Predisposition to certain diseases may also be caused by „intrinsic“ factors such as the age, sex, race and congenital individual specifics (genetic influences), the sum of which contributes to the constitution of the organism.

Many diseases of the oral mucosa manifest predominantly in patients of certain age groups (herpetic gingivostomatitis in children, ulcerative gingivostomatitis during adolescence, etc.), which may be helpful in establishing the correct diagnosis. In general, we can say that certain periods in life are associated, due to the immunological and hormonal changes, with a higher risk of developing an oral mucosal disease. At the newborn and infant age, the immunity passively acquired through the transport of IgG antibodies through the placental barrier drops steeply in the first weeks of life. Only after several weeks, the production of own immunoglobulins begins and cellular immunity is being established. Oral candidosis is a typical disease associated with this age. Another important period is the puberty, characterized by major hormonal changes in the organism, which is associated with the highest prevalence of ulcerative gingivitis (maximum between 16 and 21 years of age), infectious mononucleosis or EEM. At the old age, physiological reserves grow smaller and the number and intensity of pathological processes grows. A general decline of immune response and of the so called immunological surveillance can be observed, which leads to an increase in the occurrence of autoimmune diseases (pemphigus, Sjögren syndrome) and cancer. Hormonal dysfunction, especially in women, is associated with atrophy of the skin and mucosa, vasomotor disorders and emotional lability. Deficiency states and metabolic diseases (diabetes) develop more commonly, which may lay grounds for the development of the mucosal pathology (oral candidosis, stomatodynia). The loss of own teeth and use of dentures represent another risk factor due to the local irritation (prosthetic stomatitis, painful corners of the mouth).