The patient being thoroughly anæsthetised, and the mouth held open by the gag, the surgeon, standing on the right side of the patient, commences by making a lateral incision, preferably on that side of the cleft which is opposite to the gag; it facilitates matters to shift the gag to the opposite side of the mouth when the second incision is made. These incisions should commence a little internal and opposite to the last molar tooth (Fig. 67 A), and should be carried forward parallel to the alveolar margin to a point immediately behind the lateral incisor, terminating a little anterior to the apex of the cleft, if the alveolus be intact. The knife should be held so that the incision is always perpendicular to the varying planes of the mucous membrane, in order to prevent the edge from being bevelled, which may seriously impair its nutrition. All the structures should be cleanly divided down to the bone. [Illustration: FIG. 67A.—Diagram to indicate the extent of the incisions in Langenbeck’s operation. The thick black lines show the primary incision; the thick dotted lines the extension backwards of the same to relieve any lateral tension (made after the insertion of the stitches); the thin dotted lines indicate approximately the position of the free posterior border of the bony palate. FIG. 67B.—Shows the position of the sutures and the condition of the parts at the close of the operation.] Hæmorrhage, even to a considerable amount, naturally follows, and this should be checked by pressure with purified sponges; it will be much more serious should the palatine arteries be included in the line of incision. The distribution of the anterior and posterior palatine arteries is so variable, and their pulsation so rarely to be felt beforehand, that it is not always possible to avoid wounding one or other of them. Should this occur, it is important that the vessel be _completely_ divided, as a buttonhole in it will cause severe and protracted hæmorrhage. During the bleeding the patient’s head should be turned on one side and lowered, so as to allow the blood to run freely out of the mouth and not into the throat.