교정용 미니임플랜트를 이용한 구치 전방 견인과 교합평면 회전

Occlusal Plane Rotation by Molar Protraction Using Orthodontic Mini-Implant

Orthodontic mini-implant (OMI) has become very popular as an orthodontic anchorage in recent years because of its convenience and no need of patient’s cooperation. However, biomechanical situations sometimes cause unexpected side effects. If the retraction force from OMI does not pass the center of resistance (CR) during retraction, the whole dental arch will rotate which does not occur in conventional treatment. This case report presents the rotation of the occlusal plane by the protraction of upper molars and retraction of lower dental arch using OMIs. The patient had extracted three molars and two premolars. Since she wanted to close all the extraction space by orthodontic treatment, multiple OMIs and intermaxillary elastics were used to close the space. As a result, significant rotation of the occlusal plane was observed. When OMIs are needed for retraction or protraction, the possibility of occlusal plane rotation during treatment should be taken into account.