The effect of
bite-blocks with and without repelling magnets as proposed for the treatment of
open bite was analyzed. Twelve male juvenile monkeys were divided into three groups of four. Group A was used as control, group B was given
bite-blocks containing
samarium cobalt disks, and group C received identical
bite-blocks without active magnets. The monkeys were observed for 24 weeks before death. Histomorphometric evaluation was then performed on the molar roots, their periodontal tissues, the zygomaticotemporal
suture, and the pterygomaxillary
suture. The root surfaces of the molars in both the
bite-block group and the magnetic group were characterized by pronounced resorption that sometimes was active and occasionally undergoing repair with bony tissue. The
sutures also clearly reflected the effect of both appliances used, although more markedly in the cases of
bite-blocks containing active magnets. The surface density expressing the sutural area, was increased significantly, possibly as an adaptation to the altered functional demand. The cellular activity of the sutural surfaces also was increased markedly in both appliance groups, reflecting an ongoing adaptation. A steady state had not been reached. The study demonstrated a widespread effect of the force developed by
bite-blocks with and without magnets. The final quantity and the reversibility of the effect is not known, however. More long-term studies should be undertaken to obtain this information.