Orbicularis Oculi Research Articles

Long term effects of double charged hemihypoglossal-Facial Nerve Neurorrhaphy on the histological structure of orbicularis oculi muscle

Long term effects of double charged hemihypoglossal-Facial Nerve Neurorrhaphy on the histological structure of orbicularis oculi muscle

Factors Affecting Generalization of Ocular Myasthenia Gravis in Palembang

Introduction. Ocular myasthenia gravis (OMG) is an autoimmune disease which is characterized by weakness of extraocular muscles, levator palpebrae and orbicularis oculi, resulting in ptosis and binocular diplopia. Nearly all patients present with eyelid and extra ocular muscles involvement. Approximately 30% to 80% of patients with OMG experience a conversion to generalized myasthenia gravis (GMG) within 2 years. There are not only have ptosis and diplopia but also limb weakness,bulbar symptoms, or even respiratory failure.
 Objective. To observe the clinical features of OMG to GMG and risk factors and median time to conversion of OMG to GMG of myasthenia gravis patients in Mohammad Hoesin General Hospital Palembang.
 Method. This study is a cohort retrospective study and the data were collected from the medical records of 91 patients who were registered as myasthenia gravis patients during September 2018 to March 2020. Sosiodemographic and clinical characteristics, including onset of OMG to GMG, history of smoking, presence of thymic abnormalities, and medications received were reviewed retrospectively.
 Result. A total of 91 OMG patients were observed in this study with 32 (35,2%) patients converted from ocular myastenia gravis to general myastenia gravis. Median conversion time to GMG was 34 months. Risk factor for convertion cases of OMG to MGG was receiving immunosupressive agents(Risk: 14.7, 95% CI 4.83, 44.7), thymus hyperplasia (Risk: 3.36, CI 95% 0.33, 33.6), Female (Risk: 2.41, 95% CI 0.94, 6.17), Smoking (Risk: 1.56, 95% CI 0.31, 7.81).
 Conclusion. Ptosis was the definitive sign for OMG in this study, with all patients had ptosis, thus it needs the colaboration from neuroophthalmologist and neurologist to diagnose and manage this case. Most of converted case was female and those who receive an immunosupressive agent therapy.

A modified method for upper eyelid reconstruction with innervated orbicularis oculi myocutaneous flaps and lower lip mucosal grafts

BackgroundNumerous reports have described methods for repairing full-thickness upper eyelid defects using lower eyelid tissue. To avoid sacrificing the lower eyelid and thereby prevent lower eyelid sagging or dysfunction, we used innervated orbicularis oculi myocutaneous flaps harvested from the upper eyelid for upper eyelid reconstruction. MethodsWe modified a method reported by Moschella and Cordova for repairing full-thickness upper eyelid defects using innervated bipedicled orbicularis oculi myocutaneous flaps mobilized from the upper eyelid and labial mucosal grafts. First, we avoided the use of a Fricke flap, which is used in the original method to repair the myocutaneous flap donor site, since it can cause asymmetry of the eyebrows on both sides. Second, reconstruction of the double-fold eyelid was performed with buried sutures in the myocutaneous flap in secondary surgery, since the double eyelid fold of the original method is not necessary or is too wide for Asian people. Functional and cosmetic outcomes were assessed by six evaluators using postoperative photographs. ResultsSix patients with malignant upper eyelid tumours underwent repair of upper eyelid defects by our modified method. Donor sites of the myocutaneous flaps were repaired with a medial forehead flap in one patient with Merkel cell carcinoma, a lateral orbital flap in one patient with sebaceous carcinoma, and a two-stage skin graft in two patients with sebaceous carcinoma and basal cell carcinoma, respectively. The two remaining patients (one with sebaceous carcinoma and the other with basal cell carcinoma) required no donor site repair. Functional and cosmetic outcomes were good or excellent in most cases. ConclusionOur modified method for repairing full-thickness upper eyelid defects using innervated orbicularis oculi myocutaneous flaps resulted in optimal eyelid function and support, with morphologically satisfactory results including bilateral symmetry. This method provides a useful alternative to conventional methods of upper eyelid reconstruction.

