Evaluating effectiveness of corticotomy procedure in open bite patients by intrusion of maxillary posterior teeth with zygomatic miniplate anchorage : A retrospective study

Aim: The aim of this study was to evaluate treatment effects on root resorption and intrusion amount of corticomy procedure in anterior open bite patients with excessive vertical devolopment of posterior maxilla. Material and Method: This study was conducted on the treatment records of 16 moderate to severe anterior open bite patients (9 female, 7 male) who applied to Ege University Faculty of Dentistry and Department of Orthodontics. The mean age of patients was 19,2 years. In the buccal side zygomatic miniplates and in the palatinal side between second premolar and first molar, miniscrews were placed for anchorage. Mucoperiosteal flap was reflected under local anesthesia and corticotomy procedure was created between posterior roots in only one segment. These vertical cuts were connected with horizontally above the apex of maxillary posterior teeth at least 2 mm. 1 week after surgery 400 g intrusion forces were applied with closed NiTi coils on each side aproximately 6 months. Before and after intrusion, CBCT images were taken. Volumetric and lineer measurements were done by using Mimics Innovation Suite software. Repated measure ANOVA was used to compare root resorption and intrusion amount between right and left sides at T0 and T1. Results: Although amount of intrusion was higher in corticotomy side, the difference was not statistical significant except 2 parameters (p>0.05). Similarly volume loss was not statistically significant when compared right and left sides (p>0,05). When right and left sides were compared within themselves at T0 and T1, the differences were statistically significant (p<0.05). Conclusion: Although corticotomy is a minimally invasive procedure, it affects patient comfort with the wider removal of the soft tissue flap and the trauma surface on the bone. In addition, there was no statistically significant difference in intrusion and root resorption amounts in both sides. For this reason, it is considered that zygomatic plate application may suffice in the anterior open bite treatment.