Sir, there is controversy as to whether, during the pandemic, patients with chronic oral pain have found their symptoms getting better or worse.1,2 While some researchers have reported an exacerbation of symptoms in burning mouth syndrome patients, others have reported that chronic pain was not affected at all.

We have studied the impact of COVID-19 on patients with oral psychosomatic disorders: burning mouth syndrome, oral cenesthopathy, atypical odontalgia, phantom bite syndrome and halitophobia, who visited our clinic (Psychosomatic Dentistry Clinic in Dental Hospital, Tokyo Medical and Dental University). Patients were divided into those from April 2018 to February 2019, deemed the pre-COVID-19 group, and those from April 2020 to February 2021, as post-COVID-19. Psychological impact was assessed using the Self-rating Depression Scale (SDS) and Pain Catastrophising Scale (PCS); however, we observed no significant differences between the two groups with respect to the mean scores of these scales.

In Japan, the government declared a state of emergency repeatedly. Although there was almost no psychological exacerbation both in our study and clinically, patients often complained about the stress they experienced. Therefore, we are now concerned that a prolonged pandemic might affect the psychological health of our patients gradually, eventually giving rise to 'syndemic' situation. This term is made up of the words 'synergy' and 'epidemic' and was first coined in 1990 by Prof M. Singer to describe when two or more diseases interact with each other to exacerbate the condition.3 Conditions of health inequality caused by social stigma, poverty, stress and so on are most likely factors responsible for a syndemic to emerge.

As with our patients, initially, many were anxious only about COVID-19 infection, but now patients complain about various psychological problems associated with COVID-19 like reduced social interaction, apprehension to make hospital visits which could deprive them from receiving the necessary treatment, work stress, financial stress for those who have lost jobs, and so forth.

These psychosocial problems could have a greater influence on dental patients and we believe might lead to deterioration of their symptoms, especially in the younger generation. Thus, we believe that more mental healthcare in dental practice is necessary, even if it is by using teledentistry.