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Crow's feet lines in the lateral canthal region are a common concern among aging patients, initially appearing as dynamic wrinkles during facial expressions and becoming more pronounced with age. Botulinum neurotoxin temporarily paralyzes muscles by inhibiting acetylcholine release, smoothing wrinkles and enhancing skin's youthful appearance. Effective treatment requires tailored approaches considering individual anatomy and muscle activity. Recent cadaveric studies identified the tear trough muscle, emphasizing its role in infraorbital support and aging. Clinically, patients often present medial eye wrinkles after BoNT treatment for crow's feet, prompting exploration of underlying mechanisms and management strategies. Three cases demonstrated that medial BoNT injections in the orbicularis oculi muscle significantly improve medial eye wrinkles and tear trough appearance. The study underscores the importance of understanding muscle hyperactivity and anatomical variations for precise treatment. Enhanced injection techniques targeting specific areas can achieve better outcomes and minimize complications, particularly in culturally sensitive regions where facial expressions are valued. This research highlights the necessity for comprehensive anatomical knowledge and patient‐specific treatment strategies to address medial eye wrinkles effectively. [ABSTRACT FROM AUTHOR]

Background: The superficial musculoaponeurotic system (SMAS) is crucial for the structural integrity and dynamics of facial expressions and is a particularly important consideration during facelift surgeries. This study investigated the anatomical structure and continuity of the SMAS at the site where the zygomaticus major (Zmj) originates, which is where the SMAS extends from the lateral to the anterior aspects of the face. Knowledge of these aspects is crucial for understanding the mechanics of facial movements and also the aging process. Methods: Dissections of 66 specimens and histological analyses were used to explore the intricate relationships and attachments between the SMAS and facial muscles. Results: The findings indicated that at the Zmj origin site, the SMAS—connected to the inferior margin of the orbicularis oculi—covered the superficial surface of the Zmj fibers. As it tracked downward, the SMAS was observed to split into two layers lateral to the Zmj fibers, enveloping them both superficially and deeply. Additionally, as the SMAS continued forward, it ceased to be distinctly visible in the buccal area. Conclusions: These results provide a deeper understanding of the complex layering and interconnectivity of the SMAS, which supports facial dynamics and structural integrity. This information could be particularly useful in surgical and aesthetic procedures in the midfacial area. [ABSTRACT FROM AUTHOR]

We aimed to review the degree of standardization of frontalis muscle (FM)–orbicularis muscle advancement techniques in the management of severe congenital blepharoptosis and also study the evidence which supports the procedure correcting blepharoptosis. The undisputed rationale of all types of brow suspension in the management of severe blepharoptosis is based on the concept that slings are the conventional way to simultaneously suspend a ptotic eyelid and transmit the contractile action of the FM to the tarsal plate. Traditionally, frontalis suspension using sling has been used to treat patients with severe congenital blepharoptosis with poor levator function; however, postoperative lagophthalmos, forehead scarring, and recurrence remain major concerns. Since the early 80s, a significant number of consecutive articles have suggested that the eyelid can be effectively suspended by directly suturing FM to the tarsal plate. This review article intends to evaluate the level of standardization of FM advancement techniques in the management of severe blepharoptosis. 'In addition, to determine if the procedure should be performed in a standard manner, and is there enough evidence available to recommend FM advancement as a useful surgical technique.

Objective To explore a surgical method for the naturally dynamic double eyelid by advance and fix the levator aponeurosis flap or pretarsal fascia flap through the window of oribicularis oculi. Methods From July 2018 to January 2020, oribicularis oculi fenestration blepharoplasty were performed on 286 patients. Orbicularis oculi muscle in incisional area were completely exposed, then three 2 mm×2 mm orbicularis oculi muscle (at medial, middle and lateral ) were romoved to form windows. The levator aponeurosisor pretarsal fascia exposed in the windows, forming the levator aponeurosis flap or pretarsal fascia flap, then sutured from lower skin, lower orbicularis oculi muscle, levator aponeurosis flap or pretarsal fascia flap to upper skin in windows respectively, the other parts were sutrued lower skin with upper skin. Results All 286 patients were took out the sutures after 7 days. With up to 12 to 24 months follow-up, the new double eyelid presented smooth appearance, no obvious concave groove or step-like deformity when eyes closed. Satisfaction evaluation: 280 patients were satisfied with the outcomes, 6 patients were not satisfied. Three patients complained about asymmetry. Three patients had shallower supratarsal folds. The patients' satisfaction rate was 97.9%. Conclusion Oribicularis oculi fenestration blepharoplasty is a stable, lasting, scarless approach for natural and dynamic double-eyelid blepharoplasty. [ABSTRACT FROM AUTHOR]

Background: The superficial musculoaponeurotic system (SMAS) is crucial for the structural integrity and dynamics of facial expressions and is a particularly important consideration during facelift surgeries. This study investigated the anatomical structure and continuity of the SMAS at the site where the zygomaticus major (Zmj) originates, which is where the SMAS extends from the lateral to the anterior aspects of the face. Knowledge of these aspects is crucial for understanding the mechanics of facial movements and also the aging process. Methods: Dissections of 66 specimens and histological analyses were used to explore the intricate relationships and attachments between the SMAS and facial muscles. Results: The findings indicated that at the Zmj origin site, the SMAS—connected to the inferior margin of the orbicularis oculi—covered the superficial surface of the Zmj fibers. As it tracked downward, the SMAS was observed to split into two layers lateral to the Zmj fibers, enveloping them both superficially and deeply. Additionally, as the SMAS continued forward, it ceased to be distinctly visible in the buccal area. Conclusions: These results provide a deeper understanding of the complex layering and interconnectivity of the SMAS, which supports facial dynamics and structural integrity. This information could be particularly useful in surgical and aesthetic procedures in the midfacial area.

