Split-Overlapping Genioplasty: Surgical Technique, Morphological and Radiological Long-Term Outcomes.

[BACKGROUND] The overlapping bone flap genioplasty, described by Tessier, was developed to treat major retrognathia or long and retruded chins. For 15 years, we have used a modified version of this technique to avoid its drawbacks. The aim of this article is to describe our modification and evaluate the long-term morphologic and radiologic outcomes.

[PATIENTS AND METHOD] The authors included every split-overlapping genioplasty performed in our department between 2004 and 2014. Demographics, surgical data, and complications were recorded. Radiologic bone resorption was evaluated comparing preoperative, day-1 postoperative, and year-1 postoperative cephalometric x-rays. Morphologic outcomes were evaluated on standardized pre- and postoperative views using an analogic Likert scale.

[SURGICAL TECHNIQUE] The main modification of the procedure consists in separating the posterior cortex of the transplant using a reciprocating saw. After overlapping the reduced transplant onto the mandible, the posterior cortex is used as an apposition graft to soften the labiomental crease.

[RESULTS] Forty-seven patients were analyzed during this period. In 44 patients, the procedure was combined with mandibular and/or maxillary osteotomy. The average reduction of symphysis height was 5 mm, and the average pogonion advancement was 4.3 mm. After 1 year, we recorded 7% average bone resorption. No major complications (nerve injury, hematoma, among others) were reported. Morphologic outcomes were deemed satisfactory or very satisfactory in the vast majority of cases.

[CONCLUSION] Split-overlapping genioplasty is a safe and reliable procedure with stable, long-lasting outcomes. This versatile technique is particularly useful for the correction of a massive symphysis or high and retruded chins.