Facial nerve regeneration after facial allotransplantation: A longitudinal clinical and electromyographic follow-up of lip movements during speech

Long-term outcomes and future challenges in face transplantation

Face transplant (FT) has emerged as a groundbreaking option for patients with severe facial deformities, resulting from congenital disorders, trauma, or tumor ablation. Although reconstructive surgery has made significant strides, the challenges of restoring both form and function remain, particularly in centrally located defects. This review explored the long-term outcomes of FT, addressing its challenges and potential pitfalls. A systematic review following the PRISMA guidelines was conducted, encompassing articles published in English from November 2005 to January 2023, which were searched across PubMed, MEDLINE, and EMBASE databases. Keywords included "face transplant," "face transplant outcomes," and "face transplant long-term." Data on surgical teams, patient demographics, transplant specifics, rejection episodes, additional surgeries, and patient-reported outcomes were extracted and analyzed. In total, 34 articles met the inclusion criteria. Over the 2 decades, 48 FT procedures were performed, with 23 patients followed for at least 3 years. Predominantly, patients were men (80%), averaging 31 years in age. Ballistic trauma (44.6%) and burns (25.5%) were common causes of injury. Chronic rejection emerged as a significant concern, leading to graft loss and necessitating retransplantation in 2 patients. Additional surgical procedures were often required. FT offers a remarkable solution for individuals with extensive facial disfigurement. Successful outcomes depend on factors, such as patient selection, multidisciplinary collaboration, psychiatric evaluation, and post-operative care. Nevertheless, challenges persist, including the need for lifelong immunosuppression and risk of chronic rejection. Although FT has transformed lives, continued success in this evolving field hinges on the ongoing research and vigilant patient management.

The significance of split-face studies and electromyography in forehead rejuvenation

BACKGROUND

Botulinum toxin is a neurotoxic substance with a wide range of uses, from the treatment of musculoskeletal spasms to antiaging regimens by improving wrinkles. Split-face studies in which drugs are injected in the right and left sides of the faces have been actively conducted in botulinum toxin studies. In this study, we aimed to investigate the reliability of a split-face study for determining the effectiveness of botulinum toxin based on eyebrow height and movement, and electromyography results.

METHODS

Thirty-one women aged 35 to 55 years were included in the study. Eyebrow height was measured as the distance from the eyebrows to the upper eyelid margin on the primary gaze, and eyebrow movement was measured as the distance when the forehead was wrinkled for 5 seconds. A noninvasive method was used for electromyography of the frontalis muscles.

RESULTS

No statistically significant differences in right and left eyebrow heights and movements, and electromyography findings (p= 0.256, p= 1.000, and p= 0.978, respectively) were found. Pearson correlation analysis showed that electromyography muscle activity is positively associated with eyebrow movement, respectively (p< 0.001).

CONCLUSION

We advocate the reliability of split-face study and the usefulness of electromyography of frontalis muscle in forehead rejuvenation research.

Longitudinal Recovery of Speech Motor Function Following Facial Transplantation: A Prospective Observational Study

OBJECTIVES

Although facial transplantation is considered effective for restoring facial appearance, research on speech outcomes following surgery is limited. More research is critically needed to inform patients of expected rates and extent of recovery, and to develop interventions aimed at improving speech outcomes.

METHODS

Four patients in early recovery (3 weeks-24 months postsurgery) and three patients in late recovery (36-60 months postsurgery) were included. Clinical measures of speech recovery, including speech intelligibility measured using the Sentence Intelligibility Test, a lip strength testing device (Iowa Oral Performance Instrument), and kinematic measures of lip and jaw function measured using high-resolution 3D optical motion capture were used to describe the rate and extent of functional speech and lip recovery, describe and compare the rate of functional speech recovery and kinematic lip and jaw changes in early and late stages of recovery, and explore the association between kinematic measures and functional speech.

RESULTS

Speech intelligibility, speaking rate, and lip strength were below normative values in the first 2 years of postsurgery. Participants in the first 2 years of recovery demonstrated steeper slopes of improvement in clinical and kinematic measures than participants in the later stages of recovery (36-64 months). Gains in jaw range of movement and gains in lip speed and range of movement were significantly correlated with rates of sentence intelligibility improvement. Gains in lip strength were not associated with functional speech improvement.

CONCLUSIONS

These findings motivate ongoing work aimed at developing interventions for improving motor speech function in this population.

