Abstract
Purpose: Perceived stress is associated with temporomandibular disorder (TMD), but whether cortisol levels are elevated in individuals with TMD is unknown. We hypothesized that cortisol concentration, a biomarker of hypothalamic-pituitary-adrenal (HPA) axis function, was elevated in TMD cases relative to controls, and that perceived stress was positively correlated with cortisol concentration.
Methods: In this case control study, TMD case status was determined by examiners using TMD Research Diagnostic Criteria. Participants (n=116) aged 18 to 59 years were recruited from within a 50 mile radius of the University of North Carolina at Chapel Hill. Following examination, cases (n=45) and controls (n=71) completed the 14-item Perceived Stress Scale using a reference interval of the past 3 months. Approximately 100 strands of hair were cut from the posterior vertex segment of their scalp. The 3 centimeters of hair most proximal to the scalp was analyzed with a commercially available salivary cortisol enzyme immunoassay adapted for hair cortisol. This length corresponds to the last 3 months of systemic HPA axis activity.
Results: TMD cases perceived higher stress than controls (p=0.001). However, hair cortisol concentration was lower in TMD cases than controls (p<0.001). The correlation coefficient revealed a weak negative relationship (r=-0.188) between perceived stress and hair cortisol concentration (p=0.044). In analysis stratified by case status, the relationship of perceived stress and hair cortisol concentration was non-significant for cases (p=0.169) and controls (p=0.498).
Conclusion: Despite greater perceived stress, TMD cases had lower hair cortisol concentrations than controls and the 2 measures of stress were weakly and negatively correlated.
- Temporomandibular joint disorders
- Epidemiology
- Factor, psychosocial
- Hormones, hypothalamic pituitary regulating
Footnotes
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Cynthia Ann Lambert, CDA, RDH, MS, is a clinical assistant professor at the Department of Dental Ecology, a clinical research coordinator at the Department of Operative Dentistry at the University of North Carolina School of Dentistry, Chapel Hill. Anne Sanders, MS, PhD, MS, is an assistant professor at the Department of Dental Ecology, School of Dentistry, University of North Carolina at Chapel Hill. Rebecca S. Wilder, BSDH, MS, is a professor, Director of Faculty Development and Director of Graduate Dental Hygiene Education at the University of North Carolina School of Dentistry. Gary D. Slade, BDSc, DDPH, PhD, is a John W. Stamm Distinguished Professor of Dentistry, Department of Dental Ecology at the UNC School of Dentistry, Chapel Hill. Stan Van Uum, MD, PhD, FRCPC, is the Program Director of Endocrinology and Metabolism and Associate Professor of Endocrinology & Metabolism at the Department of Medicine, Western University, London, Ontario. Evan Russell MSc, is affiliated with the University of Toronto, Western University. Gideon Koren MD, FRCPC, FACMT, is the Director of the Motherisk Program at the Hospital for Sick Children, Professor of Pediatrics, Pharmacology, Pharmacy and Medical Genetics at the University of Toronto and a Professor of Medicine, Pediatrics and Physiology/Pharmacology at the Ivey Chair in Molecular Toxicology at the University of Western Ontario. William Maixner, DDS, PhD, is a Mary Lily Kenan Flagler Bingham Distinguished Professor and Director, Regional Center for Neurosensory Disorders, University of North Carolina at Chapel Hill.
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This study supports the NDHRA priority area, Clinical Dental Hygiene Care: Investigate the links between oral and systemic health.
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This project won 1st place in the ADHA Sigma Phi Alpha Journalism Award Competition, June 2012, under the master or doctoral level category. Award provided by a generous grant from Johnson & Johnson Healthcare Products, Division of McNEIL PPC, Inc.
- Copyright © 2013 The American Dental Hygienists’ Association