A Composite Tissue Flap for Double-Eyelid Blepharoplasty in Asian Patients: A Retrospective Study.

Double-eyelid blepharoplasty, the procedure to create supratarsal crease, has been one of the most popular cosmetic operations in Asia for many years. This study aimed to assess the effectiveness and safety of a surgical procedure using a composite tissue flap for double-eyelid blepharoplasty. A surgical technique was introduced and patients having blepharoplasty with this technique from January 2017 to August 2019 were retrospectively studied. In this technique, a composite tissue flap consisted of the posterior septum and levator aponeurosis was formed and fixed with orbicularis oculi muscle and tarsus. The cosmetic outcomes, patient satisfaction, and complications from the documented medical records were analyzed. Eighty female and 1 male patients had blepharoplasty with the proposed technique and were followed up from 6 months to 42 months. Six patients were found to have mild blepharoptosis. As for cosmetic outcomes, 71patients were graded as good, 7 patients were graded as fair, and only 1 patient was graded as poor. Those patients who were not graded as good had visible scarring, shallow eyelid crease, or asymmetry. The overall patient satisfaction was as high as 95.1%. Mild hematoma formation occurred in 3 patients and no infection or blepharoptosis was observed. One patient complained of asymmetry and 2 patients complained of unilateral crease fading as the complications. The technique is effective to develop durable and natural-looking double eyelids with minimal complications. It could also be an option for mild ptotic patients who ask for double-eyelid blepharoplasty.

Optimizing Location of Subdermal Recording Electrodes for Intraoperative Facial Nerve Monitoring

The purpose of this study is to determine if different facial muscle groups demonstrate different responses to facial nerve stimulation, the results of which could potentially improve intraoperative facial nerve monitoring (IOFNM). IOFNM data were prospectively collected from patients undergoing cochlear implantation. At different stages of nerve exposure, three sites were stimulated using a monopolar pulse. Peak electromyography (EMG) amplitude (μV) in four muscle groups innervated by four different branches of the facial nerve (frontalis-temporal, inferior orbicularis oculi-zygomatic, superior oribularis oris-buccal, and mentalis-marginal mandibular) were recorded. A total of 279 peak EMG amplitudes were recorded in 93 patients. At all three stimulating sites, the zygomatic branch mean peak EMG amplitudes were statistically greater than those of the temporal, buccal, and marginal mandibular branches (P< .05). At stimulating Site C, the marginal mandibular branch mean peak EMG was stronger than the temporal or buccal branches (P< .05). Of the 279 stimulations, the zygomatic branch demonstrated the highest amplitude in 128 (45.9%) trials, followed by the marginal mandibular branch (22.2%). When utilized, IOFNM should be performed with at least two electrodes, one of which is placed in the orbicularis oculi muscles and the other in the mentalis muscle. However, there is wide variability between patients. As such, in cases of suspected variant nerve anatomy or increased risk of injury (intradural procedures), surgeons should consider using more than two recording electrodes, with at least one in the orbicularis oculi muscle. 3 Laryngoscope, 131:E2329-E2334, 2021.

The influence of luminous intensity on the eyelid aperture and measurement of the margin reflex distance

ABSTRACT Purpose To evaluate whether the flashlight feature of smartphones can be used to replace the traditional flashlight for measuring MRD and investigate the relation between increasing light intensities and MRD measurements. Methods A prospective clinical study was conducted with 40 individuals from Hospital de Clínicas de Porto Alegre. Outcome measures: MRD1, MRD2, and palpebral fissure height (PFH) were analyzed by photographic record using different intensity light sources. Results Flashlight (10 lux): MRD1 mean: 3.97 mm ±1.16; PFH mean: 9.87 mm ±1.53; Smartphone (100 lux) MRD1 mean: 4.02 mm ±1.17; and PFH mean: 9.62 mm ± 1.45 (p > .05). Using a dimmable source of light resulted in a mean reduction of the PFH of 0.75 mm with the highest light intensity (1200 lux). There was no statistically significant association between MRD changes and the iris color, age, and gender of the subjects. Conclusions There was no statistically significant difference between the MRD measurements using traditional flashlights compared to higher intensity smartphone flashlight. Using a dimmable source of light, there is a statistically significant reduction in palpebral fissure with higher light intensity, which occurs mostly by upper eyelid lowering, probably due to orbicularis oculi muscle contraction. A smartphone with a built-in flashlight can be used to replace the traditional flashlight in clinical practice without prejudice to the evaluation of the MRD.

