Splint or orthopedic appliance is routinely used in the treatment of temporomandibular disorders (TMD). This appliance is used to alter occlusal relationship and to redistribute occlisal forces, to prevent wear and mobility of the teeth, to reduce bruxim and parafunction, to treat masticatory muscle pain and dysfunction, and to alter structural relationship of the TMJ. There are 2 kinds of splint, the permissive and non permissive. Stabilization splint and bite plane are permissive splints, and anterior repositioning appliance is a non permissive splints. Each kind of splint has its own indication. There is strong evidence that splint therapy is succesful in the treatment of TMD but there is no consensus of opinion on how splints work.