Three-Dimensional Video Analysis of the Paralyzed Face Reanimated by Cross-Face Nerve Grafting and Free Gracilis Muscle Transplantation: Quantification of the Functional Outcome:

The effect of various muscle transfer procedures on eye closure and blinking in longstanding facial palsy patients

BACKGROUND

Facial palsy causes paralytic lagophthalmos, which remarkably deteriorates a patient's quality of life. In cases where denervation time is over 18-24 months (longstanding facial palsy), a free or pedicled muscle transfer is needed to replace the denervated orbicularis oculi muscle.

PURPOSE

The purpose of this systematic review is to investigate the effect of various eye sphincter substitution procedures (free or pedicled muscle transfers) in longstanding facial palsy patients on eye closure and blink.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we performed a systematic review of the Embase, Medline, Web of Science and Cochrane Library databases and Google Scholar. Our literature search yielded 4322 articles. Following a full-text review, 4 retrospective cohort studies and 21 case series were selected for this review. Meta-analyses using R package meta (version 6.5-0) were conducted.

MAIN FINDINGS

All free and pedicled muscle transfers in this review showed an improvement in the scores and measurements on eye closure and blink. The pedicled temporalis muscle transfer was the procedure most commonly performed as eye reanimation surgery and showed consistent good results. Using the random effects model, the pooled effect of mean difference in lagophthalmos after gentle eye closure post-operatively versus pre-operatively (mm) in patients who received a pedicled (temporalis) muscle transfer was -6.19 (I2 = 85%, 95% CI: -7.89; -4.49) whereas it was -4.11 (I2 = 85%, 95% CI: -7.26; -0.95) for free (gracilis or platysma) muscle transfers. The pooled proportion of patients with complete eye closure after surgery was 0.69 (I2 = 49%, 95% CI: 0.54; 0.82) in patients who received a pedicled (temporalis) muscle transfer and 0.40 (I2 = 74%, 95% CI: 0.13; 0.74) in patients who received a free (platysma) muscle transfer.

CONCLUSIONS

Unlike smile reanimation, dynamic eye closure and blink restoration are rather neglected topics in facial reanimation. The pedicled temporalis muscle transfer is often recommended as the first treatment of choice for eye reanimation in longstanding facial palsy patients since it is a reliable, straightforward procedure, that does not require complex microsurgery. However, with the advancements in the field of microsurgery, free muscle transfers are promising therapies, which may regenerate voluntary and spontaneous blinking.

Gracilis Muscle-Free Flap Objective Improvement of Oral Commissure Excursion in Facial Palsy Reanimation Surgery: Systematic Review and Meta-Analysis

Background: Facial palsy patients face significant challenges. Gracilis free flap transfer is a key procedure in facial reanimation. Objective: This study aims to analyze oral commissure excursion improvement after gracilis free flap transfer and the differences regarding donor nerve: cross-facial nerve graft (CFNG), hypoglossal or spinal accessory nerves, motor nerve to masseteric (MNTM), and most recently, double anastomosis using both the MNTM and CFNG. Methods: A systematic review and meta-analysis were conducted of studies reporting oral commissure excursion improvement after free gracilis muscle transfer. Pooled proportions were calculated using a random-effects model. Results: Eighteen studies, 453 patients, and 488 free gracilis flaps were included. The mean change in perioperative oral commissure excursion was 7.0 mm, for CFNG 7.2 mm, for MNTM 7.7, and for double anastomoses 5.5 mm. Conclusions: There is a significant improvement in oral commissure excursion after gracilis muscle-free flap. Unfortunately, we could not make definitive conclusions regarding the optimal choice of donor nerve.

Donor nerve selection in free gracilis muscle transfer for facial reanimation. A systematic review and meta-analysis of clinical outcomes

BACKGROUND

One of the critical factors in facial reanimation is selecting the donor nerve. The most favored neurotizers are the contralateral facial nerve with a cross-face nerve graft (CFNG) and motor nerve to the masseter (MNM). A relatively new dual innervation (DI) method has shown successful results. This study aimed to compare the clinical outcomes of different neurotization strategies for free gracilis muscle transfer (FGMT).

METHODS

The Scopus and WoS databases were queried with 21 keywords. Three-stage article selection was performed for the systematic review. Articles presenting quantitative data for commissure excursion and facial symmetry were included in meta-analysis, using random-effects model. ROBINS-I tool and Newcastle-Ottawa scale were used to assess bias and study quality.

