Nerve entry points in the mimic musculature of the horse head.

Facial expressions are important in pain recognition in horses, but current observation-based pain scales remain subjective. A promising technique to quantitatively measure subtle changes in expression patterns, including changes invisible to the human eye, is surface electromyography (sEMG). To achieve high-quality and reliable sEMG signals, unilateral placement of bipolar electrodes is required in relation to the motor endplates (MEP). We aimed to localize the nerve entry points (NEPs; where the nerve branch first pierced the muscle belly) and the direction of the terminal nerve endings to estimate MEP locations of the innervating nerves in five equine facial muscles involved in pain expression. Three cadaveric Dutch Warmblood horse heads were dissected to identify the NEPs in the musculi caninus, levator anguli oculi medialis, nasolabialis, masseter and zygomaticus. These points were marked with pins and measured in relation to a reference line between two anatomical landmarks near the origin and insertion of the respective muscle. Relative distances were calculated from the most caudally situated landmark. NEPs were located at 33%-38% (caninus), 69%-86% (levator anguli oculi medialis) and 0%-18% (zygomaticus) from the caudal landmark. The nasolabialis showed two innervations zones. Its NEPs were located at 47%-72% (dorsal muscle branch) and 52%-91% (ventral branch). All terminal nerve endings were found to run in rostral direction. The masseter showed numerous NEPs diffusely spread within the muscle belly. Therefore, calculation of relative positions was not performed. These results could form the basis for feasibility studies and standardization of bipolar electrode positioning in vivo to measure facial muscle activity patterns in horses.

Selective Neurectomy for Postfacial Paralysis Synkinesis: A Systematic Review.

Facial synkinesis is characterized by unintentional contractions of facial musculature secondary to aberrant facial nerve healing. The associated impairment in facial functioning results in a significant decrease in patients' quality of life. The mainstay treatment for postfacial paralysis synkinesis (PFPS) is chemodenervation and physiotherapy, which requires long-term maintenance neurotoxin injections. This can lead to treatment resistance. Selective neurectomy of the distal branches of the facial nerve has been suggested as an effective surgical treatment of PFPS. This study aims to provide a comprehensive systematic review evaluating the efficacy of selective neurectomy for patients presenting with PFPS. Ovid MEDLINE, Ovid Embase, PubMed, Web of Science, and CINAHL were searched from inception until July 2022. Studies that investigated postoperative outcomes of pediatric and/or adult patients who underwent selective neurectomy as a treatment for PFPS were included. The database search identified 1,967 studies, and 11 were ultimately included based on inclusion and exclusion criteria. These 11 studies represented 363 patients. Studies reported on outcomes following selective neurectomy with or without adjuvant therapies for patients with PFPS. The main outcome categories identified were clinician-reported outcomes and patient-reported outcomes. The studies that used clinician-reported outcomes found an improvement in both synkinesis and facial nerve paralysis (FNP) outcomes following selective neurectomy according to their respective grading systems. Three studies looked at patient-reported outcomes and found increased patient-reported quality of life and satisfaction following selective neurectomy. The most reported complications were upper lip contracture, uneven cheek surface, lagophthalmos, and temporary oral incompetence. Selective neurectomy has demonstrated stable or improved synkinesis, FNP, and quality of life outcomes in patients with PFPS. This approach should be considered for patients with PFPS, particularly for patients with refractory symptoms or those who are unable to undergo continued medical management.

Functional and esthetic reconstruction of composite lower lip defects with a motor-innervated chimeric facial artery buccinator myomucosal-submental island flap.

OBJECTIVE: This study aimed to assess the functional and esthetic outcomes of a chimeric innervated buccinator myomucosal-submental island flap (BMM-SIF) for large composite lower lip reconstruction. METHODS: This retrospective study included five patients who underwent lower lip tumor resection and BMM-SIF reconstruction at the Hospital of Stomatology, Sun Yat-sen University, between August 2021 and February 2023. Lip function was evaluated using water leakage, cheek puffing tests, and superficial electromyography. Lip appearance was observed using photographs and evaluated through subjective interviews. Donor-site conditions, including facial symmetry and mouth opening, were monitored. RESULTS: All the BMM-SIFs survived. Drooling was the main complication observed shortly after surgery. The water leakage test showed complete oral competence for liquid holding in the 7th month; however, moderate air leakage was present in two patients. Electromyography revealed myoelectric signals from the innervated buccinator at the recipient site. Facial expression and food intake were typically managed. The shape and projection of the vermilion were harmonious and satisfactory for each patient. Neither microstomia nor mouth opening limitation was observed, with an average inter-incisor distance of 37.25±4.4 mm. CONCLUSION: Chimeric motor-innervated BMM-SIF effectively reconstructed large full-thickness lower-lip defects with satisfactory functional and esthetic outcomes.

