Disarticulation of the entire bone has been very rarely performed.[111] If necessary, it can be performed without any incision into the mouth, by one semilunar sweep from one articulation to the other, passing along the lower margin of each side of the body, and just below the symphysis of the chin.
Disarticulation of the Ramus without opening into the cavity of the Mouth.—That this operation is possible, though it may not be often required, is shown by the following case by Mr. Syme. It was a tumour of the ramus, extending only as far forwards as the wisdom-tooth:—
"An incision was made from the zygomatic arch down along the posterior margin of the ramus, slightly curved with its convexity towards the ear, to a little way beyond the base of the jaw. The parotid gland and masseter muscle being dissected off the jaw, it was divided by cutting-pliers immediately behind the wisdom-tooth, after being notched with a saw. The ramus was then seized by a strong pair of tooth-forceps, and notwithstanding strong posterior attachments, was drawn outwards, its muscular connections divided and turned out entire. There was thus no wound of the mucous membrane of the mouth, the masseter and pterygoid muscles were not completely divided, and the facial artery was intact."[112]
Fergusson[113] holds that even the very largest tumours of the lower jaw may be successfully removed without opening into the orifice of the mouth at all by division of the lips. A large lunated incision below the lower margin of the bone, with its ends extending upwards to within half an inch of the lips, will give free access, and yet avoid both hæmorrhage and deformity, as the labial artery and vein are not cut, and there is no trouble in readjusting the lips. Some tumours of lower jaw can be removed without any wound of skin.
CHAPTER VIII.
OPERATIONS ON MOUTH AND THROAT.
Salivary Fistula, Operation for.—After a wound or abscess of the cheek, in which the parotid duct is implicated, a salivary fistula is very apt to remain. The saliva thus discharges in the cheek, giving rise to considerable annoyance, as well as injury to the digestion. It is by no means easy to cure this. Perhaps the best operation is the one of which a rude diagram is given (Fig. xxviii.). The duct (c) communicates with the fistula (d). One end of a thread, either silken or metallic, should be passed through the fistula, and then as far backwards as convenient through the cheek into the mouth; the needle should then be withdrawn, the thread being left in. The other end being threaded should then be re-inserted at the fistula, and carried forwards in a similar manner; the needle should be again unthreaded in the mouth and withdrawn; the two ends should then be tied pretty tightly inside, and allowed to make their way by ulceration into the cavity of the mouth. A passage will thus be obtained for the saliva into the mouth, and every possible precaution should be taken to enable the external wound to close.
