Discomfort associated with wearing an intraoral splint represents a problem in the management of temporomandibular joint (TMJ) internal derangement. This study evaluated whether the use of a mandibular splint during the day and a maxillary splint at night could be more comfortable and therefore as efficacious in internal derangement treatment as a maxillary splint (AR splint). Fifty (50) patients (average age 28.8; range 14-63) with confirmed internal derangement in at least one TMJ were divided into three groups: 20 patients treated with AR splint (Group I); 20 patients treated with a SVED (Sagittal Vertical Extrusion Device) and a MORA (Mandibular Anterior Repositioning Splint) (Group II); and 10 patients who underwent no treatment (Control Group). Joint noise, pain intensity and its character (as constant or chewing/biting pain), muscular pain, and subjective relief were evaluated monthly before treatment began (T0) and for six months thereafter. The following results were found: 1. Subjects in Group I and Group II displayed a significant decrease in joint pain (p<0.001), constant pain (p<0.001), chewing/biting pain (p<0.001), joint noise and muscle pain from the beginning through the sixth month follow-ups; 2. At T1 and T2, subjects in Group II reported significantly lower discomfort associated with the devices than subjects in Group I. The use of two splints seems to be as efficacious as the use of an AR maxillary splint; however an AR splint is considered more comfortable by patients, especially during the first months of therapy.