RESULTS

One hundred forty-seven articles containing FGMT were systematically reviewed. Most studies indicated CFNG as the first choice. MNM was primarily indicated in bilateral palsy and in elderly. Clinical outcomes of DI studies were promising. 13 studies including 435 observations (179 CFNG, 182 MNM, 74 DI) were eligible for meta-analysis. The mean change in commissure excursion was 7.15 mm (95% CI: 4.57-9.72) for CFNG, 8.46 mm (95% CI: 6.86-10.06) for MNM, and 5.18 mm (95% CI: 4.01-6.34) for DI. In pairwise comparisons, a significant difference was found between MNM and DI (p = 0.0011), despite the superior outcomes described in DI studies. No statistically significant difference was found in resting and smile symmetry (p = 0.625, p = 0.780).

CONCLUSIONS

CFNG is the most preferred neurotizer, and MNM is a reliable second option. Outcomes of DI studies are promising, but more comparison studies are needed to draw conclusions. Our meta-analysis was limited by incompatibility of the assessment scales. Consensus on a standardized assessment system would add value to future studies.

'Are dynamic procedures superior to static in treating the paralytic eyelid in facial paralysis?'

BACKGROUND

Facial nerve weakness can cause deficient eye closure with reduced corneal protection. Surgical remedies can be static to oppose the levator muscle (lid loading) or dynamic procedures, which act to increase the strength of closure. This retrospective cohort study compares these groups. The hypothesis is that dynamic reconstruction has advantages over static techniques in terms of eye closure, symptomatic improvement, blink restoration, and complication rate.

METHODS

Two cohorts were compared: those treated with a gold weight insertion into the upper eyelid and those who had received dynamic reconstruction. These included temporalis transfer; cross face nerve grafting alone (CFNG) and CFNG followed by free tissue transfer. Assessments included standard photography and video; measurement of eyelid excursion including residual gap and if full eye closure was possible. The presence of the blink reflex and symptoms of dry eye was assessed.

RESULTS

Overall improvement in eye closure was similar with the gold weight compared to dynamic procedures (5.1 mm vs 5.3 mm). Dynamic procedures however gave improved results in terms of symptom relief and restoration of blink. They also had fewer complications and revision rates overall.

CONCLUSION

The study confirms the hypothesis that dynamic reconstructions of the paralysed eyelid confer advantages compared to simple lid loading techniques. Improvements in lid excursion are similar, but symptom improvement and blink restoration are significantly better. A decision regarding eyelid reanimation should be made early in the patient's journey of facial reanimation to allow for accurate planning and placement of nerve grafts at an early stage.

Seminal Studies in Facial Reanimation Surgery: Consensus and Controversies in the Top 50 Most Cited Articles

ABSTRACT

Facial paralysis can impair one's ability to form facial expressions that are congruent with internal emotion. This hinders communication and the cognitive processing of emotional experience. Facial reanimation surgery, which aims to restore full facial expressivity is a relatively recent undertaking which is still evolving. Due in large part to published techniques, refinements, and clinical outcomes in the scientific literature, consensus on best practice is gradually emerging, whereas controversies still exist.Taking stock of how the discipline reached its current state can help delineate areas of agreement and debate, and more clearly reveal a path forward. To do this, the authors have analyzed the 50 seminal publications pertaining to facial reanimation surgery. In longstanding cases, the free gracilis transfer emerges as a clear muscle of choice but the nerve selection remains controversial with prevailing philosophies advocating cross facial nerve grafts (with or without the support of an ipsilateral motor donor) or an ipsilateral motor donor only, of which the hypoglossal and nerve to masseter predominate. The alternative orthodoxy has refined the approach popularized by Gillies in 1934 and does not require the deployment of microsurgical principles. Although this citation analysis does not tell the whole story, surgeons with an interest in facial reanimation will find that this is a good place to start.

The sternohyoid muscle flap for new dynamic facial reanimation technique: Anatomical study and clinical results

BACKGROUND

Long-term facial nerve palsy has a highly negative impact on patients' quality of life. In 2016, Alam reported one case of facial reanimation with the sternohyoid muscle after publishing a preclinical study in 2013. Despite the potentially ideal characteristics of this muscle for reanimation of facial palsy, this technique is still not widely used. The objective of our description of cases was to present the clinical results obtained with the surgical procedure and the study on cadavers to confirm the anatomical findings.

METHODS

This work describes the anatomical study of the vascular and nervous pedicle of the sternohyoid muscle compared with clinical results from a series of patients with long-term facial paralysis who underwent facial reanimation between June 2016 and September 2019, through the insertion of the sternohyoid muscle into the masseteric nerve.

RESULTS

The anatomical study was conducted in eight human hemi-necks. In five cases (62%), the vascular pedicle was provided by the superior thyroid artery, and the entrance of the ansa cervicalis to the muscle was constant 1.8 cm from the distal insertion. This series included ten patients who underwent the surgery technique of facial reanimation using the sternohyoid muscle, with a 90% (n = 9) of reinnervation; 100% (n = 10) of flaps were viable, and none of the patients showed complications in the donor area.

