Other Congenital Deformities of the Face.—Macrostoma is an abnormal enlargement of the mouth in its transverse diameter, due to imperfect fusion of the maxillary and mandibular processes.
Microstoma is due to excessive fusion of the maxillary and mandibular processes. In some cases the buccal orifice is so small as only to admit a probe.
Facial cleft is due to non-closure of the fissure between the nasal and maxillary processes. It passes upwards through the lip and cheek to the lateral angular process of the frontal bone.
Mandibular cleft occurs in the middle line of the lower lip, and may extend to, or even beyond, the chin; it is due to non-union of the two lateral halves of the mandibular arch.
These various deformities are treated by plastic operations carried out on the same principles as for hare-lip.
Fistulæ of the Lower Lip.—Two small openings, about the size of a pin's head, are occasionally met with on the free border of the lower lip, near the middle line. On passing a probe, each is found to lead into a narrow cul-de-sac, which runs for about an inch laterally and backwards under the mucous membrane. Watery, saliva-like fluid exudes through the openings. These fistulæ frequently occur in several members of the same family, and are usually associated with hare-lip. The treatment consists in dissecting them out.
Injuries of the Soft Parts of the Face.—Owing to its free blood supply, the skin of the face has great vitality, and even when severely lacerated it not only survives, but shows such resistance to bacterial infection that primary union frequently takes place. In plastic operations, also, even extensive flaps seldom become infected, and they heal so rapidly that the sutures can be removed in two or three days.
In incised wounds the bleeding is usually free at first, but unless one of the larger arteries, such as the external maxillary (facial) or temporal, is injured, it soon ceases. Paralysis of the muscles of expression may follow if the facial nerve is injured; and loss of sensation may result from injury to the supra-orbital or infra-orbital nerves. If the parotid gland is implicated, saliva may escape from the wound, but it usually ceases in a few days; if the duct is involved, a persistent salivary fistula may form.
Punctured wounds may perforate the orbit, the cranial cavity, or the maxillary sinus, and be followed by infective complications, particularly if the point of the instrument breaks off and is left in the wound.
Contused and lacerated wounds result from explosions and injuries by firearms, and foreign bodies, such as particles of stone or coal, or grains of gunpowder and small shot, may lodge in the tissues. Every effort should be made to remove such foreign bodies, as if left embedded they cause unsightly pigmentation of the skin. Ligatures are seldom necessary for the arrest of hæmorrhage unless the larger branches are injured, as the bleeding from smaller twigs is arrested by the sutures. The edges of the wound are approximated by means of Michel's clips, or by a series of interrupted horse-hair stitches, and for this purpose a fine Hagedorn needle is to be preferred, as it leaves less mark than the ordinary bayonet-shaped needle. If the mucous membrane of the mouth or of the eyelid is implicated, its edges should be approximated by a separate row of catgut stitches.