Background: Even though upper blepharoplasty is one of the most commonly performed procedures in esthetic surgery, there is still no consensus regarding the management of the orbicularis oculi muscle (OOM). Aim: To compare outcomes of upper eyelid blepharoplasty with or without OOM excision using surface electromyography in a 12 month follow-up. Methods: A prospective, randomized, single-blinded comparative split-face study was conducted on 26 patients with dermatochalasis. Skin-only upper blepharoplasty was performed on a randomly selected side, and on the contralateral side, a strip of OOM was resected as well. The functional outcomes were assessed using sEMG, and the esthetics were evaluated independently by the operating surgeon, blinded patients, and three blinded ophthalmic surgeons. Results: The RMS values of maximal contraction of the OOM were statistically significantly lower two weeks after blepharoplasty than the values before surgery in both groups (p < 0,001) and reached the preoperative values after six months. Lagophthalmos occurred in 2 cases in the skin-muscle group (7.69%), and no incidence of lagophthalmos was observed in the skin group. There were comparable esthetic outcomes on both operated sides. Conclusions: This study is an objective and quantitative report using surface electromyography on upper blepharoplasty with or without a strip of OOM excision. Our results showed that OOM fully recovers after the stripping procedure. The resection of the skin-OOM flap showed no difference in long-term cosmetic results. Therefore, we recommend OOM preservation during upper blepharoplasty unless muscle excision is well-grounded. [ABSTRACT FROM AUTHOR]

Objectives: Benign essential blepharospasm (BEB) is a focal dystonia characterized by involuntary contractions of the orbicularis oculi and periocular muscles. We aimed to investigate the effects of muscle receptor levels on the etiopathogenesis of blepharospasm by evaluating the orbicularis oculi estrogen receptor (ER) and androgen receptor (AR) levels. Methods: Four blepharospasm patients (2 females and 2 males) who underwent upper lid blepharoplasty and/or orbicularis myomectomy and 4 healthy cases (2 females, 2 males) that had upper lid blepharoplasty were included. The pretarsal, preseptal, and orbital parts of the orbicularis muscles of the patients who underwent orbicularis myomectomy and the waste muscle tissue materials taken from the preseptal orbicularis muscles of the patients who had only upper blepharoplasty were analyzed. Immunohistochemical staining was performed with estrogen alpha and androgen. Results: In healthy men, the orbicularis oculi muscle was stained with ER at a moderate intensity and with AR at a high intensity. In men with blepharospasm, the orbicularis oculi were not stained with ER at all, but at a high intensity with AR. In healthy women, the orbicularis oculi were stained with ER and AR at a high intensity (>50%). In women with blepharospasm, the staining intensities of both receptors were moderate. Conclusion: We determined a decrease in ER and AR in females and almost the absence of ER in males with BEB. This decrease in ER may be associated with a functional abnormality in mitochondria and the decrease in hormonal receptors may be associated with sarcopenia in orbicularis oculi muscle fibers. [ABSTRACT FROM AUTHOR]

The orbicularis oculi (OOc) is a sphincteric muscle of the eyelids, whereas contraction of the orbicularis oris (OOr), another sphincteric muscle, causes narrowing of the lips. Facial muscle fibers normally blend with adjacent muscles. However, muscle fibers connecting the various facial muscles that have different actions and that are located at distant sites, such as the OOc and the OOr have been rarely reported. Herein, we report a rare case of connecting fibers between the inferior margin of the OOc and the OOr. These connecting fibers were blended with the OOr between the inserting fibers of the levator labii superioris and levator anguli oris. Contraction of such variant muscles might affect typical facial expressions. [ABSTRACT FROM AUTHOR]

This study aimed to determine the anatomical connections between the inferior fibers of M. orbicularis oculi (OOc inf.) and the M. levator labii superioris alaeque nasi (LLSAN), providing anatomical variations of the connecting fibers. This study examined the OOc and LLSAN of 44 specimens from 22 embalmed adult Korean cadavers. Connecting fibers between the OOc inf. and LLSAN were observed in 29.5 % of the specimens. Connecting patterns of the OOc inf. to the LLSAN were classified into three categories according to the directions of the connecting fibers; Type I (13.6 %), in which some of the OOc inf. coursed medially to blend with the lateral originating fibers of the LLSAN. Type II (11.4 %), in which some of the OOc inf. descended vertically to blend with the LLSAN. Type III (4.5 %), in which both types I and II were found simultaneously. Some of the OOc inf. coursed medially to blend with the lateral originating fibers of the LLSAN, and some of the OOc inf. descended vertically to blend with the LLSAN. These findings provide greater knowledge of the connecting fibers between the OOc inf. and LLSAN, thereby helping us understand complicated expressions, inject BoNT-A into related wrinkles, and analyze EMG activities. [ABSTRACT FROM AUTHOR]

