Augmentation genioplasty with hard tissue replacement implants.

[PURPOSE] This study assessed the soft tissue changes produced by the placement of hard tissue replacement (HTR) polymer chin implants for augmentation genioplasty and evaluated the dimensional stability as well as any bony changes associated with the implants.

[PATIENTS AND METHODS] The study group consisted of 18 patients (3 males, 15 females) with an average follow-up of 21.5 months (range, 12 to 44 months). All implants were placed through an intraoral incision and stabilized to the symphysis with a single 2.0-mm diameter titanium screw. Preoperative, postoperative, and long-term cephalometric radiographs were analyzed for changes in soft tissue thickness in the chin region, implant stability, and the presence of bone resorption.

[RESULTS] The net hard tissue chin augmentation achieved averaged 6.0 mm (range, 4.5 to 9 mm). Average preoperative soft tissue thickness was 12.1 mm (range, 11 to 14.5 mm) and postoperatively it was 10.6 mm (range, 10 to 13.5 mm). The average increase in soft tissue projection was 77.6% (range, 71.4% to 83.3%) of the implant thickness. There was no radiographic evidence of implant migration or bony resorption beneath the implant.

[CONCLUSIONS] HTR implants appear to be a predictable means of augmenting the chin, providing the desired aesthetic change, without causing resorption of underlying bone.