The oral medicine is the part of dentistry responsible for diagnosing and treating diseases originating in the mouth (called primary) and general diseases affecting this area (known as secondary), affecting structures of the oral cavity or adjacent. The oral drug is not merely the inspection of teeth but checks tongue, palate, lips, cheeks, and floor of the mouth in order to detect both benign and malignant diseases is important to treat in time. The conditions can be diagnosed with an intraoral and extraoral visual examination of the mouth and through additional tests such as x-rays, biopsies, cultures, blood tests and microbiological tests. Also, a good diagnosis must take into account the patient's history. Treatment depends on the type of disease but may include the administration of drugs or surgery, either to repair the damage or to remove the lesion.