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Recently, the research on the stem cells is developing rapidly in the odontology. Mesenchymal stem cells (MSCs) have the possibility useful for the stem cell treatment and the tissue engineering. STRO-1 is one of the mesenchymal stem cell markers. In this study, we examined the characterization of STRO-1 positive cells derived from human wisdom tooth germs (hWTGs) compared with STRO-1 negative cells. As positive control, we used human mesenchymal stem cells (HMSC) on purchase. STRO-1 positive cells derived from hWTGs showed Alcian blue positive matrix like HMSC when cultured in chondrogenic induction medium. STRO-1 negative cells from hWTGs did not show such matrix. Nodule formation stained with Alizarin red was performed not only by STRO-1 positive cells but also STRO-1 negative cells cultured in osteogenic induction medium. It is suggested that STRO-1 positive cells derived from hWTGs are useful for the stem cell treatment and the tissue engineering.

The concentration and distribution of alpha 2HS glycoprotein in teeth from patients with heritable dentin disorders were examined utilizing immunological techniques. ELISA for the quantitative determination showed lower concentrations of alpha 2HS glycoprotein in dentins of patients with heritable disorders than in the control; some cases contained very low and others intermediate concentrations. Immunohistochemical findings indicated that the concentration of this protein was correlated to the regularity of the dentinal tubules. This result suggests that alpha 2HS glycoprotein is incorporated into dentin in concomitance with the development of the dentinal tubule, especially with the deposition of peritubular dentin. Incorporation of this protein into dentin is thought to involve the function of odontoblasts.

We examined the isolation of mesenchymal stem cells from human wisdom tooth germs (hWTGs) or human periodontal ligament (hPDL) and compared their characteristics. Collection rate of STRO-1 positive cells from WTGs was 6.01% but from PDL was 2.22%. After 7 days’ culture, alkaline phosphatase activity of stem cells derived from WTGs was increased and it was statistically higher than those of PDL stem cells. After 14 days, protein content of stem cells derived from WTGs became statistically higher than those of PDL stem cells. It is suggested that hWTGs are useful for stem cell treatment and tissue engineering.

We examined the immunohistochemical localization and isolation of mesenchymal stem cells in human wisdom tooth germs. Pericytes of blood vessels in the dental papilla and ameloblasts were stained strongly, but odontoblasts reacted weakly with STRO-1 and CD146. The STRO-1 positive cells represented approximately 7% of the total cell population. It is suggested that human wisdom tooth germs are useful for the stem cell treatment and the tissue engineering.

The presurgical nasoalveolar molding plate appliance with stent (PNAM) extended from the palatal molding plate; to correct the nostril shape of infants with cleft lip and palate is well known. The PNAM appliance is based on the finding that a high degree of plasticity is maintained in the cartilage of infants during the first 6 weeks after birth. However, on the current PNAM protocol described by Grayson et al. the nasal stent is supposed to be an adjunct to the palatal molding plate after reducing the severity of the alveolar cleft width. We have used the modified Hotz's plate from the setup model and built up the nasal stent even before reducing the severity of the alveolar deformity. In this study we assess the effects of the modified Hotz's plate and the modified PNAM appliance for the alveolar and palatal form. The lateral deviation of the incisal point, the width of the palatal cleft, and the degree of curvature of the palatal vault were first evaluated on plaster models. The PNAM group is smaller on the lateral deviation of the incisal point than the modified Hotz's group. The decreased average width of the palatal cleft and curvature of the palate, was almost the same in both the modified Hotz's and PNAM groups. In comparison with the modified Hotz's plate, the modified PNAM appliance also improves the molding of the alveolar segments and reduces cleft width.