Changes of eyebrow muscle activity with aging: functional analysis revealed by electromyography

Enhancing aesthetic outcomes: The role of biomechanics in periorbital and eyelid cosmetic surgery

Cosmetic periorbital and eyelid surgery is a commonly performed procedure in facial plastic surgery. Understanding the biomechanics of periorbital anatomy and its role in aesthetic surgery is essential for achieving optimal outcomes. This review explores the biomechanical processes involved in periorbital age changes and analyzes the impact of cosmetic surgery approaches on these processes. By maintaining the initial mechanical equilibrium of the brows, eyelids, septal fat, and blepharoplasty folds, periorbital and eyelid cosmetic surgery can effectively rejuvenate the appearance. Disruption of this equilibrium can lead to the migration of anatomic components, resulting in signs of aging. Surgeons, by applying biomechanical concepts, can tailor the forces exerted upon the different structures to manifest the patient's aesthetic aspirations. The key to success in periorbital and eyelid cosmetic surgery lies in re-establishing a dynamic mechanical equilibrium within the periorbital framework.

Factors that affect eyelid show and their importance in upper eyelid blepharoplasty: a systematic review

An understanding of the complexity of the surgical anatomy of the upper eyelid and the surrounding structures is mandatory when trying to minimize complications and achieve excellent cosmetic results during eyelid surgery. Postoperative upper eyelid asymmetry is one of the most common causes of patients' dissatisfaction, and several parameters should be taken into consideration when performing cosmetic blepharoplasties and ptosis surgery. Tarsal platform show and brow fat span are two of the most important variables pertaining to the perception of beauty and youthfulness that every oculoplastic and facial plastic surgeon should address when performing such surgery. The aim of this review paper is to provide a detailed anatomy of the upper eyelid and the surrounding structures, to highlight all the relevant factors that contribute to the perception of beauty and the changes that occur to the aging face and to address the preoperative factors that need to be carefully examined before performing upper eyelid surgery.

Does Double-Eyelid Blepharoplasty Improve Forehead Wrinkles? A Prospective Study Using FACE-Q Scale and Anthropometric Measurements

BACKGROUND

Single eyelids are common among Asians. It is not uncommon to see people with single eyelids raise their eyebrows to wide open their eyes. This results in frequent compensatory contraction of the frontalis muscle and thus leads to deep forehead wrinkles. Double-eyelid blepharoplasty creates a larger visual field. In theory, patients who receive the surgery will stop overusing the frontalis muscle. Therefore, the forehead wrinkles can be improved.

METHODS

35 patients who underwent double-eyelid blepharoplasty were enrolled. FACE-Q forehead wrinkle assessment scale was adopted to evaluate the forehead wrinkles preoperatively and postoperatively. In addition, anthropometric measurements were taken to indirectly evaluate frontalis muscle contraction in maximum eye-opening position.

RESULTS

According to the FACE-Q scale, forehead wrinkles were improved after double-eyelid blepharoplasty, and the improvement was long-lasting in the 3-month follow-up. This was because the frontalis muscle contraction reduced after the surgery, as shown by the anthropometric measurements.

CONCLUSION

This study used subjective and objective methods to prove that double-eyelid surgery improves forehead wrinkles.

LEVEL OF EVIDENCE IV

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Expert Opinion on Non-Surgical Eyebrow Lifting and Shaping Procedures

Eyebrow elevation and reshaping are common concerns that we handle in everyday practice, and we have noticed that the trend is shifting from a medical concern to a cosmetic one. Several eyebrow lift methods are available, both invasive and non-surgical. The method of choice depends on several factors, such as patient expectations and beliefs, financial budget, acceptance of downtime and the available tools in the practice. In this article, we review the recent literature on non-surgical eyebrow lift methods to provide an overview of the current state of this field. We discuss seven different methods for eyebrow lift and reshaping, including botulinum toxin, dermal fillers, fractional radiofrequency, high-intensity focused ultrasound, thermo-mechanical ablation, lasers, and threads. Moreover, we provide practical insight into the procedure, injection techniques, expected results, and patient satisfaction rate.

