will make their appearance. In the majority of
cases, however, we shall see them all before the end
of the eleventh year, and the canines a year later.
In the meantime all the new teeth must be
carefully examined every three or four months for
indications of approximal decay, which the prac-
tised eye will detect by the appearance of slight
opacity, long before the patient is aware of any
defect in the tooth. The upper incisors are pecu-
liarly liable to this, and their position in the mouth
renders it a matter of extreme importance to detect
and check the first symptoms of caries, so that the
appearance of the mouth may not suffer. Young
practitioners should accustom themselves to the
constant use of the mirror in these examinations.
A good mirror, kept warm by dipping it in hot
water, to prevent condensations from the breath
upon its surface, will be of the greatest possible
service to the operator, enabling him to detect the
earliest appearance of that whitish opacity which
indicates the progress of caries from the interstices.
Holding the mirror so as to throw a strong light
upon the lingual surface of the tooth makes this
opacity distinctly visible, in many cases before
48
DENTAL PRACTICE.
sensibility in the tooth has caused a suspicion of mis-
chief. Famiharity with the use of the mirror, and
with the use of instru-
ments from the reflected
image, will be found to
be a great advantage in
nearly all operations on
the teeth. The silvering
of a good mirror can and
should be done in such a
manner that it cannot be
affected by moisture, and
the handle should be broad
and thin, so that it can
be held under perfect con-
trol between the fingers,
leaving the finger ends
free for other uses. Figs
15 and 16 will show the
form of handle which I
have found most con-
venient for use, and the
manner of holding it
while operating on front
teeth is shown in Fig. 17.
It is a great assistance
to the dentist to be able
to work with the mirror,
as he can then do anything
^. ,^ that is necessary in the
Fig. 15.— Showing Fig. 16.— Side . ...
form of mirror. view of same, preparation of CaVltlCS in
THE PERMANENT TEETH.
49
approximal surfaces, and packing the fillings, with-
out resorting to the use of wedges to press the teeth
apart, and without cutting away the labial surface
of the tooth, and so spoihng its appearance. All the
cutting away should be from the lingual surface,
Figure 17.— Manner of holding the mirror, so as to leave the fingers free
for holding the lips back, holding the napkin, etc., etc.
and if an dividing file can be passed between the
teeth, it is all that is necessary to take away from
the labial approximal surface, for any filling, no
matter how extensive the decay may be, provided, of
course, that the labial surface is not already broken
down before the treatment is commenced. But,
fortunately perhaps, caries in front teeth will have
made most serious progress before the labial surface
breaks down, because the action of the front teeth
in biting the food comes upon the lingual surface,
and as that breaks down, the attention of even the
50 DENTAL PEACTICE.
most careless person is called to the mischief that
is going on by the sharpness of the broken edges
of the cavity, and doubtless to a certain extent the
decay is checked by the cleansing action of attri-
tion, while there is very little pressure on the labial
surface to cause breakage. Thus we often find
extensive caries in front teeth, extending even to
the pulp, while the labial surface is nearly, or quite,
intact ; and this teaches us a lesson in treatment,
for if, in filling front teeth, we shape the surfaces
treated so as to take advantage of this self-cleansing
process, we shall find that our work will stand
better than if we attempt to restore the original
contour of the tooth. But this is a topic that I
shall refer to again, when the subject of permanent
fillings is under consideration, as the teeth we are
now treating of are much too young for that class
of work. What we want to do is to stop the decay,
if possible, before it has made serious progress,
while it can be cut away with the chisel, or the
engine disk ; but, personally, I prefer the chisel for
this work, because I can use the mirror so as to see
better what I am doing, and I have never yet found
a disk that I could work with as rapidly as I can
with the chisel. This is a most admirable method
of treating a tooth when the decay is superficial;
and, if the surface is well polished after cutting
away the decay, it is quite as safe, if not more so,
than it can be with the best filling that can be
made. Unfortunately this treatment is limited to a
comparatively small number of cases ; and when the
THE PERMANENT TEETH. 51
decay is too deep to be cut away without too much
loss of substance, the cavity must be filled. We
therefore cut away from the lingual surface all the
friable, fragile edges of enamel, and remove all the
softened dentine, taking care always to leave the
cavity larger inside than it is at the orifice. When
only the calcareous portion of the dentine is
destroyed, leaving a cartilaginous substance that
is tough and firmly attached, it will do no harm to
leave some of the latter at the base of the cavity,
although every particle must be removed from the
edges that will be exposed to the action of the
oral fluids after a filling has been inserted. This
substance, if protected, will often be re-calcified,
and become dense, healthy dentine, forming an
excellent covering for the pulp ; but when any of it
is left in the tooth, it is good practice to wipe out
the cavity with carbolic acid immediately before the
filling is inserted, care being taken, of course, to
dry the cavity again before filling. Whether the
acid has any effect in stimulating the process of re-
calcification may be a question, but it certainly acts
to soothe and comfort an irritable surface of dentine,
and that is quite sufficient justification for its use.
