基于蒙特卡罗方法的牙组织光学相干层析(OCT)成像模型，研究了不同牙组织的OCT非失真成像深度。通过模拟入射高斯光束以及光在牙组织中的传输，分别获得了单层牙釉质、单层牙本质以及两层牙组织结构的二维仿真OCT图像，与实验结果具有定性的一致性。通过分析二维仿真OCT图像所对应的一维OCT信号，分别得到了三种牙组织结构的平均非失真成像光学深度。研究结果表明，OCT系统对牙齿组织的非失真成像光学深度在150~2400 μm之间，其中牙釉质的非失真成像深度要远大于牙本质的成像深度。所得的结果对于在实验中利用OCT图像对组织结构有效信息进行判断具有一定的参考价值。

We study non-distorted imaging depths of optical coherence tomography (OCT) system in different tooth tissues based on Monte Carlo modeling of tooth OCT imaging. Two-dimensional simulated OCT images of single tooth enamel, dentin and two-layer tooth tissues are obtained by simulating the incident Gaussian beam and light propagation in dental tissues. The simulated images exhibit qualitative agreement with the experimental ones. The average non-distorted imaging depths of three kinds of dental tissue structure are gained through the analysis of one-dimension OCT signals corresponding to the simulated OCT images. It is indicated that the non-distorted imaging depths of the OCT system in dental tissues are 150~2400 μm, the non-distorted imaging depth of the enamel is much greater than that of the dentin. The results have certain reference value for the judgment on effective tissue structure information in experimental OCT images.