Möbius and Möbius-like patients: etiology, diagnosis, and treatment options

Clinical and Genetic Correlation in Neurocristopathies: Bridging a Precision Medicine Gap

Neurocristopathies (NCPs) encompass a spectrum of disorders arising from issues during the formation and migration of neural crest cells (NCCs). NCCs undergo epithelial-mesenchymal transition (EMT) and upon key developmental gene deregulation, fetuses and neonates are prone to exhibit diverse manifestations depending on the affected area. These conditions are generally rare and often have a genetic basis, with many following Mendelian inheritance patterns, thus making them perfect candidates for precision medicine. Examples include cranial NCPs, like Goldenhar syndrome and Axenfeld-Rieger syndrome; cardiac-vagal NCPs, such as DiGeorge syndrome; truncal NCPs, like congenital central hypoventilation syndrome and Waardenburg syndrome; and enteric NCPs, such as Hirschsprung disease. Additionally, NCCs' migratory and differentiating nature makes their derivatives prone to tumors, with various cancer types categorized based on their NCC origin. Representative examples include schwannomas and pheochromocytomas. This review summarizes current knowledge of diseases arising from defects in NCCs' specification and highlights the potential of precision medicine to remedy a clinical phenotype by targeting the genotype, particularly important given that those affected are primarily infants and young children.

Physiopathologic Bases of Moebius Syndrome: Combining Genetic, Vascular, and Teratogenic Theories

Moebius syndrome (MBS) is a congenital cranial dysinnervation disorder (CCDD) characterized by a bilateral palsy of abducens and facial cranial nerves, which may coexist with other cranial nerves palsies, mostly those found in the dorsal pons and medulla oblongata. MBS is considered a "rare" disease, occurring in only 1:50,000 to 1:500,000 live births, with no gender predominance. Three independent theories have been described to define its etiology: the vascular theory, which talks about a transient blood flow disruption; the genetic theory, which takes place due to mutations related to the facial motor nucleus neurodevelopment; and last, the teratogenic theory, associated with the consumption of agents such as misoprostol during the first trimester of pregnancy. Since the literature has suggested the existence of these theories independently, this review proposes establishing a theory by matching the MBS molecular bases. This review aims to associate the three etiopathogenic theories at a molecular level, thus submitting a combined postulation. MBS is most likely an underdiagnosed disease due to its low prevalence and challenging diagnosis. Researching other elements that may play a key role in the pathogenesis is essential. It is common to assume the difficulty that patients with MBS have in leading an everyday social life. Research by means of PubMed and Google Scholar databases was carried out, same in which 94 articles were collected by using keywords with the likes of "Moebius syndrome," "PLXND1 mutations," "REV3L mutations," "vascular disruption AND teratogens," and "congenital facial nerve palsy." No exclusion criteria were applied.

Case report: Identification of a novel variant p.Gly215Arg in the CHN1 gene causing Moebius syndrome

Background: Moebius Syndrome (MBS) is a rare congenital neurological disorder characterized by paralysis of facial nerves, impairment of ocular abduction and other variable abnormalities. MBS has been attributed to both environmental and genetic factors as potential causes. Until now only two genes, PLXND1 and REV3L have been identified to cause MBS. Results: We present a 9-year-old male clinically diagnosed with MBS, presenting facial palsy, altered ocular mobility, microglossia, dental anomalies and congenital torticollis. Radiologically, he lacks both abducens nerves and shows altered symmetry of both facial and vestibulocochlear nerves. Whole-exome sequence identified a de novo missense variant c.643G>A; p.Gly215Arg in CHN1, encoding the α2-chimaerin protein. The p.Gly215Arg variant is located in the C1 domain of CHN1 where other pathogenic gain of function variants have been reported. Bioinformatic analysis and molecular structural modelling predict a deleterious effect of the missense variant on the protein function. Conclusion: Our findings support that pathogenic variants in the CHN1 gene may be responsible for different cranial congenital dysinnervation syndromes, including Moebius and Duane retraction syndromes. We propose to include CHN1 in the genetic diagnoses of MBS.