A Retrospective Study of Double Eyelid Surgery for Sunken Upper Eyelid in Chinese.

The aim of this study was to explore the effective technique of double eyelid surgery for mild, moderate, and severe sunken upper eyelid in Chinese. According to the degree of the sunken upper eyelid, different procedures were performed. For mild sunken upper eyelid, the key technique was named eyelid volume redistribution (EVR)-1 technique, which was advancing or folding the pretarsal orbicularis oculi muscle flap toward up to the upper margin of the incision. For moderate sunken upper eyelid, the EVR-2 technique included EVR-1 technique and releasing orbital fat toward the upper margin of the tarsus. The other surgical steps were the same as conventional double eyelid surgery. For severe sunken upper eyelid, 2 steps were needed. The first step was eyelid volume augmentation (EVA). This technique injected fat into the retroorbicularis oculi fat layer. The second step was conventional double eyelid surgery which was performed 3 to 6 months later. One hundred sixty-seven patients with sunken upper eyelid underwent double eyelid surgery. In addition to the ameliorative recontouring of the sunken deformity, natural double eyelid was created. All patients had no complication, such as infection, skin irregularities, and lumps. The edema, bruising, and temporary ptosis recovered in 2 weeks. The edema resulted from double eyelid surgery, which last about 2 to 3 months. Our study showed that EVR-1, EVR-2, and EVA techniques have stable surgical results for mild, moderate, and severe sunken upper eyelids in Chinese. The procedures are simple, safe, and have less complications and preferable clinical reference value.

Ocular surface and tear film changes after eyelid surgery

: Eyelid surgery is widely and extensively used in facial plastic and reconstructive surgeries. There are many categories of eyelid surgeries, the most common of which include blepharoplasty, ptosis surgery, and eyelid reconstruction. In many cases, these procedures are combined, and there are many different techniques for each type of operation. Upper eyelid blepharoplasty usually includes the excision of skin, preseptal orbicularis oculi muscle, and orbital fat. Common methods of lower eyelid blepharoplasty are the skin-muscle flap, the skin flap, and the transconjunctival. Ptosis surgery is mainly divided into three types: transcutaneous, transconjunctival, and sling surgery. Surgeons often used the Hughes or Cutler-Beard Bridge Flaps in eyelid reconstruction. Different types and methods of surgery have their own advantages and disadvantages, and postoperative complications may occur. Therefore, postoperative complications of eyelid surgeries, such as dry eye symptoms, should be taken into serious consideration. Relevant literature involving these complaints can be found in PubMed by searching the terms “dry eye”, “eyelid”, “surgery”, and other related keywords. Moreover, various ocular surface and tear film alterations may be detected using the Ocular Surface Disease Index (OSDI), tear film breakup time, Schirmer test, fluorescein staining, and lissamine green staining after various eyelid surgeries. As dry eye disease is prevalent in the general population, it is more urgent to figure out what we can learn from these complaints. Further exploration in this field may help surgeons to choose a better surgical method and give an accurate evaluation of the postoperative effect.

Macaque monkey trigeminal blink reflex circuits targeting orbicularis oculi motoneurons.

