Treatment of Class II Deep-Bite with Twin-Block Appliance: A Case Report

Functional treatment is one of the most effective treatment methods for the correction of skeletal deviations of individuals who has a growth potential. When Class II deep-bite is treated in late growth period with molar extrusion, relapse commonly occurs under masticatory pressure. However, as the early treatment provides better muscular adaptation, risk of relapse decreases in deep-bite individuals. Our patient was a girl who had a 10 year 1 month years old chronological and 10 year 6 month skeletal age and in MP3= period according to hand wrist film. In the clinical examination a convex profile, Class II molar and canine relationship and a traumatic deep-bite was recorded. Overbite and overjet were 9 mm and 5 mm respectively. Freeway space was 2 mm. In radiological examination it was observed that she was in mixed dentition. Maxillary and mandibular dental arch crowdings were 0 mm and 3.5 mm, respectively The twin-block appliance was applied for the correction of mandibular retrog-nathism. Twin-block treatment phase was 10 months. After functional treatment phase the patient underwent fixed Edgewise orthodontic treatment. The fixed orthodontic treatment phase was 8 months. By the combination of the functional treatment with twin-block appliance and fixed orthodontic treatment an ideal maxil-lomandibular relationship, normal overbite and overjet and a harmonious profile were achieved.