Depressor Muscles Research Articles

Favorable Clinical Outcomes After Humeral Head Depressor Muscle Coactivation Training With EMG for Patients With Arthroscopic Rotator Cuff Repair: A Randomized Controlled Trial.

The coactivation (Co-A) of shoulder muscles that contribute to humeral head depression can lead to mechanical unloading of the subacromial structures during abduction and thus can be beneficial for patients with arthroscopic rotator cuff repair (ARCR). The present study aims to examine the effectiveness of humeral head depressor muscle Co-A (DM-Co-A) training on clinical outcomes in a sample of patients with ARCR. We hypothesized that DM-Co-A training with medioinferior vector during glenohumeral exercises can improve clinical results in the rehabilitation of ARCR. Randomized controlled single-blind study. Level 1B. A total of 27 patients who underwent ARCR after a medium-sized rotator cuff tear and completed their Phase 1 training with ≥80% compliance were included. Together with 14 weeks of conservative treatment (6 weeks of Phase 2 training and 8 weeks of Phase 3 training), synchronized "DM-Co-A Training" was applied to the treatment group with an electromyography (EMG) biofeedback (EMG-BF) device. Patients in the treatment group were asked to voluntarily activate the humeral head depressor muscles guided by visual and auditory feedback of the EMG-BF device during the Phase 2 and Phase 3 conservative treatment exercises performed by the control group. Demographic characteristics of the participants were recorded. Visual analog scale and universal goniometer were used to assess pre- and posttreatment pain severity and joint range of motion, respectively. The Disabilities of Arm, Shoulder and Hand Questionnaire, Revised Oxford Shoulder Score, Modified Constant-Murley Shoulder Score, and the Western-Ontario Rotator Cuff Index were used to assess functionality. There was a clinically meaningful improvement in pain severity, active ROM excluding internal rotation, and functionality in the treatment group compared with the control group (P < 0.05). A 14-week duration DM-Co-A with EMG may be beneficial in the postoperative rehabilitation of patients after ARCR.

The synaptic drive of central pattern-generating networks to leg motor neurons of a walking insect is motor neuron pool specific.

Rhythmic locomotor activity, such as flying, swimming, or walking, results from an interplay between higher-order centers in the central nervous system, which initiate, maintain, and modify task-specific motor activity, downstream central pattern-generating neural circuits (CPGs) that can generate a default rhythmic motor output, and, finally, feedback from sense organs that modify basic motor activity toward functionality.1,2,3 In this context, CPGs provide phasic synaptic drive to motor neurons (MNs) and thereby support the generation of rhythmic activity for locomotion. We analyzed the synaptic drive that the leg MNs supplying the three main leg joints receive from CPGs in pharmacologically activated and deafferented preparations of the stick insect (Carausius morosus). We show that premotor CPGs pattern the tonic activity of five of the six leg MN pools by phasic inhibitory synaptic drive. These are the antagonistic MN pools supplying the thoraco-coxal joint and the femur-tibial joint4,5 and the levator MN pool supplying the coxa-trochanteral (CTr) joint. In contrast, rhythmic activity of the depressor MN pool supplying the CTr joint was found to be primarily based on a phasic excitatory drive. This difference is likely related to the pivotal role of the depressor muscle in generating leg stance during any walking situation. Thus, our results provide evidence for qualitatively differing mechanisms to generate rhythmic activity between MN pools in the same locomotor system.

Preoperative assessment of depressor anguli oris to prevent myectomy failure: An anatomical study using high-resolution ultrasound

