Effect of cetirizine, a histamine (H1 ) receptor antagonist, on bone modeling during orthodontic tooth movement in rats

Introduction Histamine (H1 ) receptor antagonists are widely used drugs for treatment of allergic conditions. Although histamine was shown to be involved in bone remodeling, the aim of this study was to determine the effects of cetirizine, an H1 receptor antagonist, on bone modeling processes during orthodontic tooth movement. Methods We used 3 groups of Wistar rats: control group (n = 16), appliance-only group (n = 16) and cetirizine group (n = 16). Each animal of the last 2 groups was fitted with a superelastic closed-coil spring appliance and treated daily with saline solution or cetirizine. Tooth movement was measured weekly from day 0 to day 42. Gene expression levels for bone turnover markers cathepsin K and osteocalcin were determined by means of real-time polymerase chain reaction. Histologic samples were analyzed by using histomorphometry. Results Cetirizine decreased the amount of tooth movement from day 28 onward ( P