If Smokers melanosis is destroyed by excessive smoking, as in the hard palate of reverse smokers, who smoke with the glowing part of the cigarette inside the mouth for different reasons, a pale depigmented surface is first seen, indicating the loss of the protecting melanin. Then a red inflammation sometimes occurs and cancer development may follow. In reverse smokers it is important to regularly inspect the  areas with Smokers melanosis to detect any melanin destruction, in order to stop smoking in time and thus prevent a cancer to develop. Epidemiology
A study in Sweden showed that 21.5% of smokers and 3% of nonsmokers (genetic pigmentation or unknown cause) had lesions that could be classified as an oral melanin pigmentation. A gingival melanin index in 4 degrees was established. Already with a consumption of 1-3 cigarettes a day 9.3% of all 20.333 examined showed a smokers melanosis. Pipe smokers had smokers melanosis in 16.8%. One year after the start of cigarette smoking a clinically visible smokers melanosis could be seen in 12.3% of women, and 17% among men. In cigarette smokers who quit smoking, the number of individuals with smokers melanosis becomes slowly less frequent after 2–3 months, but can still be seen in a few former smokers three years after smoking stop. Although clinically visible genetic melanin pigmentations in the mouth are present in several ethnic groups all over the world, more mucosal areas will be melanin-pigmentet if tobacco products are used.
They are produced by the dendritic, octopus-like melanocytes, seen between the epithelial cells situated closest to the epithelium/connective tissue border.In tobacco-users the melanocytes are stimulated to produce melanin granules and to distribute them out to the surrounding epithelial cells for further transport to the mucosal surface, like the mechanism in melanin-pigmented skin. Small amounts of melanin-like granules together with other electron-dense particles can also be seen within large melanosome complexes in the underlying connective tissue. If the granules derive from the epithelium,  a phenomenon known as melanin incontinence, is not known. In Caucasians these granules are not expected to influence on the clinically observed degree of smokers melanosis. Causes
Smoking or the use of nicotine-containing drugs is the cause to Smokers melanosis,. Also tar-components (benzopyrenes) are known to stimulate melanocytes to melanin production, and other unknown toxic agents in tobacco may also be the cause. These chemical agents have a polycyclic, chain-like structure. Environmental tobacco smoke from parents is causing smokers melanosis in their children    Swedish snuff causes a small elevation of oral melanin pigmented individuals from 3.0% to 4.7%. Nicotine tablets have shown to stimulate to melanin pigmentation of the oral mucosa. Treatment and prognosis
Lesions usually disappear between 3 months to 3 years for those who stop smoking. Smokers melanosis is a benign, normal physiological reaction, and does not develop into cancer. If it does not disappear, however, a biopsy can verify the diagnosis.