LEVEL OF EVIDENCE

3 Laryngoscope, 132:2359-2367, 2022.

Donors for nerve transplantation in craniofacial soft tissue injuries

Neural tissue is an important soft tissue; for instance, craniofacial nerves govern several aspects of human behavior, including the expression of speech, emotion transmission, sensation, and motor function. Therefore, nerve repair to promote functional recovery after craniofacial soft tissue injuries is indispensable. However, the repair and regeneration of craniofacial nerves are challenging due to their intricate anatomical and physiological characteristics. Currently, nerve transplantation is an irreplaceable treatment for segmental nerve defects. With the development of emerging technologies, transplantation donors have become more diverse. The present article reviews the traditional and emerging alternative materials aimed at advancing cutting-edge research on craniofacial nerve repair and facilitating the transition from the laboratory to the clinic. It also provides a reference for donor selection for nerve repair after clinical craniofacial soft tissue injuries. We found that autografts are still widely accepted as the first options for segmental nerve defects. However, allogeneic composite functional units have a strong advantage for nerve transplantation for nerve defects accompanied by several tissue damages or loss. As an alternative to autografts, decellularized tissue has attracted increasing attention because of its low immunogenicity. Nerve conduits have been developed from traditional autologous tissue to composite conduits based on various synthetic materials, with developments in tissue engineering technology. Nerve conduits have great potential to replace traditional donors because their structures are more consistent with the physiological microenvironment and show self-regulation performance with improvements in 3D technology. New materials, such as hydrogels and nanomaterials, have attracted increasing attention in the biomedical field. Their biocompatibility and stimuli-responsiveness have been gradually explored by researchers in the regeneration and regulation of neural networks.

The Association of Frontal Alopecia with a History of Facial and Scalp Surgical Procedures

INTRODUCTION

The prevalence of frontal fibrosing alopecia (FFA) is increasing worldwide, though the pathogenesis remains unknown. Anecdotal reports describe alopecia occurring in an FFA pattern following facial surgical procedures, but this potential link remains unexplored.

OBJECTIVE

The objective of this study is to determine if a significant association exists between the diagnosis of FFA and a history of facial and scalp surgical procedures.

METHODS

This retrospective study comparing data from frontal alopecia patients to controls was conducted at a tertiary medical center. Additionally, a literature review was conducted on scarring alopecias occurring from scalp procedures.

RESULTS

Fifty percent of frontal alopecia patients (n = 54) reported a history of facial surgical procedures compared to 9.8% of controls (n = 51) (OR: 7.8 [95% CI: 2.77-25.98, p < 0.001]). Although no significant differences were observed in current daily facial sunscreen use, sunscreen use prior to alopecia onset was significantly higher in frontal alopecia (p = 0.295; p = 0.021). Sunscreen use was not a significant modifier in the association between frontal alopecia and facial surgical procedures (p = 0.89).

CONCLUSIONS

A significant association exists between frontal alopecia clinically consistent with FFA and a history of facial surgery, the nature of which is unclear. The role of sunscreen use and frontal alopecia development in this setting needs to be better elucidated.

Long-term Outcomes After Facial Allotransplantation: Systematic Review of the Literature

BACKGROUND

Facial vascularized composite allotransplantation (fVCA) represents a reconstructive approach that enables superior improvements in functional and esthetic restoration compared with conventional craniomaxillofacial reconstruction. Outcome reports of fVCA are usually limited to short-term follow-up or single-center experiences. We merge scientific literature on reported long-term outcome data to better define the risks and benefits of fVCA.

METHODS

We conducted a systematic review of PubMed/MEDLINE databases in accordance with PRISMA guidelines. English full-text articles providing data on at least 1 unique fVCA patient, with ≥3 years follow-up, were included.

RESULTS

The search yielded 1812 articles, of which 28 were ultimately included. We retrieved data on 23 fVCA patients with mean follow-up of 5.3 years. More than half of the patients showed improved quality of life, eating, speech, and motor and sensory function following fVCA. On average, the patients had 1 acute cell-mediated rejection and infectious episode per year. The incidence rates of acute rejection and infectious complications were high within first-year posttransplant but declined thereafter. Sixty-five percent of the patients developed at least 1 neoplastic or metabolic complication after transplantation. Chronic vascular rejection was confirmed in 2 patients, leading to allograft loss after 8 and 9 years. Two patient deaths occurred 3.5 and 10.5 years after transplant due to suicide and lung cancer, respectively.

CONCLUSIONS

Allograft functionality and improvements in quality of life suggest a positive risk-benefit ratio for fVCA. Recurrent acute rejection episodes, chronic rejection, immunosuppression-related complications, and heterogeneity in outcome reporting present ongoing challenges in this field.

