Soft tissue response following genioplasty combined with anterior segmental osteotomy

Abstract

Genioplasty is an excellent adjunctive procedure that can be performed with other maxillofacial operations 1 because of its predictability and stability. [1][2][3][4][5][6][7][8][9][10][11] Postoperative results generally satisfy patients, with few complications. 2,12 However, genioplasty alone is not sufficient to correct chins combined with bimaxillary protrusion. Anterior segmental osteotomy (ASO) is frequently performed in Asian patients with bimaxillary dentoalveolar protrusion. 13,14 The advantages of this procedure are dramatic change, fast results, and minimal relapse, compared with orthodontic treatment. 14,15 Soft-to hard-tissue ratios are essential for predicting soft-tissue response in genioplasty. According to a systematic review of soft-to hardtissue ratios of the chin in orthognathic surgery, 16 the horizontal ratio at pogonion (Pog) ranged from −0.27:1 to −0.70:1 (mean, 0.52:1) in setback genioplasty, and from 0.53:1 to 0.99:1 (mean, 0.85:1) in advancement genioplasty. The vertical Background: The authors' main aim was to analyze soft-tissue response of the chin following genioplasty with anterior segmental osteotomy, which enables optimal surgical planning of genioplasty. Methods: Sixty-two patients who underwent genioplasty with concomitant anterior segmental osteotomy were divided into three groups depending on the direction of pogonion (Pog) movement: G1 (without sagittal change), G2 (advancement genioplasty), and G3 (setback genioplasty). All genioplasties included height reduction. Hard-and soft-tissue measurements with cephalometry were performed at T1 (before surgery), T2 (after surgery), and T3 (after orthodontic treatment) for the analysis of sagittal and vertical changes. Correlation and regression analyses were conducted to analyze soft-to hard -tissue movement and soft-tissue thickness changes. Results: During the T1 to T2 period, the horizontal soft-to hard-tissue ratio at Pog was 0.85 in G2 and 0.80 in G3, and the vertical ratio at menton (Me) was 0.9 for all groups. The correlation coefficients were 0.64 (G2) and 0.83 (G3) at Pog and 0.9 (all), 0.85 (G1), 0.95 (G3) at Me. There was no significant correlation between initial soft-tissue thickness and soft-tissue response ratio. During the T2 to T3 period, no significant relapses were observed, which demonstrates the stability of anterior segmental osteotomy combined genioplasty. Conclusions: Clinically and statistically significant soft-tissue responses were demonstrated at Pog and Me. The higher values in G3 in particular suggest that setback genioplasty with anterior segmental osteotomy is an effective treatment alternative to conventional two-jaw surgery in some patients with bimaxillary prognathism with macrogenia.

EVALUATION OF THE EFFECTIVENESS OF GENIOPLASTY USING BIOPOLYETHYLENE (Su-por) IMPLANTS

“…7 There are many different surgical techniques genioplasty described in the scientific literature, using osteotomy, chin implantation or fillers. [8][9][10] For many years, horizontal osteotomy was performed to enlarge the chin. Genioplasty has a significant effect on facial symmetry.…”