目的 探究3种口内扫描仪用于获取最大牙尖交错位（MIP）咬合关系的准确度，为临床实践提供参考。 方法 招募10名上下颌牙列完整、咬合关系正常的受试者。对照组采用面弓转移和咬合记录将位于MIP的上下颌石膏模型固定在𬌗架上，并使用桌面扫描仪对固定的模型进行扫描以获得数字化模型数据；实验组分别使用Trios 3、Carestream 3600以及Aoralscan 3口内扫描仪对受试者进行口内扫描以获取位于MIP时上下颌口扫模型数据。在对照组数字化模型的上下颌双侧中切牙、尖牙和第一磨牙上设置测量点并测量上下颌对应同名牙上测量点之间的距离，获得测量的距离之和D_A，同时计算模型中切牙区、尖牙区以及第一磨牙区的测量点间距离之和，分别记为D_I、D_C、D_M。将添加测量点的对照组上下颌模型分别与实验组上下颌口扫模型进行精确匹配，计算匹配后对照组模型的D_A、D_I、D_C和D_M。对对照组和实验组获得的D_A、D_I、D_C、D_M进行统计学分析，以评估3种口内扫描仪记录咬合关系的准确度。 结果 对照组D_A、D_I、D_C、D_M的值分别为（39.58±6.40）、（13.64±3.58）、（14.91±2.85）、（11.03±1.56）mm，Trios 3组相应的值为（38.99±6.60）、（13.42±3.66）、（14.55±2.87）、（11.03±1.69）mm，Carestream 3600组相应的值为（38.57±6.36）、（13.56±3.68）、（14.45±2.85）、（10.55±1.41）mm，Aoralscan 3组相应的值为（38.16±5.69）、（13.03±3.54）、（14.23±2.59）、（10.90±1.54）mm。方差分析显示无论是整体偏差D_A（P=0.96），还是局部偏差D_I（P=0.98）、D_C（P=0.96）、D_M（P=0.89），3种口内扫描仪获取的数字化模型与对照组模型之间差异均无统计学意义。 结论 在规范的操作流程下，3种口内扫描仪获取的MIP咬合关系与传统方法无差异，满足临床诊疗的需求。

Objective This clinical study aimed to assess the trueness of three intraoral scanners for the recor-ding of the maximal intercuspal position (MIP) to provide a reference for clinical practice. Methods Ten participants with good occlusal relationship and healthy temporomandibular joint were recruited. For the control group, facebow transferring procedures were performed, and bite registrations at the MIP were used to transfer maxillary and mandibular casts to a mechanical articulator, which were then scanned with a laboratory scanner to obtain digital cast data. For the experimental groups, three intraoral scanners (Trios 3, Carestream 3600, and Aoralscan 3) were used to obtain digital casts of the participants at the MIP following the scanning workflows endorsed by the corresponding manufacturers. Subsequently, measurement points were marked on the control group’s digital casts at the central incisors, canines, and first molars, and corresponding distances between these points on the maxillary and mandibular casts were measured to calculate the sum of measured distances (D_A). Distances between measurement points in the incisor (D_I), canine (D_C), and first molar (D_M) regions were also calculated. The control group’s maxillary and mandibular digital casts with the added measurement points were aligned with the experimental group’s casts, and D_A, D_I, D_C, and D_M values of the aligned control casts were determined. Statistical analysis was performed on D_A, D_I, D_C, and D_M obtained from both the control and experimental groups to evaluate the trueness of the three intraoral scanners for the recording of MIP. Results In the control group, D_A, D_I, D_C, and D_M values were (39.58±6.40), (13.64±3.58), (14.91±2.85), and (11.03±1.56) mm. The Trios 3 group had values of (38.99±6.60), (13.42±3.66), (14.55±2.87), and (11.03±1.69) mm. The Carestream 3600 group showed values of (38.57±6.36), (13.56±3.68), (14.45±2.85), and (10.55±1.41) mm, while the Aoralscan 3 group had values of (38.16±5.69), (13.03±3.54), (14.23±2.59), and (10.90±1.54) mm. Analysis of variance revealed no statistically significant differences between the experimental and control groups for overall deviation D_A (P=0.96), as well as local deviations D_I (P=0.98), D_C (P=0.96), and D_M (P=0.89). Conclusion With standardized scanning protocols, the three intraoral scanners demonstrated comparable trueness to traditional methods in recording MIP, fulfilling clinical requirements.