Periodontal histomorphometry and status of aged sheep subjected to ovariectomy, malnutrition and glucocorticoid application

Objective: Ageing, hypogonadism, malnutrition, and the application of glucocorticoids have adverse effects on skeletal homeostasis. Herein we determined to which extent the periodontium undergoes catabolic changes under these conditions in a sheep model. Methods: Six old sheep with a mean age of 7.5 +/- 1.0 years were subjected to ovariectomy, calcium/vitamin D-restricted diet, and intramuscular administration of approximately 2 g methylprednisolone. Six adult sheep with a mean age of 3.8 +/- 0.9 years remained untreated and served as controls. First and second premolars of both jaws were subjected to histological analysis. The distances from the gingival margin (GM) and from the alveolar bone crest (ABC) to the cemento-enamel junction (CEJ) were determined. Periodontal attachment was given as the ratio between the dimension of the periodontal ligament and the alveolar bone. Clinical data were collected by counting the number of teeth missing, teeth with gingival recession, and teeth with a probing depth > 4 mm. Results: We report that distance between GM and CEJ (2.1 +/- 1.7 mm and 6.6 +/- 2.6 mm maxilla; -0.4 +/- 1.4 mm and 3.2 +/- 1.5 mm mandible), and between ABC and CEJ (-3.4 +/- 1.3 mm and 1.8 +/- 2.7 mm maxilla; -3.5 +/- 1.1 mm and -0.1 +/- 1.4 mm mandible) are significantly lower in test than in control animals. in line with these findings, periodontal attachment was 67% in the maxilla and 86% in the mandible of the test group and almost completely preserved in the control group. Clinical evaluation showed that the overall number of teeth with recessions was significantly higher in the test compared to the control group (4.9 +/- 2.4 and 2.3 +/- 3.6), but not the number of teeth missing and teeth with a probing depth > 4 mm. Conclusions: Together these findings suggest that in sheep, the cumulating effects of ageing, hypogonadism, malnutrition and glucocorticoid application can cause substantial catabolic changes of the periodontium. (C) 2009 Elsevier Ltd. All rights reserved.