Hyaline layer of Hopewell-Smith Hyaline layer of Hopewell-Smith In tooth development, the hyaline layer of Hopewell-Smith is the most peripheral layer of initially unmineralized dentin that forms immediately subjacent to the cementodentinal junction (CDJ). It eventually mineralizes, but not before the rest of the dentin is already mineralized. It is 0.5-0.8 µm thick and contains enamel matrix-like protein as well as the proteins one would expect to find in dentin. It is into this hyaline layer that the initial fibers of the periodontal ligament embed themselves. The hyaline layer aids cementum in binding to the dentin. The rationale behind the use of enamel matrix
Development of the nervous system intellectual disability. The mammalian central nervous system (CNS) is derived from the ectoderm—the outermost tissue layer—of the embryo. In the third week of human development the neuroectoderm appears and forms the neural plate along the dorsal side of the embryo. The neural plate is the source of the majority of neurons and glial cells of the CNS. A groove forms along the long axis of the neural plate and, by week four of development, the neural plate wraps in on itself to give rise to the neural tube, which is filled with cerebrospinal fluid (CSF). As the embryo develops, the