The Use of Technical 'Standard All-on-Four' in the Maxilla

Among the factors that should be considered for the rehabilitation of atrophic jaws is mainly the anatomy of edentulous jaw, which offers trouble installing fixtures in view of the proximity to the maxillary sinus and nasal cavity. There are several possibilities to rehabilitate atrophic arcs, autogenous grafts, distraction osteogenesis, angled and short implants have been widely used in clinical practice. Thus, advanced surgical techniques are disclosed in the literature, such as the all-on-four standard technique. This technique consists of inserting four implants for a complete rehabilitation, and inclining a previously straight distal implant 45°, allowing anchorage in better bone (jaw previous zones), use of longer implants and decreasing the size of the prosthetic cantilever. The purpose of this literature review was to evaluate the scientific articles who observed the behavior of dental implants installed by the all-on- four technique in the maxilla. Initially, using the key words, 62 articles were obtained. After applying the inclusion criteria, 19 articles were selected. In each study the following were evaluated parameters: success rate of angled and axial implants, bone loss, and prosthetic complications. Finally, seven studies contemplated the requirements to be in this review. The literature of the art "all-on- four" standard in edentulous jaws showed that both angulated and axial implants have high success rate (92.8% to 99.3%) and similar bone loss. Therefore, the all-on-four standard technique is a viable option in the medium- and long-term for immediate fixed prosthetic rehabilitation in atrophic jaws.