Department of Orthodontics, Institute of Oral Health Science, Ajou University School of Medicine, Suwon, South Korea.
Division of Orthodontics, Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, San Francisco, CA, USA.
Clin Oral Investig. 2022 Oct;26(10):6275-6281. doi: 10.1007/s00784-022-04579-7. Epub 2022 Jun 13.
The purpose of this study was to investigate the heritability of dental cephalometric variables by analyzing vertical linear measurements and angular measurements of the upper incisor, canine, and first molar.
Among the 553 Korean patients who participated in twin studies conducted at Samsung Medical Center, 150 patients had their lateral cephalometric radiograph data included in this study. The group was comprised of 36 monozygotic (MZ) twins (males, 16 pairs; females, 20 pairs), 13 dizygotic (DZ) twins (males, 7 pairs; females, 6 pairs), and 26 same-sex sibling pairs (males, 11 pairs; females, 15 pairs). All patients were over 20 years old with a mean age of 39.75 years. Lateral cephalometric diagrams and linear measurements (6 vertical factors, 6 horizontal factors) were taken. Three axial planes were measured for each tooth; intraclass correlation coefficients (ICCs) were obtained for each group and heritability was calculated using Falconer's method.
ICCs of vertical linear measurements (average 0.837, P < 0.01) and the tooth axis of the central incisor and canine (average 0.679, P < 0.001) were higher in the MZ group compared to the DZ and sibling groups; thus, these variables showed high heritability.
Orthodontic treatment aiming to alter the tooth axis of the maxillary central incisor or canine or other vertical factors with greater heritability can be difficult, requiring strategic treatment planning to achieve desired treatment outcome and stability.
The active early treatment to gain tooth eruption space can lead to normal tooth position.
本研究旨在通过分析上颌切牙、尖牙和第一磨牙的垂直线性测量值和角度测量值，来研究牙颌面的解剖结构在多大程度上可归因于遗传因素。
在三星医疗中心进行的双胞胎研究中，有 553 名韩国患者参与了该研究，其中 150 名患者的侧位头颅侧位片数据被纳入本研究。该组包括 36 对同卵双胞胎（男 16 对，女 20 对）、13 对异卵双胞胎（男 7 对，女 6 对）和 26 对同性同胞对（男 11 对，女 15 对）。所有患者年龄均在 20 岁以上，平均年龄为 39.75 岁。拍摄了侧位头颅侧位片，并进行了线性测量（6 个垂直因素，6 个水平因素）。每颗牙齿测量 3 个轴面；计算每组的组内相关系数（ICC），并采用 Falconer 法计算遗传率。
垂直线性测量的 ICC（平均 0.837，P<0.01）和上颌中切牙和尖牙牙轴的 ICC（平均 0.679，P<0.001）在同卵双胞胎组中均高于异卵双胞胎组和同胞组，提示这些变量具有较高的遗传性。
对于上颌中切牙或尖牙牙轴或其他具有较高遗传性的垂直因素的正畸治疗，改变其牙轴可能较为困难，需要制定策略性的治疗计划，以达到预期的治疗效果和稳定性。
积极的早期治疗以获得牙齿萌出空间，可导致正常的牙齿位置。
