A Cephalometric Analysis Comparing Anteroposterior Mandibular Growth of Treated and Non-Treated Cl 1 and Cl II, Patients

Abstract

This study was conducted to investigate any anteroposterior mandibular growth that occurs after orthodontic treatment is completed and to determine how it might compare with growth in untreated subjects of comparable age.

The research sample consisted of 15 males and 23 females who prior to orthodontic treatment had either an Angle Class I or Class 11 division 1 malocclusion. The control group of 14 males and 16 females had normal Class I occlusions. All subjects were Caucasians.

A standardized technique for taking lateral cephalometric radiographs was used at the time of debanding and 2 1/2 to 4 1/2 years later for follow up (post-treatment) radiographs.

The deband and post-treatment radiographs of each subject were traced and superposed. Measurements were compared to the expected normal values of the control group at a comparable age.

With the “t” test, the following significant differences of 0.05 probability or less were found. Effective mandibular length was less than normal in the male Class II treated malocclusion at the time of debanding, and actual mandibular length was greater than normal in the female Class I treated malocclusion at the time of deband and post-treatment periods.

Growth was compared between the Class I and Class II treated malocclusion samples within each sex group. No significant differences were observed which suggests that the growth potential of the mandible, with either a Class I or Class II malocclusion, will be the same after treatment.