Ken Yaegaki
DDS, PhD
Clinical Professor, Oral Biological & Medical Sciences
yaegaki@interchange.ubc.ca
Contact Info:
www.dentistry.ubc.ca/AboutUs/FacultyStaffList/detail.asp?user_id=153
Research Interest:
Periodontal Pathogenesis by Volatile Sulphur Compounds Causing Oral Malodor
In 1964 Dr. J. Tonzetich, the University of British Columbia, started the first detailed biochemical studies on oral malodour. His more notable achievements include the discovery that volatile sulfur compounds (VSC) are the principal causes of oral malodor. And that these VSC could be accurately measured in mouth air using gas chromatographic techniques. It was a common clinical observation that individuals with periodontal disease frequently suffered from halitosis. I explored this relationship and found that VSC concentrations increased with the severity of periodontal disease. Moreover, my colleagues and I also concluded that VSC may have an important role in the etiology of periodontal disease and may accelerate periodontal disease, because VSC increases collagen solubility and degradation and the permeability of the oral mucosa, and decreases the synthesis of collagen (the major component of the extracellular matrix). My laboratory continues to investigate the influence of VSC on periodontal tissues in order to understand the mechanisms whereby VSC produces their effects, and perhaps lead to way of blocking their pathogenic effects.
Clinical Research into the treatment of Halitosis (Oral Malodor)
The production of VSC is related to various factors including psychological factors. The social effects of halitosis, however, are in the last analysis dependent of the perceptions of the people involved. There are people who have bad breath and worry about it, people who have bad breath and don't worry about it, people who don't have bad breath and logically don't worry about it and finally people who don't have bad breath and think that they do and worry about it, a group sometimes called halitophobics. Halitophobics sometimes alter their interactions with other members of society to such an extreme degree that it disrupts their whole. I am developing methods to identify and treat such patients. The methods involve objective measurements of breath odor by GC and sensory methods, psychological testing, counseling and behavioral modifications.
Selected Publications
Yaegaki, K. and Sanada, K. "Volatile sulfur compounds in mouth air from clinically healthy subjects and patients with periodontitis" J. Periodont. Res. 27:233-238, 1992.
Yaegaki, K. and Sanada, K. "Biochemical and clinical factors influencing oral malodour in periodontal patients" J. Periodontol. 63:783-789, 1992.
Johnson, P., Yaegaki, K. and Tonzetich, J. "Effect of volatile thiol compounds on protein metabolism by human gingival fibroblasts" J. Periodont. Res. 27:553-561, 1992.
Johnson, P.W., Yaegaki, K., and Tonzetich, J. " Effect of methyl mercaptan on synthesis and degradation of collagen in human gingival fibroblasts" J. Periodont. Res., 31:323-329, 1996.
Yaegaki, K. and Coil, J.M., "Clinical Dilemmas Posed by Psychosomatic Halitosis Patients" Quintessence International, 30:302-306,1999.
Yaegaki, K. and Coil, J.M., "Clinical Application of the Questionnaire for Diagnosis and Treatment for Halitosis" Quintessence International, 30:328-333, 1999.
Yaegaki, K. and Coil, J.M., "Genuine Halitosis, Pseudo-Halitosis and Halitophobia: Classification, Diagnosis and Treatment" Compendium 21 (10A):880-890, 2000.
Books
Yaegaki, K., BAD BREATH; Research Perspectives (editor, Rosenberg, M.), Ramot Publishing-Tel Aviv University, Chapter 6, p87-108, 1995.
Yaegaki, K., Matsudaira, H., Sano, R. and Kitamura, T. Bad Breath, A Multidisciplinary Approach (editors, van Steenberghe, D. and Rosenberg, M.), Leuven, Leuven Univ. Press, p217-230, 1996.
Yaegaki, K. BAD BREATH; Research Perspectives, Second edition (editor, Rosenberg, M.), Ramot Publishing-Tel Aviv University, Appendix 3, p227-231, 1997.
Yaegaki, K. ed. Clinical Guideline for Halitosis, Quintessence Pub. (Tokyo), 2000.
