Orbicularis oculi muscle activity during computer reading under different degrees of artificially-induced aniseikonia.

Background: Aniseikonia is a binocular vision disorder that has been associated with asthenopic symptoms. However, asthenopia has been evaluated with subjective tests that make difficult to determine the level of aniseikonia. This study aims to objectively evaluate the impact of induced aniseikonia at different levels on visual fatigue by measuring the orbicularis oculi muscle activity in the dominant and non-dominant eyes while performing a reading task. Methods: Twenty-four collegiate students (24.00 ± 3.86 years) participated in this study. Participants read a passage for 7 minutes under four degrees of aniseikonia (0%, 3%, 5% and 10%) at 50 cm. Orbicularis oculi muscle activity of the dominant and non-dominant eye was recorded by surface electromyography. In addition, visual discomfort was assessed after each task by completing a questionnaire. Results: Orbicularis oculi muscle activity increased under induced aniseikonia (i.e., greater values for the 10% condition in comparison to 0%, and 3% conditions (p = 0.034 and p = 0.023, respectively)). No statistically significant differences were observed in orbicularis oculi muscle activity for the time on task and between the dominant and non-dominant eyes. Additionally, higher levels of subjective visual discomfort were observed for lower degrees of induced aniseikonia. Conclusion: Induced aniseikonia increases visual fatigue at high aniseikonia degrees as measured by the orbicularis oculi muscle activity, and at low degrees as measured with subjective questionnaires. These findings may be of relevance to better understand the visual symptomatology of aniseikonia.

Why do marionette lines appear? Exploring the anatomical perspectives and role of thread-based interventions.

The pathogenesis of marionette lines involves a complex interplay of anatomical, physiological, and age-related factors leading to the development of wrinkles around the oral commissures. This exploration delves into the distinct anatomical predispositions observed among different ethnicities, emphasizing the role of compact modiolus structures and muscle compositions. Notably, individuals of East Asian descent exhibit inherent facial structures that predispose them to pronounced sagging around the oral commissures during aging. The emergence of distinct facial lines, such as the commissural line and the melolabial fold, contributes to the formation of marionette lines. This specific wrinkle pattern, resembling a marionette puppet's mouth contours, is influenced by various factors like bone resorption, gravitational forces, fat compartment variations, muscle compression, ligament tethering, and skin aging. Treatment strategies for marionette lines encompass diverse interventions, including filler injections, botulinum neurotoxin, surgeries targeting fat reduction, thread lifting, and volumizing fillers. These approaches aim to address the underlying causes and mitigate the appearance of marionette lines. Botulinum neurotoxin injections, for instance, weaken specific facial muscles, reducing downward strain and aiding in tissue retraction. Anatomical considerations during procedures are crucial to avoid nerve or vascular damage. Delicate manipulation and precise entry points are essential to prevent inadvertent injuries, particularly concerning blood vessels like the facial artery and nerves like the mental nerve. Technical guidelines for procedures targeting marionette lines involve specific techniques like cogged thread reverse methods and volumizing thread placements. Attention to entry points, tissue engagement, and the direction of threads is crucial for effective treatment outcomes, minimizing complications, and ensuring patient safety.

Electrical stimulation of the lower eyelid orbicularis oculi muscle improves periocular dark circles.

BACKGROUND: We developed and tested the safety and efficacy of a cosmetic device to improve dark circles using electrical muscle stimulation of the orbicularis oculi muscle. METHODS: Overall, 18 participants (36 eyes) were studied. The following five items were evaluated before and after the intervention:(1) the Clinical Dark Circle Score using clinical findings and photographs, (2) transcutaneous oxygen partial pressure (TcPO2) on the lower eyelid, (3) thermography, (4) two-dimensional laser blood flowmetry, and (5) spectrophotometry. RESULTS: The mean score at baseline was 2.0 ± 0.90 (mean ± standard deviation), and that at the end of the study was 1.2 ± 1.0 (Wilcoxon signed-rank sum test, p < 0.0001), indicating a significant reduction. The spectrophotometer showed a significant decrease in a* and L* values before and after use (Wilcoxon signed-rank sum test, p < 0.0001). There was also a weak negative correlation between the change in score and the change in blood flow and TcPO2 measured using a laser perfusion device (Spearman's rank correlation coefficient, r = -0.32 and -0.39, respectively). Stratified analysis of the baseline score showed a strong negative correlation between the change in score and the change in spectrophotometric a* in the subjects/group with mild periocular dark circles (Spearman's rank correlation coefficient, r = -0.46). Contrastingly, no correlation was observed for any of the measurements in the subjects/group with severe periocular dark circles. After 1 month, no device-related ophthalmic adverse events were observed in any of the participants. CONCLUSION: Electrical muscle stimulation could improve periocular dark circles, especially in the subjects/group with mild periocular dark circles, and was safe.

