三种典型形态涎石唾液流场仿真模型研究

An analysis of numerical models of salivary flow field with three typical sialolith shapes

目的研究唾液流场对涎石形态的影响,为腮腺导管内涎石形成机制以及手术方式的选择提供理论依据。方法利用正常腮腺造影计算机断层扫描进行腮腺导管系统三维重建,分别构建圆形、卵圆形、流线型三种典型形态的涎石唾液流场仿真模型,应用计算流体动力学分析不同形态涎石与唾液流场变化关系,并通过病例和文献回顾进行模型验证。结果静息状态与刺激状态下阻塞区域三种不同形态涎石的唾液流速均不同,差异有统计学意义(P<0.05)。静息状态下卵圆形涎石的低流速区域(流速<0.1 mm/s)大于其他两种涎石,差异有统计学意义(P<0.05)。刺激状态下圆形与卵圆形涎石涡流区域面积分别为0.092 mm2跟0.087 mm2,差异无统计学意义(P>0.05),流线型涎石无涡流区域。结论导管内涎石的形态会导致病变周围区域唾液流速的不同,而唾液流体力学特性的改变同样会影响矿物质的沉积而影响涎石最终的形态。

Objective To clarify the evolution mechanisms of sialolith and provide the theoretical basis for surgical approach of sialolithiasis by investigating the effect of salivary flow field on the shapes of sialolith. Methods Simulated models of salivary flow field with three typical shapes of sialolith（ovid, round and streamlined） were established after CT sialography of Stensen′ s duct. Then the computational fluid dynamics method was employed to analyze the relationship between sialolith shapes and salivary flow field. A retrospective analysis and a literature review were used to verify the numerical simulation.Results The salivary velocity of three typical sialolith in the obstructive area were significantly different（P〈0.05） both in stimulated and unstimulated conditions. The area of low velocity（flow rates 0.1 mm / s） in unstimulated condition around the oval stone was the largest, followed by those around the round and streamlined stones（P〈0.05）. Whereas in the stimulated state, the area of local vortexes around the round and oval was 0.092 mm2 and 0.087 mm2, respectively, with no significant difference（P〉0.05）. Local vortex was not founded around the streamlined stone. Conclusion The different salivary flow rates and flow patterns caused by different sialolith shapes can in turn affect the mineral deposition and the final shape of sialolith.