Fig. 68.—Face presentation. (Bumm.)
Face positions take their names from the location of the chin (mentum—Latin). Thus the most frequent face position is the right-mento-posterior.
The diagnosis is not easy and may not be conclusive until the bony prominences of the face, such as the nose and orbital ridges can be distinguished by vaginal examination.
Fig. 69.—Descent of the chin in face presentation. (Bumm.)
The delivery is protracted from three to five hours beyond the average by this complication, and the mortality is higher both for mother and child. The face is badly swollen and disfigured, but the normal condition of the tissues will be restored by the end of a week. Most face cases terminate spontaneously, but operative interference is not infrequent on account of danger to mother or child.
Version or manual correction of the presentation may be done before engagement.
Forceps is the operation of choice after the head is fixed in the pelvis, but it may be necessary to precede the delivery by a preparatory pubiotomy, or in case of failure, to do a craniotomy on the dead child.
If the chin does not rotate forward under the symphysis, the labor is impossible without pubiotomy or the destruction of the child. In general, the case should be left to nature unless some definite indication to interfere develops.