Myectomies of the lower lip depressor muscles have unexplained high failure rates. This study aimed to examine the depressor anguli oris (DAO) muscle using high-resolution ultrasound to identify potential anatomical explanations for surgical failures and to determine the accuracy of utilizing preoperative ultrasound assessment to improve myectomies. Anatomical features of DAO and the surrounding anatomy were examined in 38 hemifaces of human body donors using high-resolution ultrasound and dissection. The ultrasound and dissection measurements showed the DAO muscle width to be 16.2±2.9 versus 14.5±2.5mm, respectively, and the location of the lateral muscle border 54.4±5.7 versus 52.3±5.4mm lateral to the midline. In 60% of the cases, the facial artery was either completely covered by lateral DAO muscle fibers or was found to be in direct contact with the lateral border. Significant muscle fiber continuity was present between the DAO and surrounding muscles in 5% of cases, whereas continuity between the depressor labii inferioris and surrounding muscles was considerably more common and pronounced. High-resolution ultrasound can accurately reveal important preoperative anatomical information in myectomies. Two potential explanations for the surgical failures were discovered: an overlap of lateral DAO muscle fibers over the facial artery could lead to inadequate resections and continuity with the surrounding muscles might lead to muscle function takeover despite adequate resections. Both can be uncovered preoperatively by the surgeon through a brief, directed ultrasound examination, which may allow for modification of the surgical plan to reduce surgical failure.

Twist is required for muscle development of the adult legs in Henosepilachna vigintioctopunctata.

Although muscle development has been widely studied in Drosophila melanogaster, it was a great challenge to apply to developmental processes of other insect muscles. This study was focused on the functional characterization of a basic helix-loop-helix transcription factor gene twist in an herbivorous ladybird Henosepilachna vigintioctopunctata. Its transcript (Hvtwist) levels were detected in all developmental stages. RNA interference (RNAi)-aidedknockdown of Hvtwist at the penultimate larval instar stage impaired pupation, and caused a deformed adult in the legs. The tarsi were malformed and did not support the bodies in an upright position. The climbing ability was impaired. Moreover, around 50% of the impaired adults had a malformed elytrum. In addition, they consumed less foliage and did not lay eggs. A hematoxylin-eosin staining of the leg demonstrated that the tibial extensor (TE)and the tibial flexor (TF)muscles were originated from the femurs while levator and depressor muscles of the tarsus (TLand TD) were located in the tibia in the control adults, in which tarsal segments were devoid of muscles. RNAi treatment specific to Hvtwist expression markedly impaired TE and TF muscles in the femurs, and prevented the development of TL and TD muscles in the tibia. Therefore, our findings demonstrate Twist plays a vital role in the myogenesis in H. vigintioctopunctata adult legs.

Upper beak depression instead of elevation dominates cranial kinesis in woodpeckers.

The value of birds' ability to move the upper beak relative to the braincase has been shown in vital tasks like feeding and singing. In woodpeckers, such cranial kinesis has been thought to hinder pecking as delivering forceful blows calls for a head functioning as a rigid unit. Here, we tested whether cranial kinesis is constrained in woodpeckers by comparing upper beak rotation during their daily activities such as food handling, calling and gaping with those from closely related species that also have a largely insectivorous diet but do not peck at wood. Both woodpeckers and non-woodpecker insectivores displayed upper beak rotations of up to 8 degrees. However, the direction of upper beak rotation differed significantly between the two groups, with woodpeckers displaying primarily depressions and non-woodpeckers displaying elevations. The divergent upper beak rotation of woodpeckers may be caused either by anatomical modifications to the craniofacial hinge that reduce elevation, by the caudal orientation of the mandible depressor muscle forcing beak depressions, or by both. Our results suggest that pecking does not result in plain rigidification at the upper beak's basis of woodpeckers, but it nevertheless significantly influences the way cranial kinesis is manifested.

Parallel And Divergent Morphological Adaptations Underlying The Evolution of Jumping Ability in Ants.

