and from the open mouth foul-smelling saliva, streaked with blood, escapes; the face is of an ashy-grey colour, the lips dark and swollen.  On the inner aspect of the cheek is a deeply ulcerated surface, with sloughy shreds of dark-brown or black tissue covering its base; the edges are irregular, firm, and swollen, and the surrounding mucous membrane is infiltrated and oedematous.  In the course of a few hours a dark spot appears on the outer aspect of the cheek, and rapidly increases in size; towards the centre it is black, shading off through blue and grey into a dark-red area which extends over the cheek (Fig. 23).  The tissue implicated is at first firm and indurated, but as it loses its vitality it becomes doughy and sodden.  Finally a slough forms, and, when it separates, the cheek is perforated.

Meanwhile the process spreads inside the mouth, and the gums, the floor of the mouth, or even the jaws, may become gangrenous and the teeth fall out.  The constitutional disturbance is severe, the temperature raised, and the pulse feeble and rapid.

The extremely foetid odour which pervades the room or even the house the patient occupies, is usually sufficient to suggest the diagnosis of cancrum oris.  The odour must not be mistaken for that due to decomposition of sordes on the teeth and gums of a debilitated patient.

The prognosis is always grave in the extreme, the main risks being general toxaemia and septic pneumonia.  When recovery takes place there is serious deformity, and considerable portions of the jaws may be lost by necrosis.

[Illustration:  FIG. 23.—­Cancrum oris.

(From a photograph lent by Sir George T. Beatson.)]

Treatment.—­The only satisfactory treatment is thorough removal under an anaesthetic of all the sloughy tissue, with the surrounding zone in which the organisms are active.  This is most efficiently accomplished by the knife or scissors, cutting until the tissue bleeds freely, after which the raw surface is painted with undiluted carbolic acid and dressed with iodoform gauze.  It may be necessary to remove large pieces of bone when the necrotic process has implicated the jaws.  The mouth must be constantly sprayed with peroxide of hydrogen, and washed out with a disinfectant and deodorant lotion, such as Condy’s fluid.  The patient’s general condition calls for free stimulation.

The deformity resulting from these necessarily heroic measures is not so great as might be expected, and can be further diminished by plastic operations, which should be undertaken before cicatricial contraction has occurred.

BED-SORES