This is really nothing new in implant dentistry. We have known from the early Branemark days that four implants placed in the anterior mandible will adequately support a mandibular fixed prosthesis. The interesting part of this technique is the use of implants that can be placed at an angle to maximize support.

Some nice information for this technique is on the Nobel Pharma site at https://www.nobelbiocare.com/se/en/home/products-and-solutions/treatment-concepts/all-on-4.html