Abstract:

Objective To evaluate the soft profile and hard tissue changes after maxillary protraction with skeletal anchorage implant in treatment of Class Ⅲ malocclusion during growth period. Methods 18 patients with skeletal Class Ⅲ malocclusion were treated with maxillary protraction for about 9 months, （3.5±0.1）N, with skeletal anchorage implant and face mask. Cephalometric records were analyzed to assess the changes of maxillo-facial structure of the hard and soft tissue before and after treatment. Results All patients’Class Ⅲ profiles were corrected. Maxillary growth increased, chin clockwise rotated, facial convexity angle increased, lower lip protrusion decreased. Facial vertical height ratio, nasolabial angle, upper lip protrusion and mentolabial sulcus changed unconspicuously. Upper incisors kept in sites, lower incisor upright, maxilla moved forwards. SNA, ANB significantly increased. SNB decreased and the mandible clockwise rotated. Conclusion The maxilla is effectively protracted without significant rotation by using skeletal anchorage implant. The undesired effects of conventional protraction therapies, such as labial tilt of upper anterior teeth and extrusion of the maxillary molars, are reduced or eliminated with skeletal anchorage implant. These effects can conspicuously correct profiles of the patients with skeletal Class Ⅲ malocclusion, make the profile more harmonious and
aesthetic.

Key words: skeletal anchorage implant, skeletal Class Ⅲ malocclusion, protraction, facial soft profile changes