CONCLUSIONS

The sternohyoid muscle showed itself as a reliable muscle as a free flap in facial reanimation, and alternative to the gracilis flap. The surgical technique was safe, without any complications, with excellent excursion, recovery, and aesthetic results.

Toward an Automatic System for Computer-Aided Assessment in Facial Palsy

Importance: Quantitative assessment of facial function is challenging, and subjective grading scales such as House-Brackmann, Sunnybrook, and eFACE have well-recognized limitations. Machine learning (ML) approaches to facial landmark localization carry great clinical potential as they enable high-throughput automated quantification of relevant facial metrics from photographs and videos. However, the translation from research settings to clinical application still requires important improvements. Objective: To develop a novel ML algorithm for fast and accurate localization of facial landmarks in photographs of facial palsy patients and utilize this technology as part of an automated computer-aided diagnosis system. Design, Setting, and Participants: Portrait photographs of 8 expressions obtained from 200 facial palsy patients and 10 healthy participants were manually annotated by localizing 68 facial landmarks in each photograph and by 3 trained clinicians using a custom graphical user interface. A novel ML model for automated facial landmark localization was trained using this disease-specific database. Algorithm accuracy was compared with manual markings and the output of a model trained using a larger database consisting only of healthy subjects. Main Outcomes and Measurements: Root mean square error normalized by the interocular distance (NRMSE) of facial landmark localization between prediction of ML algorithm and manually localized landmarks. Results: Publicly available algorithms for facial landmark localization provide poor localization accuracy when applied to photographs of patients compared with photographs of healthy controls (NRMSE, 8.56 ± 2.16 vs. 7.09 ± 2.34, p ≪ 0.01). We found significant improvement in facial landmark localization accuracy for the facial palsy patient population when using a model trained with a relatively small number photographs (1440) of patients compared with a model trained using several thousand more images of healthy faces (NRMSE, 6.03 ± 2.43 vs. 8.56 ± 2.16, p ≪ 0.01). Conclusions and Relevance: Retraining a computer vision facial landmark detection model with fewer than 1600 annotated images of patients significantly improved landmark detection performance in frontal view photographs of this population. The new annotated database and facial landmark localization model represent the first steps toward an automatic system for computer-aided assessment in facial palsy. Level of Evidence: 4.

Effectiveness and safety of the use of gracilis muscle for dynamic smile restoration in facial paralysis: A systematic review and meta-analysis

BACKGROUND

Smiling is a fundamental component of social interactions. Significant challenges arise for patients with facial palsy. One of the key procedures for dynamic smile restoration is the microneurovascular transfer of a gracilis muscle. We aimed to assess the effectiveness and safety of dynamic smile reanimation surgery using the free gracilis muscle unit in patients with facial palsy.

METHODS

We conducted a systematic review and meta-analysis of studies reporting surgical outcomes of dynamic smile restoration using free gracilis muscles identified from EMBASE, Medline, and Web of Science databases from their inception to March 15, 2018. Two-stage screening and data extraction were performed by two independent reviewers. Pooled proportions were calculated using random-effects models.

RESULTS

Thirty-one studies including 1647 patients who underwent 1739 free gracilis flaps were included. Twelve (38.7%) studies measured perioperative smile excursion change using six different tools. Six of these studies were homogeneous and were used in meta-analyses of smile excursion improvement, which revealed a mean change of 7.5 mm (95% CI 6.0-9.0 mm, I² 86.7%) perioperatively. Twenty (64.5%) studies reported perioperative complications, and pooled proportions of flap failures were of 2.9% (95% CI 1.3-4.5%, I² 47.7%).

CONCLUSIONS

Dynamic smile restoration using a free gracilis muscle may represent an effective procedure to regain oral commissure motion and is associated with an approximately 3% rate of flap failure. Masseteric nerve coaptations lead to larger improvements in perioperative smile excursion (10 mm) than cross-facial nerve grafts (6.8 mm). Future studies with homogeneous reporting of smile excursion and patient-reported outcome measures are needed.

