Page 832 - My FlipBook

830 THE DEVELOPMENT OF ESTHETIC FACIAL CONTOURS.
A most wonderful provision of Nature iu dentition causes the full-
sized crowns of teeth to erupt, as regards time, somewhat in proportion
to the natural growth and enlargement of the jaws. And even when
they do not erupt earlier than is normal, or Avhen their natural eruption
is not interfered with by the prematur(> extraction of the deciduous
teeth, they arc usually obliged to take an irregular position or attitude
at first, and await the growth of the jaw which permits them to become
regular.
It is perhaps a safe general rule to never extract a permanent tooth
for the purpose alone of correcting a dental irregularity, unless the jaw
has ceased growing ; and never then unless it is shown by a careful study
of the position of the teeth—their relation and occlusion—that the den-
tal arch should not be expanded ; or by a study of the j^hysiognomy,
that the alveolo-dental arch should not be enlarged.
In a study of the relations of the teeth, the jaws, and the physiog-
nomy of a child with the view of determining the advisability of extrac-
tion to correct or prevent the ultimate production of a facial deformity
or marked imperfection of the features, it may become necessary to
study the physiognomies of both parents and possibly other members
of the family, to correctly determine the influence of inheritance.
In this comparison of temperament, physical frame, features, and
teeth, it may require no more than a glance to furnish all the data that
will be of practical use.
Usually but one parent accompanies the little patient, and a study
of that one physiognomy may be a sufficient guide ; if not, other mem-
bers of the family should be seen.
If there be a marked difference in the parents it may not be difficult
to determine from which the child has inherited the teeth, by the
peculiar shape and size of the incisors alone. But in regard to the
maxillje in an undeveloped condition there will be more difficulty,
though it is well to remember that the deciduous teeth are rarely irregu-
lar or disproportionate in size to the frame and facial features. If, there-
fore, there be a more than natural difference in the size of the permanent
and deciduous teeth it will indicate union of inharmonious types.
In this connection it must not be forgotten that the crowns of the per-
manent incisors are almost invariably far too large for their undevel-
oped surroundings. The apparently disproportionate size of the cen-
tral incisors to that of the jaw is a subject of frequent and anxious
parental comment. If the occlusion of the incisor teeth be far from a
normal type in their anterior relations, and the same condition exists
with either parent, it is an indication of what the child will become if
unaided by dental skill, especially if a similarity be noted in other
particulars.