Jumping is a rapid locomotory mode widespread in terrestrial organisms. However, it is a rare specialization in ants. Forward jumping has been reported within four distantly related ant genera: Gigantiops, Harpegnathos, Myrmecia, and Odontomachus. The temporal engagement of legs/body parts during jump, however, varies across these genera. It is unknown what morphological adaptations underlie such behaviors and whether jumping in ants is solely driven directly by muscle contraction or additionally relies on elastic recoil mechanism. We investigated the morphological adaptations for jumping behavior by comparing differences in the locomotory musculature between jumping and non-jumping relatives using X-ray micro-CT and 3D morphometrics. We found that the size-specific volumes of the trochanter depressor muscle (scm6) of the middle and hind legs are 3-5 times larger in jumping ants, and that one coxal remotor muscle (scm2) is reduced in volume in the middle and/or hind legs. Notably, the enlargement in the volume of other muscle groups is directly linked to the legs or body parts engaged during the jump. Furthermore, a direct comparison of the muscle architecture revealed two significant differences between jumping vs. non-jumping ants: First, the relative Physiological Cross-Sectional Area (PCSA) of the trochanter depressor muscles of all three legs were larger in jumping ants, except in the front legs of Odontomachus rixosus and Myrmecia nigrocincta; second, the relative muscle fiber length was shorter in jumping ants compared to non-jumping counterparts, except in the front legs of O. rixosus and M. nigrocincta. These results suggest that the difference in relative muscle volume in jumping ants is largely invested in the area (PCSA), and not in fiber length. There was no clear difference in the pennation angle between jumping and non-jumping ants. Additionally, we report that the hind leg length relative to body length was longer in jumping ants. Based on direct comparison of the observed vs. possible work and power output during jumps, we surmise that direct muscle contractions suffice to explain jumping performance in three species, except for O. rixosus, where the lack of data on jumping performance prevents us from drawing definitive conclusions for this particular species. We suggest that increased investment in jumping-relevant musculature is a primary morphological adaptation that separates jumping from non-jumping ants. These results elucidate the common and idiosyncratic morphological changes underlying this rare adaptation in ants. まとぅみ (Okinawan language-Uchinaaguchi) (Japanese) РЕЗЮМЕ (Kazakh) ZUSAMMENFASSUNG (German).

Modeling the musculoskeletal system of an insect thorax for flapping flight

Indirect actuation of the wings via thoracic deformation is a unique mechanism widely observed in flying insect species. The physical properties of the thorax have been intensively studied in terms of their ability to efficiently generate wingbeats. The basic mechanism of indirect wing actuation is generally explained as a lever model on a cross-sectional plane, where the dorsoventral movement of the mesonotum (dorsal exoskeleton of the mesothorax) generated by contractions of indirect muscles actuates the wing. However, the model considers the mesonotum as an ideal flat plane, whereas the mesonotum is hemispherical and becomes locally deformed during flight. Furthermore, the conventional model is two-dimensional; therefore, three-dimensional wing kinematics by indirect muscles have not been studied to date. In this study, we develop structural models of the mesonotum and mesothorax of the hawkmoth Agrius convolvuli, reconstructed from serial cross-sectional images. External forces are applied to the models to mimic muscle contraction, and mesonotum deformation and wing trajectories are analyzed using finite element analysis. We find that applying longitudinal strain to the mesonotum to mimic strain by depressor muscle contraction reproduces local deformation comparable to that of the thorax during flight. Furthermore, the phase difference of the forces applied to the depressor and elevator muscles changes the wing trajectory from a figure eight to a circle, which is qualitatively consistent with the tethered flight experiment. These results indicate that the local deformation of the mesonotum due to its morphology and the thoracic deformation via indirect power muscles can modulate three-dimensional wing trajectories.

The Surgical Anatomy of the Jowl and the Mandibular Ligament Reassessed

IntroductionA visible jowl is a reason patients consider lower facial rejuvenation surgery. The anatomical changes that lead to formation of the jowl remain unclear. The aim of this study was to elucidate the anatomy of the jowl, the mandibular ligament and the labiomandibular crease, and their relationship with the marginal mandibular branch of the facial nerve.Materials and MethodsForty-nine cadaver heads were studied (16 embalmed, 33 fresh, mean age 75 years). Following preliminary dissections and macro-sectioning, a series of standardized layered dissections were performed, complemented by histology, sheet plastination and micro-CT.ResultsThe jowl forms in the subcutaneous layer where it overlies the posterior part of the mandibular ligament. The mandibular ligament proper exists only in the deep, sub-platysma plane, formed by the combined muscular attachment to the mandible of the specific lower lip depressor muscles and the platysma. The mandibular ligament does not have a definitive subcutaneous component. The labiomandibular crease inferior to the oral commissure marks the posterior extent of the fixed dermal attachment of depressor anguli oris.ConclusionJowls develop as a consequence of aging changes on the functional adaptions of the mouth in humans. To accommodate wide jaw opening with a narrowed commissure requires hypermobility of the tissues overlying the mandible immediately lateral to the level of the oral commissure. This hypermobility over the mandibular attachment of the lower lip depressor muscles occurs entirely in the subcutaneous layer to allow the mandible to move largely independent from the skin. The short, elastic subcutaneous connective tissue, which allows this exceptional mobility without laxity in youth, lengthens with aging, resulting in laxity. The development of subcutaneous and dermal redundancy constitutes the jowl in this location.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 www.springer.com/00266."Graphical

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

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. 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. 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. 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. 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.

