Aphthous stomatitis, or recurrent aphthous stomatitis (RAS), commonly referred to as a canker sore or salt blister, is a common condition characterized by the repeated formation of benign and non-contagious mouth ulcers (aphthae) in otherwise healthy individuals. The cause is not completely understood but involves a T cell-mediated immune response triggered by a variety of factors which may include nutritional deficiencies, local trauma, stress, hormonal influences, allergies, genetic predisposition, certain foods, dehydration, some food additives, or some hygienic chemical additives like SDS (common in toothpaste). These ulcers occur periodically and heal completely between attacks. In the majority of cases, the individual ulcers last about 7–10 days, and ulceration episodes occur 3–6 times per year...