Seminar content: The prognosis for oral squamous cell carcinoma is one of the worst, with a 5-year survival rate of 50%. This makes it clear what responsibility the dentalpractice team has in the early detection of suspicious lesions in order to increase the survival rate of these affected patients. The aim of this course is therefore to motivate dentists and dental hygienists to recognize, understand and communicate all types of mucosal lesions, focusing on the clinical appearance of the most common stomatological diseases and differentiating between harmless and suspicious lesions.