하순 깨물기 습관을 가진 골격성 II급 성장기 환자의 액티베이터 치험례

Activator Treatment in a Girl with Skeletal Class II Malocclusion with Lower Lip Biting Habit

Abnormal oral habits interfere with normal growth of the maxillofacial complex due to imbalance of the muscles involved. In skeletal Class II malocclusion, lip biting habit which emerges as a compensation for excessive overjet can inhibit the forward growth of the mandible. In this case report, the patient had a habit of biting the lower lip, which was trapped between the upper and lower incisors, showing large overjet, deep bite, and retruded mandible. It was necessary to correct the abnormal teeth and jaw relations to break the habit. Orthodontic treatment began with myofunctional therapy for lip seal training and a 2 by 4 appliance to reduce the overjet and make an aesthetic smile. After removing the bonded appliance, an activator was used to accelerate the mandible growth and lip training was continued. Lower lip biting habit disappeared with decreased overjet, leading to balanced facial growth.