123, 124. Ditto ditto ditto 122. Fibrous tumour of lower jaw (University College) Original 272 Spencer Wells 273, 274 130. Large osteo-sarcoma of lower jaw 131. Patient, after its removal . 132. Large osteo-sarcoma of lower jaw (Author) after removal . 133. 139. Patient, after operations 141. Girl, after removal of cancer of lower jaw (Author) Fergusson 298 Fergusson 314 143. Tumour of centre of lower jaw 144. Incision for removal of lower jaw 145. Closure of jaws by cicatrices (Author) 146. Effects of Esmarch's operation 147. Closure of jaws and cicatrix of cheek (Author). 148. Effects of operations. 149. Shields for application to gums (Clendon) THE INJURIES AND DISEASES OF THE JAWS. CHAPTER I. FRACTURE OF THE LOWER JAW. FRACTURE of the lower jaw is usually the result of direct violence, though Professor Pancoast met with a case in which fracture of the neck of the bone had resulted from a violent fit of coughing in an old man upwards of seventy years of age. (Gross's "Surgery," p. 964.) Blows received on the jaw in fighting or a kick from a horse are the most common causes of the accident; but falls from a height upon the face also produce some of its most serious forms, owing to the comminution resulting. The unskilful application of the dentist's "key" has been known to produce a complete fracture of the bone, but more frequently in former years than at the present time, when that instrument has been almost entirely superseded by the forceps. Fractures of the alveolus, however, are often unavoidable during the extraction of the molar teeth, even in the most skilful hands, since the position assumed by the fangs is occasionally such that extraction without displacement of the bone to some extent is impossible. These cases ordinarily give, however, little inconvenience, since the removal of the alveolus only hastens the absorption which must necessarily ensue upon the removal of the teeth, unless indeed the fracture should be so extensive as to affect B the alveoli of the neighbouring teeth, in which case exfoliation of a troublesome character may be produced. On this subject, which is of considerable interest to those practising dental surgery, I may quote a passage from a paper in the "Dental Cosmos," by Dr. J. Richardson, which illustrates the difficulty which may be met with. He says: "I have never come to regard extracting teeth as an operation free from liability to grave complications. I seize hold of a tooth to-day with more misgiving, with more caution, than I did the first year of my practice. Eleven years' experience may be supposed to have given me some confidence and expertness in this operation, yet with each year's added experience the operation grows in importance, and dictates greater vigilance and prudence. I feel my way through the operation with more and more caution, guard every movement with greater circumspection, and magnify my skill more and more with every success. Through eleven years my experience has been free from serious accident, but the catastrophe came at last when I had no possible reason to expect it. "Within the past two months I fractured the inferior jaw severely in attempting to remove the anterior right inferior molar. It was in this way. The patient was a lady about twenty-five years of age. The crown of the tooth was much decayed, but I had a firm hold upon the neck. Alternate lateral traction was made upon the tooth, moderately at first, but increasing at every movement of the forceps. There seemed to be complete immobility of the tooth until the instant of its giving way, which it did with the outward movement of the forceps. I comprehended instantly, from the enlargement of the gum below the processes, that a fracture of the maxilla had occurred. On examination I found the detached portion adhering firmly to the fangs of the tooth, and extending antero-posteriorly about an inch and a quarter, and in depth about three-fourths of an inch or more. I made no further attempts to remove either the tooth or fragment of bone, but pressed them firmly back to their places, and directed the patient to keep the mouth persistently closed. I hoped for a reunion of the fractured parts."—British Journal of Dental Science, August, 1863. Gunshot injuries of the face may produce the most terrible injuries of the lower jaw by splintering and removing large portions of it; and the mere explosion of gunpowder in its immediate neighbourhood, as when a pistol is fired into the mouth by a suicide, will produce a fracture of the bone. (See chapter on "Gunshot Injuries.") Fractures of the lower jaw are remarkable for the fact that they are almost always compound towards the mouth, though the skin is rarely involved except in gunshot injuries. The fibrous tissue of the gum being very inelastic, tears readily when the bone is broken across, and thus the saliva and the air come in contact with the fractured surfaces. This statement only applies, however, to fractures of the body of the bone, for when the ramus, or still more the coronoid process or condyle are broken, the bone is too deeply seated for the injury to extend into the mouth. Fracture may occur at various points in the lower jaw, and the body of the bone is the portion most frequently injured (in 24 out of 25 cases recorded by Hamilton); the ramus from its position and coverings being much less liable to injury except from extreme violence, such as the passage of a wheel over the face or a gunshot injury. The coronoid process is occasionally broken off obliquely, and the neck of the jaw has been repeatedly broken on one or both sides of the bone in cases subjected to great violence. In the body of the jaw the fracture appears to occur most frequently in the neighbourhood of the canine tooth, this position being determined probably by the greater depth of its socket, and the consequent weakness of the bone at that point; but the fracture may happen at any other point, and has been known to occur exactly at the symphysis in cases too old to admit of separation of the two portions of the bone. Of the twenty-four cases of fracture of the body recorded by Hamilton, one was perpendicularly through the symphysis, twelve were through the body, and five through |