Palatal mucoperiosteal wound healing in the rat

The objective of this study was to analyze the changes in tissue architectu re and matrix composition during healing of palatal wounds of immature rats , and to compare this with rats of the same age that did not receive mucope riosteal wounds. Wounds were made in the mucoperiosteum of the palate of 35 -d-old rats. Samples were evaluated histologically at numerous points in ti me after wounding. The DNA, hydroxyproline and sulphated glycosaminoglycan contents were determined at 8, 15, 30, and 60 d post-wounding. Eight-d-old granulation tissue contained 43% less hydroxyproline, and 100% more glycosa minoglycans and cells than unwounded palatal tissue of 43-d-old rats. Sixty -d-old wounds contained 100% more DNA and 39% more hydroxyproline than unwo unded tissue of 95-d-old rats. At the same time, densely packed and transve rsely aligned collagen fibres were present. It is concluded that palatal mu coperiosteal wounds made in 35-d-old rats heal with distinct scar tissue fo rmation. The scar contains more collagen than nonwounded palatal tissue of rats of the same age. Therefore, this model may be of use for the developme nt of therapies aiming to reduce palatal scarring.