The trigeminal blink reflex plays an important role in protecting the corneal surface from damage and preserving visual function in an unpredictable environment. The closing phase of the human reflex, produced by activation of the orbicularis oculi (ObOc) muscles, consists of an initial, small, ipsilateral R1 component, followed by a larger, bilateral R2 component. We investigated the circuitry that underlies this reflex in macaque (Macaca fascicularis and Macaca mulatta) monkeys by the use of single and dual tracer methods. Injection of retrograde tracer into the facial nucleus labeled neurons in the principal trigeminal nucleus, and in the spinal nucleus pars oralis and interpolaris, bilaterally, and in pars caudalis, ipsilaterally. Injection of anterograde tracer into the principal trigeminal nucleus labeled axons that directly terminated on ObOc motoneurons, with an ipsilateral predominance. Injection of anterograde tracer into pars caudalis of the spinal trigeminal nucleus labeled axons that directly terminated on ipsilateral ObOc motoneurons. The observed pattern of labeling indicates that the reticular formation ventromedial to the principal and spinal nuclei also contributes extensive bilateral input to ObOc motoneurons. Thus, much of the trigeminal sensory complex is in a position to supply a monosynaptic drive for lid closure, and the adjacent reticular formation can supply a disynaptic drive. These findings indicate that the assignment of the R1 and R2 components of the blink reflex to different parts of the trigeminal sensory complex cannot be exclusively based on subdivision connectional relationships with facial motoneurons. The characteristics of the R2 component may be due, instead, to other circuit properties.

An Update on Subciliary Lower Eyelid Blepharoplasty.

The subciliary lower eyelid blepharoplasty has evolved considerably to create a more harmonious natural appearance with a fuller and unoperated look and also to minimize the complications. While lower eyelid malposition was very common in the past, now this complication is significantly reduced by attention to preoperative evaluation, meticulous surgical planning, precise surgical technique, and postoperative care. Various prophylactic maneuvers maintaining/strengthening lower lid support can be utilized to prevent lower lid malposition including preservation of the pretarsal orbicularis oculi muscle, conservative resection of skin and muscle, and suspension of the orbicularis oculi muscle and/or tarsus to the periosteum of the lateral orbital rim. The release of the orbicularis retaining ligament and surgical transposition of orbital fat over the rim rather than excision allows for smoothing of the lid-cheek junction, filling the tear trough deformity, and reducing the appearance of bulging fat in the lower eyelid. In this article the reader will find a comprehensive approach for achieving a smooth contour with gradual blending at the lower eyelid-cheek junction while maintaining/restoring normal lower lid support. A descriptive outline of postoperative care is also provided to help in optimal healing for the patient.

Effect of Occipital Nerve Stimulation (ONS) on the Orbicularis Oculi Reflex Triggered by a Standardized Air Flow in Patients with Chronic Migraine-A Prospective, Randomized, Interventional Study.

IntroductionOccipital nerve stimulation (ONS) is a specific form of peripheral neuromodulation used in the treatment of chronic pain disorders. A particular field of application is in the therapy of treatment-refractory headaches, especially of chronic migraine. The precise mode of action is unknown. It is presumed that central and peripheral sensitization are reduced in patients with chronic headache. The aim of this study was to examine the effect of ONS on pain-modulatory mechanisms in the trigeminocervical area in patients with chronic migraine.MethodsIn a balanced repeated measurements design in eight patients with chronic migraine with and without active ONS, we analyzed which effects ONS had on the orbicularis oculi reflex dynamically elicited by corneal air flow.ResultsThe orbicularis oculi reflex in active ONS (7.38 ± 20.14 eyelid closures/minute) compared to inactive ONS (18.73 ± 14.30 eyelid closures/minute) is significantly reduced (p = 0.021).ConclusionsThe results show that under active ONS compared to inactive ONS in patients with chronic migraine, the orbicularis oculi reflex, dynamically triggered by a standardized air flow, is significantly reduced. This suggests that ONS is able to directly counteract the trigeminally mediated central sensitization in chronic migraine and protectively reduce the effects of aversive peripheral stimulation.

