Abstract: Objective    To study the three-dimensional correlation between maxilla and mandible in adults. Methods    A retrospective analysis was conducted on clinical and imaging data from 105 adult patients treated at Tongliao People′s Hospital between January 2010 and December 2018. Spiral CT scans were acquired and converted to DICOM format，and lateral cranial views were generated using Dolphin 11.95 software. Patients were classified into three groups based on ANB（angle formed by the maxillary alveolar ridge，nasal root，and mandibular alveolar ridge）：GroupⅠ（0° ≤ ANB < 5°）（54 cases），Group Ⅱ（ANB ≥ 5°）（30 cases），and Group Ⅲ（ANB < 0°）（21 cases）. Three-dimensional reconstruction of the maxilla and mandible was performed using Mimics Research 21.0 software to measure volume，surface area，length，width，and height among groups. Compare the differences in measured parameters among the groups and analyze their correlations. Results    Significant differences existed in surface area，length，and height of mandibles（all P < 0.05）. Further inter-group comparisons revealed that Group Ⅱ mandibles exhibited significantly smaller surface areas and heights compared to GroupsⅠand Ⅲ，while Group Ⅲ mandibles demonstrated markedly longer lengths than GroupsⅠand Ⅱ，with all differences being statistically significant（all P < 0.05）. In GroupⅠ，mandibles showed correlations with maxillas in volume，surface area，and length（r values being 0.583，0.273 and 0.476，respectively，all P < 0.05）. In Group Ⅱ，there was correlation in volume and surface area（r values being 0.556 and 0.444，both P < 0.05），and the same was with Group Ⅲ（r values being 0.712 and 0.649，both P < 0.05）. Conclusion    The volume and surface area of the maxilla and mandible are correlated，but the length，width and height in three dimensions are not significantly correlated.

Key words: maxilla, mandible, growth and development

摘要： 目的    研究成人上颌骨与下颌骨三维方向的相关性。方法    选取2010年1月至2018年12月于通辽市人民医院就诊的105例成人患者临床和影像学资料进行回顾性分析。采用螺旋CT获取扫描图像并生成DICOM格式，输入Dolphin 11.95软件生成头颅侧位片，根据ANB（上牙槽座点、鼻根点和下牙槽座点构成的角）将所有患者分为骨性Ⅰ类（0° ≤ ANB < 5°）组（54例）、骨性Ⅱ类（ANB ≥ 5°）组（30例）和骨性Ⅲ类（ANB < 0°）组（21例）。通过Mimics Research 21.0软件对所有患者的上颌骨和下颌骨进行三维重建，测量各组上颌骨和下颌骨的体积、表面积、长度、宽度、高度，比较各组间测量数据差异并分析其相关性。结果    3组下颌骨的表面积、长度、高度比较，差异均有统计学意义（均P < 0.05）。进一步组间比较发现，骨性Ⅱ类组下颌骨表面积和高度明显小于骨性Ⅰ类组和骨性Ⅲ类组，骨性Ⅲ类组下颌骨长度明显大于骨性Ⅰ类组和骨性Ⅱ类组，差异均有统计学意义（均P < 0.05）。骨性Ⅰ类组上颌骨与下颌骨的体积、表面积、长度具有相关性（r值分别为0.583、0.273、0.476，均P < 0.05），骨性Ⅱ类组体积、表面积具有相关性（r值分别为0.556、0.444，均P < 0.05），骨性Ⅲ类组体积、表面积具有相关性（r值分别为0.712、0.649，均P < 0.05）。结论    上颌骨与下颌骨的体积和表面积存在相关性，但其三维方向上的长度、宽度、高度间相关性并不明显。

关键词: 上颌骨, 下颌骨, 生长发育