Quantitative characterization of changes in cellularity and collagen fiber size in contracting palatal wounds

Standard surgical wounds with either plain or undermined margins were created in the hard palates of 15 beagle pups by excising a strip of mucoperiosteum adjacent to molars. Healing was monitored, the pups were sacrificed at intervals from five to 31 days after surgery. Longitudinal data were collected for body weight and wound contraction. Examination of histologic sections of the wounds and adjacent tissues involved visual light microscopic assessments of fibroblast population density and computerized image analysis microscopy for quantification of population densities of three sizes of collagen fibers. Wounds with undermined margins showed less contraction than did those having plain margins. Findings on changes in the morphologic character of the maturing granulation tissues included quantitative documentation of (a) decreases in the population density of fibroblasts, (b) marked decreases in the number of thin (reticular) fibers, (c) marked increases in the number of medium sized fibers, and (d) slight increases in the number of coarse fibers.