Periodontal space histomorphometry after orthodontic movement in short-term diabetic rats

The impact of diabetes on the turnover of connective tissue is well-established, still, quantitative analysis of its effect on the orthodontic movement is scarce. Objectives: This study aimed to assess the histomorphometric changes in the areas of the periodontal ligament resulted from experimental tooth movement in short-term diabetic rats. Methods: Forty rats, 20 normal and 20 streptozotocin-induced diabetic rats, were treated, in a split mouth design, with a 25 cN closed coil spring to tip the left upper molar mesially. Undecalicified parasagittal sections of left and right molar teeth and surrounding tissues were prepared for histomorphometry at 3, 7, 14 and 21 days. Images of maxillary first molar disto-buccal root and its periodontal ligament were captured at 5.0x of magnification and tracings were made designed to divide the selected root and its periodontal ligament into four equally dimensioned quadrants. For each quadrant, the means of areas of the periodontal ligament were compared between experimental and control side (paired t test), between normal and diabetic rats (independent t test) at each timepoint, and across times within each group (ANOVA). Results: Significant differences were evidenced between the experimental and control side mainly at the distocervical quadrant at day 3, 7 and 14 after experimental tooth movement for normal rats (p<0.01), and at day 3, 14 and 21 for diabetic rats (p<0.05). There was no difference between the areas of periodontal ligament of normal and diabetic group except the mesiocervical quadrant at day 7 (p<0.05). Across times within each group, changes were observable in the distocervical and distoapical quadrants, although not statistically significant, at day 3 and 7. Conclusions: It was concluded that the short-term diabetic state demonstrated little clinical impact on the experimental tooth movement.