Neuromotor Speech Recovery Across Different Behavioral Speech Modifications in Individuals Following Facial Transplantation

Despite signs of facial nerve recovery within a few months following face transplantation, speech deficits persist for years. Behavioral speech modifications (e.g., slower-than-normal speaking rate and increased loudness) have shown promising potential to enhance speech intelligibility in populations with dysarthric speech. However, such evidence-based practice approach is lacking in clinical management of speech in individuals with facial transplantation. Because facial transplantation involves complex craniofacial reconstruction and facial nerve coaptation, it is unknown to what extent individuals with face transplant are capable of adapting their motor system to task-specific articulatory demands. The purpose of this study was to identify the underlying articulatory mechanisms employed by individuals with face transplantation in response to speech modification cues at early and late stages of neuromotor recovery. In addition, we aimed to identify speech modifications that conferred improved speech clarity. Participants were seven individuals who underwent full or partial facial vascularized composite allografts that included lips and muscles of facial animation and were in early (~2 months) or late (~42 months) stages of recovery. Participants produced repetitions of the sentence “Buy Bobby a puppy” in normal, fast, loud, and slow speech modifications. Articulatory movement traces were recorded using a 3D optical motion capture system. Kinematic measures of average speed (mm/s) and range of movement (mm³) were extracted from the lower lip (± jaw) marker. Two speech language pathologists rated speech clarity for each speaker using a visual analog scale (VAS) approach. Results demonstrated that facial motor capacity increased from early to late stages of recovery. While individuals in the early group exhibited restricted capabilities to adjust their motor system based on the articulatory demands of each speech modification, individuals in the late group demonstrated faster speed and larger-than-normal range of movement for loud speech, and slower speed and larger-than-normal range of movement for slow speech. In addition, subjects in both groups showed overreliance on jaw rather than lip articulatory function across all speech modifications, perhaps as a compensatory strategy to optimize articulatory stability and maximize speech function. Finally, improved speech clarity was associated with loud speech in both stages of recovery.

Facial nerve electrodiagnostics for patients with facial palsy: a clinical practice guideline

PURPOSE

Facial nerve electrodiagnostics is a well-established and important tool for decision making in patients with facial nerve diseases. Nevertheless, many otorhinolaryngologist-head and neck surgeons do not routinely use facial nerve electrodiagnostics. This may be due to a current lack of agreement on methodology, interpretation, validity, and clinical application. Electrophysiological analyses of the facial nerve and the mimic muscles can assist in diagnosis, assess the lesion severity, and aid in decision making. With acute facial palsy, it is a valuable tool for predicting recovery.

METHODS

This paper presents a guideline prepared by members of the International Head and Neck Scientific Group and of the Multidisciplinary Salivary Gland Society for use in cases of peripheral facial nerve disorders based on a systematic literature search.

RESULTS

Required equipment, practical implementation, and interpretation of the results of facial nerve electrodiagnostics are presented.

CONCLUSION

The aim of this guideline is to inform all involved parties (i.e. otorhinolaryngologist-head and neck surgeons and other medical specialists, therapeutic professionals and the affected persons) and to provide practical recommendations for the diagnostic use of facial nerve electrodiagnostics.

Accelerated chronic skin changes without allograft vasculopathy: A 10-year outcome report after face transplantation

BACKGROUND

Long-term outcomes after face transplantation are rarely reported in the scientific literature. Here we present outcome data of a partial face allograft recipient 10 years after transplantation.

METHODS

Medical records were reviewed for functional and psychosocial outcomes as well as complications. Histopathologic analyses of autopsy tissues and characterization of skin immune cells were performed.

RESULTS

The patient retained long-term motor and sensory function, though with a noticeable drop in sensory function after year 5. Social reintegration of the patient was marked by reconnection with his family and participation in public social activities. Immunosuppressive therapy consisted of tacrolimus (target levels 6-8 ng/mL after the first year), mycophenolate, and prednisone, while steroids were completely weaned between years 1 and 7. One acute cellular rejection episode of grade II or higher occurred on average per year and led to chronic skin changes (papillary dermal sclerosis with superficial hyalinization, epidermal thinning with loss of rete ridges, perieccrine fibrosis), but the allograft vessels, muscles, adipose tissue, and bone were spared. Allograft skin was characterized by increased number of CD4+ TNF-α/IL17A producing T-cells as compared with native skin. Long-term kidney function was maintained at 60 mL/min estimated glomerular filtration rate. Unfortunately, the preexisting hepatitis C virus infection with liver cirrhosis was resistant to 3 treatments with new direct-acting antivirals and eventually hepatocellular carcinoma developed, causing the patient's death 10 years after transplantation.

