§I.
1. The lower jaw, a kind of moveable hammer, destined, to use the
words of a certain physiologist, to triturate the aliments against the
almost immoveable anvil of the upper jaw, is more exposed to the action
of external bodies, and consequently to fractures, than most of the
other bones of the face. But all parts of it are not alike subject to
such accidents. Common in its body, but less frequent in its branches
or sides, fractures sometimes occur in the two processes in which its
branches terminate. One of these processes, concealed by the zygoma,
embosomed in the temporal muscle, and covered by the masseter, is less
liable to fractures than the other, which serves as the centre of the
motions performed by the bone, and is protected externally only by the
parotid gland.
§II.
2. A fracture of the condyle may sometimes arise from a
_counter-stroke_, as when, in consequence of some external force being
applied from before backwards, and from below upwards against the
chin, this process is driven against the projecting rim of the glenoid
cavity; at other times it may be the effect of an immediate or direct
stroke, as when a body in motion strikes with force against the region
of the joint, and does violence to that portion of the bone.
3. But in whatever manner the fracture may be produced, it generally
occurs in the slender part of the bone which supports the condyle,
below the insertion of the pterygoideus externus. It is characterized
by a pain more or less acute, necessarily accompanying the motions of
the jaw; by a difficulty more or less considerable, in the performance
of these motions; by a crepitation, oftentimes distinct, when, in
consequence of the angle of the jaw being pushed forward, or the jaw
itself alternately depressed and elevated, the separated surfaces rub
against each other; by an inequality of surface sometimes perceptible
directly over the fractured condyle; by the ease with which, on being
pushed forward, it may be forced into the depression beneath the
zygoma; and by its remaining stationary, during the movements of the
lower jaw, from which it is separated. These signs, though generally
characteristic, are subject to an uncertainty proportioned to the
swelling that occurs in the part.
4. In this accident a displacement is almost always produced by
muscular action. The pterygoideus externus, being attached to the
condyle, draws it forward and upward, towards the external wing of
the pterygoid apophysis, its fixed point of insertion. On the other
hand, the body of the bone is left behind, being held by the masseter
and external pterygoid muscles, the course of which is opposed to a
displacement in the same direction; so that there always exists a
separation, more or less perceptible, between the two fragments of bone.
5. Hence, if proper means be not used to restore the contact between
the broken ends of the bone, the following consequences will be likely
to occur: 1st. Their reunion will be tedious, because in every bone
this process is, in point of rapidity, inversely proportioned to
the separation of the divided surfaces: 2dly, This reunion may even
entirely fail to take place, if the bone be subject to the slightest
movements, as I have witnessed in a particular case, where the
condyle, not being reunited to the other part, exfoliated, and was in
part discharged through the external integuments: 3dly, Under such
circumstances, the callus produced in the process of healing, being
situated near to the joint, and rendered irregular and deformed by the
separation of the parts, is apt to impede muscular action, and do a
permanent injury to the functions of the jaw.
§ III.
6. As the whole apparatus in this case consists in a passive resistance
to the active powers employed in producing a displacement, it follows
from what has been said (4), that the bandage intended to prevent
this displacement, and by that means to guard against the accidents
specified above (5), ought, either effectually to bring back to its
natural situation, the condyle which is drawn forward, or pull in this
last direction (that is, forward) the body of the bone which is still
retained in its usual position, in order that it may thus be brought
into contact with the condyle.
The first of these measures is impracticable, in consequence of the
situation of the condyles, which are too deeply enveloped by the
surrounding parts, and offer a hold too small to be acted on. The
second, therefore, remains to be adopted, and is the more easily
executed, in as much as the angle of the jaw, from its projecting and
being but slightly covered by the integuments, may without difficulty
be directed from behind forward by a proper force.
7. The fingers of the surgeon temporarily supply this force, at the
time of reduction; but it is necessary that it should be permanently
kept up by means of the apparatus. This end is attained, in the
following manner:
Place behind the angle of the jaw, which must be first pushed forward,
thick compresses, to fill up the hollow under the ear, and form an
eminence higher than the surface of the surrounding parts; pass over
these compresses, in an oblique manner, the bandage commonly used in
lateral fractures of the bone, the application of which must in this
case commence on the sound side.
These compresses, being more projecting than the surrounding surface,
will necessarily sustain a greater pressure, because the compression
made by a bandage is in proportion to the projection of the part on
which it is applied. Hence, being firmly supported, they will retain
the body of the bone in a line with the displaced condyle (4).
8. In addition to this mode of applying the bandage, it is necessary
that the fractured bone should be kept in a state of perfect rest. The
internal pterygoid and masseter muscles, tending by their contractile
efforts to draw the angle of the jaw backwards, sometimes overcome the
resistance of the apparatus, and, by producing a second displacement,
give rise to the accidents formerly mentioned (5).
Let the lower jaw be now brought into perfect contact with the upper
one, and not separated from it during the first few days after the
injury, except so far as may be necessary for the admission of
nourishing broths. Should a tooth have been lost, the space which it
occupied will furnish, without disturbing the bone, an opening for the
conveyance of nourishment to the patient. Let talking, laughing, and
every thing that might produce a separation between the body of the
bone and the condyle, be carefully avoided. The further treatment of
the accident should be such as is generally applicable to all fractures
of bones, and need not be at present particularly detailed.
The following cases, reported by citizen Giraud, second surgeon to the
Hotel-Dieu, will confirm the advantages of this mode of treatment.
CASE I. Margaret Bessonet, aged thirty-four, was admitted into the
hospital on the 10th of May, 1791. On the preceding day she had
received a violent fall on her chin: a severe pain, and a preternatural
mobility in the left side of the jaw, had been the immediate
consequences of the accident: from these symptoms, taken in conjunction
with those formerly mentioned (3), Desault discovered that a fracture
of the condyle existed, which he reduced and supported in the usual
manner (7).
After being somewhat uneasy during the first few days, the patient
became reconciled to the action of the bandage, which, by inattention,
had been two or three times disturbed and put out of order, but which,
by being carefully reapplied, and aided by the necessary precautions
(8), restored to the bone its natural form and solidity, by the
thirtieth day, and on the thirty-sixth the patient was discharged
perfectly cured. The only inconvenience she experienced, was a slight
difficulty in the motions of the jaw, an effect naturally resulting
from the long continued inactivity of the muscles, but which was soon
removed by means of exercise.
CASE II. Claudius Laurat, aged twenty-seven, fell as he was carrying
a heavy burden. In his fall his chin struck with violence against a
beam that lay in his way. In an instant he experienced a sharp pain
in his right temple, and found it almost impossible to move his jaw.
Two hours afterwards a considerable swelling appeared in the part,
extending from the angle of the jaw above the ear. The patient was
admitted into the Hotel-Dieu, where the circumstances of the fall and
the symptoms that followed, gave satisfactory evidence of a fracture of
the condyle. It was reduced and supported as in the preceding case. On
the day following, the swelling was removed, doubtless by means of the
compression which had been made on it; the other symptoms (3), hitherto
scarcely perceptible, became more obvious; the bandage was reapplied,
and the disease terminated, in about twenty-nine days, in the same
manner with that of case 1.