title: The regulation of fiber arrangement in advanced cellular cementogenesis of human teeth.
abstract: This study observed cellular cementum in fully formed human premolars by light and electron microscopy to elucidate how cementoblasts regulate the fiber arrangement in cementum. Cementoblasts had wing-like processes encircling the principal fibers, where Sharpey's fibers were dense. On the cementum-facing side, wing-like processes were segmented into finger-like processes in parallel with the cementum surface. Observations suggested that with the segmentation intrinsic fibers appeared around principal fibers in close association with finger-like processes. Where Sharpey's fibers were few or absent, where intrinsic fibers were the main fibrous element of the cementum, cementoblasts had only few or no wing-like processes, but had finger-like processes not associated with the wing-like processes on the cementum-facing side. On the basis of the origin of the finger-like processes the main results suggest that there are two kinds of cementoblasts: one has finger-like processes associated with wing-like processes and secretes intrinsic fibers from the finger-like processes to incorporate the principal fibers for tooth support. The second type has finger-like processes not associated with wing-like processes, this type secretes intrinsic fibers from the finger-like processes to adjust the cementum thickness.
authors.affiliation: Department of Oral Anatomy II, Hokkaido University School of Dentistry, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: T
authors.initials: T
authors.lastname: Domon
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: N M
authors.initials: NM
authors.lastname: Islam
authors.forename: R
authors.initials: R
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Wakita
mesh_terms: D000328:Adult; D025021:Cementogenesis; D003094:Collagen / Q000648:ultrastructure; D003239:Connective Tissue Cells / Q000166:cytology; D003739:Dental Cementum / Q000166:cytology* / Q000648:ultrastructure; D006801:Humans; D008855:Microscopy, Electron, Scanning; D009805:Odontogenesis; D010513:Periodontal Ligament / Q000166:cytology
chemical_list: D003094:Collagen