Introduction: This retrospective study aimed to quantify the impact of COVID-19 on the orthodontic appointment and make an analysis of orthodontic emergencies that occurred during the pandemic .

Methods: A total of 628 patients were randomly sampled from 3489 subjects who were undergoing active orthodontic treatment of fixed appliances and the medical records were reviewed . Orthodontic emergency (OE) occurrence was analyzed from 617 patients who had explicit return-visit records after the COVID-19 outbreak . Wilcoxon signed-rank tests, Chi-square tests and a binary logistic regression were performed .

Results: The return-visit of 98.6% patients was delayed significantly with an increase over 8.98 ± 4.76 weeks (P <0.001). In general , 32.3% patients suffered from various OEs while waiting for their first return-visit and bracket/band debonding was the most frequently reported category . Most of OEs didn ’ t receive timely treatments due to the lockdown . The incidence was nearly twice higher than that of the normal appointment times . No correlation was found between OE occurrence and different demographic/clinical characteristics of patients . The therapeutic progress of patients, especially those in stage 3, was postponed due to the occurrence of OEs .

Conclusions: Regardless of the limitations, our study suggested it ’ s highly possible that the COVID-19 pandemic has delayed appointments of fixed orthodontic patients . Orthodontic emergencies did bother a minority of patients and couldn ’ t be settled in time during the lockdown, which had a negative impact on the near-term treatment progress and should be prevented . Further studies are required to investigate the long-dated influence of COVID-19 on orthodontic practices.