Genial Bone Advancement Trephine (GBAT) "During a GBAT procedure, surgeons make a small window in the lower jaw where the tongue attaches to the jaw. The piece of bone, along with the attachment for the tongue, is pulled forward and down, then fastened to the outside of the lower jaw. A small titanium plate is used to affix the bone. This, in turn, pulls the tongue away from the back of the airway, decreasing the chance that the tongue will obstruct the airway space during sleep." - Sleep Review Magazine.