Extreme resorption of alveolar ridge represents a major challenge in prosthetic rehabilitation. It is a consequence of a long period of edentulousness jointed with local and systemic factors that cause ridge resorption and loss of the vertical dimension of occlusion. Dynamic processes of resorption and remodeling of the alveolar bone result in anatomical-morphological changes of the denture bearing area, and a decrease in the vertical dimension of occlusion (VDO). These changes have the adverse effect on the retention and stabilization of removable prostheses, which can lead to functional disorders, muscle pain, and temporomandibular disorders. The resorption is higher in complete prostheses due to entirely mucosal load, so complete prostheses can be retained with implants that improve masticatory function, reduce destabilizing movements of the prosthesis, and consequently reduce the resorption of alveolar ridge due to the even distribution of forces on the supporting area. In extreme resorption of alveolar ridge, the insertion of conventional implants is not possible due to atrophy of the alveolar ridge and reduction of the buccolingual width of the ridge, so mini dental implants (MDI) are used. The insertion requires less bone thickness in the vestibule-oral direction, with appropriate height and quality. Proper measurement of the vertical dimension of occlusion and intermaxillary relations is crucial for successful prosthetic rehabilitation of patients. Removable prosthesis must not be made with inadequate VDO due to the physiologically unacceptable position of the condyle in the temporomandibular joint, which results in strain, pain in the masticatory muscles and joint, and ultimately unfavorable lower denture movements that contribute to further resorption and lowering of the VDO. The patient’s appearance are also conditioned by the VDO, because, due to the reduced height of the lower third of the face, patients look older, the corners of the lips are hung, and the chewing and speech functions are significantly reduced. The rehabilitation of the lost vertical dimension in patients with extreme resorption of alveolar ridge should be given a lot of attention, because it represents a key step in the development of a satisfactory removable prosthesis.