. Common diseases of farm animals. Veterinary medicine. is flattened from side to side. As the tooth Ijecomes worn off, the length of the free portion is maintained by a pushing out of the tooth, and a corresponding shortening of the portion that is fixed or imbedded in the jaw. The table surface of the unworn incisor tooth is covered with enamel, and in the middle por- tion the enamel forms a deep cup. After tlie tooth has become worn the margin of the table portion is then limited by a ring of enamel. This is termed the encircling enamel ring. The central portion of the taljle shows a second
. Common diseases of farm animals. Veterinary medicine. is flattened from side to side. As the tooth Ijecomes worn off, the length of the free portion is maintained by a pushing out of the tooth, and a corresponding shortening of the portion that is fixed or imbedded in the jaw. The table surface of the unworn incisor tooth is covered with enamel, and in the middle por- tion the enamel forms a deep cup. After tlie tooth has become worn the margin of the table portion is then limited by a ring of enamel. This is termed the encircling enamel ring. The central portion of the taljle shows a second ring, the central enamel ring, that limits the cup margin (Fig. 54). As the table surface repre- sents a cross section of the tooth, its appearance and shape will then depend on the portion of the tooth that it represents. From year to year, there is a gradual shortening in the lateral diameter, and an apparent increase in the diameter from before to behind. These changes in shape are from a long, narrow table surface to an Fig. 55.—Table surfaces of nippers at OVal, frOUl OVal tO circukr and difforentages. ^ four years; B. six years; f^.^^^j^ circular tO triaUgular (Fig. C, nine years, and/), fifteen years of age. '- \ e^ 55). As the original free por- tion of the tooth wears off, the cup becomes shallow and smaller until the remnant is represented by a mere dot of enamel that finally disappears from the posterior portion of the table. After the cup has moved from the central portion of the crown and occupies a more posterior position, the dental star, which. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Craig, Robert Alexander, 1872-. Philadelphia London, J. B. Lippincott company
Size: 2297px × 1088px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookpublisherphilad, booksubjectveterinarymedicine, bookyear1919
