connected with the bone forming the insertion of the temporal muscle, and reach down to the last molar tooth. According to Sanson, fractures of the coronoid process do not admit of union.

Considerable inflammation frequently follows a fracture of the jaw, even of a simple kind, particularly if it has been neglected or overlooked for some hours. The face becomes swollen, and the tissues beneath the chin infiltrated with serum, which is sometimes converted into pus, giving rise to troublesome abscesses.

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CHAPTER II.

COMPLICATIONS OF FRACTURE OF THE LOWER JAW.

The

Wounds of the face are rare accompaniments of fracture of the lower jaw, except in cases of gun-shot injury, and when found are usually the result of a kick from a horse. wound itself requires treatment on ordinary principles, and is of little moment as regards the fracture (which is doubtless "compound" also into the mouth), except as interfering with the application of the necessary retentive apparatus. In a case of extensive fracture of the lower jaw, the result of a kick from a horse, which I saw in the Westminster Hospital, under Mr. Holthouse's care, the lip and chin were extensively torn; and in a case of Mr. Berkeley Hill's, in University College Hospital, the result of a fall, the wound beneath the chin very much interfered with the application of a modified form of Lonsdale's apparatus, which it was found necessary to employ.

Hæmorrhage, beyond that resulting from laceration of the gums, is rarely met with, since, although theoretically one would imagine that the inferior dental artery would frequently be torn across, this appears not to be the case; a result due, no doubt, to the fact that the elasticity of the artery allows of its stretching sufficiently to avoid rupture. In the Lancet of 12th October, 1867, a case of fractured jaw is reported, under the care of Mr. Maunder, in which severe hæmorrhage into the mouth occurred, through a fissure in the gum behind the last molar tooth. This was effectually controlled by digital compression of the carotid artery, which was maintained for two hours and a half, after which no further bleeding occurred. Secondary hæmorrage has also been met

with, for Stephen Smith, of New York, reports a case of double fracture in which about a pint of blood was lost from the seat of fracture on the twentieth day. Injury of the soft parts about the jaws may give rise to severe hæmorrhage, requiring prompt treatment; thus Mr. Lawson has reported (Medical Times and Gazette, 1862,) a case in which it became necessary to lay open the face in order to secure the facial and transverse facial arteries, torn by the wheel of a cart, which had fractured both the upper and lower jaws.

Dislocation and fracture of the teeth are not unfrequently met with, the former being the direct result of a blow, or the consequence of the fracture running through the socket, and the latter the result of direct violence, or, in the molar region particularly, in consequence of indirect force through the neighbouring teeth; or from the teeth being forcibly driven against those of the upper jaw. (Tomes.) Where the fracture has passed through the socket, the tooth may fall between the edges of the bone and prevent their proper coaptation, and this should be borne in mind where a tooth is missing and difficulty is experienced in setting a fracture, since Erichsen mentions a case where union was prevented until the tooth was removed. In the molar region the crown of the tooth may be broken off, one fang remaining in situ and the other dropping into the fracture, as was the case with the patient under my own care, from whom specimen 2 of the King's College Museum was taken. Teeth which are merely loosened, generally become reattached and useful, and should therefore not be removed.

In the Appendix will be found a case (No. 1) for which I am indebted to Mr. Margetson of Dewsbury, in which double fracture of the jaw occurred with dislocation of several of the teeth, and fracture of the left second bicuspid, the crown of which was imbedded for more than two years in the tissues of the mouth, behind the incisor teeth. Mr. Margetson removed the crown from its abnormal position and also the fang; and both, together with a plaster cast, showing very well the deformity resulting from the fracture of the jaw,

were sent in with this essay, and are in the Museum of the College of Surgeons. (1001 A.)

The front teeth may be broken off, with the portion of the alveolus containing them, by a horizontal fracture, either alone or in combination with a vertical fracture through the thickness of the bone. Specimen 1 of University College shows a vertical fracture through the symphysis, with a horizontal fracture running through the alveolus on the right side, separating the portion containing the right lateral incisor and canine and first bicuspid teeth. Such a fragment may be made to re-unite if treated at once, but when some days have elapsed and the fragment is only attached by a portion of gum, removal must necessarily be performed. A case of the kind was recently under my own care, in the person of a man aged sixty, who had had a blow on the left side of the jaw six days before I saw him. I found a loose piece of alveolus three-quarters of an inch in length, and containing the left incisors and canine teeth, which was merely held by a portion of gum, there being no other injury to the jaw.

The preparation accompanied this essay, and is now in the Museum of the College of Surgeons. (484 A.)

In fracture of the lower jaw in children-a very rare accident-when the fracture happens to involve the cavity in which a permanent tooth is being developed, exfoliation of the tooth, with a portion of the alveolus, is almost certain to ensue, as was noticed by Mr. Vasey in a case occurring in St. George's Hospital.

Paralysis and neuralgia from injury to the inferior dental nerve may be the immediate result of the accident, or be caused at a later period by some pressure arising from the development of callus. In by far the greater number of cases no injury of the nerves accrues, and this may be partly explained, as Boyer originally pointed out, by the fact that "the greater part of these fractures takes place between the symphysis and the foramen by which the nerve comes out."

A case of paralysis of the inferior dental nerve, from a gunshot wound of the ramus, which was under my care

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some years ago, will be subsequently referred to; and Malgaigne describes a specimen, in the Musée Dupuytren, also the result of gunshot injury, in which the dental nerve was ruptured, and its canal obliterated at the seat of fracture. (See Fig. 7.)

Temporary paralysis of the inferior dental nerve must be of rare occurrence, since Malgaigne did not meet with it; and Hamilton thinks that "the explanation may be found in the fact that the fragments seldom overlap to any appreciable extent, and that even the displacement in the direction of the diameters of the bone is generally inconsiderable, or, if it does exist, it is easily and promptly replaced." He thinks, moreover, that temporary anæsthesia of the chin might not improbably be overlooked at first, and would have ceased by the time the apparatus was removed. A. Bérard saw a case of vertical fracture without displacement between the second and third molar teeth, in which complete temporary anæsthesia of the lip and chin as far as the median line existed (Gazette des Hôpitaux, 10th August, 1841). A case of temporary paralysis of the dental nerve, from fracture, is mentioned also by Robert (Gazette des Hôpitaux, 1859, p. 157), occurring in a woman, aged sixty-four, who was run over by a carriage, and who also suffered from fracture and displacement of the malar bone, with permanent anesthesia of the infra-orbital nerve.

The cases of convulsions coincident with fracture of the jaw, recorded by Rossi and Flajani, would appear to have been due to injury of the brain, the result of the original accident and unconnected with the fracture, but it may happen that direct injury may be inflicted on the skull by the broken jaw. Thus Dr. Lefèvre (Journal Hebdomadaire, 1834) gives the case of a sailor, aged twentytwo, who fell from a height upon his chin with the following result. There was almost complete inability to open the mouth, the jaws being tightly closed and the lower drawn backwards and a little to the left. There were tenderness and ecchymosis in the left temporo-maxillary region, and a little blood flowed from the left ear. The