Methods:
In this descriptive longitudinal study, growth increments of 58(29 girls and 29 boys) normal occlusion adolescents were followed from 9 to 11 years by means of two cephalograms taken in NHP.The cephalograms were scanned from the archives of Qazvin Dental School. 42 measurements were performed on each of the cephalograms which the second series were evaluated after superimposition on true vertical and anterior cranial base with registration of four points. The measurements were performed by OrthosurgerX software. Significant changes in the variables were indicated by means of paired t-test in each sex. Gender variations were studied by student t-test.
Results: : From the 15 distances studied, three remained constant only in boys (Posterior cranial base length, S-Ar, ANS- ptm). The angles and parameters that remained constant in girls were SNB, ANPog, Basal , Gonial, upper incisor to palatal plane, IMPA, PrNA and CL/ML ,Overbite and overjet . In boys there were no significant differences between the angles also overbite and overjet in these years.
Conclusions: : Craniofacial angles remained constant in boys but changed in girls during two years follow-up from 9 to 11 years of age, but the dimensional changes were significant in both sexes.