CONCLUSION

This report suggests that face transplants can maintain their function for at least 10 years. Chronic skin changes can occur independently of allograft vasculopathy.

Ocular Considerations in Face Transplantation: Report of 2 Cases and Review of the Literature

PURPOSE

Periorbital injuries are common in face transplantation (FT) candidates. It is therefore essential that the ophthalmologist play a central role in the multidisciplinary treatment of these patients. In this study, the authors perform a comprehensive review of all procedures involving periorbital components, provide an update for the ophthalmology community regarding the current state of the field, and present 2 cases.

METHODS

A comprehensive review of the literature for all FT procedures including periorbital components was performed. The authors also present 2 patients who received FT including periorbital components for extensive facial disfigurement. One patient sustained high-energy avulsive ballistic injury and underwent a total face, double jaw, and tongue transplant in 2012. The second patient received a total face, eyelids, ears, and skeletal subunits transplant for extensive facial burns in 2015.

RESULTS

Literature review demonstrated that 22 (54%) of the 41 patients undergoing FT received allografts containing periorbital components. Only 14 cases (64%) reported on the presence of ocular and periocular complications. The most common complications consisted of lower eyelid ectropion and lagophthalmos, and nearly all required revisional procedures. Both patients presented with significant periorbital scarring and demonstrated good visual acuity and aesthetic outcomes at postoperative follow up between 6 and 28 months.

CONCLUSIONS

Face transplantation can address extensive facial and periorbital disfigurement with satisfactory functional and aesthetic outcomes. The majority of FT performed to date have included periorbital components, and postoperative ocular and periocular complications are common. It is critical for ophthalmologists to play a central role in the care of these patients.

Recognizing Emotional Expression as an Outcome Measure After Face Transplant

IMPORTANCE

Limited quantitative data exist on the restoration of nonverbal communication via facial emotional expression after face transplant. Objective and noninvasive methods for measuring outcomes and tracking rehabilitation after face transplant are lacking.

OBJECTIVE

To measure emotional expression as an indicator of functional outcomes and rehabilitation after face transplant via objective, noninvasive, and nonobtrusive software-based video analysis.

DESIGN, SETTING, AND PARTICIPANTS

This single-center case-control study analyzed videos with commercially available video analysis software capable of detecting emotional expression. The study participants were 6 patients who underwent face transplant at Brigham and Women's Hospital between April 2009 and March 2014. They were matched by age, race/ethnicity, culture, and sex to 6 healthy controls with no prior facial surgical procedures. Participants were asked to perform either emotional expressions (direct evaluation) or standardized facial movements (indirect evaluation). Videos were obtained in a clinical setting, except for direct evaluation videos of 3 patients that were recorded at the patients' residences. Data analysis was performed from June 2018 to November 2018.

MAIN OUTCOMES AND MEASURES

The possibility of detecting the emotional expressions of happiness, sadness, anger, fear, surprise, and disgust was evaluated using intensity score values between 0 and 1, representing expressions that are absent or fully present, respectively.

RESULTS

Six patients underwent face transplant (4 men; mean [SD] age, 42 [14] years). Four underwent full face transplants, and 2 underwent partial face transplants of the middle and lower two-thirds of the face. In healthy controls, happiness was the only emotion reliably recognized in both indirect (mean [SD] intensity score, 0.92 [0.05]) and direct (mean [SD] intensity score, 0.91 [0.04]) evaluation. Indirect evaluation showed that expression of happiness significantly improved 1 year after transplant (0.04 point per year; 95% CI, 0.02 to 0.06 point per year; P = .002). Expression of happiness was restored to a mean of 43% (range, 14% to 75%) of that of healthy controls after face transplant. The expression of sadness showed a significant change only during the first year after transplant (-0.53 point per year; 95% CI, -0.82 to -0.24 point per year; P = .005). All other emotions were detectable with no significant change after transplant. Nearly all emotions were detectable in long-term direct evaluation of 3 patients, with expression of happiness restored to a mean of 26% (range, 5% to 59%) of that of healthy controls.

CONCLUSIONS AND RELEVANCE

Partial restoration of facial emotional expression is possible after face transplant. Video analysis software may provide useful clinical information and aid rehabilitation after face transplant.

