Inhibitory effect of neutralization of macrophage colony-stimulating factor in mechanical loading-induced osteoclastogenesis and odontoclastogenesis

Orthodontic tooth movement is achieved by the process of repeated alveolar bone resorption by osteoclasts. However, orthodontic force-induced root resorption by odontoclasts leads to serious problems. We established mechanical loading-induced tooth movement in a mouse model, in which a nickel-titanium coil spring was inserted between the upper incisors and the upper first molar. Macrophage colony-stimulating factor (M-CSF) is essential for osteoclastogenesis and odontoclastogenesis. We examined the effect of neutralization of M-CSF on mechanical loading-induced osteoclastogenesis and odontoclastogenesis in the mouse model. Mice were injected locally with M-CSF neutralization antibodies during mechanical loading-induced tooth movement. The number of osteoclasts and odontoclasts were counted in horizontal sections of the upper first molar after staining with tartrate-resistant acid phosphatase. The neutralization of M-CSF significantly inhibited osteoclastogenesis and odontoclastogenesis. These results suggested that the neutralization of M-CSF might be useful in controlling orthodontic tooth movement and root resorption.