This study analyzed anxiety and depression of 1241 respondents, with 587 orthodontic patients and 220 TMD patients during the COVID-19 epidemic. The average K10 score of all respondents was 18.65 with a median of 17.0, which was noticeably higher compared with normative population13,14, and even residents experienced environmental catastrophe15. Though there might be difference between races, it was quite evident that the epidemic had severe adverse effects on mental health.
Level of both anxiety and depression was shown to be higher in TMD patients. The null hypothesis that all variables have the same influence on psychological distress was rejected. TMD symptoms were related to pain frequency, psychological distress, jaw disfunction and parafunctional behaviors16. Previous study has shown that orofacial pain was associated with poorer oral health-related quality of life and signs of psychological distress17, with which our study agreed.
Through multiple linear regression analysis, psychological status of orthodontic patients was not found statistically different from general population. There were many researchers using the Oral Health Impact Profile (OHIP-14) to assess oral health-related quality of life (OHRQoL) on patients in orthodontic treatment18–20 and it was acknowledged that the orthodontic patients had higher negative impacts than the control group20. Psychological distress correlated with quality of life21, but QoL is a quite different concept from psychological distress. As for adults in their 20 s, the rate of positive perception towards orthodontic treatment was up to 63.2%22. Also, aesthetics is a major concern in orthodontic treatment for individuals, other than symptoms like orofacial pain and jaw disfunction in TMD patients. These reasons contributed to the difference of psychological status of TMD patients and orthodontic patients.
The proportion of females is more than that of males, both in orthodontic patients and TMD patients, which was in accordance with the trend that females were more likely to seek orthodontic treatment23, and have higher risk of TMD as well24. Agreed with our findings, a cross-sectional survey conducted in 1400 university students of China using the same scale showed females were more vulnerable to psychological distress25. In the regression models, using either anxiety score or depression score as the dependent variable, years of age were negatively correlated with psychological status. Youngsters might have more access to the severity of the epidemic through smartphones and developed higher odds of distress, while some elder people were not much cared about the disease. Similarly, previous study has shown psychological distress decreased through the range of 20–64 years of age26. Furthermore, respondents reporting close contact with individuals from Hubei province were associated with increased distress level. This sub-sample was relatively small, compared with respondents out of the epicenter, but the mental health of patients with confirmed COVID-19, patients with suspected infection, quarantined family members, and medical personnel was of the greatest concern2.
In terms of the perception of COVID-19, both average knowledge score and severity score of the COVID-19 were up to 4-4.5. When asked about the possibility of infection, the degree of the answers distributed to a relatively lower level, with the mean value below 2.5. These data revealed that the Chinese government had achieved great success on the disease disclosure, as well as the disease prevention and control. As for the main concerns about the influence of COVID-19, objective choices like impact on work/study and on daily life accounted more, while more subjective ones were relatively less concerned, such as isolation from family/society and psychological barriers and distrust among people.
However, these latter two attitudinal items mentioned above were related to high anxiety and depression. This certainly highlights the need to carry out mental health care in addressing the issue of distress in dental patients and general residents. Another prominent finding is that higher score in infection possibility of people around you was related to higher anxiety, whereas higher score in infection possibility of yourself indicated increasing odds of depression. The diagnosis of anxiety and depression tends to co-occur, and their symptoms are highly correlated27. However, they are not quite the same concept, which also supported the use of two-factor structures of K10 in accordance with Brooks’s study12.
One limitation of this study was that we didn’t include the severity of the symptoms in TMD patients, types of appliances in orthodontic patients or other possible independent variables. It has been shown that compared to removable appliances, fixed appliances resulted in a significant negative effect on OHRQoL18, and this independent variable might also be related to psychological status.
Though the sample size was substantial, another limitation was that based on the number of people who had access to the online questionnaire, we estimated overall response rate was approximately between 60–70%, but the specific number was not quite clear, which might to some extent impair the representativeness of the study sample.