COVID-19 pandemic and Zagreb earthquakes as stressors in patients with temporomandibular disorders

Objective To evaluate stress effect of COVID-19 pandemic and Zagreb earthquakes on symptoms of temporomandibular disorders (TMD). Materials and Methods One hundred and two previously diagnosed TMD patients were contacted by email to participate in an online survey about impact of those events on current and/or new symptoms, perceived stress, anxiety and symptom intensity in time-points at the baseline, following pandemic and following earthquake. We compared data between earthquake-affected and non-affected respondents. Results Response rate was 79.4%. Effects stress had on deterioration of symptoms were significantly different between earthquake-affected and non-affected (p = .024). In earthquake-affected, numerical pain rating scale (NPRS) scores significantly increased between baseline and after COVID-19 (p > .001) and between baseline and after earthquakes (p > .05). However, scores insignificantly dropped from COVID-19 to after earthquakes time-points. In earthquake-affected, positive correlation was found between impact of COVID-19 on stress and NPRS (p < .001) and between earthquakes' impact on stress and NPRS (p < .001). Earthquake-affected respondents reported significantly more new behavioral habits when compared to non-affected (p = .048). Conclusions A series of stressful events do not necessarily have a cumulative effect, but are likely to have a complex interaction (e.g., acute stress might trigger the protective mechanisms), which could have decreased pain scores after the earthquakes.