微种植支抗钉压低上前牙改善露龈笑的临床研究

Maxillary anterior teeth intrusion by using mini-implant to improve gummy smile

目的：探讨应用微种植支抗钉压低上前牙改善露龈笑的临床疗效。方法选择20例露龈笑患者，常规排齐上下牙列后，于上颌两侧侧切牙与尖牙根尖上方的牙槽间隔植入微型种植支抗钉，每侧加载100g力，持续牵引5-6个月，拍摄治疗前后照片、曲面断层片及头颅侧位片，测量微笑时牙龈显露量的变化，上颌第一磨牙及上颌中切牙垂直向改变，上唇软组织变化，并对测量结果进行统计分析。结果患者侧貌及露龈笑改善明显，上颌前牙临床牙冠明显变短，牙髓活力正常。牙根无明显吸收。U1- SN距、U1- PP距显著减小（P＜0.01），U6- PP距、U6- SN距未见明显增大（P＞0.05），上唇长度（ULL）增大（P＜0.05），上唇突度（ULP）减小（P＜0.05）。结论微种植支抗钉可显著压低上前牙改善露龈笑，治疗安全、有效，值得临床广泛推广应用。

Objective To evaluate the efficacy of mini- implant used for maxil ary anterior teeth intrusion to improve gum-my smile of patients. Methods Mini- implants were applied between the upper lateral incisor and the canine on both sides after the maxil ary and mandible dentition were regularly arranged in 20 patients. Then 100g force was applied to intrude the upper anterior teeth for 5- 6 months. Photos, panoramic radiograph and lateral cephalometric X ray were taken before and after the treatment. Vertical changes on maxil ary first molars and maxil ary central incisor and soft tissue changes on upper lip were recorded. Results The facial profile and gummy smile of patients improved significantly after treatment. The clinical crowns of anterior teeth were significantly reduced and the pulp vitality of anterior teeth was normal. No obvious root absorption was found. U1- PP and U1- SN decreased significantly （P〈0.01）. ULL increased while ULP decreased （P〈0.05）. No significant increases were observed in U6- PP and U6- SN （P〉0.05）. Conclusion Gummy smile can be corrected effectively and safely by intruding upper anterior teeth with mini- implant.