Page 441 - My FlipBook

GLOSSARY OF TECHNICAL TEEMS AND PHRASES. 289
Disto-linguo-occlusal angle. The angle of a bicuspid or molar tooth formed
by the junction of its distal, lingual and occlusal surfaces at a point.
Disto-occlusal angle. The angle formed by the junction of the distal and
occlusal surfaces of the bicuspids and molars. It forms the distal marginal ridge
of the occlusal surfaces of these teeth.
Drill. A cutting instrument for boring holes. Usually bibeveled, but may be
square ended.
Dynamometer. An instrument for the registration of force in its application
in mechanics, or in testing the strength of materials. See Figures 164, 165, Vol. 1.
Dystrophy. Dys — imperfect, defective, bad ; trophy — growth. The condition
resulting from defective formation or growth. Defective or perverted nutrition.
Embrasure. The open space on either side of the contact point, to the occlusal
(or ineisal) of the septal tissue. These are called the buccal (or labial), and the
lingual embrasures. It is through these that food, crushed between the teeth and
divided by the contact points, glides upon the sloping surfaces of the septal gingivae
to either side of the arch.
Enamel. The tissue covering the dentin of the crown portion of the tooth.
Enamel cap. The covering of the crown of the tooth, composed of enamel.
Enamel, curled. See Curled enamel.
Enamel margin. The junction of a wall of a cavity with the surface of the
tooth. It is continuous, forming the outline of the cavity. See Cavo-surface angle,
and Outline form.
Enamel rods. The form elements of which the enamel is made up. They are
in the form of minute rods of extremely hard calcific material. These are cemented
together in a solid mass by an intervening cement substance that leaves no openings.
The general course of the enamel rods is from the dento-enamel junction to the sur-
face of the tooth. On all parts the ends of the enamel rods are presented to the
surface of the tooth.
Enamel rods, inclination of. Used in describing either normal or abnormal
inclination of the enamel rods from a direction perpendicular to the surface of the
tooth. See Inclination.
Enamel, straight. See Straight enamel.
Enamel wall. That portion of the wall of a cavity which is composed of enamel.
See Figure 8, ew, Vol. 2.
Endemic, a. Peculiar to or prevailing in some particular district or region. An
endemic disease is one which is local; which is neither sporadic nor epidemic.
Enzyme. Any digestive body, or digestive fluid, such as pepsin, trypsin, ptyalin,
pancreatin, etc.
Epulis. A tumor upon the gum.
Erosion. A defect in a surface of a tooth characterized by a progressive loss of
substance, leaving a polished or smooth surface which can not be accounted for by
abrasion.
Esthetic. Pertaining to the science of esthetics, which treats of the pleasing
and beautiful.
Etiology. The science of the causes of disease. This includes predisposing and
exciting causes, remote and near, general and local, hereditary and immediate, or
acquired.
Excavating bur. A moderately coarse cut bur designed for use in the prepara-
tion of carious cavities in teeth for filling.