Moebius Syndrome: A Case Report on an Uncommon Congenital Syndrome

Moebius syndrome (MS) is rare. It is defined by congenital bilateral paralysis of the sixth and seventh cranial nerves, resulting in an absence of mimicry and strabismus responsible for major relational disorders. Other cranial nerves can also be affected (third, fourth, fifth, ninth, tenth, and twelfth cranial pairs). In the majority of cases, MS is sporadic, causing problems with sucking, swallowing, breathing, and phonation. Associated malformations have also been reported. The disease is not progressive, and management is mainly symptomatic. We report a three-year-old girl who presented with facial asymmetry and in whom the MS was confirmed through magnetic resonance imaging (MRI). A multidisciplinary approach was conducted on our patient and is currently being followed up in the neuropediatrics department, and an ophthalmological examination is scheduled. Additionally, she had medical consultations with a plastic surgeon for smile rehabilitation. On the other hand, psychological support was maintained.

MODIFIED GRACILIS MUSCLE FLAP IN FACIAL REANIMATION: U-SHAPED DESIGN

BACKGROUND

Surgical treatment of long-term facial palsy has been reported using various techniques, including functioning muscle-free flaps. The free gracilis muscle flap is the most common because of its many advantages. Our study presents a modified way of shaping the gracilis muscle for transfer to the face to improve the restoration of natural smiles.

METHODS

This retrospective study assessed 5 patients who received the classical technique and 43 patients who received modified, U-shaped, free gracilis muscle flap for smile reanimation from 2013 to 2018. The surgery is single-staged. Preoperative and postoperative photos were taken. Functional outcomes were evaluated using the Terzis and Noah score and the Chuang smile excursion score.

RESULTS

The mean patient age at the time of operation was 31 years. The length of gracilis muscle harvested was 12-13 cm. Of the 43 patients who received U-shaped design-free gracilis muscle, results were excellent for 15 (34.9%), good for 20 (46.5%), and fair for 8 (18.6%) followed the Terzis and Noah score. The Chuang smile excursion score was 2 for 16.3%, 3 for 46.5%, and 4 for 37.2% of 43 patients. Of the 5 patients who underwent classical technique, there are no excellent results based on the Terzis and Noah score. The Chuang smile excursion score was only 1 and 2.

CONCLUSIONS

The U-shaped modification to the gracilis muscle-free flap is a simple and effective technique to help restore a symmetrical and natural smile in patients with facial palsy.

Moebius Syndrome: An Updated Review of Literature

Moebius Syndrome, is a rare, non-progressive congenital neuropathological syndrome characterized primarily by the underdevelopment of the facial (CN VII) and abducens nerve (CN VI). Other features of Moebius Syndrome include facial nerve paresis, ophthalmoplegias, orthodontic deficiencies (including crowded dentition, swollen and hyperplastic gingiva, dental calculus, etc.), musculoskeletal abnormalities, and impaired mental function. Due to the rarity of the disorder, very few case studies have been reported in the literature. This article summarizes the significant features of the disease according to commonalities in reported cases, along with several newly recognized features cited in recent literature. We have explored the different diagnostic criteria and the newly recognized imaging modalities that may be used. Understandably, the condition detrimentally affects a patient's quality of life; thus, treatment measures have also been outlined. This study aims to provide updated literature on Moebius Syndrome MBS and improve understanding of the condition.

Facial Expression Time Processing in Typical Development and in Patients with Congenital Facial Palsy

Temporal dynamics of behavior, particularly facial expressions, are fundamental for communication between individuals from very early in development. Facial expression processing has been widely demonstrated to involve embodied simulative processes mediated by the motor system. Such processes may be impaired in patients with congenital facial palsy, including those affected by Moebius syndrome (MBS). The aims of this study were to investigate (a) the role of motor mechanisms in the processing of dynamic facial expression timing by testing patients affected by congenital facial palsy and (b) age-dependent effects on such processing. Accordingly, we recruited 38 typically developing individuals and 15 individuals with MBS, ranging in age from childhood to adulthood. We used a time comparison task where participants were asked to identify which one of two dynamic facial expressions was faster. Results showed that MBS individuals performed worse than controls in correctly estimating the duration of facial expressions. Interestingly, we did not find any performance differences in relation to age. These findings provide further evidence for the involvement of the motor system in processing facial expression duration and suggest that a sensorimotor matching mechanism may contribute to such timing perception from childhood.

