Page 554 - My FlipBook

296 PATHOLOGY OF THE HARD TISSUES OF THE TEETH.
Matrix. A mold in which anything is formed. A thin sheet of metal closely
fastened on a tooth to form a fourth surrounding wall of a proximal cavity in a
tooth. A platimim or gold lining of a cavity in which a porcelain or gold inlay is
baked or fused. The mold formed of an investment into which gold or other metals
are cast.
Median line. The anterior-posterior perpendicular central line of the body.
Mesial. Toward the median line. Those surfaces of the teeth which, as they
stand in the arch, and following its curve, are toward the median line, are called
mesial surfaces.
Mesial angle. A contraction of mesio-incisal angle, also of mesio-bucco-occlusal
angle (q. v.)
Mesial cavities. Cavities in the mesial surfaces of the teeth.
Mesial inclination. An inclination or leaning of a tooth mesially.
Mesially. A direction toward the median line following the curve of the arch
formed by the teeth.
Mesio-buccal angle. The angle formed by the union of the mesial and buccal
surfaces of the bicuspids and molars.
Mesio-bucco-occlusal angle. The angle formed by the junction of the mesial,
buccal and occlusal surfaces of the bicuspids and molars at a point.
Mesio-distal. From mesial to distal; as, the mesio-distal diameter of the
lower first molar.
Mesio-distallt. a direction from the mesial toward the distal following the
curve of the dental arch.
Mesio-distal plane. A contraction of axio-mesio-distal plane (q. v.).
Mesio-incisal angle. The angle formed by the junction of the mesial surface
and cutting edge, or incisal surface, in the incisors and cuspids.
Mesio-labial angle. The angle formed by the union of the mesial and labial
surfaces of the incisors and cuspids.
Mesio-lingual angle. The angle formed by the union of the mesial and lingual
surfaces of the teeth.
MESlo-LlNGUAi GROOVE. A developmental groove running from the mesial sur-
face diagonally to the lingual surface in upper first molars that have the fifth cusp.
Mesio-linguo-occlusal ANGLE. The angle formed by the junction of the mesial,
lingual and occlusal surfaces of the bicuspids and molars at a point.
Mesio-occlusal ANGLE. The angle formed by the union of the mesial and
occlusal surfaces of the bicuspids and molars. It forms the mesial marginal ridge
of the occlusal surfaces.
Metabolism. The sum of the nutritive processes in cells and organs of living
things. It includes the vital phenomena of absorption, assimilation and nutrition
on the one hand and the biochemical changes in the liberation of waste products on
the other.
Micrometer. An instrument for the measurement of very minute divisions of
space. They are made to measure divisions of one thousandth or one ten-thousandth
of an inch; one hundredth, or one thousandth of a millimeter, etc.
MiCROPHOTOGRAPH. A photograph of microscopic size made of any ordinary
object. In this the image produced is very much smaller than the object.
Mobile. Having wide movements, as mobile features, mobile lips, etc. The
features of a person may be very mobile so that the teeth come prominently into view
in laughing and speaking. This does not mean prominent teeth. See Immobile.