Success rate and complications of Bollard-modified miniplates for bone-anchored maxillary protraction in growing patients: A single-surgeon retrospective cohort study.
INTRODUCTION The objective of this study was to evaluate the success rate, stability, and complications of Bollard-modified miniplate anchorage for bone-anchored maxillary protraction (BAMP) in a large cohort of growing patients treated by a single surgeon with long-term follow-up. METHODS This retrospective cohort study included 299 growing patients with maxillary hypoplasia and Class III malocclusion who underwent Bollard-modified miniplate placement for BAMP between January 2007 and December 2019. A total of 1196 miniplates were placed. The mean follow-up duration was 4.2 years. Outcomes were assessed at both the miniplate level and the patient level. Patient-level logistic regression analysis was performed to evaluate the association of age at surgery and sex with adverse events. RESULTS The overall success rate of Bollard-modified miniplate anchorage was 96.5%. During orthodontic loading, 50 miniplates (4.2%) developed mobility or inflammation; after conservative management, 18 regained stability, 24 were removed and successfully replaced, and 8 were removed and not replaced. Complications were more frequent in the maxilla than in the mandible (odds ratio [OR], 3.09; 95% confidence interval [CI], 1.70-5.61; P <0.001). Younger age at surgery was independently associated with a higher likelihood of complications (OR, 0.70; 95% CI, 0.51-0.96; P = 0.025), miniplate removal (OR, 0.68; 95% CI, 0.48-0.98; P = 0.036), and miniplate replacement (OR, 0.62; 95% CI, 0.42-0.92; P = 0.018). Sex was not significantly associated with any of these outcomes. CONCLUSIONS Bollard-modified miniplate anchorage for BAMP showed high long-term success and low complication rates in growing patients. Complications were more frequent in the maxilla than in the mandible, and younger age was associated with a higher likelihood of adverse events. These findings support the use of Bollard-modified miniplates as a reliable skeletal anchorage system for BAMP in children and adolescents.