Abstract: Objective To explore the clinical effects of anterior maxilla micro-implant anchorage on the anterior teeth intrusion to improve gum-smile . Methods Fifteen patients with gum- smile and deep overbite with mean age of 9.7 ± 5.4 were selected , and micro- implant anchorages were inserted into the labial alveolar bone between the central incisors and the lateral incisor roots. Then 0.6 N force was used in each side, and duration of the intrusion anterior teeth on average was 6.2 ± 1.6） months. Relative parameters of soft and hard tissues before and after treatment were measured by cephalometric X-ray films. SPSSl3.0 software was used for statistical analysis. Results The vertical intrusion of the anterior teeth and the length of crown of incisors were reduced significantly (P <0.01), and both the overbite and overjet approached the normal range. Conclusions Micro- implant anchorage is effective in intruding anterior teeth, correcting the deep overbite and improving gum- smile.

Key words: gum-smile, mini-implant anchorage, anterior teeth intrusion, cephalometric analysis