When we are satisfied with the excavation, we
dry the cavity carefully with some shreds of amadou,
absorbent cotton, or bibulous paper (all of which are
used for this purpose, but I prefer the amadou, when
it is of good quality), and then we fill with gutta-
percha, which must not be overheated, but just suffi-
ciently warmed to be compressible between the
52 DENTAL PRACTICE.
fingers. The packing should be done with fine
instruments, the edges especially being packed with
quite as fine instruments as would be used for gold,
all being well warmed, but not hot. The corners
and fissures must be carefully packed, because the
use of a plastic material offers no excuse for careless
work ; and the surface may be smoothed with a
warm burnisher ; but if it cannot be made quite
smooth in this way, a strip of tape may be
moistened with chloroform and used as in polish-
ing ^a metallic filling ; the chloroform, being a
solvent of the gutta-percha, will leave a perfectly
smooth surface. Such a filling will not take a
quarter of the time that we should be compelled to
spend in making and finishing a filling of gold, and
it should be quite understood that it is not expected
to be permanent. Yet, the work being done with
equal care, I would much sooner trust the gutta-
percha in these young mouths than the gold, and
certainly the pain during the operation, and the
sensibility of the tooth to thermal changes after-
wards, are all in favour of the gutta-percha. If the
gutta-percha fails, it will be from wearing away,
and not from new decay at the cervical edge, and
a new filling can be inserted in five minutes without
any new excavation ; but unless there is a large
surface exposed to wear, the filling will last three or
four years (many of them are not touched again for
ten or twelve years), and when it is desirable to
renew it, a gold filling will have a much better
chance than it would have had at first.
THE PERMANENT TEETH. 53
It may be said that the gold fiUings would last
too, if the teeth were kept clean ; but we cannot
make boys and girls of ten and twelve years of age
as careful as they will be at eighteen or twenty,
when pride in their personal appearance becomes a
strong motive. We must not cease to preach clean-
liness to them, for it reminds them that there is a
difference between cleanliness and filthiness, but
our preaching will not make all of them take as
much care as they ought to take of their teeth.
This being the case, I think it better to defer the
gold fillings to a period nearer the time when we
shall have the assistance of personal vanity as an
incentive to taking care of the work we do for them.
We shall often find teeth that are more or less
imperfectly covered with enamel, sometimes from
inherited malformation, and sometimes from illness
occurring in early infancy, while the process of
development of the permanent teeth is going on.
In the former case the imperfection will have com-
menced with the earliest stage of development of
the enamel, that is at the cutting edge of the
incisors and the points of the cusps in the molars,
and it may extend over the whole crown of the
tooth, or, as is more frequently the case, over a
third or half of the tooth (Figs. ]8 and 19), and then
the enamel may be quite perfect on the remainder
of the crown. The defective portion may be
absolutely without enamel, there may be small
detached patches of enamel affording no protec-
tion to the tooth, or it may be interrupted with
54
DENTAL PRACTICE.
pits and jQssures, but still serviceable over a good
of the affected surface. If the defect is
Figures 18. — Showing defective formation of enamel on two upper central
incisors.
