You are presented with a paragraph from a COVID-19 literature. Classify the topics of this piece of text by choosing from the following categories:

- Epidemic Forecasting: The content relates to predictions about the spread of COVID-19.
- Treatment: The paragraph discusses therapeutic methods or medication for COVID-19.
- Prevention: The content covers measures to prevent the spread of COVID-19.
- Mechanism: The paragraph explains the biological mechanisms of the virus.
- Case Report: The content is a report of a COVID-19 case.
- Transmission: The paragraph discusses how COVID-19 is transmitted.
- Diagnosis: The content is about diagnosing COVID-19 in individuals.

Your classification should be provided as an element within a JSON array. The array should be formatted with topics enclosed in double quotes and separated by commas, following the JSON format, for example: ["Topic1", "Topic2", ...]. Include all applicable topics within the array. Your output should be a valid JSON array, and no additional text should be included in your response.

Article:

INTRODUCTION: This retrospective study aimed to quantify the impact of coronavirus disease 2019 (COVID-19) on the orthodontic appointment and make an analysis of orthodontic emergencies (OEs) that occurred during the pandemic. METHODS: A total of 628 patients were randomly sampled from 3489 subjects who were undergoing active orthodontic treatment with fixed appliances, and the medical records were reviewed. 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% of the patients was delayed significantly with an increase over 8.98 +/- 4.76 weeks (P <0.001). In general, 32.3% of the patients suffered from various OEs while waiting for their first return-visit, and bracket or band debonding was the most frequently reported category. Most OEs did not receive timely treatments because of the lockdown. The incidence was nearly 2 times higher than that of the normal appointment times. No correlation was found between OE occurrence and different demographic and clinical characteristics of patients. The therapeutic progress of patients, especially those in stage 3, was postponed because of the occurrence of OEs. CONCLUSIONS: Regardless of the limitations, our study suggested that it is highly possible that the COVID-19 pandemic has delayed appointments of fixed orthodontic patients. OEs did bother a minority of patients and could not be settled in time during the lockdown, which had a negative impact on the near-term treatment progress and should have been prevented. Further studies are required to investigate the long-dated influence of COVID-19 on orthodontic practices.
["Prevention"]