Changes in Articulatory Control Pre- and Post-Facial Transplant: A Case Report

Purpose Facial transplantation involves partial or total replacement of neuromuscular and skeletal structures of the face, head, and neck using donor tissues and is among the most extensive facial reconstructive procedures. This case report compares changes in speech production and articulator movement in a 44-year-old man from pretransplant to a 13-month posttransplant period. Method Speech production and articulator movement data were examined at 5 time points, once pretransplant and 4 times posttransplant (4, 7, 10, and 13 months), and compared to 4 healthy controls. A motion capture system was used to track jaw and vertical/horizontal lip movement during nonspeech and speech tasks. Speech intelligibility, jaw displacement, lip aperture, and movement variability were measured. Results Speech intelligibility varied across the study period and was restored to control status by 7 months posttransplant. Jaw displacement and lip aperture in the vertical plane significantly increased over time for nonspeech and speech tasks. Changes in horizontal lip movements over time were minimal. Jaw and lip movement variability fluctuated over time and was greater than the controls by 13 months posttransplant. Discussion Findings quantify changes in articulator movement and contributions to improved speech production following facial transplant. Changes reflect the adaptability of the speech motor system and are discussed in relation to pretransplant speech motor control patterns.

Software-based video analysis of functional outcomes of face transplantation

INTRODUCTION

Assessment of outcomes after face transplantation (FT) is necessary to provide sound evidence on the benefits of this life-giving surgery. Current methods for outcomes assessment, however, are imprecise or prone to subjectivity. Software-based video analysis may allow fast, objective and retrospective assessment of restoration of facial movements and functions after FT.

PATIENTS AND METHODS

We recorded videos of 7 subjects before as well as every 3-6 months after facial transplantation. Patients performed the same sequence of facial movements in every video: smile, open mouth, purse lips, wrinkle nose, frown, close eyes, and lift eyebrows. The videos were retrospectively analyzed using EMOTIENT software, which is capable of automatic tracking and detailed measurements of facial movements and expressions. These measurements were subsequently compared to the same patient at different time points, as well as to the normal population.

RESULTS

Open mouth, wrinkle nose and smile functions significantly improved in all patients when compared to pre-transplant functions; this improvement was significant at 3, 6, and 12 months after transplant, respectively. Lip purse, eye closure and frown functions improved by 6, 9, and 18 months after transplantation, respectively; however, improvement in these particular functions was not significantly with respect to pre-transplant. Face transplantation did not improve any of the patients' ability to lift their eyebrows. Most remarkably, mouth opening and smiling functions both reached values comparable to the normal population at 3 and 12 months after transplantation, respectively.

CONCLUSION

Software-based video analysis provides a valuable assessment tool capable of objective, precise and reproducible analysis of facial movements and functions after FT.

Recovery of facial expressions using functional electrical stimulation after full-face transplantation

BACKGROUND

We assessed the recovery of 2 face transplantation patients with measures of complexity during neuromuscular rehabilitation. Cognitive rehabilitation methods and functional electrical stimulation were used to improve facial emotional expressions of full-face transplantation patients for 5 months. Rehabilitation and analyses were conducted at approximately 3 years after full facial transplantation in the patient group. We report complexity analysis of surface electromyography signals of these two patients in comparison to the results of 10 healthy individuals.

METHODS

Facial surface electromyography data were collected during 6 basic emotional expressions and 4 primary facial movements from 2 full-face transplantation patients and 10 healthy individuals to determine a strategy of functional electrical stimulation and understand the mechanisms of rehabilitation. A new personalized rehabilitation technique was developed using the wavelet packet method. Rehabilitation sessions were applied twice a month for 5 months. Subsequently, motor and functional progress was assessed by comparing the fuzzy entropy of surface electromyography data against the results obtained from patients before rehabilitation and the mean results obtained from 10 healthy subjects.

RESULTS

At the end of personalized rehabilitation, the patient group showed improvements in their facial symmetry and their ability to perform basic facial expressions and primary facial movements. Similarity in the pattern of fuzzy entropy for facial expressions between the patient group and healthy individuals increased. Synkinesis was detected during primary facial movements in the patient group, and one patient showed synkinesis during the happiness expression. Synkinesis in the lower face region of one of the patients was eliminated for the lid tightening movement.

CONCLUSIONS

The recovery of emotional expressions after personalized rehabilitation was satisfactory to the patients. The assessment with complexity analysis of sEMG data can be used for developing new neurorehabilitation techniques and detecting synkinesis after full-face transplantation.