Smoker's breath, a form of halitosis caused by tobacco use, is not simply caused by the presence of smoke particles on the tongue and teeth. According to a number of hospitals, tobacco can create bad breath in a multitude of ways.
The most obvious way that tobacco causes oral odor is its ability to linger in the saliva and the air of the lungs, giving off the smells of tar, carbon dioxide, formaldehyde and ammonia.
The University of Chicago Medical Centers has said that the hot gases in cigarette and cigar smoke may also dry out the tongue and throat, giving anaerobic bacteria - microorganisms that thrive in a dry dental environment - the chance to grow. Oral bacteria emit sulfuric compounds that can be detected by most noses in even trace amounts.
New York Presbyterian Hospital (NYPH) has stated that smoking contributes to gingivitis and periodontal disease, each of which can give the mouth a sour odor and lead to tooth decay.
Dental decay is itself an agent of bad breath, since rotted teeth act like a Petri dish for oral microorganisms. Furthermore, NYPH warned that smoking and chewing tobacco products can decrease an individual's ability to taste. Minus this crucial sense, it may be harder for people with halitosis to taste it on their tongues.
Brushing the teeth twice daily and rinsing with a specialty breath freshening product may mitigate some of the halitosis caused by tobacco.