Transfer of the deep temporal nerve for eyelid reconstruction in Mobius syndrome - an anatomic feasibility study and proposed surgical approach

Facial paralysis may result in significant functional, esthetic, and psychological morbidity. Mobius syndrome is a form of bilateral congenital facial paralysis that is particularly difficult to treat owing to the lack of readily available donor nerves, particularly in the upper face. In this study, we evaluate the feasibility of using the deep temporal nerves as donors for the innervation of free muscle grafts in the periorbital region. Preserved and fresh cadaver facial halves are dissected, and the course of the deep temporal nerves delineated. We find the middle branch of the deep temporal nerve to be located consistently 4.6 cm from the posterior edge of the tragus along the zygomatic arch, giving an easily identifiable surface landmark for our donor. Finally, we outline a proposed surgical approach for using the middle deep temporal nerve to innervate a free muscle graft to the eyelids through an interpositional nerve graft.

Cephalometric Analysis of the Craniofacial Morphology in Patients With Moebius Syndrome

BACKGROUND

Patients with Moebius syndrome may present a wide range of associated orofacial malformations, however, their craniofacial morphology has not been established via controlled cephalometric studies.

OBJECTIVE

To present our institution's findings in the cephalometric evaluation in patients with Moebius syndrome.

METHODS

Retrospective, cross-sectional study that included patients with Moebius syndrome over 9 years of age who had lateral cephalometric radiographs. Cephalometric analysis measurements of Ricketts, Steiner, and McNamara were performed. Quantitative data are expressed as mean and standard deviation, and qualitative data are expressed in totals and percentages. Comparative statistics between classic and incomplete Moebius and between patients older and younger than 16 years of age were performed.

RESULTS

Twenty-four patients were included (54.2% females), mean age 17.46 ± 8.85 years. Fifteen patients (62.5%) had classic Moebius syndrome, and nine (37.5%) had incomplete Moebius. Sixty-six percent of the patients presented either micrognathia or retrognathia, 95% showed mandibular hypoplasia, and 75% had a skeletal class II. Maxillary height was increased resulting in a vertical growth pattern. Upper and lower incisors tended towards proclination, and upper and lower lips protruded over cephalometric markings, and a long upper lip was evidenced in 41% of the patients. No significant differences were noted when comparing classic and incomplete Moebius syndrome. Patients younger than 16 years of age had significantly larger sella-nasion-A point and sella-nasion-B point angles, and a higher proportion of skeletal class II cases.

CONCLUSIONS

Patients with Moebius syndrome have a vertical maxillary growth, micro or retrognathia, developing a skeletal class II and lip protrusion.

Diagnosis and treatment of speech disorders in children with Moebius syndrome

BACKGROUND

Moebius syndrome (MS) is characterized by congenital bilateral paralysis of the facial and abducens nerves. Clinical features include feeding problems, dysarthria, dysphagia, sialorrhea, strabismus, and lack of facial expression. Patients with MS frequently present with dysphagia during infancy. Further on during childhood a severe speech disorder is a common feature. However, articulation deficits in patients with MS are scarcely reported in the related scientific literature.

OBJECTIVE

The aim of this study is to describe speech deviations, intelligibility and sialorrhea in patients with MS.

MATERIAL AND METHODS

Eighty-seven patients with MS were prospectively studied. Age ranged from 4 to 18 years. A complete Speech and Language Pathology (SLP) evaluation was performed in all cases. The evaluation focused on articulation placement, sialorrhea and intelligibility of speech.

RESULTS

Sialorrhea was detected in 23% of the patients. Abnormal articulation placement of bilabial phonemes was observed in 68% of the patients. Another 50% of the patients presented with articulation placement errors in other phonemes. Intelligibility was classified as adequate in 18% of the cases. Mildly affected intelligibility was found in 51% of the patients. Speech was considered moderately unintelligible in 20% of the cases. Unintelligible speech was found in 11% of the patients.

CONCLUSIONS

From the results of this prospective study it can be concluded that a high percentage of patients with MS are at high risk of presenting with moderate to severe speech disorders. Thus, an early SLP intervention should be provided for this population in order to enhance speech development and reducing the risk of severe oral communication impairments.