Prepulse inhibition vs cognitive modulation of the hand-blink reflex

The excitability of brainstem circuitries mediating defensive blinking in response to abrupt sensory inputs is continuously modulated by cortical areas, e.g., the hand-blink reflex (HBR), elicited by intense electrical median nerve stimulation, is enhanced when the stimulated hand is close to the face, with the behavioural purpose to optimize self-protection from increased threat. Here we investigated whether such cortically mediated HBR facilitation can be influenced by prepulse inhibition (PPI), which is known to occur entirely at the subcortical level. Twenty healthy volunteers underwent HBR recordings in five experimental conditions. In conditions 1 and 2, the stimulated hand was held either near (1) or far (2) from the face, respectively. In conditions 3 and 4, stimulation of the hand near the face was preceded by a peri-liminal prepulse to the index finger of the contralateral hand held either near (3) or far from the face (4). In condition 5, participants self-triggered the stimulus eliciting the HBR. We observed a reproducible HBR in 14 out of 20 participants and measured onset latency and area of the HBR in orbicularis oculi muscles bilaterally. HBR area decreased and latency increased in condition 2 relative to condition 1; HBR area decreased and latency increased markedly in condition 3, and somewhat less in condition 4, relative to conditions 1 and 2; self-stimulation (condition 5) also suppressed HBRs, but less than prepulses. These findings indicate that PPI of the HBR is more robust than the cognitive modulation exerted by top-down cortical projections. Possibly, an attentional shift to a prepulse may serve to reduce blinking in response to perturbation when it is convenient, in a given situation, not to interrupt ongoing visual processing.

Long-term therapy with botulinum toxin in facial synkinesis: Retrospective data analysis of data from 1998 to 2018.

Treatment with botulinum toxin A (BoNT) is the therapy of choice for many patients with facial synkinesis. Repeated injections relieve hypertonicity and hyperkinesis of reinnervated mimic muscles. Aim of the study was to prove if the injection regime and dosage of BoNT change during long-time therapy. Retrospective analysis of patients´ data, who were treated for synkinesis with BoNT from 1998 to 2018. Tertiary referral facial nerve centre. Injection pattern of BoNT was based on clinical symptoms, observations of the specialist and on previous treatment pattern. Onabotulinumtoxin (OnaBoNT), Incobotulinumtoxin (IncoBoNT) and Abobotulinumtoxin (AboBoNT) were available for treatment. Patients consulted our department for following treatment as soon as the symptoms re-occurred. Change in dosage and injection pattern, the time intervals between treatments over the entire therapy period. Seventy-three patients were repeatedly injected. The median number of treatments was 18, the median treatment interval was 3.0months. During the initial treatment, orbicularis oculi and the mentalis muscles were the most frequently injected muscles (94%). During repeated treatment, the number of injected muscles increased significantly (P<.0001), whereas the dose per muscle remained stable. The initial dose was 24U (95%-CI 22-27U) for OnaBoNT and IncoBoNT; 69U for AboBoNT(95%-CI 44-94U). We observed a significant increase in dosage for OnaBoNT and IncoBoNT (P<.0001) during the long-term therapy. The time intervals between treatments were stable for all three BoNT preparations (P>.05). We observed significant change in treatment dose and injection pattern of BoNT in patients with facial synkinesis. These results provide an orientation in dose finding and injection regimen of BoNT in the long-term course of therapy.

Disabling muscle of Riolan: A novel concept of orbicularis oculi myectomy for refractory benign essential blepharospasm.

To examine the effectiveness of orbicularis oculi myectomy with disabling the muscle of Riolan in patients with benign essential blepharospasm refractory to botulinum toxin-A (BTX-A) injection. This retrospective, observational study included 25 patients. After removal of the redundant skin and underlying orbicularis oculi muscle (OOM) with or without extended OOM removal to the area of the superior orbital rim, the tarsal plate and the gray line were vertically severed at 2 points to disable the muscle of Riolan. The surgical effectiveness was evaluated using the visual analogue scale (VAS), functional disability score (FDS), and the presence or absence of necessity or enhanced effectiveness of BTX-A injection after surgery. The symptoms improved in 23 patients (92.0%). The VAS and total FDS were significantly improved from 8.4 ± 1.7 to 4.0 ± 2.4 (reduction rate, 50.7 ± 35.6%) and from 74.6 ± 22.2 to 34.7 ± 25.3 (reduction rate, 53.4 ± 27.4%) after surgery, respectively (both, p < 0.001). Among the 23 patients whose symptoms improved after surgery, BTX-A injection was not required in 11 of them (47.8%). Among the remaining 12 patients (52.2%), the effectiveness of BTX-A was post-operatively enhanced in eight patients (34.8%). There were no serious complications, and none of the patients experienced madarosis. Disabling the muscle of Riolan is a valuable option of OOM myectomy in patients with refractory benign essential blepharospasm, without the development of serious complications, including madarosis.

