the purpose of this study was to quantitate differences in the nature of the correction of Angle´s Class II div 1 malocclusion dependent on the patients age at the time of treatment.
The sample consisted of 27 fsmsle patients in the adolescent group with a mean initial records age of 11.8 years and 25 female patients in the adult group with a mean starting age of 21.1 yrs. Lateral cephalometric head films were taken before and after orthodontic treatment with four bicuspid extraction.
The results were obtained as follows.
1. None of maxillary skeletal parameters exhibited a significantly different in tretment change between adolescents and adults. But, in mandibular skeletal measurements, there were significant differences between two. groups. (P<0.05)
2. Measures of vertical dimension in the adults remained unchanged during treatment, reflecting the effective absence of growth.
3. The steepness of occlusal plane in the adults changed significantly.(P4. According to the Johnston analysis, there was a significant difference in the total molar correction between two groups.(P5
According to the Johnston analysis, differential mandibular´growth in the adolescents contrubuted 63% of the total molar correction, with orthodontic tooth movement accounting for the remaining 37%. In the adults, dental movement comprised 99% of the correction.
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