The systemic factors in periodontal disease.

Regarding the blood studies, several in­ vestigators . have reported higher than normal values for total calcium, total cholesterol, uric acid, sugar and phos­ phatase (in gingival blood) in various percentages of their cases. Lower than normal values have been reported for vitamin C, erythrocyte count and carbon dioxide combining power. Other workers have failed to confirm the findings for calcium, uric acid, sugar and cholesterol. In view of the uncertainty of these re­ sults, we1'4 carried out a comprehensive blood study in 229 cases, divided into four groups. There were 54 cases in the control group which consisted of in­ dividuals free from periodontal disease; 77 cases in the periodontosis group (Group A ) ; 59 cases in a more advanced periodontosis group (Group B ) ; and 39 advanced cases of periodontitis. The mean ages were 33.5, 27.3, 39.1 and 48.8, respectively. Group A ,' predominantly females, in­ cluded either young individuals whose roentgenograms showed signs of severe alveolar bone loss, generally in specific areas, or patients in whose mouths local factors were not prominent and apparently did not account for the severe loss of alveolar bone. As a rule, the gingivae appeared pink and stippled but there was slight erythema of the interdental papil­ lae in several areas in a majority of the cases. Little or no calculus was present. A diagnostic sign was the migration of the maxillary or mandibular incisors with resulting diastemata. Roentgenographic examination revealed loss of alveolar bone in the first molar and incisor regions. In many regions there was a radiolucency of the alveolar crest and a widening of the periodontal membrane. More alveolar bone was present about the bicuspid teeth in both arches, especially the mandible. These observations were rather constant