RESUMO
Objective: To study the clinical effects of minimally invasive corticotomy, Piezocision, as an adjunct to orthodontic treatment for the cases with missing mandibular first molar. Methods: 29 patients without mandibular first molar were devided into 2 groups and treated by orthodontic treatment with Piezocision (group A, n = 14) and routine orthodontic treatment (group B, n = 15) respectively. The movement distance and periodontal status of mandible second molar after force loading were compared between the 2 groups. Results: At 14, 28, 56, 84 days after add force loading, the movement distance of mandible second molar in group A were longer than in group B (P ＜ 0. 05) . 84 days after force loading, there was no significant difference (P＞ 0. 05) about the periodontal indices in group A compared with those before force loading. Bleeding index (BI) and periodontal depth (PD) in group B were increased 84 days after loading (P ＜ 0. 05) . There was no significant (P＞ 0. 05) of periodontal indices between the 2 groups at 84 days after force loading.Conclusion: Piezocision can accelerate orthodontic tooth movement of mandible second molar and can enture the periodontal health.