A comparison of craniofacial Class I and Class II growth patterns.
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.
Riesmeijer
Arnold M
AM
Department of Orthodontics, College of Dentistry, The Ohio State University, Columbus, Ohio, USA.
Prahl-Andersen
Birte
B
Mascarenhas
Anna K
AK
Joo
Bert H
BH
Vig
Katherine W L
KW
D000293:Adolescent; D002508:Cephalometry; D002648:Child; D003430:Cross-Sectional Studies; D016208:Databases, Factual; D005147:Facial Bones / Q000000981:diagnostic imaging / Q000254:growth & development; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008297:Male; D008311:Malocclusion, Angle Class I / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008312:Malocclusion, Angle Class II / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008445:Maxillofacial Development; D008824:Michigan; D009426:Netherlands; D009820:Ohio; D011859:Radiography; D012016:Reference Values; D012727:Sex Characteristics; D012886:Skull / Q000000981:diagnostic imaging / Q000254:growth & development*; D044465:White People