Aesthetic implications of depressor supercilii muscle block with botulinum toxin type A

INTRODUCTION

When applying botulinum toxin in the upper third of the face, it is important to consider the balance between the elevator and depressor muscles of the eyebrows. Depressor supercilii muscle block leads to elevation of the medial portion of the eyebrow and correction of the oblique lines in the frown.

OBJECTIVES

The intention is to highlight the importance of the depressor supercilii muscle block as a useful tool to reposition the medial portion of the eyebrow.

PATIENTS AND METHODS

Three cases are presented, in whom botulinum toxin is applied conventionally and subsequently on the depressor supercilii muscle after the subjective sensation of flattening of the glabella and increasing distance between the eyebrows referred by the patients.

RESULTS

The application of botulinum toxin type A on the depressor supercilii muscle is an effective measure to facilitate the elevation of the medial portion of the eyebrow, after the conventional application in between the eyebrows treating the orbicularis, corrugator, and procerus muscles.

CONCLUSIONS

Depressor supercilii muscle block can be considered when applying botulinum toxin type A in the upper third of the face, in cases where there is loss of facial aesthetic harmony. This is given by the subjective perspective of the patient due to a change in the natural expression of their face with a sensation of flattening of the glabella and distancing of the medial portion of the eyebrows, occurring after the use of a conventional technique at that anatomical level, where patients may report a "feline" or "avatar" appearance.

Objective quantification of the impact of blepharoplasty on the superior visual field

Background

Blepharoplasty has both aesthetic and functional benefits in patients with pseudoptosis; however, previous studies could not demonstrate its beneficial effects quantitatively and objectively. The authors objectively analyzed the visual field before and after surgery and investigated whether measurements of the visual field can be applied as a suitable predictor of surgical outcomes.

Methods

In total, 18 eyelids in nine patients with pseudoptosis who had undergone simple skin excision blepharoplasty were evaluated prospectively from February to May 2016. The visual fields were analyzed preoperatively and 3 months postoperatively using the Goldmann kinetic perimetry test. The visual field test area was assessed using Adobe Photoshop.

Results

Blepharoplasty had an average 4.99-fold beneficial effect on the superior visual field. In particular, more improvement was seen in the superior temporal quadrant than in the nasal quadrant. No correlation was found between the preoperative margin-to-reflex distance 1 (MRD1) and the surgical outcome (P=0.119). However, there was a strong correlation between the preoperative superior visual field and the surgical outcome (P=0.001).

Conclusions

Using the Goldmann kinetic perimetry test, we objectively and quantitatively proved the beneficial effect of blepharoplasty on patients with pseudoptosis. Furthermore, we demonstrated that the preoperative visual field is a better preoperative surgical outcome predictive factor than the preoperative MRD1.

Firing rate trajectories of human occipitofrontalis motor units in response to triangular voluntary contraction intensity

During voluntary contractions, limb muscle motor unit (MU) firing rates accelerate over a small force range and saturate in response to increasing contraction intensity. In comparison, facial muscles are cranially innervated, and some function without crossing joints. Therefore, the MU firing rate behaviour and characteristics of saturation were explored in a facial muscle that moves skin and facia during voluntary contractions. We evaluated the firing rate trajectory in response to triangular voluntary contraction ramps in the occipitofrontalis muscle of 11 adult participants. Intramuscular electromyography of the frontalis aspect was used to record single MU trains followed up to maximal voluntary contraction intensities. Firing rates were measured from each MU sample, with the firing rate trajectory fit as both exponential (i.e., saturation) and linear models that were compared statistically. The rate coding behaviour of frontalis MUs was broad, as the peak firing rate (mean 76 Hz) was ninefold greater than the firing rate at recruitment threshold (mean 8 Hz). Across 20 MU samples, only 40% (8 MU samples) were determined to have a firing rate trajectory that saturated and had slow acceleration in response to increasing voluntary drive until maximum. The exponential curve of the firing rate trajectory had ~ tenfold lower acceleration as compared to prior reports in limb muscles. These results across all MU samples indicated that voluntary control of the frontalis muscle requires relatively slower accelerating or linear MU firing rate trajectories, suggesting that movements of facial muscles may be directly representative of extrinsic synaptic inputs.

