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94 MECHANICAL DENTISTRY AND METALLURGY.

surface of the teeth to the plate should be as accurate as
possible, so as to exclude particles of food, and to furnish
such a basis to each tooth as will provide most effectuallv
against fracture when acted upon by the forces applied to
them in the mouth. The gtun extremities of the teeth
should also be accurately jointed, by grinding carefully from
their proximate edges until the joints will be rendered inca-
pable of ready detection in the mouth, care being taken that
this coaptation of the adjoining surfaces is uniform, for if
confined to the outer edge alone portions of the gum enamel
may be broken away in the process of soldering. There
are cases of a mixed character that render it more difficult
to effect a harmonious and symmetrical arrangement of the
teeth, as where a limited number of the natural teeth at
intervals have been long absent, and the excavations in the
ridge consequent on absorption alternate with other points
upon the ridge in a comparatively unchanged condition. To
give uniformity to the denture by restoring perfectly the
rec[uired circle of the arch in such cases W'ill necessitate the
employment of plain and single gum teeth conjointly.
Whenever necessary, those portions of the base occupied by
the plate teeth may be cut away in such a manner as to
permit the latter to be adjusted directly to the unabsorbed
gum.
Arranging the Teeth for a Full Upper and Lower Denture.
—In the process of grinding the teeth to the base, above
and below, the operator should commence by first arranging
the superior central incisors, and then pass back from tooth
to tooth, grind and adjust, until the entire upper set is ar-
ranged. The superior central incisors should be placed
parallel with each other, but the cutting edges of the laterals
and the points of the cuspids should incline slightly toward
the median line of the mouth. The anterior six may be
made to describe, with more or less exactness, the segment