Wen Cheng, Wang Huan Huan, Muhetaer Huo Jia, Xie Fan, Han Rui, Wu Jin Cheng
Department of Stomatology, The Third Affiliated Hospital of Shenzhen University, Shenzhen Luohu Hospital Group Luohu People's Hospital, Shenzhen, Guangdong, China.
Clin Exp Dent Res. 2025 Feb;11(1):e70063. doi: 10.1002/cre2.70063.
As a combination of curve of Spee and curve of Wilson, the Monson sphere reflects the arrangement of teeth in three-dimensional (3D) space. For occlusal analysis, the Monson sphere can provide an important reference for prosthetic reconstructions or orthodontic treatments.
The purpose of this study was to generate and investigate the 3-D Monson sphere through a complete digital workflow with intraoral scanning models and custom software.
Sixty-four Chinese adults (32 males and 32 females) with individual normal occlusion were recruited, and their intraoral scanning models were obtained using a digital intraoral scanner. Twenty-six landmarks on the scanning models were digitized using a reverse engineering software. Monson's sphere was generated and evaluated by fitting a sphere to the cusp tips using a least-squares method by means of custom software program. Mann-Whitney's U test was performed to test the radius difference of Monson's sphere between males and females. One-sample t-test was used to test the statistical significance (α = 0.05).
Monson's sphere could be generated by means of digital scanning combined with customed software. The mean radius of Monson's sphere was 77.35 ± 13.38 mm, which was lower than the theoretical value proposed by Monson. Furthermore, there were significant differences between males and females in Monson's sphere radius (p < 0.001).
This study explores a new best-fit algorithm for generating 3-D Monson's sphere by complete digital workflow. The radius of Monson's sphere in Chinese adults was lower than the classical value of four-inch proposed by Monson. There was a significant difference between males and females. Monson's sphere value found in this study could be used as a reference for prosthetic reconstruction and orthodontic treatment and be applied to improve dental treatment results.
作为司皮曲线和威尔逊曲线的组合，蒙森球面反映了牙齿在三维（3D）空间中的排列情况。对于咬合分析，蒙森球面可为修复重建或正畸治疗提供重要参考。
本研究旨在通过使用口腔内扫描模型和定制软件的完整数字工作流程来生成并研究三维蒙森球面。
招募了64名具有个体正常咬合的中国成年人（32名男性和32名女性），使用数字口腔内扫描仪获取他们的口腔内扫描模型。使用逆向工程软件对扫描模型上的26个标志点进行数字化处理。通过定制软件程序，采用最小二乘法将球体拟合到牙尖，从而生成并评估蒙森球面。进行曼-惠特尼U检验以测试男性和女性之间蒙森球面半径的差异。使用单样本t检验来检验统计学显著性（α = 0.05）。
通过数字扫描结合定制软件可以生成蒙森球面。蒙森球面的平均半径为77.35 ± 13.38 mm，低于蒙森提出的理论值。此外，男性和女性在蒙森球面半径上存在显著差异（p < 0.001）。
本研究探索了一种通过完整数字工作流程生成三维蒙森球面的新的最佳拟合算法。中国成年人的蒙森球面半径低于蒙森提出的四英寸的经典值。男性和女性之间存在显著差异。本研究中发现的蒙森球面值可作为修复重建和正畸治疗的参考，并应用于改善牙科治疗效果。