Reading of ingroup politicians' smiles triggers smiling in the corner of one's eyes.

Spontaneous smiles in response to politicians can serve as an implicit barometer for gauging electorate preferences. However, it is unclear whether a subtle Duchenne smile-an authentic expression involving the coactivation of the zygomaticus major (ZM) and orbicularis oculi (OO) muscles-would be elicited while reading about a favored politician smiling, indicating a more positive disposition and political endorsement. From an embodied simulation perspective, we investigated whether written descriptions of a politician's smile would trigger morphologically different smiles in readers depending on shared or opposing political orientation. In a controlled reading task in the laboratory, participants were presented with subject-verb phrases describing left and right-wing politicians smiling or frowning. Concurrently, their facial muscular reactions were measured via electromyography (EMG) recording at three facial muscles: the ZM and OO, coactive during Duchenne smiles, and the corrugator supercilii (CS) involved in frowning. We found that participants responded with a Duchenne smile detected at the ZM and OO facial muscles when exposed to portrayals of smiling politicians of same political orientation and reported more positive emotions towards these latter. In contrast, when reading about outgroup politicians smiling, there was a weaker activation of the ZM muscle and no activation of the OO muscle, suggesting a weak non-Duchenne smile, while emotions reported towards outgroup politicians were significantly more negative. Also, a more enhanced frown response in the CS was found for ingroup compared to outgroup politicians' frown expressions. Present findings suggest that a politician's smile may go a long way to influence electorates through both non-verbal and verbal pathways. They add another layer to our understanding of how language and social information shape embodied effects in a highly nuanced manner. Implications for verbal communication in the political context are discussed.

The three layered structure of orbicularis oris and buccinator complex with partial connection at the modiolus and partial direct continuation.

PURPOSE: This study aimed to clarify the structural arrangement of the orbicularis oris (OOr), the buccinator, and the other perioral muscles around the modiolus. METHODS: The perioral muscles in seventeen cadavers fixed with formalin were dissected in situ and/or in isolated muscle specimens, and their layers were reconstructed schematically upon pantomographic view of the skeleton to evaluate their actions. RESULTS: The buccinator was composed of three parts including upper and lower oblique parts in its superficial layer and a middle transverse part in its deep layer. The superior and inferior OOr were composed of an inner marginal part (IM) and an outer labial part (OL) in each. The perioral muscles as a whole were arranged in three layers. The first layer consisted of the depressor anguli oris and the OL of superior OOr connected at the modiolus in a vertical direction. The second layer consisted of the upper and inner oblique part of buccinator and a part of the OL of inferior OOr connected at the modiolus in a horizontal direction. The third layer contained the middle transverse part of buccinator continuous with the IM of both OOr and a part of the OL of inferior OOr without connection to the modiolus. CONCLUSIONS: The different arrangement of the three layers of perioral muscles around the modiolus could serve as a good basis to predict the actions of the individual perioral muscles on the movement of lips in open/close of the oral fissure and widening/narrowing of the lip width.

Developmental, Physiological and Phylogenetic Perspectives on the Expression and Regulation of Myosin Heavy Chains in Craniofacial Muscles.

