Vertical dimension is in reality the most fundamental consideration in treatment planning. The recording of jaw relations in the treatment of edentulous patients aims at facilitating the adaptation of the complete dentures to the masticatory system to give an optimal and comfortable function. To achieve this goal, the recording must include an appropriate vertical dimension of occlusion and stable occlusal contacts in harmony with the TMJ, masticatory muscle functions and finally with the relationship between the prosthesis and the oral and the facial musculature. This article will review the literature regarding the effect of altering the OVD on the health of TMJ.