A text-book of dental histology and embryology, including laboratory directions . Incisor tip showing stratification or incremental lines. Rods at A were fully formedat the time the rods at B were beginning to form. (About 50 X) B were just beginning to be formed at the dento-enameljunction. A layer of functioning ameloblasts occupiedthis position. The bands of Retzius are always curved APPEARANCES CHARACTERISTIC OF ENAMEL 63 and usually pass obliquely across the enamel rods, butare parallel neither with the dento-enamel junction or thesurface of the enamel. As they pass toward the gingival Fi
A text-book of dental histology and embryology, including laboratory directions . Incisor tip showing stratification or incremental lines. Rods at A were fully formedat the time the rods at B were beginning to form. (About 50 X) B were just beginning to be formed at the dento-enameljunction. A layer of functioning ameloblasts occupiedthis position. The bands of Retzius are always curved APPEARANCES CHARACTERISTIC OF ENAMEL 63 and usually pass obliquely across the enamel rods, butare parallel neither with the dento-enamel junction or thesurface of the enamel. As they pass toward the gingival Fig. 27. Stratification of enamel; the cusp of a bicuspid: De, dento-enamel junction; Ed,enamel defect showing in the heavy stratification band: Ig, interglobular spaces inthe dentine. (About 40 X) 64 CHARACTERISTICS OF THE ENAMEL TISSUE the angle which they form with the axis of the tooth becomesgreater. Any disturbance of nutrition which affects theformation of enamel is always shown in the increased distinct-ness of the bands (Fig. 27). The bands of Retzius, therefore, form a record of theformation of the tissue, and by their study the points ofbeginning calcification and the manner of the developmentof the tooth crown may be followed. This will be con-sidered again in connection with the grooves, pits, andnatural defects of the enamel. Fig. 28
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectteeth, bookyear1912
