Also known as a Subperiosteal Implant. This is a metal framework that rests on top of the jawbone but underneath the gum tissue. Posts protrude through the gums to hold the denture.
These are largely considered outdated or "historical" in modern dentistry. They were used for patients who did not have enough bone height for standard (endosteal) implants. Today, bone grafting and All-on-4 techniques have mostly replaced them.
An implant framework that sits on the bone rather than going into it.