BACKGROUND: Implantation of alloplastic materials has become the preferred method of primary chin augmentation.1 While silicone had been the most commonly used implant, newer porous materials including MedPor and Gore-Tex have seen growing application due to improved tissue ingrowth and fibrovascularization allowing for improved stabilization.2 However, there remains a paucity of literature comparing implant performance, complication profiles, and outcomes to determine the safest and most reliable implant material used for primary chin augmentations. Objectives: This review aims to provide evidence-based recommendations for preferred implant use in primary chin augmentation through systematic evaluation of the current literature.
METHODS: The PubMed database was queried on March 14, 2021. Primary selection criteria included all studies reporting data on patients who underwent alloplastic chin augmentation without any additional surgical chin procedures such as osseous or sliding genioplasty, fat grafting, autologous grafting, and adjunctive use of fillers. Complications reported included aesthetic dissatisfaction, malposition, infection, extrusion, revisions, and removal.
RESULTS: We evaluated 39 articles reviewing the use of alloplastic materials in primary chin augmentation, yielding > 3,104 patients, 12 categories of implant materials, and 4 categories of surgical techniques. Study designs included 31 retrospective case series, 5 retrospective cohort/comparative studies, 2 case reports and 1 prospective case series. The average ASPS level of evidence was 3.81 ± 0.76. The three implant materials with the largest study numbers were silicone (7), MedPor (16), and Gore-Tex (4). Among all reviewed implants, HTR polymer demonstrated the highest rate of total complications (11.1%, n = 27). Silicone implants had the largest sample size (n = 825) and demonstrated a significantly lower rate of aesthetic dissatisfaction (0.26%) compared to MedPor (n = 435; 1.9%, p < .01) and Gore-Tex (n = 387; 2.3%, p < .001). Gore-Tex, but not MedPor, demonstrated higher total complication rates (5.1%) compared to silicone implants (3.4%, p < .01); furthermore, there was no difference between Gore-Tex and MedPor. Other reviewed implants include Mersilene mesh, Proplast II, and polypropylene mesh, although analysis of these materials was limited by low statistical power. Genioplasties performed with supraperiosteal implantation showed the highest complication rate of 14.02% over 2 studies (107 patients). Subperiosteal implantations, the more commonly utilized surgical plane for implant placement, had a complication rate of 4.63% (26 studies, 2179 patients). A statistically significant difference was found between subperiosteal and supraperiosteal approaches (p < .0001). The surgical approach with the lowest complication rate was using an extraoral incision (2.5%, n = 1,118) compared to intraoral incision (3.96%, n = 1,011). The average length of follow-up was 43.9 months (range: 2 weeks to 15 years).
CONCLUSIONS: Overall complications for primary chin augmentation are very rare, and there are clinically insignificant differences in complication rates among the most commonly used implants such as silicone, MedPor, and Gore-Tex.3-5 This review suggests that equivalent patient satisfaction and outcomes can be achieved using any of these materials for alloplastic chin augmentation.
REFERENCES:
1. Gross EJ, Hamilton MM, Ackermann K, Perkins SW. Mersilene mesh chin augmentation. A 14-year experience. Archives of facial plastic surgery. 1999;1(3)doi:10.1001/ARCHFACI.1.3.183
2. Klawitter JJ, Bagwell JG, Weinstein AM, Sauer BW, Pruitt JR. An evaluation of bone growth into porous high density polyethylene. Journal of Biomedical Materials Research. 1976/3// 1976;10(2):311-323. doi:10.1002/JBM.820100212
3. Scaccia FJ, Allphin AL, Stepnick DW. Complications of Augmentation Mentoplasty: A Review of 11,095 Cases. http://dxdoiorg/101177/074880689301000306. 2016/11// 2016;10(3):189-195. doi:10.1177/074880689301000306
4. Chao JW, Lee JC, Chang MM, Kwan E. Alloplastic Augmentation of the Asian Face: A Review of 215 Patients. Aesthetic surgery journal. 2016/9// 2016;36(8):861-868. doi:10.1093/ASJ/SJW013
5. Mahler D. Chin augmentation--a restrospective study. Annals of plastic surgery. 1982;8(6):468-473. doi:10.1097/00000637-198206000-00005