Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 16 6 2020 06 24 465 472 Mina Khayamzadeh Department of Oral Medicine, School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran Iraj Mirzaii-Dizgah Department of Physiology, AJA University of Medical Sciences, Tehran, Iran Pegah Aghababainejad Private Practice, Tehran, Iran Sareh Habibzadeh Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. AND Department of Prosthodontics, School of Dentistry, International Campus, Tehran University of Medical Sciences, Tehran, Iran Mohammad Javad Kharazifard Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran 2019 07 18 2019 12 01 Objectives: Parafunctional habits, as one of the etiological factors of temporomandibular disorders (TMD), are an individual’s response to increased stress. During stress and depression, biomarkers such as cortisol and salivary alpha-amylase (SAA) are secreted in the saliva. The present study aimed to investigate whether there is a correlation between salivary stress biomarkers and parafunctional habits. Materials and Methods: Thirty-two cases, from May to September 2015, were selected based on two standard stress questionnaires, namely the depression anxiety stress Scale-21 (DASS-21) and the Beck Anxiety Inventory (BAI). Saliva samples were collected to examine the level of unstimulated salivary cortisol and SAA. The significance of the results was assessed via student’s t-test and Mann-Whitney test (α=0.05). Results: The mean concentrations of cortisol and SAA in unstimulated saliva were significantly higher in the case group than in the control group (P=0.01 and 0.44, respectively). The mean scores of anxiety, stress, and depression were significantly higher in the case group than in the control group (P<0.05). Conclusion: It seems that the levels of salivary cortisol and SAA, as well as stress, anxiety, and depression scores, are higher in patients with parafunctional habits. https://fid.tums.ac.ir/index.php/fid/article/view/3233 https://fid.tums.ac.ir/index.php/fid/article/download/3233/1790