龈缘轮廓三维统计模型建模技术研究

Research on Modeling Technology of 3D Statistical Model for Gingival Contours

为建立龈缘轮廓统计模型,提出了一种利用三角网格牙颌模型进行龈缘形态建模的方法。首先对牙颌模型进行离散曲率分析、最短路径搜索来探测龈缘特征线;根据特征线的微分特性进行单颗牙龈缘划分;然后通过B样条曲线拟合构建出每颗牙齿封闭光滑的龈缘轮廓线,并利用曲线的控制顶点作为龈缘训练形状向量;最后通过对形状训练集进行主成分分析来建立统计形状模型。实验结果表明该方法不仅能够自动而快速地提取出单颗牙齿龈缘轮廓,而且建立的统计模型能够正确而有效地捕获牙弓以及龈缘形态的重要变化特征。

A novel and automatic shape modeling methodology for gingival contours from dental triangle meshes was proposed to build a 3D statistical model. The gingival feature lines were first ob- tained from the 3D dental model through a discrete curvature analysis and shortest path searching al- gorithm. Based on the gingival line differential characteristics, the feature lines were partitioned to demarcate the gingival line of each individual tooth. Through B-- spline curve approximation to form the closed and smooth gingival contour of each tooth, the shape vector for training the model was then achieved using the control points of the B--spline curves. Finally, the statistical shape model was constructed through principle component analysis on the training set of the gingival shape vector. Experimental results demonstrate that this method can detect the gingival contours automatically and lastly, and the statistical model can capture the important variations effectively in arch and gingival morphology.