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

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

Growth of muscles and nerves in the upper eyelid: a morphometrical and immunohistochemical study using term human fetuses.

BACKGROUND: There is no information about muscle growth in eyelids with infrequent blinking in fetuses. METHODS: To examine the muscle and nerve morphology, we morphometrically and immunohistochemically examined sagittal sections of unilateral upper eyelids obtained from 21 term fetuses (approximately 30-42 weeks of gestation) and, for the comparison, those from 10 midterm fetuses (12-15 weeks). RESULTS: The approximation margin of the upper eyelid always corresponded to the entire free margin in midterm fetuses, whereas it was often (18/21) restricted in the posterior part in term fetuses. Thus, in the latter, the thickness at the approximation site to the lower lid often ranged from 0.8 to 1.6 mm and corresponded to 18-56% of the nearly maximum thickness of the lid. In the lower part of the upper eyelid, a layer of the orbicularis oculi muscles often (14/21) provided posterior flexion at 90-120° to extend posteriorly. Nerve fibers running along the mediolateral axis were rich along the approximation surface at term, but they might not be reported in the upper eyelid of adults. CONCLUSION: Being different from adult morphologies, the term eyelid was much thicker than the approximation surface and it carried a flexed muscle layer and transversely-running nerve. The infrequent blinking in fetuses seemed to provide a specific condition for the muscle-nerve growth. Plastic and pediatric surgeons should pay attention to a fact that infants' upper eyelid was unlikely to be a mini-version of the adult morphology.

Outcomes of Free Flap Transfer in Facial Reanimation: A Review.

Free functional muscle transfer is is an option for reanimating the face in chronic facial nerve paralysis. The optimal outcome in these patients is the ability to restore a spontaneous smile in response to emotion. We discuss the role of free functional muscle transfer in facial paralysis treatment, the choices of nerve used in reconstruction surgery, and the application of different types of muscle flaps in facial reanimation. In this paper, we review the relevant and up-to-date academic literature regarding the outcomes of free functional muscle flap transfer in facial paralysis patients.

Future treatment options for facial nerve palsy: a review on electrical stimulation devices for the orbicularis oculi muscle.

Facial nerve palsy can cause diminished eyelid closure (lagophthalmos). This occurs due to functional deficits of the orbicularis oculi muscle, potentially leading to sight-threatening complications due to corneal exposure. Current management options range from frequent lubrication with eye drops, to the use of moisture chambers and surgery. However, achieving functional restoration may not always be possible. Recent efforts have been directed towards the support of orbicularis oculi muscle function through electrical stimulation. Electrical stimulation of the orbicularis oculi muscle has been demonstrated as feasible in human subjects. This article offers a comprehensive review of electrical stimulation parameters necessary to achieve full functionality and a natural-looking eye blink in human subjects. At present, readily available portable electrical stimulation devices remain unavailable. This review lays the foundation for advancing knowledge from laboratory research to clinical practice, with the ultimate objective of developing a portable electrical stimulation device. Further research is essential to enhance our understanding of electrical stimulation, establish safety standards, determine optimal current settings, and investigate potential side effects.

The effect of various muscle transfer procedures on eye closure and blinking in longstanding facial palsy patients.