The Facial Aging Process From the "Inside Out"

The normal course of aging alters the harmonious, symmetrical, and balanced facial features found in youth, not only impacting physical attractiveness but also influencing self-esteem and causing miscommunication of affect based on facial miscues. With this evidence-based paper, the authors aim to provide a comprehensive overview of the latest research on the etiology and progression of facial aging by explaining the aging process from the “inside out,” that is, from the bony platform to the skin envelope. A general overview of the changes occurring within each of the main layers of the facial anatomy is presented, including facial skeleton remodeling, fat pad atrophy or repositioning, changes in muscle tone and thickness, and weakening and thinning of the skin. This is followed by an in-depth analysis of specific aging regions by facial thirds (upper, middle, and lower thirds). This review may help aesthetic physicians in the interpretation of the aging process and in prioritizing and rationalizing treatment decisions to establish harmonious facial balance in younger patients or to restore balance lost with age in older patients.

Changes in Computer-Analyzed Facial Expressions with Age

Facial expressions are well known to change with age, but the quantitative properties of facial aging remain unclear. In the present study, we investigated the differences in the intensity of facial expressions between older (n = 56) and younger adults (n = 113). In laboratory experiments, the posed facial expressions of the participants were obtained based on six basic emotions and neutral facial expression stimuli, and the intensities of their faces were analyzed using a computer vision tool, OpenFace software. Our results showed that the older adults expressed strong expressions for some negative emotions and neutral faces. Furthermore, when making facial expressions, older adults used more face muscles than younger adults across the emotions. These results may help to understand the characteristics of facial expressions in aging and can provide empirical evidence for other fields regarding facial recognition.

A Retrospective Study Supporting the Importance of Individualizing the Dose of Botulinum Toxin According to the Age

BACKGROUND

Botulinum toxin type A injection remains the leading nonsurgical cosmetic procedure worldwide with a high rate of efficacy and patient satisfaction.

OBJECTIVE

This study aims to demonstrate the importance of individualization of botulinum toxin doses to treat the upper face according to the age of the patients, considering the muscles particularities and the specificities of each face area.

MATERIALS AND METHODS

A retrospective study with 389 female patients treated with botulinum toxin type A in the upper third of the face (forehead, glabellar, and periorbital lines). Statistical analysis of the data was performed.

RESULTS

The mean age was 47.49 years old and the median total dose of botulinum toxin type A was 53.76 units, whereas the median dose in the glabella was 26.28 U, the mean forehead dose was 12.23 U, and in the periorbital area was 14.79 U, adding both sides. It is possible to observe that the doses are negatively correlated with age, except in the periorbital area, where an increase in the dose was observed.

CONCLUSION

It is important to highlight that although there is consensus on pre-established dose suggestions, the treatment should be individualized, respecting the individual characteristics of each patient.

Developing a pain intensity prediction model using facial expression: A feasibility study with electromyography

The automatic detection of facial expressions of pain is needed to ensure accurate pain assessment of patients who are unable to self-report pain. To overcome the challenges of automatic systems for determining pain levels based on facial expressions in clinical patient monitoring, a surface electromyography method was tested for feasibility in healthy volunteers. In the current study, two types of experimental gradually increasing pain stimuli were induced in thirty-one healthy volunteers who attended the study. We used a surface electromyography method to measure the activity of five facial muscles to detect facial expressions during pain induction. Statistical tests were used to analyze the continuous electromyography data, and a supervised machine learning was applied for pain intensity prediction model. Muscle activation of corrugator supercilii was most strongly associated with self-reported pain, and the levator labii superioris and orbicularis oculi showed a statistically significant increase in muscle activation when the pain stimulus reached subjects' self -reported pain thresholds. The two strongest features associated with pain, the waveform length of the corrugator supercilii and levator labii superioris, were selected for a prediction model. The performance of the pain prediction model resulted in a c-index of 0.64. In the study results, the most detectable difference in muscle activity during the pain experience was connected to eyebrow lowering, nose wrinkling and upper lip raising. As the performance of the prediction model remains modest, yet with a statistically significant ordinal classification, we suggest testing with a larger sample size to further explore the variables that affect variation in expressiveness and subjective pain experience.

