Changing the occlusal vertical dimension (OVD) has been one of the most controversial issues of restorative dentistry. The modification of the OVD may be indicated whenever it is necessary to harmonize dentofacial esthetics, provide space for planned restorations, and improve occlusal relationships. The OVD should not be considered an immutable reference, but rather a dynamic dimension within a zone of physiological tolerance that can be altered as long as the dentist respects the envelope of function. However, vertical changes in the relationship between the maxilla and mandible may have some biological, biomechanical, esthetic, and three-dimensional (3D) functional implications because the initial references of maximum intercuspation and anterior tooth relationships must be reconstructed and adjusted in a new dimension of space. This article aims to present a critical review of the relevant OVD literature and provide the clinical objectives and subjective parameters necessary to guide the clinician and laboratory technician during treatment involving OVD alterations.