BACKGROUND: Facial palsy causes paralytic lagophthalmos, which remarkably deteriorates a patient's quality of life. In cases where denervation time is over 18-24 months (longstanding facial palsy), a free or pedicled muscle transfer is needed to replace the denervated orbicularis oculi muscle. PURPOSE: The purpose of this systematic review is to investigate the effect of various eye sphincter substitution procedures (free or pedicled muscle transfers) in longstanding facial palsy patients on eye closure and blink. METHODS: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we performed a systematic review of the Embase, Medline, Web of Science and Cochrane Library databases and Google Scholar. Our literature search yielded 4322 articles. Following a full-text review, 4 retrospective cohort studies and 21 case series were selected for this review. Meta-analyses using R package meta (version 6.5-0) were conducted. MAIN FINDINGS: All free and pedicled muscle transfers in this review showed an improvement in the scores and measurements on eye closure and blink. The pedicled temporalis muscle transfer was the procedure most commonly performed as eye reanimation surgery and showed consistent good results. Using the random effects model, the pooled effect of mean difference in lagophthalmos after gentle eye closure post-operatively versus pre-operatively (mm) in patients who received a pedicled (temporalis) muscle transfer was -6.19 (I2 = 85%, 95% CI: -7.89; -4.49) whereas it was -4.11 (I2 = 85%, 95% CI: -7.26; -0.95) for free (gracilis or platysma) muscle transfers. The pooled proportion of patients with complete eye closure after surgery was 0.69 (I2 = 49%, 95% CI: 0.54; 0.82) in patients who received a pedicled (temporalis) muscle transfer and 0.40 (I2 = 74%, 95% CI: 0.13; 0.74) in patients who received a free (platysma) muscle transfer. CONCLUSIONS: Unlike smile reanimation, dynamic eye closure and blink restoration are rather neglected topics in facial reanimation. The pedicled temporalis muscle transfer is often recommended as the first treatment of choice for eye reanimation in longstanding facial palsy patients since it is a reliable, straightforward procedure, that does not require complex microsurgery. However, with the advancements in the field of microsurgery, free muscle transfers are promising therapies, which may regenerate voluntary and spontaneous blinking.

Alteraciones de las células de la microglía del sistema nervioso central provocadas por lesiones del nervio facial / Facial nerve injuries cause changes in central nervous system microglial cells

Resumen Introducción. El grupo de investigación del Laboratorio de Neurofisiología Comportamental de la Universidad Nacional de Colombia ha descrito modificaciones estructurales y electrofisiológicas en neuronas piramidales de la corteza motora producidas por la lesión del nervio facial contralateral en ratas. Sin embargo, poco se sabe sobre la posibilidad de que dichos cambios neuronales se acompañen también de modificaciones en las células gliales circundantes. Objetivo. Caracterizar el efecto de la lesión unilateral del nervio facial sobre la activación y proliferación de las células de la microglía en la corteza motora primaria contralateral en ratas. Materiales y métodos. Se hicieron pruebas de inmunohistoquímica para detectar las células de la microglía en el tejido cerebral de ratas sometidas a lesión del nervio facial, las cuales se sacrificaron en distintos momentos después de la intervención. Se infligieron dos tipos de lesiones: reversible (por compresión, lo cual permite la recuperación de la función) e irreversible (por corte, lo cual provoca parálisis permanente). Los tejidos cerebrales de los animales sin lesión (grupo de control absoluto) y de aquellos sometidos a falsa cirugía se compararon con los de los animales lesionados sacrificados 1, 2, 7, 21 y 35 días después de la lesión. Resultados. Las células de la microglía en la corteza motora de los animales lesionados irreversiblemente mostraron signos de proliferación y activación entre el tercero y séptimo días después de la lesión. La proliferación de las células de la microglía en animales con lesión reversible fue significativa solo a los tres días de infligida la lesión. Conclusiones. La lesión del nervio facial produce modificaciones en las células de la microglía de la corteza motora primaria. Estas modificaciones podrían estar involucradas en los cambios morfológicos y electrofisiológicos descritos en las neuronas piramidales de la corteza motora que comandan los movimientos faciales.

Abstract Introduction: Our research group has described both morphological and electrophysiological changes in motor cortex pyramidal neurons associated with contralateral facial nerve injury in rats. However, little is known about those neural changes, which occur together with changes in surrounding glial cells. Objective: To characterize the effect of the unilateral facial nerve injury on microglial proliferation and activation in the primary motor cortex. Materials and methods: We performed immunohistochemical experiments in order to detect microglial cells in brain tissue of rats with unilateral facial nerve lesion sacrificed at different times after the injury. We caused two types of lesions: reversible (by crushing, which allows functional recovery), and irreversible (by section, which produces permanent paralysis). We compared the brain tissues of control animals (without surgical intervention) and sham-operated animals with animals with lesions sacrificed at 1, 3, 7, 21 or 35 days after the injury. Results: In primary motor cortex, the microglial cells of irreversibly injured animals showed proliferation and activation between three and seven days post-lesion. The proliferation of microglial cells in reversibly injured animals was significant only three days after the lesion. Conclusions: Facial nerve injury causes changes in microglial cells in the primary motor cortex. These modifications could be involved in the generation of morphological and electrophysiological changes previously described in the pyramidal neurons of primary motor cortex that command facial movements.

