بررسي تغييرات رشدي اسكلتال و دنتال در مال اكلوژن كلاس II در گروه سني 7 تا 12 سال (پس از دو سال)

Dentoskeletal growth changes in untreated 7-12 year old individuals with CI II malocclusion

Background & Aim: Since making a proper orthodontic treatment plan is highly based on a thorough understanding of growth changes in dentofacial complex and due to relatively high prevalence of Class II malocclusion cases, this study was conducted to evaluate dentoskeletal growth changes in 7-12 year old class II subjects. Methods & Materials: In this longitudinal study, 8 schools were randomly selected in Tehran. After examination of 1886 students, 73 subjects were selected according to special criteria, all demonstrating a CI II molar and canine relationship. Lateral cephalogram radiographs were obtained from these individuals under NHP position in dental school of Islamic Azad University. After a period of 2 years 43 of them (23 males&20 females) could be recalled and again lateral cephalograms were taken under the same condition. The two series of cephalograms were traced and 26 angular and linear measurements were evaluated. Data were analyzed using Paired t. Wilcoxon and Mann Whitney U Result: All the 43 subjects in this research were categorized into 4 groups according to sex and age (7-9 and 10-12 year old). The 26 evaluated parameters demonstrated different dental and skeletal growth changes. Anterior cranial base in 7-9 years old boys and girls was respectively increased 2.54 ± 0.58 and 2.56 ± 1.52 mm, and increased 2± 0.67 and 2.33 ± 1.34 mm in 10-12 year old group (p<0.05). Effective maxillary length increased 4.13 ± 2.01 and 3.06 ± 2.46 mm in 7-9 years old boys and girls and 3.5 ± 1.80 and 2.5 ± 1.95 mm in 10-12 year old group (p<0.05). Elective mandibular length increased 5.67 ± 2.65 and 6.19 ± 2.83 mm in 7-9 years old boy and girl and 5.82 ± 2.40 and 5.50 ± 2.49 in 10-12 years old group (p<0.05). Ramal height significantly increased in the four groups (p<0.05). Conclusion: Results of this study can be used as clata for evaluation of orthodontic treatment procedures, especially those involving growth modifications.