Creating Lift in the Lower Face With Botulinum Toxin A Treatment: An Anatomical Overview With Videos and Case Studies Illustrating Patient Evaluation and Treatment.

BackgroundRelaxation of depressor muscles in the lower face with botulinum toxin A (BoNT-A) can create a lifting effect and dramatically improve jawline contour and resting facial expression. Even with the recent increase in interest in lower face rejuvenation, BoNT-A is a relatively under-recognized tool for treatment of this area. When treating the lower face, an understanding of anatomy and the relationship between the facial muscles is especially important, as injection patterns must be customized for consistently positive outcomes.ObjectivesThis study was aimed to provide basic knowledge of the activities of the muscles in the lower face and neck and to describe the basis for injecting BoNT-A to create lift in this area. Expert guidance for injection is also provided.MethodsAs part of a continuing medical education course on differentiating botulinum toxin products, a panel of 4 expert physician injectors participated in a live webinar to discuss the implications of increasing toxin use.ResultsThe practical guidance in this manuscript is based on the most frequently requested information by audience members and the information considered critical for success by the authors. The authors outline the functional anatomy of the lower face most relevant for BoNT-A treatment and case studies as well as methods for patient evaluation and injection technique are also provided. Videos showing treatment planning and injection technique for the lower face and neck are included.ConclusionsBoNT-A is an important nonsurgical tool for creating lift in the lower face.Level of Evidence: 5

The safety and efficacy of botulinum toxin A on the treatment of depression.

ObjectivesEffective strategy for the treatment of depression is limited. This study was to evaluate the safety and efficacy of botulinum toxin A (BoNT/A) in the treatment of depression.MethodsSeventy‐six patients were assigned to the BoNT/A group (n = 52) and sertraline control group (n = 24). For the BoNT/A group, BoNT/A was injected into the frowning muscle, depressor muscle, occipital frontalis muscle, lateral canthus, and bilateral temporal region at 20 sites. Five units per site and a total of 100 units of BoNT/A were given. Patients in the sertraline control group were medicated with sertraline 50–200 mg (114.58 ± 52.08 mg) per day. Depression was assessed by the 17‐item Hamilton Depression Scale (HAMD‐17), 14‐item Hamilton Anxiety Scale (HAMA‐14), Self‐rating Depression Scale (SDS), and Self‐rating Anxiety Scale (SAS). All participants were followed up for 12 weeks.ResultsScores of HAMD, HAMA, SDS, and SAS decreased significantly in both BoNT/A and sertraline groups after treatment for 12 weeks. Overall, there were no differences in decreased magnitude between the two groups (p > .05). The HAMA, SDS, and SAS results showed that the onset time of BoNT/A was earlier than that of sertraline. Side effects rates were 15.38% for BoNT/A and 33.33% for sertraline.ConclusionThis study demonstrated significant antidepressant effects of BoNT/A. The efficacy of BoNT/A was comparable with established antidepressant sertraline. The onset time of BoNT/A was earlier than sertraline, and the proportion of side effects was less than sertraline. Therefore, BoNT/A could be a safe and effective option for the treatment of depression.

