分型的测量均值如下：I型——宽度38.31±2.59 mm，长度37.44±2.42 mm，高度17.03±2.42 mm，体积10.52±1.72 mm³；II型——宽度37.48±2.44 mm，长度37.48±2.44 mm，高度16.79±2.42 mm，体积10.41±1.65 mm³（所有变量p>0.05）。
结论：本研究纳入的样本中，不同面型分型与面型组间均无显著统计学差异。