Many surgical approaches have been described for achieving satisfactory functionality in patients with facial paralysis, to ensure the protection of the cornea and the highest degree of physiological blinking. Out of all those available, dynamic techniques are indicated when motion recovery and synchrony are the goals pursued. Orbicularis oculi transposition (OOT) allows a genuine restoration of blinking by means of contralateral reinnervation, with minimal insult for the donor site. We present the case of a 64-year-old man with unilateral facial paralysis. A physical examination revealed a lagophthalmos of more than 5 mm. A neurophysiological study showed a mild-to-moderate axonal injury of the left facial nerve. Contralateral OOT was indicated as the first therapy option since it can restore involuntary blinking. The orbicularis muscle flap was not divided into branches, as described previously by other authors; the whole flap was transposed to the paralysed upper eyelid to achieve the highest level of potential reinnervation. Lagophthalmos was fully corrected after the surgery. The patient reported subjective improvement of symptoms, less frequent instillation of artificial tear drops and, especially, synchronous blinking with significant improvement in involuntarity. These improvements were maintained after 1 year of follow-up. Postoperative electromyographic studies confirmed the improvement in neural function. OOT can be a safe and effective option for the treatment of patients with peripheral facial paralysis, as it achieves a good restoration of blinking function with minimal morbidity in the healthy donor eye. [ABSTRACT FROM AUTHOR]

Abstract Background Unbiased in silico approaches applied to genome-wide data prioritized putative functional gene variants associating with treatment-resistant ophthalmoplegic myasthenia gravis (OP-MG). Although altered expression of genes harbouring these variants, or associated pathways, were shown in patient-derived transdifferentiated-myocyte models, gene expression in orbital-derived muscle was required to test the validity of the predictions. Methods We sampled orbicularis oculi muscle (OOM) and one paralysed extraocular muscle (EOM) from six individuals with OP-MG during blepharoptosis and re-alignment surgeries, respectively. For controls, the OOMs were sampled from four individuals without myasthenia undergoing surgery for non-muscle causes of ptosis, and one non-paralysed EOM. Using a qPCR array, expression of 120 genes was compared between OP-MG and control OOMs, profiling putative “OP-MG” genes, genes in related biological pathways and genes reported to be dysregulated in MG cases or experimental MG models, and in EOMs of cases with strabismus. Normalization was performed with two stable reference genes. Differential gene expression was compared between OP-MG and control samples using the ΔΔCT method. Co-expression was analysed by pairwise correlation of gene transcripts to infer expression networks. Results Overall, transcript levels were similar in OOMs and EOMs (p = 0.72). In OOMs, significant downregulated expression of eight genes was observed in OP-MG cases compared with controls (> twofold; p ≤ 0.016), including TFAM, a mitochondrial transcription factor, and genes related to the following pathways: atrophy signalling; muscle regeneration and contraction; glycogen synthesis; and extracellular matrix remodelling. Several microRNAs, known to be highly expressed in EOMs, are predicted to regulate some of these genes. Co-expression analyses of gene-pairs suggested high interconnectedness of gene expression networks in OP-MG muscle, but not controls (r > 0.96, p

The popularity of looking younger has been facilitated by the availability of botulinum toxin (BoNT) injection. In 2019, over 7.7 million injections of BoNT occurred, making it the number one minimally invasive cosmetic procedure in the United States. With the ease of patients obtaining BoNT in an outpatient setting, coupled with the fact that it is considered a minimally invasive procedure, most patients do not disclose the use of BoNT during the preoperative anesthesia evaluation. This case report involves a female whose recent BoNT injections interfered with neuromuscular (NM) monitoring during anesthesia. Neuromuscular monitoring was performed using the orbicularis oculi muscle with repeated train-of-four (TOF) 0/4. It was not until completion of procedure when the arms were accessible that the adductor pollicis muscle was assessed with a TOF of 2/4. During postoperative follow up, the patient revealed she had received BoNT injections prior to surgery. A review of BoNT pharmacology, barriers to NM monitoring and use of sugammadex are discussed. This case demonstrates the importance of ascertaining BoNT injection history in any case in which access to the ulnar nerve or tibial nerve is not available. [ABSTRACT FROM AUTHOR]

Objective: PrabotulinumtoxinA-xvfs (Jeuveau), a botulinum toxin type A, was approved by the Food and Drug Administration for the temporary improvement in the appearance of moderate-to-severe glabellar lines in February 2019. This article will review phase II and III clinical trials to assess the efficacy, safety, and clinical application of this novel, aesthetic-only drug. Data sources: A systematic literature review was performed using the terms "glabellar lines AND prabotulinumtoxinA" in the PubMed database. ClinicalTrials.gov was searched to identify nonpublished studies. Study Selection and Data Extraction: Articles written in English between November 2019 and June 2020 discussing phase II and phase III clinical trials were evaluated. Data Synthesis: By the primary efficacy end point on day 30, more patients achieved a greater than 2-point improvement on the Glabellar Line Scale (GLS) at maximum frown compared with baseline on day 0. The proportions of participants who responded to treatment with prabotulinumtoxinA were 67.5% and 70.4% versus 1.2% and 1.3% in placebo groups across 2 identical clinical trials (P < 0.001). Patients receiving prabotulinumtoxinA experienced greater improvement in GLS at maximum frown on day 30 (87.2%) compared with onabotulinumtoxinA (82.8%) and placebo (4.2%; P < 0.001). PrabotulinumtoxinA was well tolerated across all studies. Relevance to Patient Care and Clinical Practice: This review provides a detailed analysis of the safety and efficacy of prabotulinumtoxinA-xvfs and includes special considerations to help guide patients and clinicians. Conclusion: PrabotulinumtoxinA is a safe and effective new addition to the repository of available treatments for the appearance of glabellar lines. [ABSTRACT FROM AUTHOR]

