Facial appearance transfer and persistence after three-dimensional virtual face transplantation

Leveraging Artificial Intelligence to Assess Perceived Age and Donor Facial Resemblance After Face Transplantation

PURPOSE

A major concern for patients undergoing facial transplantation relates to postoperative appearance. This study leverages artificial intelligence (AI) visual analysis software to provide an objective assessment of perceived age and degree of resemblance to the donor.

METHODS

Postoperative images of 15 face transplant patients were analyzed by Visage Technologies Visage|SDK™ AI facial analysis software to determine perceived age. A subgroup of eight face transplant patients, for which donor and patient pretrauma photographs were available, was analyzed using the same software to determine the percent similarity match to the patients' postoperative image. Mann-Whitney and Wilcoxon rank sum tests were utilized to evaluate for perceived age and facial recognition matching percentage, respectively.

RESULTS

AI perceived age was significantly more similar to the patient age (±3.5 years) than the donor age (±9.5, P = 0.0188). For facial resemblance, patients had a significantly higher average percent similarity match to their donor's face compared to their pretrauma native face (63% vs 57%, P = 0.0391).

CONCLUSIONS

Although patients more closely resembled their donor's resemblance posttransplantation, their perceived age correlated more significantly with their actual age than their donor allograft age. The findings of this study provide a helpful framework for counseling prospective patients on their expected appearance postoperatively.

Application possibilities of artificial intelligence in facial vascularized composite allotransplantation-a narrative review

Facial vascularized composite allotransplantation (FVCA) is an emerging field of reconstructive surgery that represents a dogmatic shift in the surgical treatment of patients with severe facial disfigurements. While conventional reconstructive strategies were previously considered the goldstandard for patients with devastating facial trauma, FVCA has demonstrated promising short- and long-term outcomes. Yet, there remain several obstacles that complicate the integration of FVCA procedures into the standard workflow for facial trauma patients. Artificial intelligence (AI) has been shown to provide targeted and resource-effective solutions for persisting clinical challenges in various specialties. However, there is a paucity of studies elucidating the combination of FVCA and AI to overcome such hurdles. Here, we delineate the application possibilities of AI in the field of FVCA and discuss the use of AI technology for FVCA outcome simulation, diagnosis and prediction of rejection episodes, and malignancy screening. This line of research may serve as a fundament for future studies linking these two revolutionary biotechnologies.

Innovations and Future Directions in Head and Neck Microsurgical Reconstruction

Head and neck reconstructive microsurgery is constantly innovating because of a combination of multidisciplinary advances. This article examines recent innovations that have affected the field as well as presenting research leading to future advancement. Innovations include the use of virtual surgical planning and three-dimensional printing in craniofacial reconstruction, advances in intraoperative navigation and imaging, as well as postoperative monitoring, development of minimally invasive reconstructive microsurgery techniques, integration of regenerative medicine and stem cell biology with reconstruction, and the dramatic advancement of face transplant.

Challenges in Microsurgical Reconstruction for Craniofacial Osteomyelitis With Resultant Osteonecrosis

INTRODUCTION

Chronic osteomyelitis is characterized by compromised blood supply and eventual osteonecrosis. Definitive treatment requires aggressive resection of affected bone. The resultant defect poses a unique challenge to reconstructive surgeons. Much of the literature on craniofacial osteomyelitis focuses on infection eradication, rather than subsequent reconstruction. This article reports representative cases from our experience with free flap reconstruction for defects secondary to chronic osteomyelitis of the craniofacial skeleton.

METHODS/RESULTS

The authors selected 5 of the most difficult reconstructive cases of craniofacial osteomyelitis from our experience in a single tertiary referral institution with a follow-up of at least 6 months. Three of the 5 cases arose in the setting of previous head and neck cancer treated with resection and radiation therapy. One case had a previous surgical craniotomy complicated by osteomyelitis and multiple failed alloplastic reconstructions. The final case was due to multiple gunshots to the head, with subsequent cerebral and cranial abscess (>1000cc). In each case, the defect was successfully treated with free tissue transfer. Two cases required creation of recipient vessels with an arteriovenous loop.

CONCLUSIONS

Free tissue transfer provides a versatile and effective tool in the reconstruction of extensive craniofacial osteomyelitis defects. Furthermore, the addition of vascularized tissue can protect against further episodes of osteomyelitis. Finally, arteriovenous loops can be employed successfully when prior radiation and infection of the wound bed precludes the use of local recipient target vessels.

Craniofacial Measurements of Donors and Recipients Correlate with Aesthetic Outcome in Virtual Face Transplantation

Background:

Face transplantation is an increasingly feasible option for patients with severe disfigurement. Donors and recipients are currently matched based on immune compatibility, skin characteristics, age, and gender. Aesthetic outcomes of the match are not always optimal and not possible to study in actual cases due to ethical and logistical challenges. We have used a reproducible and inexpensive three-dimensional virtual face transplantation (VFT) model to study this issue.

Methods:

Sixty-one VFTs were performed using reconstructed high-resolution computed tomography angiographs of male and female subjects aged 20–69 years. Twenty independent reviewers evaluated the level of disfigurement of the posttransplant models. Absolute differences in 9 soft-tissue measurements and 16 bony cephalometric measurements from each of the VFT donor and recipient pretransplant model pairs were correlated to the reviewers’ evaluation of disfigurement after VFT through a multivariate logistic regression model.

Results:

Five soft-tissue measurements and 3 bony measurements were predictive of the rating of disfigurement after VFT (odds ratio; 95% confidence interval): trichion-to-nasion facial height (1.106; 1.066–1.148), endocanthal width (1.096; 1.051–1.142), exocanthal width (1.067; 1.036–1.099), mouth/chelion width (1.064; 1.019–1.110), subnasale-to-menton facial height (1.029; 1.003–1.056), inner orbit width (1.039; 1.009–1.069), palatal plane/occlusal plane angle (1.148; 1.047–1.258), and sella-nasion/mandibular plane angle (1.079; 1.013–1.150).

Conclusions:

This study provides early evidence for the importance of soft-tissue and bony measurements in planning of facial transplantation. With future improvements to immunosuppressive regimens and increased donor availability, these measurements may be used as an additional criterion to optimize posttransplant outcomes.