Periodontitis and angular alveolar lesions: a critical distinction.

Modern anthropologic and epidemiologic studies reveal that the incidence of periodontitis is low in both ancient and modern populations. The distribution of plaque and gingivitis has little or no correlation with the distribution of pathologic alveolar bone loss or with periodontitis. The assumption that a distance from cementoenamel junction to alveolar crest (CEJ-AC distance) greater than 2 mm equates with disease overlooks the interrelationship between the CEJ-AC distance and continuous eruption in compensation for tooth wear and growth of the lower face height. Anatomic, physiologic, and pathologic factors increasing CEJ-AC distances are reviewed. Where horizontal periodontitis does result from gingivitis, it is usually of minimal significance and probably occurs when the host defenses have been diminished by environmental factors commonly associated with other chronic diseases. A pulpal-alveolar explanation for localized angular alveolar lesions better fits the clinical features of this form of periodontal bone loss than does the conventional hypothesis of primary periodontal infection by specific oral bacteria.