Department of Oral Anatomy, Dental Research Institute and School of Dentistry, Seoul National University, 28-22 Yunkeun-Dong, Chongro-Ku, Seoul 110-749, Republic of Korea.
J Dent. 2013 Apr;41(4):336-44. doi: 10.1016/j.jdent.2013.01.003. Epub 2013 Jan 23.
The Monson's sphere and curve of Wilson can be used as reference for prosthetic reconstructions or orthodontic treatments. This study aimed to generate and measure the three-dimensional (3-D) Monson's sphere and curve of Wilson using virtual dental models and custom software.
Mandibular dental casts from 79 young adults of Korean descent were scanned and rendered as virtual dental models using a 3-D digitizing scanner. 26 landmarks were digitized on the virtual dental models using a custom made software program. The Monson's sphere was estimated by fitting a sphere to the cusp tips using a least-squares method. Two curves of Wilson were generated by finding the intersecting circle between the Monson's sphere and two vertical planes orthogonal to a virtual occlusal plane. Non-parametric Mann-Whitney and Kruskal-Wallis tests were performed to test for difference between sex and in cusp number within tooth position.
The mean radius of Monson's sphere was 110.89 ± 25.75 mm. There were significant differences between males and females in all measurements taken (p<0.01), within 16.87-17.27 mm. Furthermore, morphological variation derived from variability in cusp number in the second premolar and second molar were not found to influence occlusal curvature (p>0.05).
This study describes a best-fit algorithm for generating 3-D Monson's sphere using occlusal curves quantified from virtual dental models. The radius of Monson's sphere in Korean subjects was greater than the original four-inch value suggested by Monson.
The Monson's sphere and curve of Wilson can be used as a reference for prosthetic reconstruction and orthodontic treatment. The data found in this study may be applied to improve dental treatment results.
蒙森球和威尔逊曲线可作为义齿修复或正畸治疗的参考。本研究旨在利用虚拟牙模型和定制软件生成和测量蒙森球和威尔逊曲线的三维（3-D）模型。
使用三维数字化扫描仪对 79 名韩国年轻成年人的下颌牙列模型进行扫描并转换为虚拟牙模型。使用定制软件程序在虚拟牙模型上数字化 26 个标志点。使用最小二乘法拟合尖顶来估计蒙森球。通过找到蒙森球与两个垂直于虚拟咬合面的平面之间的相交圆来生成威尔逊的两条曲线。使用非参数 Mann-Whitney 和 Kruskal-Wallis 检验来检验性别和牙位内尖的数量之间的差异。
蒙森球的平均半径为 110.89±25.75mm。在所有测量值中，男性和女性之间存在显著差异（p<0.01），范围在 16.87-17.27mm 之间。此外，第二前磨牙和第二磨牙中尖的数量变化所导致的形态变异并未影响咬合曲率（p>0.05）。
本研究描述了一种使用从虚拟牙模型中量化的咬合曲线生成 3-D 蒙森球的最佳拟合算法。韩国受试者的蒙森球半径大于蒙森最初提出的四英寸值。
蒙森球和威尔逊曲线可作为义齿修复和正畸治疗的参考。本研究中发现的数据可用于改善牙科治疗效果。
