Research Grows Connecting Oral and Mental Health

By Dr. Mehmood Asghar (B.D.S, M.Phil., Ph.D.)

As dental professionals, we routinely remind our patients about the importance of maintaining good oral health, as it not only affects one’s smile and appearance but also directly affects physical health and well-being. We counsel our patients that there is a direct, two-way association between oral health and various systemic illnesses, such as cardiac and respiratory disorders, and increased risk of poor diabetic control and pre-term/ low-weight births (Amato, 2022). While the recommendations of the American Dental Council regarding this oral-systemic link are followed meticulously, dental professionals often neglect a crucial aspect; the link between oral hygiene and mental health.

The Oral-Mental Health Link

Mental health disorders are a group of chronic diseases presenting with poor treatment outcomes and high comorbidity rates. Unfortunately, the prevalence of these disorders continues to rise over the years. In 2015 alone, 322 million people suffered from various mental health issues, recording an 18.4% rise in prevalence since 2005 (Ball & Darby, 2022). In 2011, $22.8 billion were spent on treating depression in the United States (Siu & Force, 2016).

Mental health disorders have also been bi-directionally linked with systemic issues such as cardiovascular and diabetes. These issues have been postulated to stem from lifestyle factors (smoking, sedentary lifestyle, hypertension, etc.), neurotransmitter level alterations, and systemic inflammation (Siu & Force, 2016).

More importantly, mental health has been linked to increased dental health risks. A systematic review by Kisely et al. (2015) showed that people with severe mental illness had a 2.8 times higher risk of losing teeth than the general community. Furthermore, these individuals had a significantly higher prevalence of decayed, missing, and filled (DMF) teeth than those without mental disorders. Similarly, another study showed that individuals with chronic periodontitis had significantly higher levels of dental anxiety of impaired oral health-related quality of life (OHRQoL) (Levin et al., 2018). Establishing the two-way link between oral health and mental illness, Petit et al. (2021) showed that patients with higher stress, anxiety, and depression scores had worsened non-surgical periodontal treatment (SRP) outcomes.

Recently, a study examined the mental health-oral health association longitudinally and cross-sectionally, revealing interesting findings. The study, presented at the 52nd Annual Meeting & Exhibition of the American Association for Dental Oral and Craniofacial Research (AADOCR), evaluated six oral health parameters: self-rated oral health, bleeding gums, loose teeth, tooth loss, gum disease, and bone loss. The prevalence of these parameters was then assessed according to the severity of mental health issues. The results showed that all six oral health parameters had significantly higher prevalence over increasing mental health severity. For example, the adjusted odds of bone loss around teeth were 1.79 times greater [95%CI 1.30-2.46] at high versus none/low categories of internalizing problems.

Understanding the Oral-Mental Health Link

Poor dental health, particularly periodontal disease and mental health, tend to share common risk factors, such as lower education and socioeconomic levels, older age, and lifestyle changes, such as tobacco and alcohol consumption. Moreover, both diseases share contributory genetic factors. Studies on depression have established an association with genetic polymorphisms in genes coding for brain-derived neurotropic factors and serotonin. At the same time, Another study suggested that serotonin polymorphism may be associated with aggressive periodontitis.

The proposed contributory mechanism of depression toward periodontitis involves the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and behavioral health changes. It has been suggested that dysregulation of the HPA axis causes adrenal disturbances, immune dysfunction, and an increased release of pro-inflammatory cytokines that aggravate periodontal disease (Belvederi Murri et al., 2014).

Similarly, evidence suggests that periodontal disease may contribute to the onset of depression. Periodontal disease leads to increased levels of inflammatory mediators such as cytokines, including tumor necrosis factor-alpha, interleukin-1, and interleukin-6, that exacerbate the pre-existing inflammatory state and increasing the risk of depression and other mental disorders (Petit et al., 2021).

The Take-Home Message

Considering the increased prevalence of dental and mental health issues, there is a need to develop preventive mechanisms. Dental professionals are usually the first to identify health-related mental problems in patients during routine checkups, as they pick up oral health-related manifestations of stress or anxiety, such as teeth grinding, TMJ disorders, and severe periodontitis.

Hence, dentists can be at the forefront of the fight against depression and dental problems. Realizing that both issues are interlinked and complement each other, dental professionals must be on the lookout for underlying signs and take corrective measures promptly. Depression and stress affect one’s physical health and dental hygiene. More importantly, poor oral health can exacerbate mental and physical well-being issues. So, all these factors must be considered and treated together.

Author: Dr. Mehmood Asghar is a dentist by profession and an Assistant Professor of Dental Biomaterials at the National University of Medical Sciences, Pakistan. Dr. Asghar received his undergraduate and postgraduate dental qualifications from the National University of Science and Technology (NUST). He has recently received a Ph.D. in Restorative Dentistry from Universiti Malaya, Malaysia. Apart from his hectic clinical and research activities, Dr. Asghar likes to write evidence-based, informative articles for dental professionals and patients. Dr. Asghar has published several articles in international, peer-reviewed journals.

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References

• Amato, A. (2022). Oral-Systemic Health and Disorders: Latest Advances on Oral&; Gut&; Lung Microbiome Axis. Applied Sciences, 12(16), 8213. https://www.mdpi.com/2076-3417/12/16/8213
• Ball, J., & Darby, I. (2022). Mental health and periodontal and peri-implant diseases. Periodontology 2000, 90(1), 106-124. https://doi.org/https://doi.org/10.1111/prd.12452
• Belvederi Murri, M., Pariante, C., Mondelli, V., Masotti, M., Atti, A. R., Mellacqua, Z., Antonioli, M., Ghio, L., Menchetti, M., Zanetidou, S., Innamorati, M., & Amore, M. (2014). HPA axis and aging in depression: systematic review and meta-analysis. Psychoneuroendocrinology, 41, 46-62. https://doi.org/10.1016/j.psyneuen.2013.12.004
• Kisely, S., Baghaie, H., Lalloo, R., Siskind, D., & Johnson, N. W. (2015). A Systematic Review and Meta-Analysis of the Association Between Poor Oral Health and Severe Mental Illness. Psychosomatic Medicine, 77(1), 83-92. https://doi.org/10.1097/psy.0000000000000135
• Levin, L., Zini, A., Levine, J., Weiss, M., Lev, R., Chebath Taub, D., Hai, A., & Almoznino, G. (2018). Demographic profile, Oral Health Impact Profile and Dental Anxiety Scale in patients with chronic periodontitis: a case-control study. Int Dent J, 68(4), 269-278. https://doi.org/10.1111/idj.12381
• Petit, C., Anadon-Rosinach, V., Rettig, L., Schmidt-Mutter, C., Tuzin, N., Davideau, J. L., & Huck, O. (2021). Influence of psychological stress on non-surgical periodontal treatment outcomes in patients with severe chronic periodontitis. J Periodontol, 92(2), 186-195. https://doi.org/10.1002/jper.20-0105
• Siu, A. L., & Force, a. t. U. P. S. T. (2016). Screening for Depression in Adults: US Preventive Services Task Force Recommendation Statement. JAMA, 315(4), 380-387. https://doi.org/10.1001/jama.2015.18392