Estudo anatômico do pedículo vásculo-nervoso do retalho do ventre anterior do músculo digástrico / Anatomic study of the anterior belly of the digastric muscle flap neurovascular pedicle

Introdução: A paralisia facial é uma síndrome com implicações estéticas e funcionais importantes.A reanimação do segmento facial afetado pode ser realizada por diversas técnicas. Atransposição de músculos regionais inervados por outro nervo craniano não afetado é um dosmétodos utilizados com frequência. O ventre anterior do músculo digástrico, inervado pelonervo miloioideo, ramo do nervo trigêmio, é um retalho bastante usado para a reanimação dadepressão do lábio inferior. Uma maior mobilidade deste retalho poderia permitir a transposiçãodo músculo para outros segmentos da face, ampliando sua utilização na prática clínica.Método: Estudamos o pedículo vásculo-nervoso do ventre anterior do músculo digástricoem 10 cadáveres, a fim de determinar o arco de rotação do seu retalho mantendo intacto oseu nervo aferente, e estudamos os diâmetros da artéria submentoniana, responsável pelo seusuprimento sanguíneo, com o objetivo de determinar a viabilidade de eventual reanastomosemicrocirúrgica. Resultados: Encontramos um arco de rotação médio de 3,71 cm a partirda borda inferior da mandíbula. O diâmetro externo da artéria submentoniana mediu emmédia 1,05 mm, o que permitiria a anastomose microcirúrgica a outro tronco arterial daface, dando uma maior liberdade para a mobilização do retalho. Conclusão: O retalho assimmobilizado tem, portanto, potencial renovado para uso na reanimação da paralisia facial.

Introduction: Fascial palsy is a syndrome with important esthetical and functional implications.The reanimation of the affected segment of the face can be obtained with severaltechniques. The transposition of local muscles, innervated by other cranial nerves, is frequentlyused. The anterior belly of the digastric muscle flap, innervated by the milohyoidnerve, a branch of the trigeminal nerve, is commonly used to treat the denervation of theinferior lip depressor muscle. A greater mobilization of this flap could allow its transpositionto other fascial segments. Methods: We have studied the vascular and nervous pedicle ofthe anterior belly of the digastric muscle in 10 unfixed cadavers, to determine the rotationarch of the flap, keeping its nerve intact. We have also studied the diameters of the submentonianartery, responsible for the blood suply to the flap, in order to evaluate the possibilityof microsurgical anastomosis to other vascular branches. Results: We have found a medianarch of rotation of 3.71 cm from the inferior border of the mandibule. The median externaldiameter of the artery was 1.05 mm, allowing its revascularization with microsurgicaltechnique. Conclusion: This mobilization of the anterior belly of the digastric muscle flapshows a potential for further use in the reanimation of fascial palsy.

Muscle fibre types and connective tissue morphometry in frontal muscle of Norfolk rabbits (Oryctolagus cuniculus) / Morfometría de los tipos de fibra muscular y del tejido conectivo en músculo frontal de conejos Norfolk (Oryctolagus cuniculus)

The frontal muscle is formed by a complex of contractile elements which compose the set of facial muscles responsible for the expression of emotions. In view of its functional characteristics the frontal muscle consists of a mixture of high (type I) and low oxidative (type II) muscle fibres. The objective of the present study was to determine the area, diameter, and relative volume occupied by each fibre type in frontal muscles of Norfolk rabbits using nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR) histochemistry combined with morphometry. In addition, the connective tissue area (endomysium) and the number of blood vessels per fibre were evaluated. Female rabbits ranging in age from 6 to 8 months and weighing 2.8 to 3.1 kg were used. Four quadrants of samples from 12 animals were analysed. Type IIB fibres occupied the largest area compared to the other fibre types. The fibre diameter and relative volume were similar among the different fibre types identified by NADH-TR staining. No significant difference in the number of vessels per fibre was observed between the different fibre types. The endomysial area occupied the smallest area among the parameters analyzed. These findings demonstrated the intense activity of this muscle in the facial architecture of the animal. However, the low oxidative type II fibres predomination indicates more prone to muscle fatigue. The present findings may contribute to the study of myopathies involving this muscle.