Anatomical study of the masseteric and obturator nerves: Application to face transplant and reanimation procedures

The masseteric nerve (MN) and the anterior branch of the obturator nerve (ON) that innervate the transferred gracilis muscle have proved highly efficient for reanimating paralyzed facial muscles when muscle transfer is required. Previous researchers have published the total axonal load for myelinated fibers in both nerves. However, the real motor axonal load has not been established. We performed the study on 20 MN and 13 ON. The segments of the MN and the ON were embedded in paraffin, sectioned at 10 μm, and stained following a standard immunohistochemical procedure using anti-choline acetyltransferase to visualize the motor fibers. The MN has a higher axonal load than the ON. There were statistically significant differences between the axonal load of the proximal segment of the MN and the ON. These findings confirm that end-to-end anastomoses between the MN and the ON should preferably use the proximal segment. However, MN neurotomy should ideally be performed between the proximal and distal segments, preserving innervation to the deep fascicles. Our results show that the MN is ideal as a donor motor nerve for reinnervating transplanted muscle for dynamic reanimation of the paralyzed face. The neurotomy should ideally be performed between the first and second collateral branches of the MN. Clin. Anat. 32:612-617, 2019. © 2019 Wiley Periodicals, Inc.

Masseteric cooptation and crossfacial nerve grafting: Is it still applicable 22 months after the onset of facial palsy?

BACKGROUND

Eighteen months is usually considered the cutoff time within which recovery of the mimic muscle remains possible using facial nerve cooptation. Few reports on the use of cooptation after this interval have appeared. Purpose of this study is to investigate the feasibility of this procedure also after 22 months.

METHODS

Six patients treated via crossfacial nerve grafting between healthy and paralyzed middle and middle-upper facial nerve branches and masseteric cooptation of the main trunk of the paralyzed facial nerve between 20 and 24 months after the onset of palsy were analyzed. Population consisted of two males and four females ages 8-42 years (mean 24 years). Facial palsy developed after acoustic neuroma resection in three patients, after the removal of a cerebellopontine angle astrocytoma in one, and as a consequence of Bell's palsy or cerebral hemorrhage in the other two (one each). House-Brackman and Sunnybrook clinical evaluation systems and FDI questionnaire were used to assess results.

RESULTS

House-Brackman scores changed from VI before the operation for all patients to II for two patients and III for four patients. Sunnybrook scores were 0-10 before the operation, but 62-84 at the last visit. Mean FDI scores moved from 24 to 38.5 meaning a statistical high significant improvement (P < .01).

CONCLUSIONS

Masseteric/crossfacial nerve grafting is feasible for patients with palsies 20-24 months in duration, affording satisfactory functional and esthetic results and a dramatic improvement in quality of life.

Comparing Patient, Casual Observer, and Expert Perception of Permanent Unilateral Facial Paralysis

Importance

Differences in perception of facial paralysis among patients, casual observers, and experts may have implications for outcomes research and patient care.

Objective

To compare multiple domains of casual observer and expert perception with the actual experience of patients with permanent unilateral facial paralysis.

Design, Setting, and Participants

This investigation was a prospective cohort study conducted at an academic tertiary referral center. Patients with permanent unilateral facial paralysis (House-Brackmann grades IV to VI) were randomly selected from The Johns Hopkins University Division of Facial Plastic and Reconstructive Surgery clinic. A diverse group of casual observers and experts were recruited to rate their perception of each patient with facial paralysis. The study dates were July 2014 to July 2015.

Main Outcomes and Measures

Patients rated their paralysis severity, attractiveness, quality of life, and affect using established metrics. Casual observers and experts viewed standardized facial videos of each patient and then used the same metrics to rate each patient's paralysis severity, attractiveness, quality of life, and affect.

Results

The analysis yielded 40 patient observations, 6400 casual observer observations, and 200 expert observations for each outcome metric in the study. Compared with the patients' self-perception, casual observers and experts rated patients with facial paralysis more negatively in all measured domains. A multivariable mixed-effects regression showed that observers perceived patients as having greater paralysis severity (8.49 [95% CI, -0.65 to 17.64] of 100 points; SE, 4.67), being less attractive (-7.71 [95% CI, -14.92 to -0.50] of 100 points; SE, 3.68), and having a worse quality of life (-7.76 [95% CI, -14.18 to -1.34] of 100 points; SE, 3.28) compared with the patients' perceptions. Logistic regression demonstrated that observers were less likely to rate patients' affect as positive (odds ratio, 0.28 [95% CI, 0.14-0.58]; SE, 0.10) compared with the patients' self-rating. The raw data and regression analyses also showed that patients, casual observers, and experts perceived faces with higher House-Brackmann grades more negatively in all measured domains of facial perception.

Conclusions and Relevance

This study found that casual observers and experts generally perceive patients with facial paralysis more negatively than patients perceive themselves. These findings have implications for patients and facial plastic surgeons alike. They also emphasize the importance of assessing outcomes from all 3 perspectives. This pilot study lays the groundwork for developing new tools to assess the social perception of facial deformity that could lead to advancement in facial paralysis outcomes research and improved care for patients with facial paralysis.