Figure 19. — Showing defective formation of enamel on lower incisors.
owing to illness in infancy, the interrupted for-
mation may occur as a line of pits across the
surface of the tooth, or a band of defective thin
enamel, which may also extend across the surface
of an otherwise well-formed tooth; the cutting
edge or the cusps will be properly developed, then
the band of imperfect formation appears, and then
the enamel organ recovers its function, as the period
of weakness passes, and the remainder of the
crown will be perfectly covered with well- developed
enamel. (Figs. 20 and 21.) We sometimes see two
or three of these bands across the surface of the
incisors, with well-formed enamel between, marking
periods of alternate weakness and strength. Defects
of this nature are usually confined to the incisors
THE PERMANENT TEETH.
55
and first molars, though sometimes the bicus-
pids are affected to a less degree, which seems
Figure 20. — Showing a baud of defective euamel.
.-^^
iff -^ «^ ,.*x.
Figure 21. — Showing alternate bands of perfect and defective enamel across
all the upper front teeth, including the bicuspids.
to indicate that the teeth of later development
are not so liable to be affected by illness. It
may, however, be assumed that any severe illness
occurring during the first one or two years of
infantile life will be likely to affect the structure
of the teeth, and the administration of some of the
preparations of lime, known as phosphatic food,
may be very beneficial in supplying the materials
for the calcification of the enamel.
The treatment necessary in these cases of
defective enamel is to fill every pit or fissure,
where the dentine is exposed, and to file away as
much as possible of the dentine that is quite unpro-
tected on the cutting edges and grinding surfaces of
56 DENTAL PRACTICE.
the teeth ; but the use of the file and corundum
wheel must be limited to the removal of sharp
points and thin edges — in short, to mere protection,
until the patient is sixteen or seventeen years of
age, when a great deal may be done with these
instruments to improve the appearance of teeth
which at first seemed almost hopelessly misshapen.
The bicuspids are quite as much predisposed to
caries as the incisors, and while cavities in the
sulcus between the cusps may be easily and quickly
seen, much more serious mischief may be going on
in the interstices. Therefore careful examination
with thin delicate instruments, and with waxed silk,
or the loosely-twisted linen thread used by shoe-
makers, is necessary to detect the earliest indica-
tions of disintegration and roughness of the enamel
on the approximal surface. I believe that free'
excision is the best treatment for these, and for
approximal decay in all teeth, when the disease is
superficial, or has not penetrated so deeply that to
cut it away will injure the appearance of the labial
surface of the tooth. I cannot do better than to
borrow from the late Dr. Arthur's valuable work*
on this method of treatment, an illustration of
* Treatment and Prevention of Decay of the Teeth, by Eobert Arthur,
M.D., D.D.S. J. B. Lippineott & Co., Philadelphia.— A work that teaches
and strongly urges the practice of a different system of treatment from that
which is recommended here ; but it is a book that should be read by every
dental student ; and if he is convinced that the teaching is sound, the
student cannot do better than to follow the lead of a man who had the
courage of his opinions, and consistently operated as he thought, to the
lasting benefit of those who were fortunate enough to have had their teeth
under his thoughtful aud skilful treatmenti
THE PERMANENT TEETH. 57
the best way of making the V shaped spaces that
will leave the surfaces self-cleansing, and, therefore,
self-protecting. It will be observed that the spaces
are V shaped in two directions, from the labial
approximal and from the cervical approximal sm -
faces. (Fig. 22.)
Figure 22. — Sbowing the method, approved by the late Dr. Arthur, of
cutting away the approximal surfaces of the teeth for preventing decay.
But if the decay has penetrated to any extent
into the dentine, the tooth should be filled, always,
I think, with gutta-percha at first, until after the
constitutional changes at puberty, for the oral
secretions at this period are too strongly acidulated
for any other form of filling to be safe. The idea
of the V shaped space should, however, be kept in
mind in shaping the cavities for filling.
The canines are usually more dense than the
teeth on either side of them, but, nevertheless, they
are often unable to resist the effect of the carious
condition of a surface in contact with them, and
they must be treated in the same way as their
neighbours.