This review deals with the developmental origins of extraocular, jaw and laryngeal muscles, the expression, regulation and functional significance of sarcomeric myosin heavy chains (MyHCs) that they express and changes in MyHC expression during phylogeny. Myogenic progenitors from the mesoderm in the prechordal plate and branchial arches specify craniofacial muscle allotypes with different repertoires for MyHC expression. To cope with very complex eye movements, extraocular muscles (EOMs) express 11 MyHCs, ranging from the superfast extraocular MyHC to the slowest, non-muscle MyHC IIB (nmMyH IIB). They have distinct global and orbital layers, singly- and multiply-innervated fibres, longitudinal MyHC variations, and palisade endings that mediate axon reflexes. Jaw-closing muscles express the high-force masticatory MyHC and cardiac or limb MyHCs depending on the appropriateness for the acquisition and mastication of food. Laryngeal muscles express extraocular and limb muscle MyHCs but shift toward expressing slower MyHCs in large animals. During postnatal development, MyHC expression of craniofacial muscles is subject to neural and hormonal modulation. The primary and secondary myotubes of developing EOMs are postulated to induce, via different retrogradely transported neurotrophins, the rich diversity of neural impulse patterns that regulate the specific MyHCs that they express. Thyroid hormone shifts MyHC 2A toward 2B in jaw muscles, laryngeal muscles and possibly extraocular muscles. This review highlights the fact that the pattern of myosin expression in mammalian craniofacial muscles is principally influenced by the complex interplay of cell lineages, neural impulse patterns, thyroid and other hormones, functional demands and body mass. In these respects, craniofacial muscles are similar to limb muscles, but they differ radically in the types of cell lineage and the nature of their functional demands.

Identification of the Biomechanical Response of the Muscles That Contract the Most during Disfluencies in Stuttered Speech.

Stuttering, affecting approximately 1% of the global population, is a complex speech disorder significantly impacting individuals' quality of life. Prior studies using electromyography (EMG) to examine orofacial muscle activity in stuttering have presented mixed results, highlighting the variability in neuromuscular responses during stuttering episodes. Fifty-five participants with stuttering and 30 individuals without stuttering, aged between 18 and 40, participated in the study. EMG signals from five facial and cervical muscles were recorded during speech tasks and analyzed for mean amplitude and frequency activity in the 5-15 Hz range to identify significant differences. Upon analysis of the 5-15 Hz frequency range, a higher average amplitude was observed in the zygomaticus major muscle for participants while stuttering (p < 0.05). Additionally, when assessing the overall EMG signal amplitude, a higher average amplitude was observed in samples obtained from disfluencies in participants who did not stutter, particularly in the depressor anguli oris muscle (p < 0.05). Significant differences in muscle activity were observed between the two groups, particularly in the depressor anguli oris and zygomaticus major muscles. These results suggest that the underlying neuromuscular mechanisms of stuttering might involve subtle aspects of timing and coordination in muscle activation. Therefore, these findings may contribute to the field of biosensors by providing valuable perspectives on neuromuscular mechanisms and the relevance of electromyography in stuttering research. Further research in this area has the potential to advance the development of biosensor technology for language-related applications and therapeutic interventions in stuttering.

Treatment Approaches for Altered Facial Expression: A Systematic Review in Facioscapulohumeral Muscular Dystrophy and Other Neurological Diseases.

Background: Facial weakness is a key feature of facioscapulohumeral muscular dystrophy (FSHD) and may lead to altered facial expression and subsequent psychosocial impairment. There is no cure and supportive treatments focus on optimizing physical fitness and compensation of functional disabilities. Objective: We hypothesize that symptomatic treatment options and psychosocial interventions for other neurological diseases with altered facial expression could be applicable to FSHD. Therefore, the aim of this review is to collect symptomatic treatment approaches that target facial muscle function and psychosocial interventions in various neurological diseases with altered facial expression in order to discuss the applicability to FSHD. Methods: A systematic search was performed. Selected studies had to include FSHD, Bell's palsy, Moebius syndrome, myotonic dystrophy type 1, or Parkinson's disease and treatment options which target altered facial expression. Data was extracted for study and patients' characteristics, outcome assessment tools, treatment, outcome of facial expression and or psychosocial functioning. Results: Forty studies met the inclusion criteria, of which only three studies included FSHD patients exclusively. Most, twenty-one, studies were performed in patients with Bell's palsy. Studies included twelve different therapy categories and results were assessed with different outcomes measures. Conclusions: Five therapy categories were considered applicable to FSHD: training of (non-verbal) communication compensation strategies, speech training, physical therapy, conference attendance, and smile restoration surgery. Further research is needed to establish the effect of these therapies in FSHD. We recommend to include outcome measures in these studies that cover at least cosmetic, functional, communication, and quality of life domains.