Long-term results of facial animation surgery in patients with Moebius syndrome

Gracilis neuromuscular transplant is considered the gold standard for facial animation in Moebius syndrome patients. However, long-term evaluation of the results has not been critically examined in the international literature. Thus, it remains unknown how the transplanted flap changes with facial growth, and whether contraction (smiling) is maintained. Pediatric patients with Moebius syndrome who underwent facial animation surgery with at least 5 years of follow-up were retrospectively examined. Photographs taken at the 1-year and most recent follow-up visits were analyzed and compared using Emotrics software. Analyses focused on the rest position, and on gentle and maximum smiles. Eighteen patients were enrolled. Seven patients had bilateral and 11 unilateral Moebius syndrome; therefore, 25 gracilis transplants were analyzed. The latest follow-ups ranged from 5 to 13.2 years (mean 7.6 years). The three principal facial expressions that were examined did not differ significantly between 1 year and a mean of 7.6 years after surgery, but tended to improve in most patients. Commissure excursion and smile angle for the maximum smile did improve significantly (p = 0.002 and 0.029, respectively). The series examined in this study supports the limited literature regarding the long-term stability of gracilis transplantation to animate the faces of Moebius syndrome children.

Autonomic Responses to Emotional Stimuli in Children Affected by Facial Palsy: The Case of Moebius Syndrome

According to embodied simulation theories, others' emotions are recognized by the unconscious mimicking of observed facial expressions, which requires the implicit activation of the motor programs that produce a specific expression. Motor responses performed during the expression of a given emotion are hypothesized to be directly linked to autonomic responses associated with that emotional behavior. We tested this hypothesis in 9 children (M_age = 5.66) affected by Moebius syndrome (MBS) and 15 control children (M_age = 6.6). MBS is a neurological congenital disorder characterized by underdevelopment of the VI and VII cranial nerves, which results in paralysis of the face. Moebius patients' inability to produce facial expressions impairs their capacity to communicate emotions through the face. We therefore assessed Moebius children's autonomic response to emotional stimuli (video cartoons) by means of functional infrared thermal (fIRT) imaging. Patients showed weaker temperature changes compared to controls, suggesting impaired autonomic activity. They also showed difficulties in recognizing facial emotions from static illustrations. These findings reveal that the impairment of facial movement attenuates the intensity of emotional experience, probably through the diminished activation of autonomic responses associated with emotional stimuli. The current study is the first to investigate emotional responses in MBS children, providing important insights into the role of facial expressions in emotional processing during early development.

Congenital facial palsy and emotion processing: The case of Moebius syndrome

According to the Darwinian perspective, facial expressions of emotions evolved to quickly communicate emotional states and would serve adaptive functions that promote social interactions. Embodied cognition theories suggest that we understand others' emotions by reproducing the perceived expression in our own facial musculature (facial mimicry) and the mere observation of a facial expression can evoke the corresponding emotion in the perceivers. Consequently, the inability to form facial expressions would affect the experience of emotional understanding. In this review, we aimed at providing account on the link between the lack of emotion production and the mechanisms of emotion processing. We address this issue by taking into account Moebius syndrome, a rare neurological disorder that primarily affects the muscles controlling facial expressions. Individuals with Moebius syndrome are born with facial paralysis and inability to form facial expressions. This makes them the ideal population to study whether facial mimicry is necessary for emotion understanding. Here, we discuss behavioral ambiguous/mixed results on emotion recognition deficits in Moebius syndrome suggesting the need to investigate further aspects of emotional processing such as the physiological responses associated with the emotional experience during developmental age.

A proposal for new neurorehabilitative intervention on Moebius Syndrome patients after 'smile surgery'. Proof of concept based on mirror neuron system properties and hand-mouth synergistic activity

Studies of the last twenty years on the motor and premotor cortices of primates demonstrated that the motor system is involved in the control and initiation of movements, and in higher cognitive processes, such as action understanding, imitation, and empathy. Mirror neurons are only one example of such theoretical shift. Their properties demonstrate that motor and sensory processing are coupled in the brain. Such knowledge has been also central for designing new neurorehabilitative therapies for patients suffering from brain injuries and consequent motor deficits. Moebius Syndrome patients, for example, are incapable of moving their facial muscles, which are fundamental for affective communication. These patients face an important challenge after having undergone a corrective surgery: reanimating the transplanted muscles to achieve a voluntarily control of smiling. We propose two new complementary rehabilitative approaches on MBS patients based on observation/imitation therapy (Facial Imitation Therapy, FIT) and on hand-mouth motor synergies (Synergistic Activity Therapy, SAT). Preliminary results show that our intervention protocol is a promising approach for neurorehabilitation of patients with facial palsy.