El músculo frontal está formado por un complejo de elementos contráctiles que componen el conjunto de músculos faciales responsables de la expresión de emociones. A la vista de las características funcionales, el músculo frontal está constituido de una mezcla de fibras musculares de alto (tipo I) y bajo nivel de oxidación (tipo II). El objetivo del presente estudio fue determinar área, diámetro y volumen relativo ocupado por cada tipo de fibra en los músculos frontales de conejos Norfolk utilizando histoquímica para nicotinamide adenina dinucleotide tetrazolium reductasa (NADH-TR), combinado con su morfología. Además, fueron evaluados la zona de tejido conectivo (endomisio) y el número de vasos sanguíneos por fibras. Fueron utilizados conejos hembras, de edades comprendidas entre los 6 a 8 meses y con un peso de 2,8 a 3,1 kg. Se analizaron cuatro cuadrantes de las muestras de 12 animales. Las fibras tipo IIB ocuparon la mayor superficie, en comparación con los otros tipos de fibras. Los diámetros y volúmenes relativos de las fibras fueron similares entre los diferentes tipos identificados por NADH-TR. No se observaron diferencias significativas en el número de vasos por fibra, entre los diferentes tipos de fibras. El área ocupada por el endomisio fue la superficie más pequeña entre los parámetros analizados. Estos resultados demostraron la intensa actividad de este músculo en la arquitectura facial del animal. Sin embargo, el predominio de las fibras tipo II, de baja oxidación, indica más propensión a la fatiga muscular. El presente hallazgo pueden contribuir al estudio de las miopatías con la participación de este músculo.

Anatomia cirúrgica da porção terminal do nervo facial: estudo do plexo bucal / Surgical anatomy study of the terminal portion of the facial nerve: study of the buccal plexus

Estudo da anatomia cirúrgica da porção terminal do nervo facial foi realizado em cadáveres de 26 adultos e 7 fetos. Considera-se a porção terminal do nervo a partir da sua divisão em ramos temporofacial e cervicofacial, ao penetrar no parênquima da glândula parótida. Os dois ramos subdividem-se em numerosos subramos que se destinam à inervação dos músculos cutâneos da face e do platisma no pescoço. A subdivisão dos ramos temporofacial e cervicofacial já ocorre no interior da glândula, assim como diversas anastomoses, formando um plexo intraparotídeo, estudado pela maioria dos autores. A travessia dos subramos do nervo não ocorre entre dois lobos da glândula, um superficial e outro profundo, como apresentado por muitos autores. Esquemas das relações topográficas do nervo no interior da glândula são apresentados. Adiante da borda anterior da glândula forma-se outro plexo: o plexo bucal, sobre o músculo bucinador. Contribuem para a formação deste plexo principalmente os subramos bucal superior do temporofacial e o bucal inferior do cervicofacial. Considera-se também a participação do subramo mandibular ascendente encontrado com constância, mas não citado pelos autores na revisão bibliográfica. Levantou-se a hipótese deste plexo receber contribuição das fibras simpáticas que envolvem a artéria facial. Em razão de sua importância anatômica e funcional, mensurações foram feitas para determinar a localização mais freqüente do plexo bucal.

Surgical anatomy study of the facial nerve terminal portion was performed on 26 adult cadavers and 7 fetuses. The terminal portion of the nerve was considered to be from its division into temporo-facial and cervico-facial branches, as it penetrates into the parotid gland. The two branches subdivide into numerous sub-branches that innervate the cutaneous muscles of the face, and the platysma in the neck. The subdivision of temporo-facial and cervico-facial branches already occurs in the gland interior, as well as some anastomoses, forming an intra-parotid plexus, studied by the majority of authors. The crossing of the nerve sub-branches does not occur between two lobes of the gland, one superficial and other deeper, as presented by many authors. Schemes of topographical relations of the nerve at the gland interior edge are presented. Ahead of the gland interior edge another plexus is formed: the buccal plexus on the buccinator muscle. The superior temporo-facial buccal and the inferior cervico-facial sub-branches mostly contribute to the plexus formation. There also was constantly found the mandibular ascending sub-branch participation, though not mentioned by the authors on the bibliographical revision. There was formulated the hypothesis that this plexus get contribution from sympathetic fibers that involve the facial artery. Due to its anatomical and functional importance, measurements were made in order to determine the buccal plexus more frequent localization.

