Riesmeijer Arnold M, Prahl-Andersen Birte, Mascarenhas Anna K, Joo Bert H, Vig Katherine W L
Department of Orthodontics, College of Dentistry, The Ohio State University, Columbus, Ohio, USA.
Am J Orthod Dentofacial Orthop. 2004 Apr;125(4):463-71. doi: 10.1016/j.ajodo.2003.05.012.
Longitudinal craniofacial databases, including the Fels Longitudinal Study, the Michigan Growth Study, and the Nijmegen (The Netherlands) Growth Study, were compared for a set of 12 craniofacial measurements on lateral skull cephalograms. The age ranges of the subjects were 7-14 years for females and 9-14 years for males. When we compared the normally distributed databases using multiple comparisons, a small sample test statistic t for differences between means of the databases showed few statistical differences. The databases were therefore pooled, and sex-specific Class I (ANB < 4 degrees), and Class II (ANB > or = 4 degrees) subsamples were analyzed with the same t test. The sizes of these subsamples ranged from 39 to 122 at the different ages. The findings showed that the Class II samples had greater SNA and SN-GoMe angles. Compared with the Class I group, shorter mandibles were found in the younger age groups of the Class II samples. No differences were found in mandibular length (Ar-Gn) and mandibular body length (Go-Gn) in the older Class II groups compared with the Class I groups. These findings indicate that the greater mandibular lengthening in the Class II groups might have contributed to successful Class II treatment in studies in which a Class I group was the control. Because of individual biological variability, the average Class I or Class II growth pattern might not be a realistic assumption or have clinical relevance for individual patients.
对纵向颅面数据库进行了比较，这些数据库包括费尔斯纵向研究、密歇根生长研究以及奈梅亨（荷兰）生长研究，比较内容为一组关于侧位头颅X线片的12项颅面测量数据。研究对象的年龄范围为女性7至14岁，男性9至14岁。当我们使用多重比较来比较正态分布的数据库时，用于比较数据库均值差异的小样本检验统计量t显示出很少的统计学差异。因此，将这些数据库合并，并使用相同的t检验对特定性别的I类（ANB＜4度）和II类（ANB≥4度）子样本进行分析。这些子样本在不同年龄的大小从39到122不等。研究结果表明，II类样本的SNA和SN-GoMe角更大。与I类组相比，在II类样本的较年轻年龄组中发现下颌骨较短。与I类组相比，在II类较年长组的下颌骨长度（Ar-Gn）和下颌体长（Go-Gn）方面未发现差异。这些发现表明，在以I类组作为对照的研究中，II类组下颌骨更大程度的延长可能有助于II类治疗的成功。由于个体生物学变异性，I类或II类的平均生长模式可能不是一个现实的假设，或者对个体患者没有临床相关性。
