Ultrastructure of early amelogenesis in wild ‐type, Amelx‐/‐, and Enam‐/‐ mice: enamel ribbon initiation on dentin mineral and ribbon orientation by ameloblasts

ConclusionAmelogenin does not directly nucleate, shape, or orient enamel ribbons, but separates and supports the enamel ribbons, and expands the enamel matrix to accommodate continued ribbon elongation, retrograde ameloblast movement, and rod/interrod organization.

This is the first report using focused ion beam microscopy to visualize enamel ribbons at high resolution as they form, which are shown to initiate on the underlying dentin crystals. This continuity between dentin and enamel mineral has been difficult to establish with conventional thin sectioning techniques and has been debated for many years. We converted serial images into movies that allowed us to better appreciate the complex infolding of cell membranes and intercellular compartmentalization that are integral to the complex mechanism of enamel biomineralization.

Source: Molecular Genetics & Genomic Medicine - August 31, 2016 Category: Genetics & Stem Cells Authors: Charles E. Smith, Yuanyuan Hu, Jan C. ‐C. Hu, James P. Simmer Tags: Original Article Source Type: research