Background: Unbiased in silico approaches applied to genome-wide data prioritized putative functional gene variants associating with treatment-resistant ophthalmoplegic myasthenia gravis (OP-MG). Although altered expression of genes harbouring these variants, or associated pathways, were shown in patient-derived transdifferentiated-myocyte models, gene expression in orbital-derived muscle was required to test the validity of the predictions.Methods: We sampled orbicularis oculi muscle (OOM) and one paralysed extraocular muscle (EOM) from six individuals with OP-MG during blepharoptosis and re-alignment surgeries, respectively. For controls, the OOMs were sampled from four individuals without myasthenia undergoing surgery for non-muscle causes of ptosis, and one non-paralysed EOM. Using a qPCR array, expression of 120 genes was compared between OP-MG and control OOMs, profiling putative "OP-MG" genes, genes in related biological pathways and genes reported to be dysregulated in MG cases or experimental MG models, and in EOMs of cases with strabismus. Normalization was performed with two stable reference genes. Differential gene expression was compared between OP-MG and control samples using the ΔΔCT method. Co-expression was analysed by pairwise correlation of gene transcripts to infer expression networks.Results: Overall, transcript levels were similar in OOMs and EOMs (p = 0.72). In OOMs, significant downregulated expression of eight genes was observed in OP-MG cases compared with controls (> twofold; p ≤ 0.016), including TFAM, a mitochondrial transcription factor, and genes related to the following pathways: atrophy signalling; muscle regeneration and contraction; glycogen synthesis; and extracellular matrix remodelling. Several microRNAs, known to be highly expressed in EOMs, are predicted to regulate some of these genes. Co-expression analyses of gene-pairs suggested high interconnectedness of gene expression networks in OP-MG muscle, but not controls (r > 0.96, p < 0.01). Significant inverse directions of gene-pair correlations were noted in OP-MG versus controls OOM networks (r ≥ 0.92, p < 0.001) involving most OP-MG genes overlapping prominently with muscle atrophy/contractility and oxidative metabolism genes.Conclusions: The gene expression in orbital muscles derived from OP-MG individuals compared with normal controls, support the pathogenic hypothesis previously generated from whole genome sequence analyses. Repression of gene transcripts in OP-MG orbital muscle implicate tissue-specific regulatory mechanisms, which may inform future biomarker discovery approaches. [ABSTRACT FROM AUTHOR]

Facial expressions of pain are composed of a subset of pain-indicative muscle movements. Amongst this subset, contracting the muscles surrounding the eyes (orbicularis oculi muscle) is the most frequent response and has been linked specifically to pain intensity, a fundamental aspect of the sensory dimension of pain. To further explore this link, the present study used functional magnetic resonance imaging (fMRI) to test the hypothesis that orbicularis oculi activation during pain reflects the magnitude of brain responses in areas being involved in processing the sensory dimension of pain.Facial and brain (BOLD) responses to experimentally-induced heat pain applied to the left lower leg were assessed in twenty-two healthy participants after verbal suggestions were given to specifically increase perceived pain intensity and in control conditions involving no suggestion.Increases in pain intensity produced the expected changes in facial responses characterized by a stronger contraction of the orbicularis oculi muscle. A regression model further demonstrated that stronger increases in orbicularis oculi activity reflected a larger increase in the BOLD response to the noxious stimulus in the leg area of the primary somatosensory cortex (S1) and a larger decrease in medial prefrontal activity consistent with previous finding suggesting disinhibition. Importantly, the positive coupling of orbicularis oculi with S1 activity was not accounted for by changes in other facial muscles.These results are consistent with the notion that facial expressions of pain differentially encode the multi-dimensional pain experience and reflect, at least partly, the activity of the spino-thalamo-cortical pathway targeting the primary somatosensory cortex.

Background: Tissue fillers are generally safe and well tolerated by patients. However, complications do occur and may be very severe, such as intravascular injection (with occasional residual tissue loss, visual and neurological sequelae) and late nodularity and swelling. Methods to lessen the likelihood of complications have been the subject of much recent literature. Depth of injection has been identified as a key safety consideration. Patients/Methods: The role of injection of facial filler into the muscular layer of the face is explored in this article. Literature was explored using available search facilities to study the role of injections in or around this layer in the production of significant adverse reactions. Results: A body of literature seems to suggest that injection into mimetic musculature of the face especially the musculature in the periorbital and perioral regions is prone to adverse reactions. Conclusions: Injection of agents into the perioral and periorbital mimetic muscular layer may produce, product clumping, displacement, and tendency to late nodularity and swelling. It also risks intravascular injection as compared to injection of other layers of the face. Injection into the mimetic muscles especially the sphincteric muscles should be avoided to minimize the risk of complications. [ABSTRACT FROM AUTHOR]

The integrity of the temporal and zygomatic branches of the facial nerve is essential for the functionality of the periorbital area, since they supply motor fibers to the periocular muscles, particularly the orbicularis oculi. The branches are vulnerable to injury due to post-traumatic lacerations in the temporo-zygomatic region, but also during surgery, for the removal of malignant or benign tumors of the area, reconstructive procedures, plastic surgery interventions, temporomandibular joint surgery, as well as surgery for cranio-facial anomalies or surgical treatment of zygomatic bone fractures. Numerous authors have attempted at defining the areas of safety or increased risk of facial nerve injury, but there are inconsistencies in the existing literature, due to differences in the terminology of the anatomic layers, in the level of dissection and variability of the structures used as landmarks. The purpose of this paper is to gather and structure the relevant existing information regarding the anatomical landmarks that allow avoidance of injury to the temporal and zygomatic branches of the facial nerve, and to corelate the findings with applications during specific high-risk surgical procedures. [ABSTRACT FROM AUTHOR]

