A custom jawline implant creates the most significant change to the lower third of the face as any other surgical procedure. In many cases it creates an even greater change than a sagittal split mandibular osteotomy even if combined with a sliding genioplasty. This is because it can add significant jawline width which no mandibular osteotomy can do.
Because it covers the entire surface of the inferolateral surface of the lower jaw, secure positioning is of paramount importance. While such jawline implants are custom made, this unfortunately does not mean they ‘snap fit’ into place…as they don’t. You have one smooth inner surface of the implant and one smooth outer surface of the bone. This provides ample opportunity for the implant to slide into undesired positions on the bone as there is no locking mechanism or points of engagement. And with the long length of the implant (angle to angle) any slight deviation in alignment can become magnified by the trajectory of the implant around the arc of the lower jaw.
Over the years I have evolved through various points of screw fixation but have now settled on double screw fixation at the three corners. (chin and jaw angles) This is the most secure method of preventing rotation, particularly the horizontal axis of alignment of the chin. The setting of the chin position is the primary key maneuver before aligning and securing the jaw angles. While at the jaw angles the insertion of the screws is at the top flange of the implant, at the chin their position can be variable based on the thickness of the chin portion of the implant. Larger chin projections are best done through the front edge of the implant with long 2.0mm screws.
Three point fixation with double screws for most custom jawline implants is the best positioning technique. There are thinner implants where single screw fixation might be used or even in replacement implants that already has an established and well healed pocket where this would be sufficient.
Dr. Barry Eppley