Polymelia, vent duplex, cloacal bursa duplex and triple caeca in a broiler chick

Congenital abnormalities are common among avian and mammalian species. They could be partial or total drift from the normal structural organization of the organ-systems. This article is aimed at reporting the occurrence of multiple abnormalities in a 3-week-old broiler chick. Ante mortem, post-mortem, radiological and osteological investigations were carried out, to ascertain the number and form of abnormalities present in the chick. A total of four different congenital abnormalities were discovered in this chick. These include: polymelia (presence of supernumerary or accessory limb which is usually malformed); double vents (vent duplex); double cloacal bursae (bursa duplex) and triple caeca. Radiological and postmortem examinations revealed the attachment of the accessory limb to the caudal depressor muscle as a form of synsarcosis, via a tendon that originated from the deep fossa of the modified femoral head of the accessory limb. The right vent was patent whereas the left was not. The two cloacal bursae were almost the same size, while the three caeca showed slight variation in length but typical features of the avian caecum (base, middle (body) and apex) were clearly visible. However, most cases of congenital anomalies in the avian species occur as multiple defects, with the most common being polymelia. The latest finding in this report is the discovery of double cloacal bursae (bursae of Fabricius), which has not been reported in the avian species.

Tip Droop Prevention in Rhinoplasty: Dynamic Effect of Strut Graft on Smiling versus Depressor Muscle Release.

Background:Aesthetic rhinoplasty is one of the most challenging procedures performed by aesthetic surgeons. Tip droop, especially on smiling, may not be noted by the surgeon postoperatively but can be concerning to patients. Our aim was to determine if the division of the depressor septi nasi or its combination with a columellar strut graft during rhinoplasty produce a measurable reduction in nasal tip droop on smiling.Methods:A retrospective casenote and photograph review was conducted on patients who had undergone aesthetic endonasal rhinoplasty, performed by a single surgeon between 2015 and 2019. In total, 29 patients had release of the depressor septi nasi muscle, whilst 11 had release of the muscle along with a strut graft. Lateral smiling photographs were taken postoperatively. Tip droop was measured as a variation of the nasolabial angle from rest to smiling using the Frankfurt line.Results:Photographs were taken at a mean of 14 months postoperatively. In the group who had muscle release only, a mean increase in nasolabial angle of 3.66 degrees was seen when smiling when compared with rest. In the group who had muscle release combined with strut graft, a mean increase of 2.27 degrees was seen. When using a columellar strut along with muscle release, tip droop on smiling was reduced.Conclusions:This study demonstrates that columellar strut grafting in combination with muscle release can alleviate drooping of the tip better than muscle division alone after rhinoplasty. The columellar strut graft provides tip stability and can therefore be used to enhance dynamic outcomes after rhinoplasty.

Chimeric Latissimus Dorsi Flap in One-Stage Reconstruction of Depressor Muscle Dysfunction and Depression Deformity in the Perimandibular Area.

Depression deformity and paralysis of depressor muscles (DMs) may occur following tumor resection in the perimandibular region. Obtaining satisfactory results is challenging. The authors report 3 cases of 1-stage reconstruction by transferring neurovascular chimeric latissimus dorsi (LD) musculo-adipose flaps, with satisfactory results. Three patients with depression deformity and DMs dysfunction after tumor resection in the perimandibular region underwent chimeric LD flap transfer. The flap comprised 1 portion with adipose tissue for augmentation, and the other contained muscle bellies with 1 or 2 neural pedicle (s) for DM reanimation. In case 1, the neural pedicle was sutured to the contralateral marginal mandibular branch. In case 2, the neural pedicle was sutured to the ipsilateral marginal mandibular branch. In case 3, the neural pedicle was sutured to both branches of the facial nerve. All patients were satisfied with the deformity corrections. However, contractions of the transferred muscles varied. Case 1 showed insufficient contraction. Case 2 had excessive muscle contraction. In case 3, the muscle had double innervation, and well-balanced contraction was maintained for 3 years. Neurovascular chimeric LD flaps are versatile and useful for secondary reconstruction after tumor resection for functional loss of mimetic muscles. The ipsilateral facial nerve may be an effective motor source.

Anatomical Features in Lower-Lip Depressor Muscles for Optimization of Myectomies in Marginal Mandibular Nerve Palsy.