Treatment with synchronized radiofrequency and facial muscle stimulation: Histologic analysis of human skin for changes in collagen and elastin fibers.

BACKGROUND: Skin's exposure to intrinsic and extrinsic factors causes age-related changes, leading to a lower amount of dermal collagen and elastin. AIM: This study investigated the effects of a novel facial muscle stimulation technology combined with radiofrequency (RF) heating on dermal collagen and elastin content for the treatment of facial wrinkles and skin laxity. METHODS: The active group subjects (N = 6) received four 20-min facial treatments with simultaneous RF and facial muscle stimulation, once weekly. The control subject (N = 1) was untreated. Skin biopsies obtained at baseline, 1-month and 3-month follow-up were evaluated histologically to determine collagen and elastin fibers content. A group of independent aestheticians evaluated facial skin appearance and wrinkle severity. Patient safety was followed. RESULTS: In the active group, collagen-occupied area reached 11.91 ± 1.80 × 106 µm2 (+25.32%, p < 0.05) and 12.35 ± 1.44 × 105 µm2 (+30.00%, p < 0.05) at 1-month and 3-month follow-up visits. Elastin-occupied area at 1-month and 3-month follow-up was 1.64 ± 0.14 × 105 µm2 (+67.23%, p < 0.05), and 1.99 ± 0.21 × 105 µm2 (+102.80%, p < 0.05). In the control group, there was no significant difference (p > 0.05) in collagen and elastin fibers. Active group wrinkle scores decreased from 5 (moderate, class II) to 3 (mild, class I). All subjects, except the control, improved in appearance posttreatment. No adverse events or side effects occurred. CONCLUSION: Decreased dermal collagen and elastin levels contributes to a gradual decline in skin elasticity, leading to facial wrinkles and unfirm skin. Study results showed noticeable improvement in facial appearance and increased dermal collagen and elastin content subsequent to simultaneous, noninvasive RF, and facial muscle stimulation treatments.

Long-term results of orbicularis oris muscle reconstruction in primary cleft lip repair using the "basket-weave method".

The basket-weave method is an orbicularis oris muscle reconstruction method used in primary unilateral cleft lip repair. We compared the long-term results of the basket-weave method with those of a conventional method. For primary unilateral cleft lip repair, we compared the long-term results of 7 cases in which the orbicularis oris muscle was reconstructed by use of the basket-weave method, and of 7 cases in which the reconstruction was performed by use of the conventional method. The average postoperative follow-up period was 12 years and 7 months for the basket-weave method, and 11 years and 9 months for the conventional method. Using photographs of the front and elevation angle views, we evaluated the results as good if the philtrum ridge was formed on the fissure side and was almost symmetrical in height; as fair if the philtrum ridge was lower than the normal side; and as poor if the philtrum ridge had disappeared. For the basket-weave method, the results were good in 6 cases (85.7%), fair in 1 case (14.3%), and poor in 0 cases. For the conventional method, the results were good in 2 cases (28.6%), fair in 4 cases (57.1%), and poor in 1 case (14.3%). A significant difference was found between the 2 groups (Mann-Whitney U test, P = 0.0417). The philtrum ridge shape could be reconstructed by use of the basket-weave method, which gave better results in the long-term than did the conventional method for orbicularis oris muscle reconstruction in primary unilateral cleft lip repair.

SMAS repositioning technique utilizing cog thread: Anatomical perspectives.

INTRODUCTION: Face-lifting surgeries were once common among individuals over 60 years old due to skin laxity, but recent trends favor thread lifting in this age group. Understanding dynamic changes in facial anatomy during postural shifts is essential. METHOD: Fresh cadaver studies have demonstrated the passage of threads through the superficial musculoaponeurotic system (SMAS) layer, confirming the efficacy of the technique. Proper insertion depth targeting SMAS repositioning, rather than superficial skin layers, is crucial. RESULT: The natural movement of tissues secured by thread (N-Cog and N-Fix, N-Finders Inc., Korea) insertion results in lifting effects. However, complications may arise if threads affect deeper facial muscles, leading to discomfort. Fibrous septa play a significant role in guiding thread placement, with different densities influencing thread maneuverability and tissue response during lifting. CONCLUSION: Procedures targeting SMAS repositioning using threads aim to maintain the new position of relocated tissues. Understanding structural variations in facial regions informs thread selection and placement. Aligning threads with tissue movement and the intended SMAS layer positioning is vital to prevent complications. Balancing thread insertion depth and tissue traction is critical for successful outcomes. Modern thread lifting techniques prioritize SMAS repositioning, enhancing lifting effects while ensuring procedure safety and efficacy.

