The facial structure develops through the harmonious interaction of bones, mandibular and cervical joints, masticatory, facial and cervical muscles, connective and fatty tissue as well as tracts of conduction. The face represents the personal identity. Ten basic types of faces exist, although they are difficult to classify. No face is symmetrical (biological variance). The expressions are generated by muscles and tension of the elastic facial skin and enable the face to be an organ of expression. The cranial position supports and influences the expression. Certain diseases change the expression in such typical ways that diagnosis and prognosis of some diseases may be concluded from it.