Halitosis or bad breath is an age-old problem about which the medical profession knows very little. It is not an area likely to be chosen by a physician or dentist eager to get money for research and to establish a name for himself or herself. However, it is a condition that causes many people grief, and I receive quite a few letters asking for information about halitosis and solutions for it.
A very interesting article which appeared in the Sunday magazine section of the New York Times discussed halitosis at some length, and inspired me to do a posting on the problem. The author interviewed one of the few doctors doing research on bad breath, Dr. George Preti of the Monell Chemical Senses Center in Philadelphia, and also mentioned a dentist, Dr. Jon Richter, who runs a breath clinic, also in Philadelphia. Anyone can read the full text on the Times’ web site, for a small charge.
Standard medical texts either make no mention of halitosis, or deal with the relatively uncommon diseases which are likely to affect the breath. Breath odor is changed in distinctive ways in people suffering from advanced kidney failure, advanced liver failure, diabetic acidosis, lung abscess, and some cancers of the mouth or upper respiratory tract. However, none of these cause our everyday bad breath.
The few sources I found that mentioned halitosis at all debunk the old idea that it comes from indigestion or problems in bowel function. Some mention gingivitis — infection of the gums — as a cause, and some refer rather vaguely to fermentation of food particles in the mouth. These explanations imply that people with bad breath have poor dental hygiene and the few patients that I have seen who complained of this problem also had good dental hygiene.
In the New York Times article, Dr. Preti offered the best explanation that I have seen for ordinary bad breath. He feels that it is a result of bacteria growing in plaque far back on the tongue, where they produce foul-smelling sulphur-containing compounds as part of their bacterial metabolism. These compounds, mostly hydrogen sulphide (rotten egg smell) and methylmercaptan (sewer gas smell) are volatile and easily rise off the plaque to mingle with our breath as we inhale and exhale.
Dr. Preti also specifically discussed the disease trimethylaminuria, mentioned by our second writer. This condition comes from an enzyme deficiency which causes sufferers to produce a fish odor smell. There is no way at present to replace the missing enzyme, although I suspect that gene therapy might be able to do so in the future when all the kinks are worked out in this exciting new form of therapy for congenital diseases. For the present, Dr. Preti advises that a person with the condition not eat beans or boiled fish, but makes no recommendation for other treatments.
For the rest of us with garden variety bad breath, Dr. Preti recommends a mouthwash developed by Dr. Richter. He feels that ordinary mouthwashes are not effective. He also recommends scraping off the plaque at the back of the tongue on a regular basis. This could be incorporated into one’s daily routine of flossing and brushing the teeth.