We report here a retrospective case series of 3 MG patients suffering from difficulty opening eyes that appeared together with a diagnosis of MG. All are male patients with late-onset MG who are seropositive for anti-acetylcholine receptor antibodies. The phenomenon was characterized by difficulty opening the eyes after forced closure or reflex eye closure, improving with the ice pack test and with repeated forced eye closure but worsening with pyridostigmine treatment. We provide a detailed clinical, serological, imaging and electrophysiological examination of these patients. Electromyography evaluation did not show spontaneous muscle activity or myotonia at rest in the orbital part of the orbicularis oculi muscle. However, there was sustained muscle activity lasting several seconds in the pre-tarsal and pre-septal parts of this muscle. Videos of those reported symptoms were produced and provided. We discuss the possible neurological pathophysiology of this disorder and suggest to name this rare ocular disorder "myotonia-like disorder of the pre-tarsal and pre-septal parts of the orbicularis oculi". This study expands our knowledge of this rare clinical feature of MG and highlights the need for increased awareness of it and further investigation of this ocular manifestation. • The study describe a myotonia-like phenomenon of difficulty opening the eyes in patients with myasthenia gravis • The phenomenon appears after forced closure or after a closing reflex of the eyes • The phenomenon found in male with seropositive and late onset myasthenia gravis • An ice-pack test and repeated forced eyes closing alleviate this phenomenon, but treatment with pyridostigmine worsens it. • This phenomenon is manifested by abnormal sustained muscle activity of the pre-septal and pre-tarsal parts of the orbicularis oculi muscles [ABSTRACT FROM AUTHOR]

Objective: Repetitive jaw‐muscle activity characterized by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible, ie, bruxism, is traditionally linked to pain and unpleasantness in the active muscles. The aim of this study was to investigate the effects of standardized craniofacial muscle contractions on self‐reported symptoms. Methods: Sixteen healthy volunteers performed six 5‐minute bouts of 20% maximal voluntary contraction task of the jaw‐closing (Jaw), the orbicularis‐oris (O‐oris), and the orbicularis‐oculi (O‐oculi) muscles. Participants rated their perceived pain, unpleasantness, fatigue, and mental stress levels before, during, and after the contraction tasks on 0‐10 Numeric Rating Scales (NRS). Each muscle contraction task (= 1 session) was separated by at least 1 week and the order of the sessions was randomized in each subject. Results: All muscle contraction tasks evoked significant increases in NRS scores of pain (mean ± SD: Jaw; 3.8 ± 2.7, O‐oris; 1.9 ± 2.2, O‐oculi; 1.4 ± 1.3, P < .014), unpleasantness (Jaw; 4.1 ± 2.5, O‐oris; 2.1 ± 1.9, O‐oculi; 2.9 ± 1.8, P < .001), fatigue (Jaw; 5.8 ± 2.0, O‐oris; 3.2 ± 2.3, O‐oculi; 3.6 ± 1.9, P < .001), and mental stress (Jaw; 4.1 ± 2.1, O‐oris; 2.2 ± 2.7, O‐oculi; 2.9 ± 2.2, P < .001). The Jaw contractions were associated with higher NRS scores compared with the O‐oris and the O‐oculi contractions (P < .005) without differences between the O‐oris and the O‐oculi (P > .063). All symptoms disappeared within 1 day (P > .469). Conclusions: The results showed that submaximal static contractions of different craniofacial muscle groups could evoke transient, mild to moderate levels of muscle pain and fatigue and increased stress scores. The fatigue resistance may differ between different muscle groups. Further studies are warranted to better understand the contribution of specific craniofacial muscle groups for the characteristic presentation of musculoskeletal pain conditions in the head. [ABSTRACT FROM AUTHOR]

Repetitive nerve stimulation (RNS) is a valuable diagnostic method for myasthenia gravis (MG). However, its association with clinical severity was scarcely studied. We reviewed medical records and retrospectively enrolled 121 generalized MG patients. Sensitivity of different muscles to RNS and clinical scoring systems was evaluated. RNS testing revealed facial muscles have the highest positive rate, followed by proximal muscles and distal muscles, with the palpebral portion of the orbicularis oculi muscle most sensitive. Amplitude decrement of compound muscle action potential (CMAP) in the palpebral portion of the orbicularis oculi muscle is related to quantitative myasthenia gravis (QMG) scores, MG-specific manual muscle testing (MMT) scores and myasthenia gravis-related activities of daily living (MG-ADL) scores. We suggest that RNS testing of the palpebral portion of the orbicularis oculi muscle is a potential assessment indicator in patients with generalized MG. [ABSTRACT FROM AUTHOR]

Skeletal muscle stem cells (MuSCs) have been proposed as suitable candidates for cell therapy in muscular disorders since they exhibit good capacity for myogenic regeneration. However, for better therapeutic outcomes, it is necessary to isolate human MuSCs from a suitable tissue source with high myogenic differentiation. In this context, we isolated CD56+CD82+ cells from the extra eyelid tissue of young and aged patients, and tested in vitro myogenic differentiation potential. In the current study, myogenic cells derived from extra eyelid tissue were characterized and compared with immortalized human myogenic cells. We found that myogenic cells derived from extra eyelid tissue proliferated and differentiated myofibers in vitro, and restored DYSTROPHIN or PAX7 expression after transplantation with these cells in mice with Duchenne muscular dystrophy. Thus, human myogenic cells derived from extra eyelid tissue including the orbicularis oculi might be good candidates for stem cell-based therapies for treating muscular diseases.