Level of Evidence

NA.

A Bidimensional System of Facial Movement Analysis Conception and Reliability in Adults

Objective. To design a bidimensional facial movement measuring tool and study its reliability. Methods. We utilized the free video-analysis software Kinovea that can track preselected points during movements and measure two-point distances off-line. Three raters positioned facial markers on 10 healthy individuals and video-taped them during maximal bilateral contractions of frontalis, corrugator, orbicularis oculi, zygomaticus, orbicularis oris, and buccinator, on two occasions. Each rater also analyzed the first video twice, one week apart. For each muscle, intrarater reliability was measured by percent agreements (PA) and intraclass correlation coefficients (ICC) between two assessments of the same video one week apart and between assessments of two videos collected one week apart. Interrater reliability was measured by PA, ICC, and coefficients of variation (CV) between assessments of the first video-recording by the three raters. Results. Intrarater and interrater reliabilities were good to excellent for frontalis (PA and ICC > 70%; CV < 15%), moderate for orbicularis oculi, zygomaticus, and orbicularis oris, and poor for corrugator and buccinators. Discussion. Without formal prior training, the proposed method was reliable for frontalis in healthy subjects. Improved marker selection, training sessions, and testing reliability in patients with facial paresis may enhance reliability for orbicularis oculi, zygomaticus, and orbicularis oris.

Enhancement of facial nerve motoneuron regeneration through cross-face nerve grafts by adding end-to-side sensory axons

BACKGROUND

In unilateral facial palsy, cross-face nerve grafts are used for emotional facial reanimation. Facial nerve regeneration through the grafts takes several months, and the functional results are sometimes inadequate. Chronic denervation of the cross-face nerve graft results in incomplete nerve regeneration. The authors hypothesize that donor axons from regional sensory nerves will enhance facial motoneuron regeneration, improve axon regeneration, and improve the amplitude of facial muscle movement.

METHODS

In the rat model, a 30-mm nerve graft (right common peroneal nerve) was used as a cross-face nerve graft. The graft was coapted to the proximal stump of the transected right buccal branch of the facial nerve and the distal stumps of the transected left buccal and marginal mandibular branches. In one group, sensory occipital nerves were coapted end-to-side to the cross-face nerve graft. Regeneration of green fluorescent protein-positive axons was imaged in vivo in transgenic Thy1-green fluorescent protein rats, in which all neurons express green fluorescence. After 16 weeks, retrograde labeling of regenerated neurons and histomorphometric analysis of myelinated axons was performed. Functional outcomes were assessed with video analysis of whisker motion.

RESULTS

"Pathway protection" with sensory axons significantly enhanced motoneuron regeneration, as assessed by retrograde labeling, in vivo fluorescence imaging, and histomorphometry, and significantly improved whisker motion during video analysis.

CONCLUSION

Sensory pathway protection of cross-face nerve grafts counteracts chronic denervation in nerve grafts and improves regeneration and functional outcomes.

Facial synkinesia before and after surgical reanimation of the paralyzed face

BACKGROUND

Facial synkinesia is a common sequela of facial palsy, affecting 15 to 20 percent of patients. The rate of postoperative synkinesia after facial reanimation is not clearly established. The severity and type of synkinesia determine the degree of clinical relevance.

METHODS

One hundred sixty-seven patients with facial palsy were included in this retrospective cohort study. Three-dimensional video analysis of facial movements was performed preoperatively and 18 months after facial reanimation. The severity of synkinesia was rated subjectively on a four-degree severity scale. Objective three-dimensional analysis of synkinesia was performed on patients with 18-month follow-up times.

RESULTS

Preoperatively, 84.4 percent of patients were not affected by synkinesia, 9 percent presented with mild synkinesia, 4.2 percent presented with moderate synkinesia, and 2.4 percent presented with severe synkinesia. Postoperatively, 51 percent of all patients presented with facial synkinesia (41.8 percent mild, 17.3 percent moderate, and 1 percent severe synkinesia; some patients had more than one type). Patients treated with territorially differentiated gracilis muscle transplantation were most frequently affected (69.8 percent), followed by patients treated with gracilis muscle transplantation in combination with temporalis muscle transposition to the eye (51.8 percent). Oculo-oral synkinesia was the most frequent form of synkinesia.

CONCLUSIONS

After surgical reanimation of the paralyzed face, half of the patients presented with synkinesia. The majority of patients developed mild or moderate forms of synkinesia; therefore, the clinical relevance of synkinesia has to be seen in the context of total facial function. Because of the high prevalence of synkinesia, it should be documented and addressed in patients undergoing facial reanimation.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Seeing is believing: objectively evaluating the impact of facial reanimation surgery on social perception

OBJECTIVES/HYPOTHESIS

Objectively measure the ability of facial reanimation surgery to normalize the appearance of facial paralysis using eye-tracking technology.

