Grattage. a method of drawing by scratching paper or cardboard that has been covered with india ink with a pen or a sharp instrument. The grattage process is reminiscent of scraping an oiled surface in lithography.rattage. a method of drawing by scratching paper or cardboard that has been covered with india ink with a pen or a sharp instrument. The grattage process is reminiscent of scraping an oiled surface in lithography.
3. (Zoology) of or relating to the surface of an animal, such as a jellyfish, on which the mouth is situated. 4. (Medicine) denoting a drug to be taken by mouth Compare parenteral: an oral contraceptive.
Dental anatomy (or tooth anatomy) is a field of anatomy dedicated to the study of tooth structure. 1  Enamel Enamel is the hardest and most highly mineralized substance of the body ; 96% of enamel consists of mineral, with water and organic material comprising the rest. Enamel covers the crown of the tooth and varies in thickness over the surface of the tooth ; it is often thickest at the cusps, up to 2.5 mm, and thinnest at its border. The normal color of enamel varies from light yellow to grayish white ; since enamel is semi-translucent, the color of dentin and any restorative dental material underneath the enamel strongly affects the appearance of a tooth.