Sir, the COVID-19 pandemic brought stressful restrictions and changed our lifestyles drastically. We have reported the influence of COVID-19 pandemic on oral psychosomatic disorders (OPSD): burning mouth syndrome (BMS), atypical odontalgia, oral cenesthopathy (OC), phantom bite syndrome and so on. While there are no significant differences in the scores of Zung's self-rating depressive scales (SDS) and pain catastrophising scales at the early period of the COVID-19 pandemic (2020),1 we observed significant increases of psychiatric comorbidities and higher scores of SDS in the later period (2021).2

Our investigation for post-COVID-19 pandemic (2022) recently revealed the tendency of a re-decrease of psychiatric comorbidities. Moreover, the distribution of patients with OPSD has changed through the COVID-19 pandemic and has been returning to levels from before the COVID-19 pandemic (2018). In particular, the rate of patients with OC which shows indescribable, uncomfortable symptoms has tended to increase while that of BMS patients has decreased towards the later period of the pandemic.2 We suggest that coping well with the pandemic in BMS patients without psychiatric comorbidities3 may attribute to the decreased rate of BMS patients, besides the change of rate of OC patients. During the pandemic, the exacerbations of comorbid psychiatric disorders led to an increase of OC; the rate of BMS then decreased relatively. Post-pandemic, a reduction of psychiatric stress resulted in fewer OC patients and the relative recovery of the rate of BMS patients.

Therefore, the stressful circumstances during the COVID-19 pandemic did not simply affect onset of OPSD but may affect intolerance and vulnerability for the stressful burden that OPSD patients with psychiatric comorbidities might have. However, since the detailed symptoms of OPSD might have become more complicated through the pandemic, further studies with long-term follow-up including prognosis are required.