STUDY DESIGN

Prospective randomized controlled experiment.

METHODS

An eye-tracker system was used to record the eye-movement patterns, called scanpaths, of 86 naïve observers gazing at pictures of paralyzed faces (House-Brackmann IV-VI), smiling and in repose; before and after facial reanimation surgery; as well as normal, nonparalyzed faces. Observers gazed at each face for 10 seconds. Fixation durations for all predefined facial areas of interest were analyzed using mixed-effects linear regression.

RESULTS

Observers spent the majority of time (6.6 of 10 seconds) gazing in the central triangle region (eyes, nose, and mouth) of normal faces and paralyzed faces. There were significant deviations in fixation within the central triangle of paralyzed faces as compared to normal faces. Total fixation on the eyes remained conserved. However, total nose fixation decreased and mouth fixation increased on paralyzed faces. Facial reanimation surgery normalized many of the hemifacial gaze asymmetries caused by unilateral facial paralysis, and restored a normal distribution of gaze between the functional and paralyzed sides of the face and mouth.

CONCLUSION

There were objective differences in the way observers directed their attention to facial features when viewing normal and paralyzed faces. After facial reanimation surgery, the attentional distraction caused by facial feature irregularities was reduced. These findings are important additions to the emerging body of objective evidence indicating the effectiveness of reanimation surgery; they also suggest opportunities to optimize reconstruction.

LEVEL OF EVIDENCE

N/A.

Sternohyoid flap for facial reanimation: a comprehensive preclinical evaluation of a novel technique

IMPORTANCE

Neuromuscular reanimation of the face provides the correct specific neural functional input and thereby prevents synkinesis. Unfortunately, this ideal situation is rarely encountered in the clinical setting.

OBJECTIVES

To assess the technical feasibility of and define the surgical procedure for harvesting the sternohyoid muscle as a novel free flap for use in facial reanimation indications.

DESIGN, SETTING, AND PARTICIPANTS

Fresh, postmortem, nonfixed cadavers were used to define the anatomy and perform the flap harvest procedures. Twenty-four flap harvests were performed. Angiography was performed on the pedicle of the harvested flaps to assess potential flap perfusion. Adenosine triphosphatase staining was performed on the muscle specimens to establish fiber type.

MAIN OUTCOME MEASURES

The harvest technique, pedicle (arterial or venous), nerve length, and flap geometry parameters were characterized.

RESULTS

The sternohyoid muscle was found to be reliably vascularized by the superior thyroid artery in all cases with an appropriate arterial and venous pedicle for vascular anastomosis. The mean arterial (5.5 cm) and venous (5.9 cm) pedicle lengths are comparable with gracilis flaps. The mean motor nerve length was 10.7 cm. The inclusion of the hyoid bone allows rigid fixation, and the muscle size, fiber type, and volume profiles all compare favorably to the gracilis flap for use in the indication of facial reanimation. Mock surgical procedures were performed to define inset parameters. This flap potentially allows single-stage cross-facial neurorrhaphies to be performed.

CONCLUSIONS AND RELEVANCE

This is the first article, to our knowledge, of the sternohyoid muscle as a potential donor site for free-tissue transfer. This muscle has a predictable vascular pedicle and neural innervation along with size and fiber type parameters that make it an ideal potential free flap for facial reanimation.

LEVEL OF EVIDENCE

NA.

The clinical application of three-dimensional motion capture (4D): a novel approach to quantify the dynamics of facial animations

The aim of this pilot study was to evaluate the feasibility of measuring the change in magnitude, speed, and motion similarity of facial animations in head and neck oncology patients, before and after lip split mandibulotomy. Seven subjects (four males, three females) aged 42-80 years were recruited. The subjects were asked to perform four facial animations (maximal smile, lip purse, cheek puff, and grimace) from rest to maximal position. The animations were captured using a Di4D motion capture system, which recorded 60 frames/s. Nine facial soft tissue landmarks were manually digitized on the first frame of the three-dimensional image of each animation by the same operator and were tracked automatically for the sequential frames. The intra-operator digitization error was within 0.4mm. Lip purse and maximal smile animations showed the least amount of change in magnitude (0.2mm) following surgery; speed difference was least for smile animation (-0.1mm/s). Motion similarity was found to be highest for lip purse animation (0.78). This pilot study confirmed that surgery did influence the dynamics of facial animations, and the Di4D capture system can be regarded as a feasible objective tool for assessing the impact of surgical interventions on facial soft tissue movements.