Objective: This study aims to provide reference data about the density and distribution of muscle spindles (MS) in certain mimic muscles on human cadavers. Methods: Orbicularis oculi, orbicularis oris, zygomaticus major and buccinator muscles were obtained from 16 cadavers on both sides, and they were dissected into pieces according to muscle mass. Routine tissue processing procedures were applied to all samples. Dewaxed serial sections were stained with hematoxylin and eosin (H&E) and Masson's Trichrome staining to determine muscle spindles. They were examined and photographed under a light microscope. Results: The mean numbers of MS in the buccinator muscle were 2.22 (H&E), 2.37 (Masson's) on the right side and 2.42 (H&E), 2.16 (Masson's) on the left side. The following numbers (0.5 and 1.33) were detected on both sides for orbicularis oculi and orbicularis oris muscles, respectively. The mean numbers of MS were 2.1 (H&E), 1.85 (Masson's) on the right and 0.5 on the left for zygomaticus major. Light microscopic examination of 72 samples revealed that perimysium enclosing fascicles, skeletal muscle fibers, peripherally located nuclei, endomysium, blood vessels, and peripheral nerves were intact. External and internal connective tissue capsules and intrafusal muscle fibers were observed in the muscle spindles inside the perimysium and fascicles. Conclusion: The differences in density and distribution of muscle spindles were presented in certain mimic muscles. Therefore these differences may provide a basis to explain the mechanisms related to movement disorders of mimic muscles and functional indicators of pathological conditions. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to determine how the depressor supercilii (DS) connects to the levator labii superioris alaeque nasi (LLSAN) and inferior fibers of the orbicularis oculi (OOc INF) in the human midface. Methods: The DS was examined in 44 specimens of embalmed adult Korean cadavers. We found that the DS connected to the LLSAN or the OOc INF by muscle fibers or thin aponeuroses in 33 (75.0%) of the 44 specimens. This study was approved by the Institutional Review Board of the Catholic Kwandong University (IRB No. CKU-21-01-0101). Results: The DS was connected to both the LLSAN and OOc INF by muscle fibers or aponeuroses and had no connection to either in 5 (11.4%) and 11 (25.0%) specimens, respectively. The DS was connected to the LLSAN by the muscle fibers and thin aponeuroses in 6 (13.6%) and 4 (9.1%) specimens, respectively. The DS was connected to the OOc INF by the muscle fibers and thin aponeuroses in 5 (11.4%) and 23 (52.3%) specimens, respectively. Our findings regarding the anatomical connections of the glabellar region DS to the midface LLSAN and OOc INF provide insights on the dynamic balance between the brow depressors such as the DS and brow-elevating muscle and contribute to understanding the anatomical origins of individual variation in facial expressions. Conclusion: These results can also improve the safety, predictability, and aesthetics of treatments for the glabellar region with botulinum toxin type A and can be helpful when performing electromyography. [ABSTRACT FROM AUTHOR]

Electroneurography is one of the most useful tests for evaluating facial nerve function. Because many patients with peripheral facial palsy complain of difficulty with eye closure, recording compound muscle action potentials (CMAPs) of the orbicularis oculi (OC) is important. However, electromyographers often encounter OC CMAPs that have an initial positivity. In the present study, facial motor potentials of a healthy subject were recorded using an electrode on the acromion and electrical activities over the facial muscles were evaluated.The contralateral OC electrode was the most inactive. A CMAP recorded using two electrodes on the ipsilateral OC showed an initial positivity. It is assumed that the onset discrepancy between electrical activities of the two electrodes on the OC results in an initial positivity. Thus, the authors recommend that electromyographers avoid using a reference electrode on the ipsilateral OC for recording its CMAP. The bilateral OC montage could be useful for recording OC CMAPs. [ABSTRACT FROM PUBLISHER]

Altered corneal reflex activity is a common feature of dry eye disease (DE). Trigeminal sensory nerves supply the ocular surface and terminate at the trigeminal interpolaris/caudalis (ViVc) transition and spinomedullary (VcC1) regions. Although both regions contribute to corneal reflexes, their role under dry eye conditions is not well defined. This study assessed the influence of local inhibitory and excitatory amino acid neurotransmission at the ViVc transition and VcC1 regions on hypertonic saline (HS) evoked orbicularis oculi muscle activity (OOemg) in urethane-anesthetized male rats after exorbital gland removal (DE). HS increased the magnitude of long-duration OOemg activity (OOemgL, >200 ms) in DE compared to sham rats, while short-duration OOemg activity (OOemgS, <200 ms) was similar for both groups. Inhibition of the ViVc transition by muscimol, a GABA A receptor agonist, greatly reduced HS-evoked OOemgL activity in DE rats, whereas injections at the VcC1 region had only minor effects in both groups. Blockade of GABA A receptors by bicuculline methiodide at the ViVc transition or VcC1 region increased HS-evoked OOemgL activity in DE rats. Blockade of N-methyl-D-aspartate (NMDA) receptors at either region reduced HS-evoked OOemgL activity in DE and sham rats. GABAαβ3 receptor density was reduced at the ViVc transition, while NMDA receptor density was increased at both regions in DE rats. Loss of GABAergic inhibition at the ViVc transition coupled with enhanced NMDA excitatory amino acid neurotransmission at the ViVc transition and the VcC1 region likely contribute to altered corneal reflexes under dry eye conditions. [ABSTRACT FROM AUTHOR]

