The role of periosteum and different dissection types on callus formation:Quantitative analyses with scintigraphy in a rabbit mandible model

In this experimental study, the effects of different dissection types and t he role of the periosteum on callus formation were investigated. Forty-five rabbits were divided into three groups of 15 rabbits. In the first group, a classic subperiosteal dissection was performed to reach the mandible. In the second group, the dissection was done extraperiosteally between the per iosteum and the muscle. In the third group, the periosteum at the osteotomy line was stripped out bilaterally both on the lingual and the buccal sides (1.5 cm wide on each side). In ail groups, linear vertical osteotomy was p erformed using an oscillating saw, and fracture fragments were fixed with s urgical wire. The animals were evaluated using biomechanical (traction test ), histological, and scintigraphic methods. The most durable callus in the traction test and, scintigraphically, the most rapid remodeling were seen i n the second group. The histological study performed during week 3 revealed immature callus formation in the first and second groups, and no such form ation in the third group. At week 8 the callus was mature in the first two groups and in the third group it was seen but not mature.