Asian Upper Blepharoplasty in Women: A Comprehensive Approach for a Natural and Aesthetically Pleasing Outcome

Asian upper blepharoplasty is the most popular cosmetic procedure for Asian women. However, there is no standardized approach to this procedure and suboptimal results are still common. The aim of this article was to describe a comprehensive approach to Asian upper blepharoplasty in women and report the clinical outcomes obtained with this approach. The comprehensive approach described here for Asian upper blepharoplasty in women includes: (1) determining the height and length of the upper eyelid skin crease; (2) creating a more optimal anatomy of the upper eyelid by removing excess eyelid skin, a portion of the orbicularis oculi muscle, and septal fat; (3) reconstructing the desired anatomic structures of the upper eyelid skin crease through plication of the levator aponeurosis, if necessary, and closure of the upper eyelid skin incision through the septum and the mobile portion of the levator aponeurosis; (4) adding a medial epicanthoplasty if needed to enhance final cosmetic results. Over a 5-year period, 332 Asian women underwent upper blepharoplasty for creation of double eyelids, or conversion from less visible to more ideal double eyelids, with the above comprehensive approach. There were no surgical complications postoperatively and 326 patients (98.2%) rated their outcome satisfactory over a 5-year follow-up. Only 6 patients (1.8%) required surgical revision for asymmetry or suboptimal shape of the upper eyelid. The comprehensive approach to Asian upper blepharoplasty described here can be used for Asian women and produces a natural and aesthetically pleasing outcome and low revision rates.

Is Orbicularis Oculi Muscle Resection Necessary in Upper Blepharoplasty? A Systematic Review.

Our objective is to evaluate the evidence on the aesthetic effect and complications of skin-OOM strip resection compared to skin only upper blepharoplasty. A systematic search of EMBASE, PubMed, Cochrane and Google Scholar databases was performed using our search strategy through to 31 December 2019. Only comparative studies of the two upper blepharoplasty techniques were included. Three reviewers performed study selection process, data extraction, and quality assessment. A total of six articles were eligible for final inclusion. The included studies consist of two controlled retrospective cohorts and four small randomized controlled studies (RCT). Three of which, were double blinded. Those RCTs were assigned level 2 evidence due to small size and methodological limitations. The sample size of included was studies 407 in the two retrospective studies and 57 in the four RCTs. The outcomes showed that resection of OOM along with skin in upper blepharoplasty showed no difference in long-term aesthetic outcome when skin only procedure is performed. Muscle strip resection was associated with initially higher ophthalmological morbidity (edema, bruising, pain, dry eye, sluggish eye closure and lagopthalmos). Those resolved afew weeks later with conservative treatment. The resection of OOM along with skin in upper blepharoplasty showed no difference in long-term aesthetic outcome and was associated with initially higher ophthalmological morbidity compared to skin only procedure. While we are not suggesting that OOM resection is never required, the evidence strongly support its preservation during standard upper blepharoplasty. 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 Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Relationship Between Eyelid Pressure and Lacrimal Status in Mild Facial Nerve Palsy.

