Screw-type mouth gag for prevention and treatment of postoperative jaw limitation by fibrous tissue.

Treatment of a severe tethering of the mandible by surgery and subsequent exercise of the jaw with a newly devised mouth gag, consisting of two blocks of acrylic resin with a screw expander between them, is described. The mandible was gradually forced to open and was retained in the opened position by rotating the screw against the resistance of scar contraction without much pain. Possible development of trismus after excision of a tumor in the lower retromolar area because of surgical injury to the medial pterygoid muscle and postoperative scarring was avoided by means of the appliance.