Machine Learning-Based Interpretable Modeling for Subjective Emotional Dynamics Sensing Using Facial EMG.

Understanding the association between subjective emotional experiences and physiological signals is of practical and theoretical significance. Previous psychophysiological studies have shown a linear relationship between dynamic emotional valence experiences and facial electromyography (EMG) activities. However, whether and how subjective emotional valence dynamics relate to facial EMG changes nonlinearly remains unknown. To investigate this issue, we re-analyzed the data of two previous studies that measured dynamic valence ratings and facial EMG of the corrugator supercilii and zygomatic major muscles from 50 participants who viewed emotional film clips. We employed multilinear regression analyses and two nonlinear machine learning (ML) models: random forest and long short-term memory. In cross-validation, these ML models outperformed linear regression in terms of the mean squared error and correlation coefficient. Interpretation of the random forest model using the SHapley Additive exPlanation tool revealed nonlinear and interactive associations between several EMG features and subjective valence dynamics. These findings suggest that nonlinear ML models can better fit the relationship between subjective emotional valence dynamics and facial EMG than conventional linear models and highlight a nonlinear and complex relationship. The findings encourage emotion sensing using facial EMG and offer insight into the subjective-physiological association.

Topographic mapping of the sensorimotor qualities of empathic reactivity: A psychophysiological study in people with spinal cord injuries.

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.

Zygomaticus activation through facial neuromuscular electrical stimulation (fNMES) induces happiness perception in ambiguous facial expressions and affects neural correlates of face processing.

The role of facial feedback in facial emotion recognition remains controversial, partly due to limitations of the existing methods to manipulate the activation of facial muscles, such as voluntary posing of facial expressions or holding a pen in the mouth. These procedures are indeed limited in their control over which muscles are (de)activated when and to what degree. To overcome these limitations and investigate in a more controlled way if facial emotion recognition is modulated by one's facial muscle activity, we used computer-controlled facial neuromuscular electrical stimulation (fNMES). In a pre-registered EEG experiment, ambiguous facial expressions were categorised as happy or sad by 47 participants. In half of the trials, weak smiling was induced through fNMES delivered to the bilateral Zygomaticus Major muscle for 500 ms. The likelihood of categorising ambiguous facial expressions as happy was significantly increased with fNMES, as shown with frequentist and Bayesian linear mixed models. Further, fNMES resulted in a reduction of P1, N170 and LPP amplitudes. These findings suggest that fNMES-induced facial feedback can bias facial emotion recognition and modulate the neural correlates of face processing. We conclude that fNMES has potential as a tool for studying the effects of facial feedback.

Anatomical and Ultrasonographic Analyses of the Levator Labii Superioris Alaeque Nasi Muscle at the Level of the Nasal Ala / Análisis Anatómico y Ecográfico del Músculo Elevador Nasolabial a Nivel del Ala Nasal

SUMMARY: We aimed to determine the width of the levator labii superioris alaeque nasi muscle (LLSAN) at the level of the nasal ala through cadaveric dissections and ultrasonography (US), to provide essential anatomical information for use during both invasive and noninvasive procedures in the nasal ala region. The LLSAN was investigated in the 40 hemifaces of 20 Korean cadavers, comprising 10 males and 10 females with a mean age of 73.6 years. The LLSAN width of the 40 specimens at the level of the midpoint of the nasal ala was 5.02±2.35 mm (mean±standard deviation), and ranged from 1.45 mm to 10.11 mm. The LLSAN widths were 5.96±2.36 mm and 3.93±1.89 mm in males and females, respectively, with ranges of 2.40-10.11 mm and 1.45-6.96 mm, respectively. The LLSAN widths on the left and right sides were 4.77±2.72 mm and 5.26±1.99 mm, respectively. The proportions of the LLSAN fibers inserting into the nasal ala and upper lip were similar in 13 specimens (32.5 %), while more fibers inserted into the nasal ala in 11 specimens (27.5 %) and more fibers inserted fibers of the LLSAN into the upper lip in 16 specimens (40 %). When clinicians need to target or avoid the LLSAN, the present width and range data can be helpful for ensuring the efficacy and safely of both invasive and noninvasive procedures. In addition, the possibility of asymmetry in the width of the LLSAN in the nasal ala region should be confirmed by US before performing such procedures.