Purpose: Facial nerve palsy is frequently associated with both epiphora and dry eye, and orbicularis oculi muscle weakness or paralysis is the main cause of these symptoms. Eyelid pressure is a quantitatively measurable parameter for evaluating the tone and function of the orbicularis oculi muscle. The aim of this study was to examine the relationship between eyelid pressure and lacrimal status in patients with mild facial nerve palsy.Methods: This prospective, interventional study included 10 patients with unilateral facial nerve palsy. The severity of facial nerve palsy was determined using the CADS scale (cornea, static asymmetry, dynamic function, and synkinesis). Eyelid pressure was measured using a blepharo-tensiometer. Lacrimal status was quantified through tear meniscus height (TMH), clinical assessment of meibomian gland dysfunction (MGD) (eyelid margin abnormalities, Marx line, meibum expression, and loss of meibomian glands), corneal fluorescein staining, tear break-up time, and Schirmer test I results.Results: All 10 patients suffered from mild facial nerve palsy without eyelid ectropion or entropion, or gustatory epiphora. Lower eyelid pressure during forceful eye closure was significantly decreased in affected eyes (P = 0.007), but upper eyelid pressure during forceful eye closure and static upper and lower eyelid pressure were not significantly different between the affected and unaffected sides (P > 0.050). The TMH, MGD, and dry eye measurements showed no significant difference between the affected and unaffected eyes (P > 0.050).Conclusions: Mild facial nerve palsy is associated with decreased lower eyelid pressure during forceful eye closure. However, no other differences in upper eyelid pressure during forceful eye closure, static eyelid pressure, TMH, MGD, or dry eye disease symptoms were noted. These results imply that eyelid pressure slightly decreases due to mild facial nerve palsy, but this change may be clinically negligible.

A Novel Test of the Duchenne Marker: Smiles After Botulinum Toxin Treatment for Crow's Feet Wrinkles.

Smiles that vary in muscular configuration also vary in how they are perceived. Previous research suggests that “Duchenne smiles,” indicated by the combined actions of the orbicularis oculi (cheek raiser) and the zygomaticus major muscles (lip corner puller), signal enjoyment. This research has compared perceptions of Duchenne smiles with non-Duchenne smiles among individuals voluntarily innervating or inhibiting the orbicularis oculi muscle. Here we used a novel set of highly controlled stimuli: photographs of patients taken before and after receiving botulinum toxin treatment for crow’s feet lines that selectively paralyzed the lateral orbicularis oculi muscle and removed visible lateral eye wrinkles, to test perception of smiles. Smiles in which the orbicularis muscle was active (prior to treatment) were rated as more felt, spontaneous, intense, and happier. Post treatment patients looked younger, although not more attractive. We discuss the potential implications of these findings within the context of emotion science and clinical research on botulinum toxin.

Jitter Remains Stable Throughout a Single Fiber EMG Session in Healthy and Myasthenic Muscles.

Fatigability is the hallmark of myasthenia gravis (MG). It is not clear, however, whether there is an analogous increase in jitter during the course of a single fiber electromyography (SFEMG) session. The individual jitter values of all potentials of 76 normal and 44 myasthenic orbicularis oculi muscles were assigned a rank number according to their temporal order in which they were collected and linear regression was performed to determine if the slope of the regression line was significantly different from zero. Control and MG subjects displayed rather flat linear regression lines with non-significant positive or negative slopes. Accordingly, ROC analysis yielded areas under the curve near 0.5. We conclude that there is no systematic jitter increase during the collection of 20 potential pairs in a typical SFEMG session.

Facial mimicry is independent of stimulus format: Evidence for facial mimicry of stick figures and photographs

The present research investigated facial mimicry of the basic emotions joy, anger, and sadness in response to stimuli in different formats. Specifically, in an electromyography study, 120 participants rated the expressions of joyful, angry, and sad faces presented as photographs or stick figures while facial muscle activity was measured. Using both frequentist and Bayesian approaches to hypothesis testing, we found strong support for a facial mimicry effect: Participants showed higher zygomaticus major and orbicularis oculi activity (smiling) towards joyful faces, while they showed higher corrugator supercilii activity (frowning) towards angry and sad faces. Although participants rated the stick figures as more abstract and less interesting stimuli, the mimicry effect was equally strong and independent of the format in which the faces were presented (photographs or stick figures). Additionally, participants showed enhanced emotion recognition for stick figures compared to photographs, which, however, was unrelated to mimicry. The findings suggest that facial mimicry occurs in response to stimuli varying in their abstractness and might be more robust to social-cognitive influences than previously assumed.