A michigan-type occlusal splint with spring-loaded mandibular protrusion functionality for treatment of anterior disk...

For treatment of temporomandibular disorders Michigan-type splints are frequently used, as are mandibular advancement appliances for patients diagnosed with anterior disk dislocation. As both types show good results, the combination of these two mechanisms into one bimaxillary appliance was tested on eight patients where splint therapy had brought reduction but not complete elimination of the symptoms. An existing maxillary Michigan splint was modified so that advancement springs could be fitted and the generated forces were transmitted to a mandibular retainer, which did not interfere with the function of the splint. Treatment progress was monitored with computerized axiography and in all cases the axiographic tracings after the bimaxillary treatment showed no pattern indicative of disk dislocation under normal jaw movements. Myofascial pain symptoms, already improved by the pre-treatment with the Michigan splint, were found to be reduced further or eliminated completely. The approach of retrofitting a Michigan splint with the springs allowed for a versatile appliance, which required no occlusal alteration to the finely adapted splint but could as easily be brought back to the simple splint-functionality either for daytime use or for a period of stabilization of the result after successful treatment. Compliance was found to be very good and the short treatment period, together with the small force levels did not produce any detectable dental side effects.