All the teeth anterior to the first permanent
molars being now in position, and the child being
58 DENTAL PRACTICE.
twelve years old, we should find that there has been
a sufficient lengthening out, or growth, of the max-
illary bones beyond the first molars, to make room
for the twelve-year, or second permanent molars ;
we may also reasonably expect to see all four of
these teeth before the child is thirteen years of age.
59
CHAPTER III.
Extraction as a means of Preventing Decay.
In the preceding chapters we have noted the
progress of dentition until the second permanent
molars have appeared, and have endeavoured to
show that extraction is an unnecessary and unjus-
tifiable operation, except so far as may be absolutely
necessary in order to permit each permanent
tooth, in its turn, to come into its natural position
in the dental arch. But at this period of develop-
ment it is sometimes advisable to remove a tooth
from each side of each jaw for the conservation of a
well-arranged and comfortable set of teeth in after-
hfe.
It now becomes the duty of the dentist to con-
aider well whether he can hope to preserve all the
teeth that are in the mouth at this age. He must
take careful notice of the tendency, if any, to
approximal decay; and in considering this he will do
well to remember what has been his experience with
other and older members of the same family. He
should recall his experience with teeth that resem-
bled these in colour, shape, and density, in the
mouths of other young patients whose teeth he has
60 DENTAL PEACTICE.
watched through the natural changes at puberty ;
and he should notice whether his instructions
respecting cleanliness have been and are carefully
attended to. He should see how the upper and
lower teeth articulate, and whether they have plenty
of room, or are crowded and irregularly placed in
the dental arch ; and, in short, he must exercise
all the power that teaching and experience have
given him to form a prognosis of the effect that the
constitutional changes, now about to take place, will
have upon the teeth of the individual case before
him. He must not lay down hard and fast rules
for practice, but study the peculiarities and probabil-
ities of every case by itself, and in comparison with
others. And if family history and local appear-
ances indicate that the teeth will suffer seriously
from the excessive acidity which is natural to the
oral secretions at this period of life, there should be
no hesitation in advising the immediate removal of
the six-year molars, if the articulation is normal ; or
the second, or first bicuspids, if abnormal articula-
tion seems to indicate that the removal of these will
more effectually relieve crowding and pressure.
But in any case, the teeth which are selected for
extraction should be opposites ; that is, if decay,
or defective structure, or malposition, or space
required, points to the extraction of a molar in one
jaw, the tooth articulating with it should be the one
to be extracted from the other jaw, or else the tooth
that has no antagonist will elongate, and, by pro-
truding like a wedge into the gap that is opposite,
EXTRACTION AS A MEANS OF PREVENTING DECAY. 61
will prevent the desired separation of the other
teeth, as may be seen in Fig. 23.
Figm-e 23. — Showing how a tooth will elongate, and thus prevent the closing
up of gaps, when otber than opposite or antagonizing teeth are extracted
to reUeve crowding.
If there is no decided counter-indication, it is
always preferable to extract molars for this purpose,
because we thereby immediately protect the bicus-
pids and the second molars from approximal decay.
We do not disturb the symmetrical arrangemeut of
any of the anterior teeth that are seen by the
ordinary observer ; but, on the contrary, give them
room to correct, of themselves, many ugly irregu-
larities. We also give space to the wisdom teeth,
so that they will come earlier than they otherwise
would, and are more likely to be serviceable teeth
when they do come ; and we shall have selected for
removal the teeth that are already seriously decayed
in, at least, eighty per cent, of the cases which we
shall see in ordinary practice.
The bicuspids will at once begin to fall back,
thus isolating themselves, and making room for
the canines and incisors to gain, a little later, the
amount of space that is so essential to their preser-
vation. I have seen cases where, in one year, the
62 DENTAL PRACTICE.
gaps left by the extraction of the molars were so
filled up that, in the upper arch, there was only
about the same space between the second bicuspid
and second molar that there was between the bicus-
pids, and between the first bicuspid and the canine,
and the incisors were also perceptibly separated ;
and in the lower arch the bicuspids had fallen back
so much as to be quite safe from approximal decay.
