Department of Orthodontics, School of Dentistry, Seoul National University, Seoul, Korea.
Am J Orthod Dentofacial Orthop. 2013 Jun;143(6):810-8. doi: 10.1016/j.ajodo.2013.01.016.
To understand the growth patterns of skeletal open bite and deepbite, we present observations from 9 years of pure longitudinal data based on lateral cephalometric radiographs using mixed-effects regression model analysis.
In total, 51 children (14 years old) with extreme values for the ratio of lower anterior facial height to total anterior facial height were assigned to 1 of 2 groups: a skeletal open-bite group (11 boys, 14 girls) or a skeletal deepbite group (14 boys, 12 girls). Measurements of total anterior facial height, upper anterior facial height, lower anterior facial height, total posterior facial height, ramus height, and ratio of lower anterior facial height to total anterior facial height were obtained for all subjects. All data were analyzed and interpreted using a mixed-effects regression model analysis with random effects.
From these 4 groups at 14 years old, statistically significant differences were observed between the groups when subjects of the same sex were compared; however, statistical significance was not reached between subjects of opposite sexes in each group. Morphologic differences were clearly evident from the start and became more pronounced with age. There were statistical significances in the initial values and increases with age in all 6 variables except for increases with age in the ratio of lower anterior facial height to total anterior facial height. Statistical significance was also reached for morphologic differences between the annual increases in the ratio of lower anterior facial height to total anterior facial height and lower anterior facial height. In general, individual random variability was high in all variables when compared with the annual changes over time.
Divergent patterns were established early and became more pronounced with age, with anterior facial height dimensions primarily contributing to these differences. Individual variations were so pronounced that caution is recommended for all clinical decisions.
为了了解骨性开颌和深覆颌的生长模式，我们根据混合效应回归模型分析，呈现了 9 年的侧向头颅侧位片纯纵向数据的观察结果。
共有 51 名儿童（14 岁）的下前颜面高度与总前颜面高度的比值为极端值，被分配到 2 个组之一：骨性开颌组（11 名男孩，14 名女孩）或骨性深覆颌组（14 名男孩，12 名女孩）。所有受试者均进行了总前颜面高度、上前颜面高度、下前颜面高度、总后颜面高度、下颌支高度和下前颜面高度与总前颜面高度比值的测量。所有数据均采用随机效应混合效应回归模型分析进行分析和解释。
从这 4 个组的 14 岁儿童中，当比较同性别受试者时，观察到组间存在统计学显著差异；然而，在每个组的异性受试者中，并未达到统计学显著差异。从一开始就明显存在形态差异，且随着年龄的增长而变得更加明显。除了下前颜面高度与总前颜面高度的比值随年龄增加外，所有 6 个变量的初始值和随年龄的增加均具有统计学意义。下前颜面高度与总前颜面高度的比值和下前颜面高度的年增长率之间的形态差异也具有统计学意义。总体而言，与随时间的年变化相比，所有变量的个体随机变异性均较高。
早期就建立了发散模式，且随着年龄的增长变得更加明显，前颜面高度的维度主要导致了这些差异。个体差异如此显著，因此建议在所有临床决策中都要谨慎。
