Dentoskeletal changes in open bite treatment using spurs and posterior build-ups: A randomized clinical trial

Introduction: This single-center 2-arm parallel randomized clinical trial aimed to compare the dentoskeletal effects of bonded spurs combined with posterior build-ups vs conventional bonded spurs in the treatment of anterior open bite malocclusion in the mixed dentition. Methods: Patients aged from 7 to 11 years with anterior open bite, recruited at a university orthodontic clinic, were randomly allocated into 2 groups. The experimental group consisted of patients treated with bonded spurs combined with posterior build-ups. The comparison group comprised patients treated with conventional bonded spurs. Lateral headfilms were obtained at pretreatment and after 12 months of treatment. The primary outcome was the change in the overbite. Randomization was performed using the Web site www.randomization.com. Sequentially numbered opaque and sealed envelopes were used for allocation concealment. Blinding was applicable for outcome assessment only. Intergroup comparisons were performed using t or Mann-Whitney U tests (P <0.05). Mean difference (MD) and 95% confidence interval (CI) were obtained. Results: The experimental group included 24 patients (17 female, 7 male; mean age, 8.22 ± 1.06 years) and the comparison group comprised 25 patients (14 female, 11 male; mean age, 8.30 ± 0.99 years). Baseline demographic and cephalometric characteristics were similar between groups. After 12 months, all patients showed improvements. Both groups showed similar improvements of the overbite (MD, 0.00 mm; 95% CI, −0.92 to 0.91), similar slight decreases of the gonial (MD, 0.02°; 95% CI, −1.11 to 1.15) and mandibular plane (MD, 0.15°; 95% CI, −0.64 to 0.93) angles, and similar mandibular molar extrusion (MD, 0.14 mm; 95% CI, −0.27 to 0.56). The experimental group showed significantly smaller extrusion of the maxillary first molar than the comparison group (MD, −0.70 mm; 95% CI, −0.92 to −0.49). The other dentoskeletal variables showed similar changes without statistically significant intergroup differences. No serious harm was observed other than plaque accumulation around the spurs. Conclusions: Similar overbite increases and dentoskeletal changes were observed in both groups after 12 months of treatment. Although the experimental group showed significantly smaller extrusion of the maxillary molars, no greater counterclockwise rotation of the mandible than the comparison group was observed. Registration: This trial was registered at Clinicaltrials.gov (Identifier NCT03702881). Protocol: The protocol was not published. Funding: This trial was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES), Finance Code 001; and by grants: no. 2017/06440-3, no. 2018/05238-9 and no. 2018/24003-2, São Paulo Research Foundation (FAPESP).