Nuestro objetivo fue determinar el ancho del músculo elevador nasolabial (MENL) a nivel del ala nasal mediante disecciones cadavéricas y ecografía, para proporcionar información anatómica esencial, para su uso durante procedimientos invasivos y no invasivos, en la región del ala nasal. El MENL se estudió en 40 hemicaras de 20 cadáveres coreanos (10 hombres y 10 mujeres) con una edad media de 73,6 años. El ancho de MENL de las 40 muestras a nivel del punto medio del ala nasal fue de 5,02 ± 2,35 mm (media ± desviación estándar) y osciló entre 1,45 mm y 10,11 mm. Los anchos de MENL fueron 5,96 ± 2,36 mm y 3,93 ± 1,89 mm en hombres y mujeres, respectivamente, con rangos de 2,40 a 10,11 mm y 1,45 a 6,96 mm, respec- tivamente. Los anchos de MENL en los lados izquierdo y derecho fueron 4,77 ± 2,72 mm y 5,26 ± 1,99 mm, respectivamente. Las proporciones de fibras de MENL que se insertaban en el ala nasal y en el labio superior fueron similares en 13 muestras (32,5 %), mientras que se insertaron más fibras en el ala nasal en 11 muestras (27,5 %) y además, se insertaron fibras de MENL en el labio superior en 16 ejemplares (40 %). Cuando los médicos necesitan apuntar o evitar el MENL, los datos actuales de ancho y rango pueden ser útiles para garantizar la eficacia y seguridad de los procedimientos, tanto invasivos como no invasivos. Además, la ecografía puede ser utilizada para confirmar una posible asimetría en el ancho del MENL en la región del ala nasal antes de realizar los procedimientos.

Facial electromyography during exercise using soft electrode array: A feasibility study.

The use of wearable sensors for real-time monitoring of exercise-related measures has been extensively studied in recent years (e.g., performance enhancement, optimizing athlete's training, and preventing injuries). Surface electromyography (sEMG), which measures muscle activity, is a widely researched technology in exercise monitoring. However, due to their cumbersome nature, traditional sEMG electrodes are limited. In particular, facial EMG (fEMG) studies in physical training have been limited, with some scarce evidence suggesting that fEMG may be used to monitor exercise-related measurements. Altogether, sEMG recordings from facial muscles in the context of exercise have been examined relatively inadequately. In this feasibility study, we assessed the ability of a new wearable sEMG technology to measure facial muscle activity during exercise. Six young, healthy, and recreationally active participants (5 females), performed an incremental cycling exercise test until exhaustion, while facial sEMG and vastus lateralis (VL) EMG were measured. Facial sEMG signals from both natural expressions and voluntary smiles were successfully recorded. Stable recordings and high-resolution facial muscle activity mapping were achieved during different exercise intensities until exhaustion. Strong correlations were found between VL and multiple facial muscles' activity during voluntary smiles during exercise, with statistically significant coefficients ranging from 0.80 to 0.95 (p<0.05). This study demonstrates the feasibility of monitoring facial muscle activity during exercise, with potential implications for sports medicine and exercise physiology, particularly in monitoring exercise intensity and fatigue.

Automatic labeling of facial zones for digital clinical application: An ensemble of semantic segmentation models.

