Assessment of mandibular growth and response to functional appliance treatment in prepubertal patients with different auxologic categories

Abstract Objective To assess mandibular growth and response to functional appliance treatment in different Petrovic's auxologic categories and to investigate diagnostic and prognostic usefulness of the Lavergne-Petrovic's flow diagram. Materials and methods Eighteen patients with class II malocclusion (ANB ≥ 4°, dental class II) were selected and divided into 4 groups according to the auxologic categories. Category 2 group had 4 patients, category 3 group had 5, category 4 group had 5 and category 5 group had 4. In order to obtain patient's growth curves and detect the correct treatment time, patient's height was measured every 3 months. This method was supported by the cervical vertebral maturation method for the assessment of mandibular growth. Functional appliance and/or class II elastics, during the fixed appliance phase, were used to correct skeletal and dental relationships. Average treatment time was 31 months (Range 28-36 months). CoGn and ANB were detected in pre-treatment and post-treatment radiographs in order to assess mandibular growth. Results The highest growth was in category 5, the lowest in category 2. Rotational type improvement was generally observed. Conclusions In prepubertal class II patients, treatment success not only depends on appliance choice, clinician's ability and correct treatment time, but also on individual growth potential and facial type. Therefore Lavergne-Petrovic's flow diagram could become a great diagnostic and prognostic aid for the orthodontist.