A new concept of periodontal diseases.

Both the inflammatory and noninflammatory types of periodontal diseases begin with an aseptic, traumatic destruction of alveolar bone, caused by traumatizing parafunctions and followed by changes in the gingiva. The latter may or may not have a superimposed infectious inflammatory process. A new concept to fit these facts is proposed: periodontal diseases are autodestructive processes in the masticatory system, with or without superimposed septic inflammation. To confirm the theory of autodestruction, direct evidence as well as indirect but conclusive evidence is given for the existence of traumatizing forces in the masticatory system, for traumatic destruction of alveolar bone, for changes in the gingiva following destruction of alveolar bone, and for the parafunctions by all persons afflicted by periodontal disease. It is concluded that traumatizing parafunctions are the main factor in the etiology of periodontal diseases and that in therapy recurrences are inevitable unless parafunctions have been eliminated.