Figure 3. Analysis of naturally exfoliated primary teeth from affected girls in family 1 (p.M1T). Ground sections of normal (A,C) and defective (B,D) teeth illustrate the relative thinness (1/4 of normal) of the enamel layer in the affected teeth. The enamel prism structure of the normal teeth is evident in scanning electron micrographs (E, bar = 100 µm), but is not evident, even at twice the magnification (F, bar = 100 µm), in affected teeth. At higher magnification, prism organization that only partially approaches that observed in normal enamel (G, bar = 10 µm) could be recognized in occasional areas (H, bar = 10 µm). To the unaided eye, the enamel surface of the affected teeth looked rough (I), which was due to the presence of pits along the enamel surface that varied in size from about 10 to 30 µm (F). The dentin appeared to be normal at low (J) and high (K, bar = 10 µm) magnifications, with well-defined dentinal tubules. Arrowheads indicate the DEJ.