目的

探讨应用微种植体支抗治疗上前牙槽骨垂直向发育过度的露龈笑患者，改善牙龈显露的程度。

方法

选取16 例因上前牙槽骨垂直向发育过度导致露龈笑的患者，在侧切牙与尖牙间植入微种植体支抗，施加100 g 力压低上前牙。 治疗前后分别收集头颅定位侧位片、上前牙的根尖片、牙 模型、微笑时面下1/3 照片及上前牙的龈沟深度；对实验结果进行统计分析。

结果

压低时间为（6.7 ± 1.2）个月。 （1）牙龈显露减少（2.3 ± 0.5） mm；（2）头影测量分析显示，上中切牙阻力中心点压低（2.6 ± 0.3） mm，覆减少（2.8 ± 0.6） mm，切缘与腭平面的距离减少（3.1 ± 0.7） mm，鼻唇角增加（5.4 ± 2.9）°，P ＜0.05；（3）压低结束时，上前牙的临床牙冠变短，未见明显牙根吸收。

结论

应用微种植体支抗可以有效地压低上前牙，改善露龈笑，但牙龈的改建速度比牙齿的压低速度慢。

Objectives

To correct gummy smile of the patients with anterior alveolar vertical excess by using mini-implant anchorage.

Methods

Sixteen patients with gummy smile due to anterior alveolar excess were chosen for this clinical study. Mini-implants were implanted between the lateral incisor and the canine， and 100 g force was applied to intrude the upper anterior teeth. Records，including models， lateral cephalograms， periapical X-ray films and photos of the lowest one third of smile face， were taken before and after the treatment. Gingival exposure， gingival sulcus depth， clinical crown length and root absorption were also measured. All experimental data were collected and statistical analysis was performed.

Results

（1） The gingival exposure was decreased （2.3±0.5） mm， ranging from 1.8 to 3.1 mm. （2） The cephalometric analysis showed that the resistance center point of the upper central incisor was intruded （2.6±0.3） mm， the overbite was reduced （2.8±0.6） mm， the distance between the edge and the palate plane was decreased （3.1±0.7） mm， and the nasolabial angle was increased（5.4±2.9）° （P ＜0.05）. （3） The clinical crowns of anterior teeth were significantly reduced， but there was no obvious root absorption.

Conclusions

Gummy smile can be corrected by intruding upper anterior teeth with mini-implant anchorage. However， the gingival reconstruction lags behind the intrusion of upper anterior teeth at the same processing time.