Hard palate deformation in an animal model following quasi-static loading to stimulate that of orthodontic anchorage implants.

The aim of the present investigation was to identify adequate implant treatment for young patients. In an animal model palate deformation was investigated by acute quasi-static loading. Three series of tests (with newborn, young and adult pigs) were performed, each with two groups (one or two-point stress) and 5-7 animals per group. Discs with a diameter of 3 and 5 mm were placed in group 1 in the suture area, and in group 2 at both the right and left sides of the suture. Deformation was analysed by a computerized three-dimensional (3D) photo-imaging evaluation system. In young animals the one-point load at a significantly lower force level led to fractures in comparison with the two-point load (P < 0.001). Similar results were measured by an increase in the size of one disc from 3 to 5 mm (P < 0.001). In contrast, adult pigs showed stable results with both methods. In general, a larger disc diameter led to less instability. The one-point load seems to be suitable for adult animals, whereas a two-point load might be favourable during ossification. The advantage of the two-point load is the generation of a higher stress and therefore improved control of dental fixation. However, further tests are necessary to investigate the long-term effects.