Fig. xxvii. [107]
Three processes of bone then require attention and division.
(1.) The articulation with the opposite bone in the hard palate. To divide this, one incisor tooth at least must be drawn, the soft palate divided by a knife to prevent laceration, and the thick alveolar portion sawn through in a longitudinal direction from before backwards.
(2.) The articulation with the malar bone at the upper angle of the incision through the skin. This must be notched with a small saw in a direction corresponding to the articulation, and then wrenched asunder by a pair of strong bone-pliers.
(3.) The nasal process of the upper jaw must now be divided by the pliers, one limb of which is cautiously inserted into the orbit, the other into the nose. If the disease extends high up in this process, it may be necessary partially to separate the corresponding nasal bone, and thus reach the suture between the nasal process and the frontal bone. The pliers must now be inserted into the groove already made by the saw on the hard palate, and the separation continued to the full extent backwards. A comparatively slight force exerted on the tumour either by the hand, or (when the tumour is small) by a pair of strong claw forceps, will suffice to break down the posterior attachments of the bone and remove it entire. The necessary laceration of the soft parts behind is so far an advantage, as it lessens the risk of hæmorrhage from the posterior palatine vessels.
The hæmorrhage from this operation was at one time much dreaded, but is rarely excessive; very few vessels require ligature, except those divided in the early stages in making the skin flaps; the hollow left should be stuffed with lint, which may be soaked in the perchloride of iron should there be any oozing.
The incisions recommended for this operation have been very various, and a knowledge of some of them may occasionally be useful, on account of specialities in the shape and size of the tumour. Liston "entered the bistoury over the external angular process of the frontal bone, and carried it down through the cheek to the corner of the mouth. Then the knife is to be pushed through the integument to the nasal process of the maxilla, the cartilage of the ala is detached from the bone, and lip cut through in the mesial line; the flap thus formed is to be dissected up and the bones divided."[108] Dieffenbach made an incision through the upper lip and along the back or prominent part of the nose, up towards the inner canthus, from whence he carried the knife along the lower eyelid, at a right angle to the first incision as far as the malar bone.
In cases where the tumour is of moderate size, Sir W. Fergusson found[109] it sufficient to divide the upper lip by a single incision exactly in the middle line, this incision to be continued into one or both nostrils, if required. The ala of the nose is so easily raised, and the tip so moveable as to give great facilities to the operator for clearing the bone even to the floor of the orbit.
In cases where the tumour is larger, or the bones more extensively affected, Sir W. Fergusson preferred an extension of the foregoing incision (Fig. xxvii. B) upwards along the edge of the nose almost to the angle of the eye, and thence at a right angle along the lower eyelid, as far as may be necessary, even to the zygoma. The advantages claimed for such procedures are that the deformity is less and the vessels are divided at their terminal extremities.