Morbus Crohn is a granulomatous disease which can affect the whole gastrointestinal tract including the oral cavity. Typically the disease is chronic and progresses in stages with phases of exacerbations and remissions. Mostly it occurs between the ages of 15 and 35, as well as 60 and 80. Symptoms range from diarrhea, stomach upset and weight loss to fever. In the oral cavity, characteristic changes are hyperplasias and ulcerations of the mucosa mainly located bilaterally and in the vestibule. Treatment options are glucocorticosteroids, TNF-a-blockers, azathioprine/methotrexate partial in combination with surgical interventions.