A jaw exerciser for fibrous ankylosis of the temporomandibular joint.

hdications for the use of an individually designed jaw exerciser together with the method of fabrication and patient instructions and reports of two cases of post-traumatic progressive fibrous ankylosis of the temporomandibular joints are described. (Received for publicarion April 1984. Revised May 1985.) Introduction Jaw exercisers can be divided into five types: screw' or wedge, cast metal cap splints activated by elastic traction,' hand operated devices,' extra-oral devices activated by elastic traction,'.' and screw-type mouth gag.4 The suggested treatment for progressive fibrous ankylosis of the temporomandibular joints has been condylar surge~y,~ forced jaw manipulation under general anaesthesia with a Mason gag,5 anti-inflammatory medication and deep heat therapy with exercises" contraindicated, and the use of an acrylic screw.' The purpose of this paper is to illustrate and outline the use of the scissor-type cap splint jaw exerciser as a successful conservative form of treatment for progressive fibrous ankylosis of the temporomandibular joints. ' Rowe NL, Killey HC. Fractures of the facial skeleton. 2nd edn. London: ES Livingstone. 1968;796-802. Rahn AO. Boucher LJ. Maxillofacial prosthetics. Philadelphia: WB Saunders, 1970:176-80. ' Beumer 111 J , Curtis TA, Firtell DN. Maxillofacial rehabilitation. St. Louis: CV Mosby, 1979534-6. ' Nakajima T, Sasakura H, Kato N. Screw-type mouth gag for prevention and treatment of post-operative jaw limitation by fibrous tissue. J . Oral Surg 1980;38:46-50. ' Moore JR. Principles of oral surgery. 2nd edn. Manchester: Manchester University Press, 1976;227-38. (I Bell W. Clinical management of temporomandibular disorders. Chicago: Year Book Medical Publishers, 1982:167-212. Fabrication and instructions Since restricted movement reduces mouth opening, alginate impressions using adjusted stock trays are obtained for models of the upper and lower arches. Upper and lower cast silver cap splints are fabricated and to each splint three millimetre diameter brass rods are silver soldered to form the exerciser. The rods are designed to retain elastic bands necessary to promote opening movements (Fig. 1) when the splints are placed in the mouth. Initially the exerciser is operated for a minimum of 30 minutes and not more than 1 hour daily. The patient is advised that daily exercises will be required for six months6 and initially movement is obtained with one rubber band (diameter 90 mm, width 3 mm, thickness I mm). The tension of the elastic band draws the ends of the rods together and depresses the mandible so that the mouth is opened. Obviously the maxilla functions as anchorage in those movements and careful instructions must be given to the patient so that when maximum opening is reached the mouth is slowly closed. The exercise is repeated for the time indicated within the patient's tolerance. The patient is informed that any pain experienced during the exercise arises from muscle fatigue and the breaking down of fibrous adhesions. Initially exercises are performed with one elastic band and the patient proceeds by increasing the tension using additional elastic bands to a maximum of four. When Australian Dental Journal, December, 1985 419 Fig. ).-An anterior view of the scissor-type jaw exerciser. a mouth opening of 30 mm is reached daily exercises of 10 minutes duration are continued for six months when reassessment is made.