TEMPORO-MAXILLARY ARTICULATION. 



939 



When one condyle only is dislocated, the 

 chin is thrust forwards and towards one side 

 that, namely, on which the condyle remains 

 in place. The coronoid process of the dis- 

 located side forms a prominence even more 

 conspicuous than when both condyles are 

 displaced, but the mouth is not so wide open. 

 There is, of course, the same depression in 

 front of the ear, and the same flatness of the 

 masseteric region. 



Congenital malformation. Dr. R. W. Smith 

 of Dublin, in his Treatise on Fractures and 

 Dislocations,* gives a detailed account of the 

 dissection of a highly interesting case of " Con- 

 genital luxation of the inferior maxilla." The 

 malformation affected one side only, the 

 right, and consisted mainly of an absence, 

 or arrest of development of the condyle, the 

 only vestige of which was a small process 

 hooked inwards at its apex. This process did 

 not touch the temporal bone by a quarter of 

 an inch, and neither it nor the surface oppo- 

 site to it presented any articular cartilage, but 

 were both simply invested with periosteum. 

 There was no trace of an interarticular fibro- 

 cartilage, nor of a synovial sac, and the ex- 

 ternal lateral ligament sloped downwards and 

 forwards instead of downwards and backwards. 

 The glenoid cavity did not exist, or rather 

 the inferior root of the zygoma, which really 

 forms the glenoid cavity, was not developed. 

 There was conspicuous atrophy of the whole 

 of this side of the face in respect of the bones 

 temporal, right half of the body and right 

 rarnus of the inferior maxilla, malar, su- 

 perior maxillary, and even the right half of 

 the sphenoid, and muscles, but the nerves 

 were as large as their fellows. The most re- 

 markable of the peculiarities of the surround- 

 ing parts, and that which clearly demonstrated 

 the abnormal condition not to be the result of 

 t injury or disease, was an extreme shortness 

 of the zygomatic process of the the temporal 

 and a compensatory unusual length of that of 

 the malar bone. The former was only half an 

 inch long, whilst the latter was nearly twice 

 as long as that of the other side. During the 

 lifetime of this patient, who was an idiot, it 

 was observed that one side of his countenance 

 did not match the other, and that the dis- 

 parity was much increased when he opened 

 his mouth. He was often observed to have 

 spasmodic twitching of the abnormal side of 

 his face. 



Disease. Chronic rheumatic arthritis occa- 

 sionally affects this articulation. Both joints are 

 usually affected by it, but sometimes it attacks 

 the joint of one side only. It is most common 

 in elderly subjects. When it attacks the young 

 or middle aged, it is more rapid, accompanied 

 with more pain, and more likely to involve the 

 neck of the condyle and the ramus of the jaw. 

 The pain is often very severe but varia- 

 ble, apparently influenced by meteorological 

 changes. The lymphatic glands in the neigh- 

 bourhood of the diseased joint are much prone 



* A Treatise on Fractures in the Vicinity of Joints 

 and on Certain Forms of accidental and "congenital 

 Dislocations. Dublin, 1847. 8vo. 



to enlargement; and sometimes the enlarged 

 condyle can be felt as a bony tumour just in 

 front of the ear. The chin is thrust forward, 

 mesially when both joints are affected, and 

 towards the healthy side, as well as forwards, 

 when only one is diseased. The motion of the 

 jaw is considerably impaired. On dissection, 

 the condyle, in cases of this affection, is gen- 

 erally found to be large and broad, but some- 

 times conical, rough, and devoid of cartilage. 

 Ivory or porcellanous deposit, so common in 

 other joints when affected with chronic rheu- 

 matic arthritis, is but rarely met with in this ; 

 those abnormal ossific concretions in and 

 around the joints, which are so constantly 

 met with in the disease in question in other 

 situations, have also never been found in the 

 ternporo-maxillary joint. The interarticular 

 fibro-cartilage had disappeared in every case 

 of this affection which has been dissected and 

 published. The gleaoid cavity is enlarged, 

 divested of its articular cartilage, and presents 

 a roughened, abnormal surface. All indica- 

 tion of the disease stops suddenly at the glas- 

 serian fissure, and at the spheno-temporal 

 suture, and the enlargement of the gltnoid 

 cavity takes place at the expense of the lower 

 root of the z}'goma which generally becomes 

 entirely absorbed. 



In the report of the proceedings of the 

 Pathological Socety of London in the Medical 

 Gazette of November 30. 1849, there is an 

 account of a highly interesting case of necrosis 

 of the condyle, back part of the ramus, and 

 angle of the lower jaw in a scrofulous boy. 

 The portion of necrosed bone, which was ex- 

 hibited to the society, was removed many 

 years before, by Mr. Keate, who also had 

 examined the patient, grown to a healthy 

 man, two years before the date of the com- 

 munication. As far as could be ascertained 

 by external investigation, the lost portion of 

 bone had been perfectly restored. There was 

 no deformity, and no impairment of motion. 

 There are two other similar cases on record ; 

 one by Desault, in which the whole ramus, 

 with the condyle and coronoid process, were 

 removed, the other by Mr. Syme, in which 

 the condyle and ramus were necrosed. In 

 both these cases, also, the lost bone was per- 

 fectly restored to all external appearance, but 

 there is no record of a dissection of such a 

 case. In some cases which are on record, 

 where the whole of the lower jaw, with both 

 its condyles, has been removed, its place has 

 been supplied by condensed fibrous tissue, 

 but there has been no reproduction of bone. 



Anchylosis of the temporo-maxillary joint is 

 a very rare occurrence. There is, however, 

 one specimen of it in the Pathological series 

 of the Museum of the London College of 

 Surgeons. The fusion of the two bones is 

 complete, as is shown in the preparation by 

 a vertical, side to side, section through the 

 situation of the quondam joint. This section 

 shows that a perfectly normal-looking cancel- 

 lous structure, shelled over by a layer of dense 

 osseous tissue, is continued from the temporal 

 to the inferior maxillary bone, and exhibits no 



