Role of periosteum in the formation of jaw bone. An experiment in the rat
The aim of the present investigation was to evaluate the bone-forming capacity of the inner and outer layer of the mandibular periosteum in skeletally mature rats. Twenty-five male rats were used in this study. At control sites a Teflon capsule was placed with its opening facing the periosteum covering the lateral aspect of the mandibular ramus. At the experimental sides, a Teflon capsule was placed with its opening facing the periosteum at the subsurface of the raised flap. With this experimental model a secluded space was created adjacent to the inner layer (experimental sides) or the outer layer (control sides) of the periosteum. After healing periods of 7 and 14 days, and 1, 2, and 4 months, groups of five animals were sacrificed. In the experimental specimens, both the incidence and amount of newly formed bone in the Teflon capsules gradually decreased from 7 to 120 days, while increasing in the control capsules placed over the periosteum. At 120 days, the mean amount of new bone produced in the experimental capsules was 3% (range 0-15%) of the total space created by the capsule, while it was 68% range (41-85%) for the control capsules. [E.L.H.]
Kostopoulos, L., and T. Karring J Clin Periodont, 22:247,1995