BACKGROUND:Free functional muscle transfer to the face is a standard of facial animation. The contralateral facial nerve, via a cross-face nerve graft, provides spontaneous innervation for the ...transferred muscle, but is not universally available and has additional shortcomings. The motor nerve to the masseter provides an alternative innervation source. In this study, the authors compared donor nerve histomorphometry and clinical outcomes in a single patient population undergoing free muscle transfer to the face.
METHODS:Pediatric patients undergoing dynamic facial (re-)animation with intraoperative nerve biopsies and gracilis transfer to the face powered by either the contralateral facial nerve via a cross-face nerve graft or the motor nerve to the masseter were reviewed over a 7-year period. Myelinated nerve counts were assessed histomorphometrically, and functional outcomes were evaluated with the Scaled Measurement of Improvement in Lip Excursion software.
RESULTS:From 2004 to 2011, 91 facial (re-)animation procedures satisfied study inclusion criteria. Average myelinated fiber counts were 6757 per mm2 in the donor facial nerve branch, 1647 per mm in the downstream cross-face nerve graft at the second stage, and 5289 per mm in the masseteric nerve. Reconstructions with either innervation source resulted in improvements in oral commissure excursion and smile symmetry, with the greatest amounts of oral commissure excursion noted in the masseteric nerve group.
CONCLUSIONS:Facial (re-)animation procedures with use of the cross-face nerve graft or masseteric nerve are effective and result in symmetric smiles. The masseteric nerve provides a more robust innervation source and results in greater commissure excursion.
CLINICAL QUESTION/LEVEL OF EVIDENCE:Therapeutic, III.
ABSTRACT
Introduction
In this study we correlated results of ultrasonographic muscle thickness and contractility with facial electromyography (EMG) in patients with unilateral peripheral acute or ...chronic facial palsy.
Methods
Two hundred twenty measurements of 4 facial muscles (frontalis, orbicularis oculi, zygomaticus, and orbicularis oris) were performed in 44 patients.
Results
Facial muscle thickness at rest and during muscle contraction correlated best with EMG insertional activity, and facial muscle contractility correlated with EMG voluntary activity. The correlation was much higher at >14 days after onset of facial palsy. The orbicularis oris, followed by the frontalis muscle, showed the best correlation between ultrasound and EMG.
Conclusions
Quantitative ultrasound of facial muscles helps confirm the results of facial EMG and is of particular additional value in the first 14 days after onset when the reliability of EMG is low. Muscle Nerve 53: 755–761, 2016
Abstract We develop the concept of emotional proprioception , whereby the muscles of facial expression play a central role in encoding and transmitting information to the brain's emotional circuitry, ...and describe its underlying neuroanatomy. We explore the role of facial expression in both reflecting and influencing depressed mood. The circuitry involved in this latter effect is a logical target for treatment with botulinum toxin, and we review the evidence in support of this strategy. Clinical trial data suggest that botulinum toxin is effective in treating depression. We discuss the clinical and theoretical implications of these data. This novel treatment approach is just one example of the potential importance of the cranial nerves in the treatment of depression.
To investigate the characteristics of electromyography (EMG) signals and the starting threshold voltages of the orbicularis oris muscles (OOM) in healthy rhesus monkeys under different muscle ...movement conditions.
The EMG signals and the starting threshold voltages at different time points in 4 healthy rhesus monkeys were acquired and recorded with EMG device and evoked potentiometer. The voltage amplitude variation of EMG signals was analyzed, and the voltage amplitude range of EMG signals at the beginning of OOM contraction was established. The data were statistically analyzed by one-way ANOVA.
