Bimaxillary Total Arch Intrusion in Lingual Orthodontics for Hyperdivergent Class II Face with Asymmetry and Lip Protrusion

Abstract

Hyperdivergent Class II face is accompanied by a convex profile, while it is usually characterized by upright upper and/ or lower incisors. Thus, it is important to precisely maintain an axis of upper incisors during retraction. Particularly, axis control of upper incisors is more difficult in lingual orthodontics. Unlike in the buccal appliance, traction force pushes the wire out of horizontal slot in the lingual appliance, so sufficient moment for torque control of incisors may not be obtained. Therefore, excessive overtorque should be placed on the archwire for making same amount of moment and accomplishing incisor translation. Furthermore, to correct lip protrusion and lip incompetency in this patient, bimaxillary total arch intrusion and maximum retraction of incisors was also treatment objective to improve soft tissue problems. This case report demonstrates satisfactory results through bimaxillary total arch intrusion with translation of upper incisors and intrusion of lower incisors using palatal/lingual miniscrews and continuous arch with additional torque for axis control of incisors in lingual orthodontics.