Gene expression of insulin-like growth factors I and II in rat membranous osteotomy healing

Poorly healing mandibular osteotomies can be a difficult problem in reconst ructive surgery. Many therapies have been attempted to augment the healing of mandibular fractures, defects, or osteotomies, but these methods have su bstantial drawbacks or have been ineffective. The difficulty in treating po orly healing bony defects has led to the exploration of gene therapy as a p ossible approach to supplement or accelerate mandibular fracture healing. T o understand at what point the introduction of a suitable gene candidate mi ght be of benefit in mandibular healing, it is imperative to examine the te mporal expression of bone growth factors in a model of membranous bone heal ing. Insulinlike growth factors (IGFs) I and II are two such bone growth fa ctor candidates because of their known potent in vitro as well as in vivo e ffects on bone formation, In this study the authors demonstrate the tempora l pattern of IGF I and IGF II gene expression during mandibular osteotomy h ealing using a rat model, Their data reveal that IGF I and IGF II were elev ated 7 days after a mandibular osteotomy that was held in external fixation . The upregulation of IGF I and IGF II during mandibular bone healing under scores the importance of these growth factors in bone repair. Gene therapy utilizing recombinant viral constructs containing IGFs I and II may be of b enefit during mandibular bone healing in an effort to augment clinical scen arios of poor or retarded bony repair.