The chief points to be attended to seem to be (1.) that the incision through the skin should extend quite up to the level of the articulation; (2.) that the bone should be sawn through at the other side of the tumour, and freely cleared from all its attachments, before any attempt be made at disarticulation, for by means of the tumour great leverage can be attained, so as to put the muscles on the stretch, and allow them to be safely divided; (3.) that the articulation should always be entered from the front, not from behind, and the inner side of the condyle should be very carefully cleaned, the surgeon cutting on the bone so as to avoid, if possible, the internal maxillary artery; (4.) free and early division of the attachment of the temporal muscle to the coronoid process. 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. FOOTNOTES: [107] Diagram of operations on the jaws:--A, incision for removal of the whole upper jaw; B, incision for removal of alveolar portion and antrum; C, incision for removing the larger half of lower jaw; the opposite side is the one supposed to be operated on, and the incision is crossing the symphysis and turning up at a right angle. [108] _Operative Surgery_, p. 265.