Myectomies of the lower-lip depressor muscles, with the aim to improve facial balance in unilateral facial paralysis, have unexplained high recurrence rates. A potential explanation is that these recurrences are due to inadequate resection through the muscle width, leaving lateral muscle fibers intact. Revisit the anatomy of the lower-lip depressor muscles and suggest an optimization of the surgical technique. Perform a literature review to identify recurrence rates and surgical technique of the procedure. Ten fresh hemifaces were dissected. The following measurements of depressor labii inferioris and depressor anguli oris were made: the widths of the muscles, the distance from the mandibular midline to the lateral borders of the muscles, and the intraoral distance from the lateral canine to the lateral border of depressor anguli oris. A literature review was performed. The width of depressor labii inferioris was 20 ± 4 mm and depressor anguli oris 14 ± 3 mm. The distance from the midline to the lateral border of depressor labii inferioris was 32 ± 4 mm and 54 ± 4 mm for depressor anguli oris. The literature review revealed a mean recurrence rate of 21%. A potential optimization of the surgical technique in lower-lip depressor myectomies is to extend the muscle resection laterally. To ensure inclusion of the whole width of the depressor muscles and decrease the recurrence rates of the procedure, the measurements presented in this study should be kept in mind during surgery.

Predictive role of gnathological techniques for the treatment of persistent idiopathic facial pain (PIFP).

Persistent idiopathic craniofacial pain (PIFP) is a heterogeneous group of pain syndromes whose main characteristic is the daily presence of persistent pain for at least 3 months. The pathophysiology of PIFP is still not entirely known and probably related to biological and psychological factors. Although PIFP has been attributed to the central neuron activity, the importance of masticatory muscles as a possible pathogenic mechanism was recently demonstrated. The main purpose of our paper was to identify the physiological rest position of the mandible with minimal tonus of both the elevator and depressor muscles and the neuromuscular trajectory of mouth closing obtained by transcutaneous electrical stimulation (TENS) and maintained with the use of an occlusal device, known as orthotic. The VAS scale for facial pain and the migraine disability assessment score (MIDAS) index for patient quality of life were evaluated at the beginning of the study for the 38 subjects that came to our attention. Our research included two phases. The first phase consisted of kinesiographic and electromyographic (EMG) examinations of the masticatory muscles and a 45-min application of TENS in order to deprogram the muscular activity. Kinesio-electromyographic examinations were repeated in the second phase. The main evaluated parameter was jaw deflection or deviation on the sagittal and frontal planes before and after TENS during patient tooth occlusion. Patients that showed a significant modification of this parameter were treated with orthotics for 12 months. The results of a 12-month follow-up show a sharp reduction of the VAS (pre-orthotic 9.05, range 8-10, SD 0.8; post-orthotic 5.87, range 1-5, SD 0.7) and an improvement in the quality of life (MIDAS). Our study demonstrated the usefulness of TENS as a screening method for the application of orthotics. This non-invasive and/or non-painful procedure could be a useful complementary treatment in this patient population. The results of the study also confirm the role of masticatory muscle dynamics as a possible pathogenic mechanism in patients with PIFP.

Open Eyebrow Correction

The open brow lift is a powerful tool for facial rejuvenation of the upper third of the face which can address rhytids, upper eyelid hooding, and brow ptosis. With a history dating back over a hundred years, a variety of techniques have been described including coronal, pretrichial, mid-forehead, direct supraciliary, and transpalpebral brow lifts. These vary in terms of invasiveness and the ideal approach is determined by patient age, sex, symmetry, and anterior hairline characteristics. While endoscopic techniques became popular in the 1990s based on novelty, smaller incisions, less post-scar numbness, and a perception of less invasive nature, this technique’s popularity has diminished recently and less invasive open approaches have become more popular. Recent years have seen the numbers of all forms of brow lift become less common as neuromodulators, such as botulinum toxin, allow for chemical denervation of brow depressor muscles. This has become a truly non-invasive way to address minor forms of aging of the forehead and brow. However, for advanced cases, open brow lift remains a powerful technique which should remain in the arsenal of the plastic surgeon. This review contains 3 figures, 2 tables, and 39 references. Keywords: cosmetic surgery, facial plastic surgery, facial aging, brow ptosis, rhytids, facial nerve, supraorbital nerve, supratrochlear nerve

WNT regulates programmed muscle remodeling through PLC-β and calcineurin in Caenorhabditis elegans males.

