Although a number of approaches to implant-supported restoration of severely atrophic maxilla and mandible have been developed, most of these treatments are very costly and implicate several surgical interventions , such as bone transplants and/or sinus lifts .

An exception to this, is the all on 4 concept, which uses only four implants to support an acrylic, screw-retained prosthesis placed on the day of implant surgery. This is followed by a definitive prosthesis after total osseointegration.

This full mouth rehabilitation is an innovative technique that allows for immediate function with a fixed teeth implant-supported solution without the need for any bone grafting procedures even in atrophic lack-of-bone situations. In this technique, four implants are placed two in the anterior region of the jaw following the jaw anatomy and the two distal implants are tilted at 45° angulation posteriorly.

This arrangement allows for good implant anchorage, short cantilever length, and large inter implant distance thus favouring fruitful outcome of the treatment.