Experimental investigation of the effects of allantoin on mandibular distraction osteogenesis

This study aims to investigate the acute effect of local allantoin treatment on experimental distraction osteogenesis. A total of 14 adult New Zealand rabbits underwent mandibular distraction under general anesthesia. The control group received saline washes, while the experimental group received local allantoin (1 mg/kg). Computed tomography was used to measure bone mineral density (Hounsfield Units). Stereological analysis of decalcified tissues was performed using the Cavalieri Method, which assessed the volumes of new bone, connective tissue, and capillaries (mm³). Immunohistochemistry employed anti-RUNX2 and anti-BMP2 antibodies. It was found that the volumes of new bone, connective tissue, and capillary were higher in the experimental group than in the control group. Furthermore, anti-RUNX2 and anti-BMP2 activities were more intense in the connective tissue area of the experimental group. Using stereological and immunohistochemical methods, this study has demonstrated that allantoin, known for its antioxidant and anti-inflammatory properties, enhances bone regeneration in distraction osteogenesis. Allantoin contributes to bone healing by stimulating mesenchymal stem cells and enhancing neoangiogenesis.