The ability of a muscle to break down and reform fibers is vital for development; however, if unregulated, abnormal muscle remodeling can occur, such as in the heart following cardiac infarction. To study how normal developmental remodeling is mediated, we used fluorescently tagged actin, mutant analyses, Ca2+ imaging and controlled Ca2+ release to determine the mechanisms regulating a conspicuous muscle change that occurs in Caenorhabditis elegans males. In hermaphrodites and larval males, the single cell anal depressor muscle, used for waste expulsion, contains bilateral dorsal-ventral sarcomeres. However, prior to male adulthood, the muscle sex-specifically remodels its sarcomeres anteriorly-posteriorly to promote copulation behavior. Although WNT signaling and calcineurin have been implicated separately in muscle remodeling, we unexpectedly found that they participate in the same pathway. We show that WNT signaling through Gαo and PLC-β results in sustained Ca2+ release via IP3 and ryanodine receptors to activate calcineurin. These results highlight the utility of this new model in identifying additional molecules involved in muscle remodeling.

The Effect of Humeral Head Depressor Muscle Co-Activation Training in Terms of Functional Outcomes

The Effect of Humeral Head Depressor Muscle Co-Activation Training in Terms of Functional Outcomes

Treatment of Post-Facelift Facial Paralysis With Botulinum Toxin Type A

BACKGROUND: Nerve injuries post-facelifts are rare but cause serious functional and psychological impairment of self-esteem and quality of life.1,2 Despite being temporary in most cases, facial asymmetry typically lasts for 3 months. We present a treatment protocol for post-facelift facial nerve injuries using botulinum toxin type A (BTXA). MATERIALS AND METHODS: The study was conducted from January 2002 to June 2018. Nine patients (all female; mean age, 58 ± 8.4 years) with asymmetries due to post-rhytidectomy facial palsies were treated in the nonparalyzed side with abobotulinum toxin type A, with 6-month to 5-year follow-up. The 500-U vial was diluted in 4 ml of 0.9% saline. We considered 0.02 ml of the solution (2.5 abobotulinum toxin units) as 1 volume unit. Patients were examined after 15 days for outcomes evaluation. The dose applied to each muscle group1 varied from 1 to 2 volume unit per point. Patients were retreated after 5–6 months in case of asymmetry recurrence. RESULTS: Four patients sought early care (mean, 14.2 ± 6.4 days postoperative, ranging from 5 to 21 days). The others arrived later (mean, 225 ± 80.7 days postoperative, ranging from 150 to 360 days). Two patients had lesions affecting the upper third of the face, and symmetry was achieved after unilateral treatment of the frontalis muscle. Three patients had injury in the middle third; their treatment depended of analysis of the deviation vectors when smiling and frowning, as to decide which muscle groups should be treated (vertical: upper lip lifter muscles; upper oblique: lifters of the angle of the mouth muscles; and horizontal: risorius muscle). Four patients were affected in the lower third (inferior deviation vectors) and were treated with 2 points to paralyze the lower lip depressor muscles. Correction of asymmetry was achieved in all cases. Recovery from the nerve injury and BTXA application occurred symmetrically in both sides of the face in the following months. All patients with early onset of BTXA therapy (<30 days) had complete recovery of facial symmetry with a single application, evidence of neuropraxis. Patients with lesions of the upper third, those with late onset of BTXA treatment (>30 days), and those with >1 affected nervous branch presented definitive lesion, with partial recovery or improvement, and needed BTXA treatment every 6 months. CONCLUSION: Most facial nerve injuries post-facelifts presented favorable evolution for spontaneous resolution, except in the upper third of the face and in case of late lesions. Symmetry was achieved in all cases with low doses of BTXA in the suggested protocol points, avoiding an unhappy asymmetric patient in the following months. REFERENCES: 1. Salles AG, Toledo PN, Ferreira MC. Botulinum toxin injection in long-standing facial paralysis patients: improvement of facial symmetry observed up to 6 months. Aesthetic Plast Surg. 2009;33:582–590. 2. do Nascimento Remigio AF, Salles AG, de Faria JCM, et al. Comparison of the efficacy of onabotulinumtoxinA and abobotulinumtoxinA at the 1: 3 conversion ratio for the treatment of asymmetry after long-term facial paralysis. Plast Reconstr Surg. 2015;135:239–249.