Attending Duke University Hospital Durham, North Carolina
Abstract: 1. Statement of the problem Augmenting the volume and morphology of the cheek is a key factor in the creation of the feminine facial aesthetic. Non-customized implants are available in a variety of materials, but in general are specific to the augmentation of the malar eminence for cis-gendered females. The ideal projection for the male-to-female transgender patient is more anterior to fulfil the medial and mid-cheek projection deficient in the male three-quarter profile. Historically, a range of materials have been employed including polymethylmethacrylate, hard silicone, and polyether-ether-ketone (PEEK), however, the ideal material for custom cheek augmentation remains elusive. Complications resulting from implanted materials may include infection, exposure, migration, extrusion, seroma, and capsule formation. We sought to examine the suitability of using patient-specific implants of porous polyethylene inserted trans-orally for malar augmentation.
2. Materials and methods All patients undergoing malar augmentation by a single surgeon (EF) using a standardized procedure between 2/2020 and 9/2023 were included. The operative technique involved preoperative brushing of the teeth with 0.12% chlorhexidine gluconate solution, a mucosal incision in the maxillary vestibule from the first molar region to the canine region and subperiosteal dissection. Implant insertion required careful manipulation to avoid contact with the teeth. Each implant was secured by two zygomatic buttress screws, followed by irrigation of the pocket with chlorhexidine just before closure.
3. Methods of data analysis A retrospective review of clinical cases with at least 6 months of follow-up was conducted. The primary outcome measure was implant removal. The secondary outcome measures were implant infection and reoperation other than for implant removal.
4. Results A total of 168 porous polyethylene malar implants were inserted in 83 patients during the study period for the purpose of facial feminization.
5. Outcomes Data During the study period 2/168 (1.2 %) implants necessitated removal due to infection. There were no issues with implant exposure, migration, or extrusion. Two patients were treated with antibiotics for suspected implant infection in the immediate post-operative period that did not subsequently require removal. The two patients who required removal of an implant underwent delayed implant replacement after 4-6 weeks. The overall complication rate was 4/83 patients (4.8 %).
6. Conclusions Custom-made porous polyethylene is a safe and effective material for construction of malar implants, and the transoral insertion route conducted according to the above protocol was associated with an acceptably low infection rate. Additional measures to prevent implant infection may include soaking the implant in an antibiotic solution (e.g. vancomycin) prior to implantation, ensuring water-tight closure of the mucosa, and avoiding violation of the maxillary sinus with screw placement. Given the nature of 3D planning, screw placement can be designed and incorporated into the implant to identify the best trajectory for stabilization while avoiding the maxillary sinus.
7. References Yaremchuk MJ. Facial skeletal reconstruction using porous polyethylene implants. Plastic and reconstructive surgery. 2003 May 1;111(6):1818-27.
Metzinger SE, McCollough EG, Campbell JP, Rousso DE. Malar augmentation: a 5-year retrospective review of the silastic midfacial malar implant. Archives of Otolaryngology–Head & Neck Surgery. 1999 Sep 1;125(9):980-7.
