Department of Orthodontics, Peking University School and Hospital of Stomatology & National Center for Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices, Beijing, China.
Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.
BMC Oral Health. 2024 Aug 24;24(1):996. doi: 10.1186/s12903-024-04752-2.
The determining effect of facial hard tissues on soft tissue morphology in orthodontic patients has yet to be explained. The aim of this study was to clarify the hard-soft tissue relationships of the lower 1/3 of the face in skeletal Class II-hyperdivergent patients compared with those in Class I-normodivergent patients using network analysis.
Fifty-two adult patients (42 females, 10 males; age, 26.58 ± 5.80 years) were divided into two groups: Group 1, 25 subjects, skeletal Class I normodivergent pattern with straight profile; Group 2, 27 subjects, skeletal Class II hyperdivergent pattern with convex profile. Pretreatment cone-beam computed tomography and three-dimensional facial scans were taken and superimposed, on which landmarks were identified manually, and their coordinate values were used for network analysis.
(1) In sagittal direction, Group 2 correlations were generally weaker than Group 1. In both the vertical and sagittal directions of Group 1, the most influential hard tissue landmarks to soft tissues were located between the level of cemento-enamel junction of upper teeth and root apex of lower teeth. In Group 2, the hard tissue landmarks with the greatest influence in vertical direction were distributed more forward and downward than in Group 1. (2) In Group 1, all the correlations for vertical-hard tissue to sagittal-soft tissue position and sagittal-hard tissue to vertical-soft tissue position were positive. However, Group 2 correlations between vertical-hard tissue and sagittal-soft tissue positions were mostly negative. Between sagittal-hard tissue and vertical-soft tissue positions, Group 2 correlations were negative for mandible, and were positive for maxilla and teeth.
Compared with Class I normodivergent patients with straight profile, Class II hyperdivergent patients with convex profile had more variations in soft tissue morphology in sagittal direction. In vertical direction, the most relevant hard tissue landmarks on which soft tissue predictions should be based were distributed more forward and downward in Class II hyperdivergent patients with convex profile. Class II hyperdivergent pattern with convex profile was an imbalanced phenotype concerning sagittal and vertical positions of maxillofacial hard and soft tissues.
正畸患者的面下 1/3 硬组织对面部软组织形态的决定作用尚未得到解释。本研究旨在使用网络分析比较骨骼 II 类高角-过度生长型患者与 I 类均角-正常生长型患者的下 1/3 硬软组织关系。
将 52 名成年患者（42 名女性，10 名男性；年龄 26.58±5.80 岁）分为两组：组 1，25 例，骨骼 I 类均角-正常生长型，直面型；组 2，27 例，骨骼 II 类高角-过度生长型，凸面型。分别对两组患者进行治疗前锥形束 CT 和三维面部扫描，并对其进行重叠，手动识别标志点，并使用其坐标值进行网络分析。
（1）在矢状方向上，组 2 的相关性普遍弱于组 1。在组 1 的垂直和矢状方向上，对软组织影响最大的硬组织标志点位于上牙釉牙骨质界和下牙根尖之间。在组 2 中，垂直方向上对硬组织影响最大的标志点分布比组 1 更向前、向下。（2）在组 1 中，垂直硬组织与矢状软组织位置和矢状硬组织与垂直软组织位置的相关性均为正。然而，组 2 中垂直硬组织与矢状软组织位置的相关性大多为负。在矢状硬组织与垂直软组织位置之间，组 2 中下颌的相关性为负，上颌和牙齿的相关性为正。
与直面型 I 类均角-正常生长型患者相比，凸面型 II 类高角-过度生长型患者的软组织形态在矢状方向上变化更多。在垂直方向上，凸面型 II 类高角-过度生长型患者中，最相关的硬组织标志点分布更向前、向下，这些标志点应作为软组织预测的基础。凸面型 II 类高角-过度生长型是一种面颌软硬组织矢状和垂直位置不平衡的表型。