Teeth that are isolated do not suffer from
approximal decay. I do not mean to say that, if
it has commenced before the separation took place,
it will not go on, but it will not commence spon-
taneously in a tooth so situated, except in cases of
severe illness, or of that peculiar condition of the
oral secretions that may be seen when there is a rapid
breaking up of the constitution, either prematurely,
or from old age, when no part of a tooth seems
exempt from what has been termed senile decay.
It is therefore safe to say that, when we have suc-
ceeded in isolating all the upper teeth, and the
lower bicuspids and molars, we have effectually
protected them from approximal decay.
Some writers deny that there is any falling back
of the bicuspids after the molars are extracted, but
such writers simply do not know what they are
writing about. I have watched the growing up of
a good many families of young people ; some of them
who came to me with their first dental troubles, are
now men and women, with children of their own.
Many families have come under my care when the
elder children were well on in their teens, and the
EXTRACTION AS A MEANS OF PREVENTING DECAY. 63
younger ones still in the nursery, so that I could
compare the result of early treatment. Many had
been under the care of the best-known dentists in
both hemispheres, and thus I am sure that few men
have had a better opportunity to judge of the results
of different systems of treatment. I have extracted
the molars in a good many cases, and I have never
yet seen a case where, if they were extracted at the
proper time, the bicuspids failed to move backwards,
and so make for themselves and the front teeth
more room. I have seen a few cases where extrac-
tion of the molars was not a sufficient protection,
but I have never seen a case where I regretted
having adopted this treatment, and I have seen
many cases where, from a feeling of confidence that
I could do without it, I have not recommended it,
and would have given anything afterwards if I
could have changed my plan of practice. One
instance of this nature I can recall, the daughter of
a medical man, one of my most intimate friends.
At twelve years of age she was a strong healthy
girl, and had teeth that seemed capable of resisting
anything, and yet, before she was eighteen years
old, the bicuspids and molars were decayed on both
approximal surfaces ; there were dead pulps in three
of them ; and although she was only about a month
in every year absent from home, when she could not
consult me, she had suffered so much pain that two
of these teeth had been extracted. This was a case
where the teeth were dense and hard in structure,
and well covered with enamel. They were yellowish
64 DENTAL PRACTICE.
white in colour, and short and broad in form,
having, in fact, all the characteristics that we look
upon as indicating the best type of teeth. The
young lady was careful with them, and came often
to have them examined, and when the first indica-
tions of approximal decay appeared, I filled the
cavities (mere pin holes) with gold, thinking that if
it was suitable for any teeth it was so for these.
I know the work was well done, but the decay went
on notwithstanding all this, and I am sure that it
was only want of space, at the time when isolation
would have absolutely prevented decay, which caused
all the trouble. If I had extracted the first molars
as soon as the second molars appeared, there would
have been no occasion for any approximal fillings
up to the present time ; and when she was eighteen,
the fact that four teeth had been extracted would
have been perceptible only to a professional eye.
The second molars are, of course, perfectly
isolated from the moment of the extractions, and
approximal decay is practically impossible, but the
sulci of the grinding and buccal surfaces are liable
to suffer.
Prominent canines are always unsightly, but
they will generally right themselves after the
extraction of the molars. Unless they are much
worse than those shown in Fig 24, there is no
need for mechanical assistance to straighten them.
The lower canine on the right side may not come
quite into its place, for the lower teeth do not
change their position quite so readily as the upper
EXTRACTION AS A MEANS OF PREVENTING DECAY. 65
ones, but it is doubtful if even that will need
artificial pressure to get it into place. In this case
Figure 24. — Showing very prominent canines, age 13.
the molars were extracted immediately after the
impressions were taken.*
Dr. Arthur's method of preventing decay, by
cutting away a portion of the mesial and distal
surface of every tooth, may, perhaps, be as effective
as extraction of the molars. I confess I have never
tried it to the extent that he recommends, for I
think it is better, if possible, to have twenty-eight
teeth, well shaped and well covered with enamel,
than to have thirty-two, with a slice taken off each
side of every one of them, except the wisdom teeth,
from which it will only be necessary to cut away