There are very close relationships among deglutition, taste sensations, and facial expressions in humans. However, the associations among mimicking, swallowing, and the suprahyoid/submental muscle group (SM) during deglutition events have yet to be investigated using electrophysiological techniques to elucidate taste sensation and facial expression further. Thus, this study used surface EMG to evaluate synchronous electromyography activity in the facial and swallowing muscles during the swallowing of water and sour boluses in 20 normal healthy adults. All participants were instructed to swallow four bolus volumes (5, 10, 15, and 20 ml) each of a water bolus and a sour bolus (lemon juice) in a neutral head position. EMG recordings were obtained from the orbicularis oculi (OC; a mimic muscle), orbicularis oris (OR; a mimic and swallowing muscle), and SM (deglutition muscles) to determine whether these muscles were synchronously activated during voluntary oropharyngeal swallowing. The mimic (OC and OR) and swallowing muscles (SM) were synchronously activated in more than 90% of participants during water swallowing. Swallowing lemon juice increased the number of spontaneous swallows after the first deglutition and significantly shortened the duration of a single swallowing apnea. The present findings indicate that both taste and the intraoral trigeminal afferents of water and sour boluses excite facial neurons via the nucleus tractus solitarius and/or a central pattern generator. Additionally, sour boluses produced stronger and safer oropharyngeal swallowing in conjunction with increases in facial expressions due to the activation of facial mimic muscles. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to evaluate an improved park's technique to create a natural double eyelid and reduce scar formation., Methods: The levator aponeurosis, orbicularis oculi muscle, and dermis were fixed using subcutaneous intermittent sutures, and then the skin and the levator aponeurosis were sutured. Postoperative evaluation included double-eyelid stability, symmetry, double-eyelid curve, scar formation, and patient satisfaction., Results: Between January 2021 and August 2021, a total of 89 patients (178 eyes) underwent double-eyelid blepharoplasty by the same surgeon using this improved technique. The mean follow-up period was 15.5 months (range 10 to 18 months). Seventy-six patients were very satisfied with this surgical method, six patients were rather satisfied, and seven patients were dissatisfied. The overall satisfaction rate was 92.1%., Conclusion: This new blepharoplasty method generates a stable, natural double-eyelid line with minimal scarring., (© 2023 Zhao S et al.)

Background: The purpose of this study is to establish a relationship between the skin lines on the upper third of the face in cadavers, which represent the muscle activity in life and the skin lines achieved by voluntary contraction of the forehead, glabellar, and orbital muscles in patients. Methods: Anatomical dissection of fresh cadavers was performed in 20 fresh cadavers, 11 females and 9 males, with ages ranging from 53 to 77 years. Subcutaneous dissection identified the muscle shape and the continuity of the fibers of the eyebrow elevator and depress muscles. Subgaleal dissection identified the cutaneous insertions of the muscles. They were correlated with skin lines on the upper third of the face of the cadavers that represent the muscle activity in life. Voluntary contraction was performed by 20 voluntary patients, 13 females and 7 males, with ages ranging from 35 to 62 years. Distinct patterns of skin lines on the forehead, glabellar and orbital areas, and eyebrow displacement were identified. Results: The frontalis exhibited four anatomical shapes with four different patterns of horizontal parallel lines on the forehead skin. The corrugator supercilii showed three shapes of muscles creating six patterns of vertical glabellar lines, three symmetrical and three asymmetrical. The orbicularis oculi and procerus had single patterns. The skin lines exhibited in voluntary contraction of the upper third of the face in patients showed the same patterns of the skin lines achieved in cadavers. Conclusions: Skin lines in cadavers, which are the expression of the muscle activity in life, were similar to those achieved in the voluntary contraction of patients, allowing us to assert that the muscle patterns of patients were similar to those identified in cadavers. No Level Assigned: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors . [ABSTRACT FROM AUTHOR]

Introduction: Crows' feet wrinkles are caused by the action of the orbicularis oculi muscle on overlying skin. Treatment options range from botulinum toxin to a multitude of surgical methods. We first described our technique in 2003 and refined it in 2006. We highlight the evolution of our technique and look at our results to assess the effectiveness of our technique. Objective: The aim of this article is to show our experience of 13 years in 134 patients with our technique of orbicularis oculi myectomy. Methods: From September 2000 to July 2013, we operated on 134 patients with an age range of 28-77 years. Of these patients, 104 had myectomies via lifting and 22 via a blepharoplasty approach. Five patients had myectomies for treatment of blepharospasm and a further three patients to restore symmetry in facial palsy. An evaluation of the results was performed by two medical students. Results: Our results showed reduction of the wrinkles in all cases. For the statistical analysis the Wilcoxon test was performed. The p value was less than 0.001 showing a significant reduction of crows' feet wrinkles in both sides when the orbicularis myectomy was performed, via blepharoplasty or lifting. For myectomy performed for blepharospasm or facial palsy, the statistical analysis was not done due to the low numbers. Conclusion: In the appropriate patient, orbicularis oculi myectomy is an effective and long-term treatment for crows' feet wrinkles with a low risk of complications and high patient satisfaction. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors . [ABSTRACT FROM AUTHOR]

Background Neurosurgeons who operate in and around the pathway of the ocular nerves should have good knowledge of not only their normal anatomy but also their variations. Case Description During routine dissection of the orbits in an adult cadaver, an aberrant branch of the right trochlear nerve continued on to innervate the orbicularis oculi muscle. In this case, the trochlear nerve also provided a branch to the supratrochlear nerve. Conclusions Surgeons who operate along the pathway of the trochlear nerve such as the cavernous sinus should be aware of such an anatomic variant in order to avoid unwanted complications such as weakness of the orbicularis oculi muscle. [ABSTRACT FROM AUTHOR]

