Also, the dislocated joint cannot be moved by the patient or by another person, except within narrow limits, while a sprained joint can be moved, with the production of pain it is true, but without any mechanical obstacle. In the case of fracture near a joint there is usually increased movement in some new direction. When a dislocated joint is put in proper place it stays in place, whereas when a fractured part is reduced there is nothing to keep it in place and, if let alone, it quickly resumes its former faulty position.
Only a few of the commoner dislocations will be considered here, as the others are of rare occurrence and require more skill than can be imparted in a book intended for the laity. The following instructions are not to be followed if skilled surgical attendance can be secured; they are intended solely for those not so fortunately situated.
DISLOCATION OF THE JAW.—This condition is caused by a blow on the chin, or occurs in gaping or when the mouth is kept widely open during prolonged dental operations. The joint surface at the upper part of the lower jaw, just in front of the entrance to the ear, is thrown out of its socket on one side of the face, or on both sides. If the jaw is put out of place on both sides at once, the chin will be found projecting so that lower front teeth jut out beyond the upper front teeth, the mouth is open and cannot be closed, and the patient is suffering considerable pain. When the jaw is dislocated on one side only, the chin is pushed over toward the uninjured side of the face, which gives the face a twisted appearance; the mouth is partly open and fixed in that position. A depression is seen on the injured side in front of the ear, while a corresponding prominence exists on the opposite side of the face, and the lower front teeth project beyond the upper front teeth.
Fig. 29.
REDUCING DISLOCATION OF JAW (American Text-Book).
Thumbs placed upon last molar teeth on each side; note jaw grasped between fingers and thumbs to force it into place.
Treatment.—A dislocation of one side of the jaw is treated in the same manner as that of both sides.
The dislocation may sometimes be reduced by placing a good-sized cork as far back as possible between the back teeth of the upper and lower jaws (on one or both sides, according as the jaw is out of place on one or both sides), and getting the patient to bite down on the cork. This may pry the jaw back into place.