Muscle reinnervation in one or two stages?: experimental study in rats with end-to-side nerve graft

PURPOSE: To compare muscle reinnervation in one and two surgical stages using end-to-side neurorrhaphy (ESN) without donor nerve injury. METHODS: The experiment was performed on four groups of 20 rats. Group 1 (G1), one stage, received the graft which was sutured to the tibial nerve, with ESN, and its free stump was sutured end-to-end to the distal stump of the sectioned peroneal nerve (PN), all in the same operation. In Group 2 (G2), two stages, the nerve graft was sutured to the tibial nerve, with ESN. Two months later the PN was sectioned and its distal stump connected to the distal stump of the graft as in G1. Normal control group (Gn) received the graft only sutured to the tibial nerve, with ESN. Denervated control group (Gd), as well received the graft and had the PN sectioned and its two stumps buried in adjacent musculature, with the aim of denervating the cranial tibial muscle (CTM), the target of this study. The parameters used to evaluate CTM reinnervation were muscle mass, muscle fiber's minimum diameter and area. RESULTS: The mean CTM mass, the average of the muscular fibers areas and the average of the muscular fiber minimum diameters was higher (all p<0.0001) in G2 than in G1. Comparing the four groups, these parameters had their maximum expression in Gn and the minimum in Gd, as expected. CONCLUSION: The two stages showed better muscle reinnervation than one stage.

Evolution of the 3-dimensional video system for facial motion analysis: ten years' experiences and recent developments

Since the implementation of the computer-aided system for assessing facial palsy in 1999 by Frey et al (Plast Reconstr Surg. 1999;104:2032-2039), no similar system that can make an objective, three-dimensional, quantitative analysis of facial movements has been marketed. This system has been in routine use since its launch, and it has proven to be reliable, clinically applicable, and therapeutically accurate. With the cooperation of international partners, more than 200 patients were analyzed. Recent developments in computer vision--mostly in the area of generative face models, applying active--appearance models (and extensions), optical flow, and video-tracking-have been successfully incorporated to automate the prototype system. Further market-ready development and a business partner will be needed to enable the production of this system to enhance clinical methodology in diagnostic and prognostic accuracy as a personalized therapy concept, leading to better results and higher quality of life for patients with impaired facial function.

Investigation of the relationship between wrinkle formation and deformation of the skin using three-dimensional motion analysis

BACKGROUND

Although there have been many studies investigating facial movements using three-dimensional (3D) quantitative analysis, the possible relationship between the levels of wrinkles and the movement distance of facial skin has previously not been reported.

METHOD

Forty-four healthy Japanese women (from 20 to 50 years, average = 47.7 ± 3.6 years) were recruited for this study with written informed consent. Infrared reflective marks were attached on their forehead skin, and then moving images of facial skin motions (raising the eyebrows) were captured using two infrared cameras under infrared ray irradiation. Calibration for the absolute value of distance was established using an exact one-point 3-m cube having infrared reflective marks at each apex. The two pupils and the top of the nose were setup as fixed standard points. 3D motion analysis was then carried out using Move-tr/3D(™) software to determine the absolute distances of skin surface movements. Levels of wrinkles were determined using a 3D roughness analyzer (PRIMOS) directly at rest and when raising the eyebrows.

RESULTS

The wrinkle levels at rest showed a relatively high and significant correlation with wrinkles when strongly raising the eyebrows. Although the wrinkle levels at rest showed no correlation with the movement distance, the wrinkle levels when raising the eyebrows showed a significant correlation with the movement distance. The ratio of change based on the distance between the marks at rest and when raising the eyebrows showed similar correlation results.

CONCLUSIONS

These results suggest that both the levels of skin deformation caused by movements and the wrinkles at rest are important factors that determine the wrinkle level when raising the eyebrows. However, the level of skin deformation is not important for wrinkle levels at rest, which indicates that other factors such as skin elasticity are also important for the formation of wrinkles.

Facial mimicry after conservative parotidectomy: a three-dimensional optoelectronic study

Facial nerve paralysis is one of several possible complications following conservative parotidectomy. To assess three-dimensional facial movements non-invasively in patients with unilateral facial palsy following parotidectomy for benign tumours, the three-dimensional coordinates of 21 soft-tissue facial landmarks were recorded in 32 patients (21 HB I, 5 HB II, 6 HB III-IV; 3 months post-surgery follow-up), and 40 control subjects, during the performance of facial movements (smile, 'surprise', eye closure, single eye closure). For all symmetric animations, control subjects had larger total mobility than patients; mobility progressively decreased in patients with larger clinical grades. For asymmetric eye closures, HB I patients and control subjects had similar total movements, while HB II patients had smaller movements, especially for the paretic side eye closure; smaller total movements were found in HB III-IV patients. The method allowed the quantitative detection of alterations in facial movements. Significant differences between patients and control subjects in the magnitude and asymmetry of movements were found.

