Common Knowledge About Temporomandibular Disorders and Associated Factors With Its Symptoms: Evidence From a Portuguese Population-Based Survey

Introduction: The purpose of this article was to develop and validate a scale to assess common knowledge about temporomandibular disorders (TMDs) in the general population, evaluate the status of TMDs knowledge in the Portuguese population, quantify the severity and prevalence of TMDs-related symptoms in the general population, and assess the association between TMDs-related symptoms’ severity and demographic, medical and oral associated factors. Materials and Methods: This study was an analytical cross-sectional survey design. The sample consisted of 2165 participants selected through a snowball sampling method. The participants completed an online questionnaire regarding social and demographic characteristics, medical history, oral habits, Fonseca’s Anamnestic Index, a scale about difficulties on impulsiveness control and also the TMDs knowledge scale developed. The psychometric properties of the scale developed was tested on a small number of participants (n = 210). The P value set was 0.05. Results: Concerning psychometric properties all items showed a moderate-to-strong positive association with the loading factor. The Cronbach’s alpha was 0.956, showing good reliability. TMDs knowledge was positive in 1295 participants (59.8%). Multivariate-adjusted odds showed that female gender, diagnosis of tension-type headache, migraine, anxiety, impulsiveness, facial trauma, and parafunctional habits increased the risk of developing TMDs (adjusted odds ratios from 1.84 to 49.38). Conclusion: The scale developed is psychometrically valid and reliable and the participants had an overall positive knowledge about TMDs. A high prevalence of TMDs-related symptoms among the Portuguese population was found and the associated factors were female gender, impulsiveness, tension-type headache, migraine, anxiety, facial trauma, and parafunctional habits.