INTRODUCTION: The application of artificial intelligence to facial aesthetics has been limited by the inability to discern facial zones of interest, as defined by complex facial musculature and underlying structures. Although semantic segmentation models (SSMs) could potentially overcome this limitation, existing facial SSMs distinguish only three to nine facial zones of interest. METHODS: We developed a new supervised SSM, trained on 669 high-resolution clinical-grade facial images; a subset of these images was used in an iterative process between facial aesthetics experts and manual annotators that defined and labeled 33 facial zones of interest. RESULTS: Because some zones overlap, some pixels are included in multiple zones, violating the one-to-one relationship between a given pixel and a specific class (zone) required for SSMs. The full facial zone model was therefore used to create three sub-models, each with completely non-overlapping zones, generating three outputs for each input image that can be treated as standalone models. For each facial zone, the output demonstrating the best Intersection Over Union (IOU) value was selected as the winning prediction. CONCLUSIONS: The new SSM demonstrates mean IOU values superior to manual annotation and landmark analyses, and it is more robust than landmark methods in handling variances in facial shape and structure.

A Case Series of Isolated Smiling Tremor: What Is the Phenomenology?

BACKGROUND: Five cases of tremor only upon smiling have been reported where no facial tremor is present at rest, when talking, or with full smile. CASES: This report highlights four cases of tremor upon partial smiling, discusses the phenomenology of smiling tremor, and reviews the current literature. Four subjects with lower facial tremor present only upon smiling underwent movement disorders evaluation with video. Tremor frequencies were determined by parsing the video clips into 1-second intervals and averaging the number of oscillations per interval and were determined to be high-frequency 8 to 10 Hz irregular facial tremors with harmonic variations upon moderate effort in all cases. Slight or full-effort smiling did not elicit facial muscle oscillations. Subjects had no other signs of tremor, dystonia, or parkinsonism on examination or in family history. CONCLUSIONS: Tremor upon smiling only, or isolated smiling tremor, is a unique task- and position-specific tremor of the facial musculature.

Morphofunctional and histological patterns of blood vessels in the superficial cervicofacial musculoaponeurotic system in midlateral face regions.

OBJECTIVE: The superficial cervicofacial musculoaponeurotic system (SMAS) is a complex network formed by mimic muscles and conjunctive tissue of the superficial fascia of the face.This study aimed to introduce new anatomofunctional data on the importance of the trans-SMAS distribution pattern of the skin microperfusion of the face and to underline the role of SMAS in maintaining the homeostasis of the vascular network that crosses it. Considering the fibrous and muscular matrix of the SMAS, using COLIII and MyoH2 antibodies, together with endothelial immunohistochemistry(IHC)intercellular adhesion molecule 2 marker, we determined the correlation of these structures and their interaction. METHODS: This study included 33donors of SMAS tissues, which have been stained withregular hematoxylin and eosin (HE), and three different IHC markers have been used (collagen III, muscular tissue, and blood vessels). The samples were collected from parotid, masseteric, jugal, and zygomatic regions. Magnetic resonance angiography was used to identify the main vascular sources of the midlateral regions of the face of another 47 patients. RESULTS: Significant differences in topographic arrangement, density, and relations of the microsopic vasculature were observed between each of the four regions. Major differences were identified between the role of SMAS in each of these regions, from the parotid capsule to masseteric fascia, transition mobile part, and attaching manners in the zygomatic subunit. CONCLUSIONS: Blood vessel topography must be related with the surrounding conjunctive and muscular tissue, especially regarding facial SMAS. Intrinsic relations between these three components of the SMAS and nervous fibers can provide us important hints on the functionality of the whole system.

Optimizing Botulinum Toxin A Administration for Forehead Wrinkles: Introducing the Lines and Dots (LADs) Technique and a Predictive Dosage Model.

This study introduces the Lines and Dots (LADs) technique, a new approach for administering botulinum toxin type A (BoNT-A) in treating forehead wrinkles. (1) Background: BoNT-A application patterns in the forehead often rely solely on the anatomy of the frontalis muscle. The LADs technique proposes a combination of anatomical features with nerve pathways. (2) Methods: The technique employed a grid system aligned with the supraorbital and supratrochlear nerve pathways and used an electronic acupuncture pen for validation. This study analyzed treatment outcomes for efficacy and safety and proposed a predictive model for BoNT-A dosage. (3) Results: LADs was associated with a high satisfaction rate and low side effect incidence. The predictive model followed BoNT-A Units=0.322×Muscle Pattern Code+1.282×Line Type Code+2.905×Severity Pre-Treatment+3.947. (4) Conclusions: The LADs technique offers an alternative approach to treating forehead wrinkles, optimizing efficacy while minimizing the BoNT-A dose required.