Parallel-excision infrabrow blepharoplasty with extensive excision of the orbicularis oculi muscle in an Asian population

Background

Infrabrow blepharoplasty has become a common surgical method used to rejuvenate aged upper eyelids in Asians. In this paper, we describe the parallel excision method for infrabrow blepharoplasty as a useful alternative to the conventional elliptical excision method. The authors’ experience over a 3-year period is presented and reviewed.

Methods

A retrospective review of parallel excision infrabrow blepharoplasty cases at our hospital between 2014 and 2017 was performed. Three oculoplastic surgeons compared preoperative and postoperative photographs using the Strasser grading system.

Results

From the medical records of 123 patients, a total of 93 patients with moderate-to-severe bilateral dermatochalasis were selected as subjects. The exclusion criterion was levator function less than 8 mm. The total mean follow-up period was 2 years (range, 0.5–3.5 years). The mean skin excision height and width were 9.75 mm (range, 5–16 mm) and 58.51 mm (range, 42–75 mm), respectively. All patients who underwent surgery recovered without major complications, and all patients had high levels of satisfaction and improvements in their visual field. In the Strasser evaluation performed by the oculoplastic surgeons, most patients were found to have excellent results.

Conclusions

The parallel excision method for infrabrow blepharoplasty is a safe and effective technique that yields more natural- and youthful-looking eyelids than the conventional elliptical excision method. In our method, more effective manipulation of the orbicularis oculi muscle led to a reduction in frontalis compensation, resolution of sunken eyelids, and correction of lateral hooding.

Eyebrow Height Changes with Aging: A Systematic Review and Meta-analysis

The eyebrows play an important role in emotional facial expressions, nonverbal communication, and facial esthetics. A comprehensive understanding of the mechanisms underlying eyebrow aging is vital in allowing plastic surgeons to appropriately address these age-related changes and to recreate an aesthetically desirable outcome for patients seeking brow rejuvenation. The aim of this study is to summarize the current literature on eyebrow height changes with aging.

Variability of facial movements in relation to sexual dimorphism and age: three-dimensional geometric morphometric study

The aim of this study was to introduce suitable imaging technique and analytical methods for a detailed description of the facial movements in relation to sexual dimorphism and age in adult individuals. Removing of size factor from the analysis, we hypothesised that there will be no significant intersexual difference in facial mobility. We assume facial movements to be more pronounced in the older age category due to increasing the facial surface. We have compared five facial movements - raising eyebrows, closing eyes, pursing of the lips, inflating of the cheeks and smile - in relation to neutral expression of the human face. The material sample comprised three-dimensional facial surface models of healthy adult individuals of the Czech nationality (63 females, 58 males). Methods of geometric morphometry and multivariate statistics were used. Local tissue motion due to facial movements was expressed using colour-coded maps. The movement showing significant intersexual difference was inflating of the cheeks. Ageing in both sexes has significantly influenced the facial mobility on average after 50 years of age. Changes related to senescence have occurred in eye closing, smile and inflating of the cheeks. An enlarged facial surface has been noted in the group of individuals belonging to the older age category, what is probably the result of increased manifestation of skin folds and wrinkles. This is related to the loss of skin elasticity and overall weakening of the underlying muscles, especially in the infraorbital and cheeks area.

Changes in Eyebrow Position and Movement with Aging

Background

This study evaluated dynamic changes in eyebrow position related to aging.

Methods

Female participants were recruited and separated into two groups aged 20–30 years (the younger group, n=20; mean age, 24.8 years) and 50–70 years (the older group, n=20; mean age, 55.8 years). Photogrammetry was used to determine the eyebrow position at the medial canthus (MC), lateral limbus, lateral canthus, and lateral end point (EP) for 6 actions: smooth opening (the reference action) and closing of the eye, forward gaze, maximum opening and closing of the eye, and maximum frown. Videos were also recorded.

Results

No differences in eyebrow position were detected at the MC when opening or closing the eyes smoothly, gazing straight ahead, or closing the eyes maximally. For all 6 actions, the position of the lateral EP in the older group was significantly lower than in the younger group (P=0.003), and the smallest degree of vertical movement at this point was found in both age groups (P<0.001). Vertical movement at the 4 landmarks of the eyebrows decreased with aging.

