Palatal mucoperiosteal wound healing in the rat

The objective of this study was to analyze the changes in tissue architecture 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 mucoperiosteal wounds. Wounds were made in the mucoperiosteum of the palate of 35-d-old rats. Samples were evaluated histologically at numerous points in time 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 glycosaminoglycans and cells than unwounded palatal tissue of 43-d-old rats. Sixty-d-old wounds contained 100% more DNA and 39% more hydroxyproline than unwounded tissue of 95-d-old rats. At the same time, densely packed and transversely aligned collagen fibres were present. It is concluded that palatal mucoperiosteal wounds made in 35-d-old rats heal with distinct scar tissue formation. The scar contains more collagen than nonwounded palatal tissue of rats of the same age. Therefore, this model may be of use for the development of therapies aiming to reduce palatal scarring.