Soft- and hard-tissue changes after extraction space closure with micro-screw implant / 复旦学报（医学版）

ABSTRACT

Objective To investigate the changes of soft and hard tissues after extraction space closure with micro-screw implant as orthodontic anchorage. Methods Twenty cases were selected randomly with the first premolars extraction. Micro-screw implant was used as orthodontic anchorage. Sliding technique was used to close the extraction space. The lateral cephalograms before and after the treatment were evaluated.Results The upper incisors moved 7. 15 mm palatelly, 1. 63 mm intruded. The upper first molar moved 0. 80 mm distally, 1. 80 mm intruded. The lower incisors moved 4. 65 mm distally, 0.48 mm extruded. The lower first molar moved 0. 18 mm mesially, 1.18 mm extruded. A point, B point, upper lip, lower lip showed distal movement. Conclusions Micro-screw implant can provide acceptable and reliable anchorage in the process of extraction space closure, and improve the profile. Besides, it produces skeletal change on the maxilla.