A great variety of splints have been described in the literature but often their effectiveness and mechanisms of action are as yet unclear. The aim of the present paper was therefore to collect and evaluate studies published between 2005 and 2008, in which the effectiveness of different types of occlusal splint therapy for craniomandibular dysfunctions (CMD) was investigated. The literature review was based on the following databases: PubMed, Cochrane Library, and zm-online. A total of six studies were found that matched the search criteria for the effectiveness of occlusal splints for the treatment of CMD. Several studies assumed that it is rarely possible to demonstrate any effects that are attributable to a particular type of splint. In fact, the treatment success is influenced by many factors such as time, patient instruction, the clinician's skills, and a correct diagnosis. Keywords: centric splint, craniomandibular dysfunction, effectiveness, splint, temporomandibular disorders