Objective: To study the mental health and associated factors of Prince of Songkla University dental students.

Material and Method: The study was a cross-sectional survey study, conducted during January to February 2012. The sample included all dental students (from year 1-6) of the Faculty of Dentistry, Prince of Songkla University, Thailand. All dental students were invited to complete a questionnaire covering demographic data and smoking and drinking habits, and the Thai General Health Questionnaire 12 (Thai GHQ-12). The data were analyzed using percentage, Fisher’s exact test and multiple logistic regression analysis.

Results: There were 289 dental students (83.3%) who completed the questionnaire. Only one student was a current smoker. More male dental students were likely to receive second-hand smoke more than 4 days a week, than the female dental students (p=0.004). 111 out of 267 dental students (41.6%) had a Thai GHQ-12 score more than 2, which indicate chance of mental health problem. Multivariate analysis revealed two factors significantly associated with the students’ mental health: dental class and exercise. The clinical dental students (4th to 6th year) and no exercise dental students were 3.5 and 2.2 times more likely to have mental health problems than the preclinical dental students (95% confidence
interval; CI=2.117-5.890) and do exercise dental students (95%CI=1.310-3.802) respectively.

Conclusion: Clinical dental practice period and lack of exercise were two factors significantly associated with the possibility of acquiring mental health problems in dental students at Prince of Songkla University. Gender, smoking and drinking habits, not eating breakfast seemed not to have an influence on acquiring mental health problems.