Context: Facial palsy is a common problem encountered in clinical practice. These patients suffer serious functional, cosmetic & psychological problems with impaired ability to communicate. Functional problems around the eye are usually a first priority for the patient with facial palsy.The nerve to masseter as a direct nerve transfer to the zygomatic branch of facial nerve to reinnervate viable facial muscles within a year after the onset of paralysis has been scarcely reported. This study was contemplated to evaluate the feasibility of neurotisation of zygomatic branch of facial nerve with masseteric nerve branch of the trigeminal nerve Objectives: Establishing the anatomic relationship of masseteric nerve to masseteric muscle, determining feasibility of neurotisation of zygomatic branch of facial nerve using the nerve to the masseter and establishing fascicular correlation of the donor and the recipient nerves. Materials and Methods: Ninteen hemi-faces in ten fresh cadavers (6 Male and 4 Female)were dissected in a forensic morgue and access was by a standard preauricular incision and anterior skin flap is elevated in a subcutaneous plane. Facial nerve and its two main divisions are dissected in its full A*/extratemporal course. Zygomatic branch dissected upto zygomatic arch and the nerve to the masseter is identified within the masseter muscle, dissected proximodistally to isolate it. Feasibility of transfer of this masseteric nerve to the zygomatic branch without using nerve graft is determined. At the completion of dissection, the ends of both nerves are sent for HPE analysis to determine fascicular anatomy and count. Results: The dissection of masseteric nerve was done taking into consideration of 3 axes, that is anteroposterior (x), vertical (y) axes and mediolateral (z) for locating the nerve and for standardization of the dissection. The nerve was cut and stored in glutaraldehyde solution and subjected to histopathologic examination after fixing and staining with Haematoxilin-eosin stain. Donor masseter neve has 7-10 fascicles. Recipient zygomatic branch has 2-3 fascicles. And the buccal branch has 5-6 fascicles. Conclusion: The use of the nerve to masseter offers a simpler ipsilateral alternative for neurotisation of the facial nerve branches in patients who have an early facial nerve paralysis.

Chronic dry eye disease (DE) is associated with an unstable tear film and symptoms of ocular discomfort. The characteristics of symptoms suggest a key role for central neural processing; however, little is known about central neuroplasticity and DE. We used a model for tear deficient DE and assessed effects on eye blink behavior, orbicularis oculi muscle activity (OOemg), and trigeminal brainstem neural activity in male rats. Ocular-responsive neurons were recorded at the interpolaris/caudalis transition (Vi/Vc) and Vc/upper cervical cord (Vc/C1) regions under isoflurane, whereas OOemg activity was recorded under urethane. Spontaneous tear volume was reduced by ~50% at 14 days after exorbital gland removal. Hypertonic saline-evoked eye blink behavior in awake rats was enhanced throughout the 14 days after surgery. Saline-evoked neural activity at the Vi/Vc transition and in superficial and deep laminae at the Vc/C1 region was greatly enhanced in DE rats. Neurons from DE rats classified as wide dynamic range displayed enlarged convergent periorbital receptive fields consistent with central sensitization. Saline-evoked OOemg activity was markedly enhanced in DE rats compared with controls. Synaptic blockade at the Vi/Vc transition or the Vc/C1 region greatly reduced hypertonic saline-evoked OOemg activity in DE and sham rats. These results indicated that persistent tear deficiency caused sensitization of ocular-responsive neurons at multiple regions of the caudal trigeminal brainstem and enhanced OOemg activity. Central sensitization of ocular-related brainstem circuits is a significant factor in DE and likely contributes to the apparent weak correlation between peripheral signs of tear dysfunction and symptoms of irritation. [ABSTRACT FROM AUTHOR]

A morphological peculiarity was observed in the form of an aberrant lateral bony attachment of the orbital part of the Orbicularis oculi muscle on the zygomatic bone, during routine dissection of a cadaver of an adult male of Indian origin. Fibers of this part of the muscle are not known to show any lateral attachment on bone. This paper discusses the presentation, probable embryological cause and clinical implications of this unusual finding.

Cornea-evoked eyeblinks maintain tear film integrity on the ocular surface in response to dryness and protect the eye from real or potential damage. Eyelid movement following electrical stimulation has been well studied in humans and animals; however, the central neural pathways that mediate protective eyeblinks following natural nociceptive signals are less certain. The aim of this study was to assess the role of the trigeminal subnucleus interpolaris/caudalis (Vi/Vc) transition and subnucleus caudalis/upper cervical cord (Vc/C1) junction regions on orbicularis oculi electromyographic (OOemg) activity evoked by ocular surface application of hypertonic saline or exposure to bright light in urethane anesthetized male rats. The Vi/Vc and Vc/C1 regions are the main sites of termination for trigeminal afferent nerves that supply the ocular surface, while hypertonic saline (saline = 0.15–5 M) and bright light (light = 5k–20k lux) selectively activate ocular surface and intraocular trigeminal nerves, respectively, and excite second-order neurons at the Vi/Vc and Vc/C1 regions. Integrated OOemg activity, ipsilateral to the applied stimulus, increased with greater stimulus intensities for both modalities. Lidocaine applied to the ocular surface inhibited OOemg responses to hypertonic saline, but did not alter the response to light. Lidocaine injected into the trigeminal ganglion blocked completely the OOemg responses to hypertonic saline and light indicating a trigeminal afferent origin. Synaptic blockade by cobalt chloride of the Vi/Vc or Vc/C1 region greatly reduced OOemg responses to hypertonic saline and bright light. These data indicate that OOemg activity evoked by natural stimuli known to cause irritation or discomfort in humans depends on a relay in both the Vi/Vc transition and Vc/C1 junction regions. [ABSTRACT FROM AUTHOR]