Intrusion of Lower Incisors in Deep Overbite Cases with Mini-screws.

Objective: To evaluate the dentoskeletal effects of intrusion of the lower incisor teeth by mini-screws.

Methods: Ten patients were selected from the outpatient clinic of the Department of Orthodontics, Faculty of Dentistry, Mansoura University with Angle's Class II division I malocclusions. Age ranged from 15 to 18 years (15.4 year mean) with deep overbite (more than 1/3 the crown height of the lower incisors covered) requiring intrusion of the lower incisors. After alignment of the first molars, the second premolars ,and canines without inclusion of the lower four incisors, the cuspids were retracted on 16x22 inch stainless steel wire. For each patient, two mini-screws were inserted for anchorage for the lower incisors segment intrusion between the lateral incisor and the cuspid--one in each side and connected to a utility arch wire.

Results: The mean of overbite correction was 4.2 mm (p<. 05, and lower incisors were intruded significantly by a mean of 3.55 mm (p<.05).

Conclusions: The mandibular incisors were effectively intruded by using mini-screws as orthodontic anchorage with no significant counteractive movements in the molars.