Interocclusal orthopedic appliances of varied design and application have been employed in the treatment of myofascial pain dysfunction (MPD) and temporomandibular joint disorders (TMD). These appliances provide the practitioner with a non-invasive, reversible form of intervention to manage the patient's symptoms. Literature on the use and effectiveness of these appliances has become readily available and now requires retrospective evaluation. However, comparison of results from studies making use of interocclusal orthopedic appliance therapy is difficult due to the employment of various outcome measurement scales, subjective evaluation of patient outcome, and variability in reporting of treatment outcomes. The aim of this paper is to review the effects and success rates of the various appliances reported in the literature and provide the practitioner with useful information that may be of assistance in the prediction of outcome and success of splint appliance therapy.