title: Biomechanical and clinical considerations of a modified protraction headgear.
abstract: The choice of treatment of children with developing skeletal Class III malocclusions has always posed a dilemma. Chin cups and various types of reverse headgears with elastics have been used in the past to minimize the growth and development discrepancy of the midface and the mandibular bones. In the present article, a critique of commonly used protraction devices is presented. A modified protraction headgear design and the biomechanical considerations of its clinical use are presented in this study. The clinical results show that a modified protraction headgear with a chin cup helps in the correction of moderately severe Class III malocclusions by the anterior displacement of the maxilla and maxillary dentition, and possibly restricting or changing the direction of the growth of the mandible. This headgear can also be used to correct axial inclinations and/or mesial displacement of posterior teeth.
mesh_terms: D000202:Activator Appliances; D001696:Biomechanical Phenomena; D005115:Extraoral Traction Appliances; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D008313:Malocclusion, Angle Class III / Q000628:therapy*; D008437:Maxilla / Q000502:physiology; D008445:Maxillofacial Development; D009968:Orthodontic Appliances, Removable; D010349:Patient Compliance; D014087:Tooth Movement Techniques