T–U
tobacco use other than smoking Forms of
tobacco such as chewing tobacco and smoking
cigars. Tobacco use other than cigarette smoking is
the primary cause of oral cancers (cancers that
involve structures of the MOUTH). The two primary
forms of tobacco use other than cigarettes are
cigars and smokeless tobacco.
Cigar and Pipe Smoking
Cigar and pipe smoke contains many of the same
chemicals and carcinogens as cigarette smoke.
Because cigar and pipe smokers hold the smoke in
their mouths rather than inhaling it, the struc-
tures of the mouth have intense exposure to these
chemicals. Long-term exposure to tobacco smoke
is detrimental to the gums and TEETHand increases
the risk for CARDIOVASCULAR DISEASE(CVD).
Though the risk of LUNG CANCERfrom smoking
cigars or pipes is less than that from smoking ciga-
rettes, it is notably higher than for people who do
not smoke at all and in people who smoke three
or more cigars a day. People who regularly smoke
cigars also have higher risk forPANCREATIC CANCER,
laryngeal cancer, and ESOPHAGEAL CANCER. The
most significant cancer risks from cigar smoking
are cancers of the lips, tongue, cheeks, soft palate
(roof of the mouth), floor of the mouth, and
gums.
Smoking two to three cigars or more a day
raises the risk for CVD nearly as much as cigarette
smoking. The NICOTINEin tobacco becomes rapidly
absorbed into the BLOODcirculation through the
mucous membranes in the mouth. Nicotine stim-
ulates the smooth MUSCLEthat makes up the walls
of the arteries, causing the arteries to stiffen.
Chronic exposure to nicotine also alters the struc-
ture of the muscle fibers in the arterial walls,
reducing their FLEXIBILITY. These changes cause
HYPERTENSION(high BLOOD PRESSURE). The changes
to the arterial wall’s structure also facilitate the
accumulation of arterial plaque and atheroscle-
rotic deposits, leading to ATHEROSCLEROSIS and
increasing the risk for CORONARY ARTERY DISEASE
(CAD).Smokeless Tobacco
It is a common misperception, particularly among
young people, that smokeless tobacco is safe
because there is no smoke involved with its use.
This is not true. Smokeless tobacco contains nico-
tine, which is highly addictive. It can be as difficult
to quit using smokeless tobacco as it is to stop
smoking. A pinch or dip of smokeless tobacco con-
tains as much nicotine as three cigarettes. Forms
of smokeless tobacco include snuff, which is pow-
dery, and chewing tobacco (plugs, twists, and
loose leaf).
Smokeless tobacco is particularly damaging to
the teeth and gums. After only a few years of reg-
ular use, the gum tissue may become structurally
unstable, unable to support the teeth. Tooth loss
may be unpreventable in such circumstances. The
irritation of the tobacco against the gums and
cheeks also causes sores that can be painful or can
further erode the tissue around the base of the
teeth. Tobacco juice permanently stains the teeth
yellow or brown and erodes the enamel outer
layer, increasing the risk for DENTAL CARIES(cavi-
ties) and weakening the teeth.
About four times the concentration of nicotine
enters the blood circulation from smokeless
tobacco as from cigarette smoking. Nicotine that
enters the blood circulation by being absorbed
through the tissues of the mouth has the same
negative effects on the blood vessels as nicotine
that enters the blood circulation through the306