A study funded by the Texas Cancer Council estimates that 6.8 million Americans use snuff or chewing tobacco, and many believe that smokeless tobacco is safer than smoking cigarettes. It's not. Smokeless tobacco is more addictive because it contains higher levels of nicotine than cigarettes do, and it causes a number of oral health problems from tooth decay to cancer.
If you use smokeless tobacco, you are at a greater risk of developing cavities. Tobacco causes tooth decay, eats away at your gums and leads to tooth loss. It also causes:

Researchers have identified 28 different cancer causing substances in chewing tobacco and snuff. According to the American Cancer Society, approximately 40,000 new cases of oral cancer are reported each year in the United States. Experts estimate that tobacco use is responsible for 80 to 90 percent of these new cases. When tobacco use is combined with alcohol use, the risk of oral cancer increases.
If not detected and treated in its early stages, oral cancer can spread, leading to chronic pain, loss of function, post-surgery facial disfigurement and death.