A light microscopic investigation of the human midpalatal suture.

Biopsy samples of the human midpalatal suture, obtained from patients (age range: 10 and 30 yrs), were embedded in resin, cut with ultramicrotome and analyzed at light microscopy. The sutural connective tissue was made up of fibroblasts, collagen fibers, capillaries and nerve fibers. The sutural bone was made up of lamellar and bundle bone which alternated along both sides of the sutural connective tissue. No osteoblasts or osteoclasts were found, no signs of synostosis were ever detected. Our findings suggest that the lamellar bone replaces bundle bone when the suture is no longer involved in the growth of the palatal bones. The absence of bone remodelling shows that the sutures, at the time of sampling, were in a resting stage. Tissue architecture and cell types, so similar in samples from patients of such different ages, lead us to suppose that the sutures under examination are subject in time to very slow bone turnover.