The EMG of OOM in healthy monkeys in the quiet, natural and continuous mouth-closed state was linear and relatively stable, and the absolute value fluctuated between 15 and 50 μV. The EMG waveform increased rapidly during the natural lip contraction movement, and its amplitude fluctuated greatly, with the highest absolute value of the peak value reaching hundreds of microvolts. The amplitude of EMG induced by continuo
Facial expressions of pain are not undefined grimaces, but they convey specific information about the internal state of the individual in pain. With this systematic review, we aim to answer the ...question of which facial movements are displayed most consistently during pain. We searched for studies that used the Facial Action Coding System to analyze facial activity during pain in adults, and that report on distinct facial responses (action units AUs). Twenty-seven studies using experimental pain and 10 clinical pain studies were included. We synthesized the data by taking into consideration (1) the criteria used to define whether an AU is pain-related; (2) types of pain; and (3) the cognitive status of the individuals. When AUs were selected as being pain-related based on a "pain > baseline" increase, a consistent subset of pain-related AUs emerged across studies: lowering the brows (AU4), cheek raise/lid tightening (AUs6_7), nose wrinkling/raising the upper lip (AUs9_10), and opening of the mouth (AUs25_26_27). This subset was found independently of the cognitive status of the individuals and was stable across clinical and experimental pain with only one variation, namely that eye closure (AU43) occurred more frequently during clinical pain. This subset of pain-related facial responses seems to encode the essential information about pain available in the face. However, given that these pain-related AUs are most often not displayed all at once, but are differently combined, health care professionals should use a more individualized approach, determining which pain-related facial responses an individual combines and aggregates to express pain, instead of erroneously searching for a uniform expression of pain.
The experience of empathy for pain is underpinned by sensorimotor and affective dimensions which, although interconnected, are at least in part behaviorally and neurally distinct. Spinal cord ...injuries (SCI) induce a massive, below‐lesion level, sensorimotor body–brain disconnection. This condition may make it possible to test whether sensorimotor deprivation alters specific dimensions of empathic reactivity to observed pain. To explore this issue, we asked SCI people with paraplegia and healthy controls to observe videos of painful or neutral stimuli administered to a hand (intact) or a foot (deafferented). The stimuli were displayed by means of a virtual reality set‐up and seen from a first person (1PP) or third person (3PP) visual perspective. A number of measures were recorded ranging from explicit behaviors like explicit verbal reports on the videos, to implicit measures of muscular activity (like EMG from the corrugator and zygomatic muscles that may represent a proxy of sensorimotor empathy) and of autonomic reactivity (like the electrodermal response and Respiratory Sinus Arrhythmia that may represent a general proxy of affective empathy). While no across group differences in explicit verbal reports about the pain stimuli were found, SCI people exhibited reduced facial muscle reactivity to the stimuli applied to the foot (but not the hand) seen from the 1PP. Tellingly, the corrugator activity correlated with SCI participants' neuropathic pain. There were no across group differences in autonomic reactivity suggesting that SCI lesions may affect sensorimotor dimensions connected to empathy for pain.
To explore how sensorimotor deprivation affects empathic reactivity we recorded facial muscle (FM) and autonomic reactivity (AR) in controls and people with spinal cord injury (SCI) watching painful stimuli applied to a virtual, intact (hand) or deprived (foot) body part. SCI participants displayed reduced FM when viewing foot stimuli. AR was not differentially affected by group, stimulus or body part indicating that SCI affects sensorimotor rather than affective pain empathy.
Full face transplantation raises a new set of ethical concerns and technical difficulties when compared with partial face transplantation. Previously, it was thought that full face allografts must ...include bilateral superficial temporal and facial arteries, dictating the need for inclusion of donor parotid glands. This would lead to poor aesthetic outcomes and limit facial nerve coaptation to the level of the main trunk, which often results in synkinesias. The authors present a new approach to full facial allograft recovery based on blood supply from facial arteries alone. This approach eliminates the need to include parotid glands, enabling more distal coaptation of facial nerve branches and targeted innervation of effector muscles. The recovery can be reproducibly performed within 4 hours.
Three mock cadaver dissections and three full face transplantations were performed.
Donor facial allografts were dissected in cranio-caudal and lateral-to-medial fashion. Individual facial nerve branches were cut medial to parotid glands and coapted to corresponding recipient nerve branches. With the exception of one parotid gland used to add bulk, parotids were generally not included in the allografts. Relevant sensory nerves were coapted. External carotid arteries were dissected, leaving only bilateral facial arteries as the primary arterial supply. All full facial allografts were well perfused immediately following transplantation and are surviving.
