THE ROLE OF THE DURA IN CRANIAL BONE REGENERATION IN THE IMMATURE ANIMAL

In an animal model, the effect of transferring mature pericranial tiss ues to immature animals with cranial bone defects was tested. Isogenei c guinea pigs of different ages were used: ''infants'' (3-4 weeks) and ''adults'' (>18 months). Bilateral parietal cranial defects were made in infant guinea pigs and the guinea pigs were divided into three gro ups. In group 1 (n = 6), the infant periosteum was resected and replac ed as an autograft on one side (control), and adult periosteum was tra nsplanted as an isograft on the other (experiment). In group 2 (n = 5) , dura was used as the variable. In group 3 (n = 5), combined dura and periosteum were the variables. After 8 weeks, there was complete or n ear complete bone regeneration in all animals in which infant dura was present. There was minimal to no bone regeneration in defects in whic h adult dura was present. Unlike dura, periosteum had little influence on the capacity of the bone to regenerate.