Muscular subunits transplantation for facial reanimation

OBJETIVO: Apresentar uma alternativa técnica para reconstrução de perdas músculo-cutâneas na face com a transferência de sub-segmentos(sub-unidades) inervados do músculo grande dorsal para a substituição dos diversos músculos da mímica facial. MÉTODOS: É descrito um caso de trauma com perda de pele e músculo da mímica. Foi corrigido com a transferência microcirúrgica de uma sub-unidade de músculo grande dorsal que apresenta, forma, tamanho e peso similares aos dos músculos da mímica. Respeitou-se as origens e inserções e vetores de ação para a mímica desejada. Cada um dos sub-segmentos têm artéria e veia que irrigam a unidade muscular e também um nervo com componente motor. RESULTADOS: O paciente foi avaliado comparando-se o pré e pós-operatório de um ano com foto e vídeo com mímica em repouso e dinâmica e eletromiografia (documentada em vídeo digital). Observou-se atividade mio-elétrica dos músculos transplantados. Verificou-se que a técnica foi eficaz do ponto de vista funcional e estético. CONCLUSÃO: Esta técnica parece ser uma maneira eficaz para tratar as deformidades pós-perdas complexas de pele e músculos da face e no tratamento da paralisia facial.

Quantificação da ação do músculo frontal / Quantification of frontalis muscle action

OBJETIVO: Quantificar a ação do músculo frontal. MÉTODOS: A ação do músculo frontal foi quantificada por meio da medida da mobilidade do supercílio em 81 sujeitos normais, divididos, segundo a faixa etária, em três grupos: crianças com idades entre 6 e 12 anos (n = 20), adultos com idades entre 20 e 38 anos (n = 33) e idosos com idades entre 60 e 80 anos (n = 28). As medidas foram realizadas com o processamento digital de imagem. Obteve-se uma imagem da face do sujeito com o frontal em repouso e outra com contração voluntária da fronte. Como índice de ação frontal foi tomada a excursão do supercílio na parte média da fenda palpebral. RESULTADOS: Os valores médios da excursão superior do supercílio variaram, de acordo com o grupo etário, de 7,57 a 9,02 mm. Apesar de nítida tendência de aumento da mobilidade com a idade, as diferenças entre os três grupos não foram significativas. CONCLUSÕES: A magnitude da excursão da porção central do supercílio independe da idade.

Estudo anatômico do músculo levantador do lábio superior / Anatomical study of the levator labii superioris muscle

O autores descrevem as características anatómicas do músculo levantador do lábio superior por meio de dissecaçöes em cadáveres. Objetivo. Contribuir ao estudo dos músculos da mímica, estudando os seus detalhes anatómicos e suas relaçöes, ajudando na realizaçäo de retalhos da face. Métodos. Foram dissecadas 20 peças de cadáveres, verificando-se suas inserçöes, comprimento, largura, espessura, relaçöes, inervaçäo e irrigaçäo. Resultados. Em todos os casos, o músculo levantador do lábio superior apresentou inserçäo proximal na margem inferior da órbita e inserçäo distal de dois tipos: por meio de fibras laterais sobrepondo-se superficialmente ao músculo orbicular do lábio e de fibras profundas interdigitando-se, formando parte do embricamento do canto da boca (70 por cento); e mediante fibras sobrepondo-se superficialmente ao músculo orbicular do lábio (30 por cento). A média do comprimento foi de 24,66mm e a média da espessura, de 3,57mm. A largura em nível da inserçäo distal foi, em média, de 11,2mm, enquanto que em nível da inserçäo proximal foi, em média, de 15,96mm. Relaciona-se anteriormente ao músculo levantador do ângulo da boca, posteriormente à porçäo distal do músculo zigomático menos (90 por cento) e posteriormente à porçäo media do músculo zigomático menor (10 por cento). A inervaçäo é feita pelo ramo inferior do nervo zigomático (n. facial) e nervo infra-orbital (n. trigêmeo). Ramos da artéria angular irrigam a porçäo inferior do músculo e a artéria infra-orbital nutre a porçäo superior deste músculo.