The authors describe a new, simple, and reproducible technique of full facial allograft recovery that allows perfusion using only bilateral facial arteries. Their technique follows critical principles of targeted sensory and motor nerve coaptation.
Abstract
Background
The efficacy of facial muscle exercises (FMEs) for facial rejuvenation is controversial. In the majority of previous studies, nonquantitative assessment tools were used to assess ...the benefits of FMEs.
Objectives
This study examined the effectiveness of FMEs using a Pao (MTG, Nagoya, Japan) device to quantify facial rejuvenation.
Methods
Fifty females were asked to perform FMEs using a Pao device for 30 seconds twice a day for 8 weeks. Facial muscle thickness and cross-sectional area were measured sonographically. Facial surface distance, surface area, and volumes were determined using a laser scanning system before and after FME. Facial muscle thickness, cross-sectional area, midfacial surface distances, jawline surface distance, and lower facial surface area and volume were compared bilaterally before and after FME using a paired Student t test.
Results
The cross-sectional areas of the zygomaticus major and digastric muscles increased significantly (right: P < 0.001, left: P = 0.015), while the midfacial surface distances in the middle (right: P = 0.005, left: P = 0.047) and lower (right: P = 0.028, left: P = 0.019) planes as well as the jawline surface distances (right: P = 0.004, left: P = 0.003) decreased significantly after FME using the Pao device. The lower facial surface areas (right: P = 0.005, left: P = 0.006) and volumes (right: P = 0.001, left: P = 0.002) were also significantly reduced after FME using the Pao device.
Conclusions
FME using the Pao device can increase facial muscle thickness and cross-sectional area, thus contributing to facial rejuvenation.
Level of Evidence: 4
Dysfunction of the facial musculature can have significant physical, social, and psychological consequences. In surgeries such as cleft surgery or craniofacial bimaxillary osteotomies, the perioral ...facial muscles may be detached or severed, potentially altering their functional vectors and mimicry capabilities. Ensuring correct reconstruction and maintenance of anatomical sites and muscle vectors is crucial in these procedures. However, a standardized method for perioperative assessment of the facial musculature and function is currently lacking. The aim of this study was to develop a workflow to analyse the three-dimensional vectors of the facial musculature using magnetic resonance imaging (MRI) scans. A protocol for localizing the origins and insertions of these muscles was established. The protocol was implemented using the 3DMedX computer program and tested on 7 Tesla MRI scans obtained from 10 healthy volunteers. Inter- and intra-observer variability were assessed to validate the protocol. The absolute intra-observer variability was 2.6 mm (standard deviation 2.0 mm), and absolute inter-observer variability was 2.6 mm (standard deviation 1.5 mm). This study presents a reliable and reproducible method for analysing the spatial relationships and functional significance of the facial muscles. The workflow developed facilitates perioperative assessment of the facial musculature, potentially aiding clinicians in surgical planning and potentially enhancing the outcomes of midface surgery.
Understanding age-related changes in compartmentalized facial fat and their role in facial dynamics and aesthetics is essential to target filler injections for midface rejuvenation.
A novel ...anatomical approach ("smiling cadavers") was used to identify the main midface fat compartments involved during muscular contraction when smiling and their motion and behavior with and without filler injections. Based on these insights and the literature, a multilayering filler injection approach was developed to optimize midface rejuvenation by restoring fat volumes using rheologically different products injected into different fat compartments.
Twenty-four hemifacial dissections confirmed the presence of two fat compartment layers, separated by the orbicularis oculi muscle in the horizontal plane and by the septa in the vertical plane, and revealed the anatomical effects of facial movement. The midface is composed of deep static fat compartments and a superficial dynamic adipose layer that follows the facial movements, creating a natural dynamic appearance. A proof-of-concept study involved 130 White patients (36 to 56 years; 91 percent women). After the procedure, 95 percent of patients and 98 percent of practitioners rated facial appearance as "improved" or "much/very much improved." No major complications were reported.
The smiling cadavers method enhances understanding of dynamic facial anatomy by showing the superficial and deep fat compartments of the midface at rest and their motion during a procedure to represent a smile. The multilayered injection technique takes into account these anatomical findings to rejuvenate the midface, achieving a natural appearance at rest and during motion.
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