A prospective controlled evaluation of Class II division 1 malocclusions treated with fixed lingual mandibular growth modificator.

OBJECTIVE: To assess the net dentofacial effects of the fixed lingual mandibular growth modificator (FLMGM). MATERIALS AND METHODS: The study sample comprised 38 patients with Class II/1 malocclusion and retrognathic mandible. All were in the pubertal growth spurt. Whereas FLMGM was applied to the treatment group (n=21, mean age=13.2 years), no treatment was performed on the control group (n=17, mean age=12.5 years). Skeletal and dentoalveolar changes were assessed on digital lateral cephalograms obtained at the beginning and end of the treatment/observation period of 8 months. Paired and independent t-tests were used to assess the differences within and between groups. RESULTS: Maxillary growth was not affected by FLMGM treatment, which resulted in a significant overjet reduction of 4.1 mm, an increase in total mandibular length (Co-Gn) of 2.3 mm, chin advancement of 1.6 degrees , and upper incisor retroclination of 4.0 degrees . A reduction of 2.4 degrees in ANB was largely due to an increase of 1.8 degrees in SNB. Favorably, the lower incisors were obviously retroclined by 4.5 degrees . The changes in the vertical skeletal relationships were negligible. CONCLUSION: FLMGM was effective in treating growing Class II/1 patients and produced favorable dentofacial effects, with the matched untreated sample showing minimal changes. Lower incisor retroclination was a benefit of FLMGM treatment.