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22 MECHANICAL DENTISTRY AND METALLURGY.

trimmed to the exact length that we wish the artificial teeth
to be, it is important to know at this time that the upper
anterior teeth should be made about a line longer than the
upper lip, while the lower are that much shorter than the
lower lip. If it is a single case, either upper or lower,
the wax plate should now be removed and the articulating
border passed over the flame a few times to soften it suffi-
ciently to readily receive the imprint of the antagonizing
teeth. It should now be replaced in the mouth and the
patient directed to close the teeth gently and lightly against
it ; note carefully the points of contact, and have it repeated
by now directing the patient to close upon the wax in the
back part of the mouth, and to swallow at the same time.
This last act will usually force the teeth into the wax suffi-
ciently to imbed the cusps and cutting edges. If there is
no variation in the points of articulation, it is safe to assume
that the bite is correct. The depth to which the cutting
edges of the teeth should be imbedded in the wax must
correspond to the length of the " over-bite " of the anterior
upper teeth. Now mark the median line on the wax rim.
This cannot be safely regulated by the center of the lower
teeth or by the frenum, as either may be a little to one side
or the other, but should be determined by the face alone.
A line should be drawn across the wax to correspond as near
as possible with the center of the features.
A wax or compound impression of the antagonizing teeth
should be taken and the cast from this placed in position,
so that the cusps and cutting edges of the plaster teeth
may be gently forced into the depressions made in the wax
rim by the natural teeth. The two cast with the bite held
accurately in position are now securely attached to the
articulator, with plaster-of-Paris. Fig. 8 represents such
a case.
Where the bite for both upper and lower is to be secured,