Conclusions

Eyebrow position was unchanged at the MC with aging, except at maximal eye opening and maximal frown. No differences in eyebrow position were observed between the younger and older groups when eyes were maximally closed, except at the EP. It is important to focus on correction of the lateral EP for periorbital rejuvenation.

Anatomy of Forehead, Glabellar, Nasal and Orbital Muscles, and Their Correlation with Distinctive Patterns of Skin Lines on the Upper Third of the Face: Reviewing Concepts

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 http://www.springer.com/00266 .

Surface electromyography analysis of blepharoptosis correction by transconjunctival incisions

Upper eyelid movement depends on the antagonistic actions of orbicularis oculi muscle and levator aponeurosis. Blepharoptosis is an abnormal drooping of upper eyelid margin with the eye in primary position of gaze. Transconjunctival incisions for upper eyelid ptosis correction have been a well-developed technique. Conventional prognosis however depends on clinical observations and lacks of quantitatively analysis for the eyelid muscle controlling. This study examines the possibility of using the assessments of temporal correlation in surface electromyography (SEMG) as a quantitative description for the change of muscle controlling after operation. Eyelid SEMG was measured from patients with blepharoptosis preoperatively and postoperatively, as well as, for comparative study, from young and aged normal subjects. The data were analyzed using the detrended fluctuation analysis method. The results show that the temporal correlation of the SEMG signals can be characterized by two indices associated with the correlation properties in short and long time scales demarcated at 3ms, corresponding to the time scale of neural response. Aging causes degradation of the correlation properties at both time scales, and patient group likely possess more serious correlation degradation in long-time regime which was improved moderately by the ptosis corrections. We propose that the temporal correlation in SEMG signals may be regarded as an indicator for evaluating the performance of eyelid muscle controlling in postoperative recovery.

Reversal of neuromuscular block with sugammadex: a comparison of the corrugator supercilii and adductor pollicis muscles in a randomized dose-response study

BACKGROUND

Neuromuscular monitoring using the corrugator supercilii muscle is associated with a number of challenges. The aim of this study was to assess reversal of a rocuronium-induced neuromuscular blockade with sugammadex according to monitoring either using the corrugator supercilii muscle or the adductor pollicis muscle. We hypothesized that a larger dose of sugammadex would be required to obtain a train-of-four (TOF) ratio of 1.0 with the corrugator supercilii muscle than with the adductor pollicis muscle.

METHODS

Forty patients aged 20-60 years and 40 patients aged ≥ 70 years were enrolled. After induction of anesthesia, we recorded the corrugator supercilii muscle response to facial nerve stimulation and the adductor pollicis muscle response to ulnar nerve stimulation using acceleromyography. All patients received 1 mg/kg rocuronium. When the first twitch (T1) of TOF recovered to 10% of control values at the corrugator supercilii, rocuronium infusion was commenced to maintain a T1 of 10% of the control at the corrugator supercilii. Immediately after discontinuation of rocuronium infusion, 2 mg/kg or 4 mg/kg of sugammadex was administered. The time for recovery to a TOF ratio of 1.0 and the number of patients not reaching a TOF ratio of 1.0 by 5 min at each dose and muscle was recorded.

RESULTS

When neuromuscular block at the corrugator supercilii was maintained at a T1 of 10% of control, that at the adductor pollicis was deep (post-tetanic count ≤ 5). Sugammadex 4 mg/kg completely antagonized neuromuscular block at both muscles within 5 min. The time to a TOF ratio of 1.0 at the adductor pollicis was significantly longer in the group ≥ 70 years than the group 20-60 years (mean (SD): 178 (42.8) s vs. 120 (9.4) s, P < 0.0001). In contrast, 2 mg/kg sugammadex reversed neuromuscular blockade at the corrugator supercilii but not at the adductor pollicis, with 10 patients in the group 20-60 years and 8 patients in the group ≥ 70 years requiring an additional sugammadex (P < 0.05 vs. 4 mg/kg sugammadex).

CONCLUSION

Sugammadex 4 mg/kg was required to reverse a moderate rocuronium-induced neuromuscular block when the corrugator supercilii muscle is used for monitoring.