Mouth pain occurs with most dental diseases. It can be associated with infectious and inflammatory processes, advanced caries and its complications, allergies, neuralgia, TMJ pathology, oral injuries, and neoplasms. Painful sensations can be localized in the area of the lips, tongue, gums, jaws, palate, oropharynx. To differentiate the causes of pain in the mouth, a visual-instrumental, x-ray, ultrasound, and laboratory examination is required. Treatment consists in prescribing pharmacotherapy, physiotherapy, performing dental manipulations and operations.