Aphthous stomatitis near to the ulcer, described histologically as "perivascular cuffing". Aphthous stomatitis has been classified as a type of non-infectious stomatitis (inflammation of the mouth). One classification distinguishes "common simple aphthae", accounting for 95% of cases, with 3–6 attacks per year, rapid healing, minimal pain and restriction of ulceration to the mouth; and "complex aphthae", accounting for 5% of cases, where ulcers may be present on the genital mucosa in addition to mouth, healing is slower and pain is more severe. A more common method of classifying aphthous stomatitis is into three variants, distinguished by the size, number and location of
Stomatitis nicotina with tobacco use may be evident such as brown or black extrinsic staining of teeth from tar and other components of tobacco smoke. The cause of nicotine stomatitis is thought to be chemical or thermally induced keratosis. The chemicals in tobacco may act as irritants in this condition. Chronic heat exposure is also responsible. Pipe smoking produces more heat on the palate than any other forms of smoking. Long-term drinking of very hot beverages can also cause a similar condition. The severity of the changes correlates with the frequency of the habit. The prevalence depends on a society's use of