A comparison of cranial base growth in Class I and Class II skeletal patterns.
The purpose of this retrospective longitudinal study was to compare 7 cephalometric measurements of the cranial base in subjects with Class I and Class II skeletal patterns at ages 1 month, 2 years, and 14 years. A sample of 22 Class I and 21 Class II subjects was selected; the inclusion criteria were overjet, ANB, and Harvold unit difference. Analyses of head circumference, crown-rump length, and weight revealed no significant (P >.15) differences between the Class I and Class II infant subjects at the initial age (1 month). One angular and 6 linear measurements were first compared with a multivariate analysis of variance, which revealed significant effects for age (P <.0001) and the age by skeletal pattern interaction (P =.0266) but not for skeletal pattern (P =.3705). Analyses of variance showed significant (P <.0001) age effects for each of the cephalometric variables but no significant skeletal pattern effects (P >.10). The anterior cranial base measurement of nasion to sphenoethmoidal suture was the only variable found to have a significant age by skeletal pattern interaction (P <.006), which revealed a difference in the timing of its growth spurt that occurred between 1 month and 2 years in the Class I subjects and between 2 years and 14 years in the Class II subjects. There were no significant differences between the skeletal classes at any of the 3 ages evaluated. Conclusions from this study indicate that cranial base growth patterns are similar for Class I and Class II subjects and that the premise of a more obtuse "saddle angle" or cranial base angle in Class II skeletal patterns was not supported.
Wilhelm
B M
BM
Department of Orthodontics, Ohio State University, Columbus, OH 43218-2357, USA.
Beck
F M
FM
Lidral
A C
AC
Vig
K W
KW
D000293:Adolescent; D000367:Age Factors; D000704:Analysis of Variance; D001835:Body Weight; D002508:Cephalometry; D002675:Child, Preschool; D003393:Cranial Sutures / Q000033:anatomy & histology / Q000254:growth & development; D018568:Crown-Rump Length; D005004:Ethmoid Bone / Q000033:anatomy & histology / Q000254:growth & development; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008311:Malocclusion, Angle Class I / Q000503:physiopathology*; D008312:Malocclusion, Angle Class II / Q000503:physiopathology*; D015999:Multivariate Analysis; D009295:Nasal Bone / Q000033:anatomy & histology / Q000254:growth & development; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012886:Skull / Q000033:anatomy & histology / Q000254:growth & development; D019291:Skull Base / Q000254:growth & development*; D013100:Sphenoid Bone / Q000033:anatomy & histology / Q000254:growth & development; D013223:Statistics as Topic