Objective : To investigate the clinical efficacy of painless oral anesthesia combined with piezosurgery compared with ordinary cassette syringe combined with high speed turbine handpiece in the Fenestration operation of orthodontic traction of impacted maxillary anterior teeth. Methods : A total of 128 cases of impacted maxillary anterior teeth were treated with Fenestration operation and orthodontic traction, and the patients were randomly divided into two groups. Group A (64 patients) received painless oral anesthesia combined with piezosurgery. Group B (64 patients) received ordinary cassette syringe combined with high speed turbine handpiece. The cooperation of fenestration and the swelling and pain after operation were compared between the 2 groups. Results : The proportion of 0 and Ⅰ in the anesthesia group was 45.3% and 31.3% respectively, and the conventional group 0 and I accounted for 32.8% and 20.3% respectively. The difference between the two groups was statistically significant (Z=-2.676, P < 0.05). The pateints' cooperative degree in group A was better than that in group B (P < 0.05). The ratio of pain and swelling in the anesthesia instrument combined with Piezosurgery group was 81.2%, the conventional group had a grade I ratio of 59.4%, and the anesthesia instrument combined with Piezosurgery group was lighter than the conventional group, The difference was statistically significant (Z=-2.777, P < 0.05); anesthesia combined with Piezosurgery group after surgery accounted for 81.2% of the swelling, the conventional group of pain accounted for 71.9%, There was significant difference between the two groups (Z=-2.097, P < 0.05). Symptoms and signs as swelling and pain degree in group A were relatively minor than those in group B (P < 0.05). Conclusion It is worthy clinical promotion to use Painless oral anesthesia combined with piezosurgery in the fenestration and orthodontic traction of impacted maxillary anterior teeth, for its better cooperation and minor post-surgery reaction.

Objective: To explore the clinical application of cone beam CT in the diagnosis of traumatic anterior teeth before orthodontic treatment in order to reduce the risk of orthodontic treatment failure due to adhesion. Methods : 48 fixed orthodontic treatment cases with the history of anterior teeth trama were selected. The anterior teeth were examined by CBCT to exclude root and alveolar bone adhesions. Results : 3 cases of root-alveolar bone adhesion were found, and the upper anterioa teeth of the remaining 45 cases were successfully moved by orthodontic treatment. Conclusion CBCT examination is recommended to check the periodontal ligament in patients of fixed orthodontic treatment with the history of anterior teeth trauma in order to exclude the root-alveolar bone adhesion cases.