Authors : Mehran Mortazavi , Parisa Salehi and Ghassem Ansari
Abstract: This research was designed to evaluation the mandibular size and position in a group of 13-15 years old Iranian children with Class II division I malocclusion. A retrospective study was conducted on a series of patient?s files including radiographs for mandibular size and position in 923 individuals from Iranian southern community. The pretreatment lateral head radiographs were used from 504 children with Class II division I malocclusion (case group) and 419 children with Class I malocclusion (control group). The coordinates of 22 points were digitized and converted into 9 angles and 16 linear measurements describing the position and size of the mandible in relation to the cranial base and the dentition. Data from both groups were divided into 3 age-groups (13-15) and gender subgroups. Comparisons were made using the student?s t-test to identify differences between groups. Most of the subjects with Class II division I malocclusion represented with a larger cranial base angle, smaller and retro-positioned mandible, a protrusive dentition, a vertical growth pattern and increased facial height. A retro-positioned and short mandible seemed to be responsible for the Class II division 1 malocclusion. Such factors should be taken into account when planning the treatment for patients.
Mehran Mortazavi , Parisa Salehi and Ghassem Ansari , 2009. Mandibular Size and Position in a Group of 13-15 Years Old Iranian Children with Class II Division 1 Malocclusion. Research Journal of Biological Sciences, 4: 531-536.