A novel method to investigate the relationship between facial movements and wrinkle formation using particle image velocimetry

BACKGROUND

The possible relationship between the direction of wrinkles and the movement of facial skin has not previously been reported. Therefore, we characterized that relationship using particle image velocimetry (PIV) analysis.

METHOD

Twenty-one healthy Japanese women aged in their 20s (n = 7) or 50s (n = 14) were recruited for this study. Moving images of facial skin motions (closing the eyes tightly, raising the eyebrows) were captured using a single infrared camera under infrared ray irradiation of the skin. PIV analysis was then carried out using Flow-Vec32 software to determine the velocity and the direction of skin surface movements.

RESULTS

All skin movements caused by those motions were finished within 0.20 s. During the motion of closing the eyes, skin at the eye periphery did not move in a superior-inferior direction, but did move toward the center of the eye (pupilla) with complex flows. There was no significant difference between either age group of subjects. During the motion of raising the eyebrows, the forehead skin moved upwards (direction to parietal) with relatively uniform flows. The velocity of movement at the top was lower than at the bottom, and that difference is likely to cause a deformation on the skin surface. A significant difference between the two age groups in the velocity was observed.

CONCLUSION

The results show that the deformation of older skin on the forehead is greater than that in younger skin. The PIV analysis method is a useful tool to investigate some aspects of the relationship between facial skin movements and wrinkle formation.

Modern concepts in facial nerve reconstruction

Background

Reconstructive surgery of the facial nerve is not daily routine for most head and neck surgeons. The published experience on strategies to ensure optimal functional results for the patients are based on small case series with a large variety of surgical techniques. On this background it is worthwhile to develop a standardized approach for diagnosis and treatment of patients asking for facial rehabilitation.

Conclusion

A standardized approach is feasible: Patients with chronic facial palsy first need an exact classification of the palsy's aetiology. A step-by-step clinical examination, if necessary MRI imaging and electromyographic examination allow a classification of the palsy's aetiology as well as the determination of the severity of the palsy and the functional deficits. Considering the patient's desire, age and life expectancy, an individual surgical concept is applicable using three main approaches: a) early extratemporal reconstruction, b) early reconstruction of proximal lesions if extratemporal reconstruction is not possible, c) late reconstruction or in cases of congenital palsy. Twelve to 24 months after the last step of surgical reconstruction a standardized evaluation of the therapeutic results is recommended to evaluate the necessity for adjuvant surgical procedures or other adjuvant procedures, e.g. botulinum toxin application. Up to now controlled trials on the value of physiotherapy and other adjuvant measures are missing to give recommendation for optimal application of adjuvant therapies.

Outcomes of Microneurovascular Facial Reanimation Using Masseteric Innervation in Patients With Long-Standing Facial Palsy Resulting From Cured Brainstem Lesions

BACKGROUND

The functions of the human face are not only of esthetic significance but also extend into metaphoric nuances of psychology. The loss of function of one or both facial nerves has a remarkable impact on patients' lives.

OBJECTIVE

To retrospectively analyze the functional outcomes of microneurovascular facial reanimation using masseteric innervation.

METHODS

Seventeen patients with irreparable facial paralysis resulting from benign lesions involving the facial nuclei (n = 14) or Möbius syndrome (n = 3) were treated with free muscle flaps for oral commissural reanimation using ipsilateral masseteric innervation and using temporalis muscle transfer for eyelid reanimation. Results were analyzed by the absolute commissural excursion and commissural excursion index and by a patient self-evaluation score. Presence of synkinesis was documented. Follow-up ranged from 8 to 48 months (mean, 26.4 months).

RESULTS

Normalization of the commissural excursion index was observed in 8 of 17 patients (47%), an improvement was seen in 7 of 17 (41%), and failure was observed in 2 of 17 (12%). The individual dynamics of absolute commissural excursion and commissural excursion index changes are presented. A natural smiling response was observed in 10 of 17 patients (59%) but not in the remaining 7 (41%). This response reflected the patient's ability to relay the natural emotion of smiling through the masseteric nerve. Patients' self-evaluation scores were a level higher than objective indices.

CONCLUSIONS

Innervation of free muscle flaps with the masseteric nerve for oral commissure reanimation might play an important role in patients with lesions of the facial nuclei (as in Möbius syndrome). Synkinesis persists for long periods after surgery. However, most of the patients learned to express their emotions by overcoming this phenomenon. Despite hypercorrection or inadequate correction, patients evaluated themselves favorably.