Device problems and patient injuries reported for clear aligners: a framework from the FDA MAUDE database

Introduction: Clear aligner systems are widely used for orthodontic treatment, but the patient injuries and device problems captured in postmarketing surveillance have not been organized into a structured framework. Methods: Descriptive retrospective analysis of adverse event reports for sequential clear aligners (product code NXC) received by the FDA MAUDE database between 2015 and 2023, retrieved through the openFDA device adverse events API. Device problems, patient injuries, event type, reporter occupation and aligner system were described, and a co-occurrence matrix linked device problem categories to patient injury categories. Results: A total of 2,467 reports were analyzed and 99.1% recorded an injury. Reports rose from 43 in 2015 to a peak of 929 in 2021. SmileDirectClub and Invisalign accounted for 66.5% and 17.8% of reports. Tooth fracture (919 reports, 37.3%), necrosis (251) and hypersensitivity or allergic reaction (167) were the most frequent patient injuries; patient-device incompatibility (169) and inadequacy of device shape or size (123) were the most frequent specific device problems. In the framework, device misfit was linked to allergic reactions, oral soft-tissue injury and pain, and biocompatibility or rejection was linked almost exclusively to allergic reactions. Conclusions: Adverse event reports for clear aligners concentrate on tooth fracture and soft-tissue or allergic injuries, associated largely with device misfit and biocompatibility. The framework provides a structured basis for clinical monitoring and postmarketing surveillance.