Calcitonin as a pharmacological anchorage in orthodontics

This study aimed to evaluate the effects of salmon calcitonin administration as a pharmacological anchoring agent in orthodontics and to determine the influence of locally applied calcitonin on serum calcium levels. The secondary aim was to observe the response of dental and periodontal tissues using light microscopy.

Fourteen healthy male adult Wistar rats with an average weight of 250 g had their teeth moved, seven of which received a local injection of salmon calcitonin in the furcation region of the left upper first molar. Concurrently, the remaining seven were used as controls. In the control group, saline solution was injected in the bifurcation region of tooth 26 to subject these animals to the same stress level as those of the experimental group. After 14 days, a 6 mm diameter orthodontic elastic band was inserted between teeth 26 and 27 in all animals to induce the movement of these teeth. The rats were anaesthetised and exsanguinated on day 21. In both groups, tooth movement and serum calcium levels were measured. The jaws were dissected with straight scissors, and tissue blocks containing gingiva, bone and teeth were identified, fixed and demineralised. Then, the pieces were cut into semi-serial slices, stained with hematoxylin, eosin, and Mallory's trichrome, and analysed under an Axiophot light microscope.

There was significantly less tooth movement in the experimental group (X̄; 0,150 mm ± 0,037) than in the control group (0,236 mm ± 0,044; P = 0,003), while there was no significant difference in serum calcium levels between the two groups (controlX̄; 9,53 mg/dl ± 1,53; experimental 10,81 mg/dl ± 1,47; P = 0,15).

While calcitonin did not completely inhibit osteoclast activity, it promoted orthodontic anchorage, apparently, by local action.