The Importance of Type D Personality in the Development of Temporomandibular Disorders (TMDs) and Depression in Students during the COVID-19 Pandemic

Background: a type D personality is a factor in a person's susceptibility to general mental stress, especially during the COVID-19 pandemic. Although many studies were conducted on the relationships among stressful situations, an individual's personality, depression, and the occurrence of various diseases, e.g., cardiovascular disease or cancer, there are no analogous data on people with temporomandibular disorders (TMDs). Aim: the assessment of TMDs and depression symptoms in students with type D personality. Material and Methods: the research was carried out with the participation of 240 physiotherapy students. The study group (G1) consisted of 120 participants with type D personalities, the control group (G2) consisted of the same number of participants, without "stress" personalities. All subjects were assessed for the occurrence of TMD symptoms, as well as for depression and anxiety symptoms, using the Beck Depression Inventory (BDI), based on the proprietary questionnaire. Results: in students with type D personality symptoms, TMDs occurred significantly more often and in greater number (p = 0.00) than in those without stress personalities. The exception was the symptom of increased muscle tension, which showed no statistical difference (p = 0.22). Among the 240 respondents, depression was found in 128 people (53.3%). In the group of students with type D personalities, depression was significantly more frequent than in the group without type D personalities (p = 0.00). In participants with depression, TMD symptoms were more common, i.e., headaches, neck, and shoulder girdle pain, TMJ acoustic symptoms, increased masticatory muscle tension, teeth clenching, and teeth grinding. There was no significant difference between the incidence of depression and TMJ pain and jaw locking. There was a significant interaction between the occurrence of headaches and acoustic symptoms and the occurrence of depression. For headache and depression interactions, the OR was >1; based on the results, we may assume that a headache depends more on the occurrence of depression rather than it being a symptom of a TMJ disorder in people with type D personalities. Conclusion: type D personality and depression may contribute to the development of TMD symptoms.