Pre- and Postsurgical Orthodontics in Patients with Moebius Syndrome

The authors report a combined orthodontic-surgical correction of an adult patient's malocclusion affected by Moebius Syndrome (MS). The treatment was conducted at the Dentistry Unit and the Maxillofacial Surgery Unit of the University Hospital of Parma. Treatment of malocclusion was performed after the correction of facial mimic mobility with smile surgery. The postoperative stability and orthodontic results were good and the correction of the morphological problems related to the syndrome was very satisfactory.

Rare features associated with Mobius syndrome: Report of two cases

Mobius syndrome is a rare congenital disorder with the preliminary diagnostic criteria of congenital facial and abducent nerve palsy. Involvement of other cranial nerves, too, is common. Prevalence rate of this syndrome is approximately 1 in 100,000 neonates. It is of unknown etiology with sporadic occurrence. However, data regarding the occurrence rate in India is limited. Features such as orofacial malformations, limb defects, and musculoskeletal, behavioral, and cognitive abnormalities might be associated. A thorough evaluation to identify the condition and establishing an adequate treatment plan is of utmost important in this condition. We are reporting clinical and radiographic features of Mobius syndrome in two cases along with unusual findings of limb and neck deformity.

[Facial palsy in children]

Facial palsy (FP) in children is congenital or acquired. When present at birth (congenital), etiologies are mostly traumatic and rarely developmental. Acquired FP needs investigation. Research on the etiology helps to determine prognostic and treatment. At most times, no specific cause is found. Treatment of idiopathic FP consists of early oral corticosteroid therapy and ocular protection. Treating the sequelae is essential and the physician has to consider the dynamic balance of both sides of the face. Dynamic rehabilitation should mainly concern the inferior facial third. We recommend the lengthening temporalis myoplasty (LTM). This relevant technique ensures replicable and reliable results with a harmonious smile. Facial dynamic rehabilitation after surgical procedure (muscle tranfer or free muscle flap) must be directed toward control of voluntary movement, to move from a mandibular smile to a spontaneous and voluntary smile, thanks to brain plasticity. Furthermore, botulinum toxin is well tolerated and remains a great tool to treat a child who can support injections.

Examining the genetics of congenital facial paralysis--a closer look at Moebius syndrome

OBJECTIVES

The molecular underpinnings of Moebius syndrome (MBS) are diverse. This article provides a comprehensive summation of the genetic and etiologic literature underlying this disorder. Elucidating the genetic causes of the disorder can aid in earlier detection and treatment planning.

DESIGN

Articles from 1880-2013 were selected and reviewed by six researchers to understand all of the molecular theories and chronicity of advancements in the literature.

RESULTS

Mutations in the MBS1, MBS2, and MBS3 gene loci all have contributed to the development of MBS through various pathways. HOX family genes coding for homeobox domains, also, have been implicated in the abnormal development of the human brain. These are among the numerous genes that have been linked to the development of MBS.

CONCLUSION

Our study codified nascent findings of the molecular determinants of MBS. These findings add to a growing database of MBS-associated mutations and can be used to diagnose MBS and clarify pathogenesis.

[Eye and systemic manifestations of Mobius syndrome]

INTRODUCTION

Mobius syndrome is characterized by damage in the nucleus of the sixth and seventh cranial nerves, with subsequent facial palsy and abduction limitation of the eyes. The aim of this article is to describe the ophthalmological findings of the Mobius syndrome in Mexican children.

PATIENTS AND METHODS

A cross-sectional, retrospective, observational and descriptive study was conducted. A review was made of the clinical charts of patients with Mobius syndrome who were seen in the National Institute of Pediatrics in Mexico, between the years 2000 and 2010.

RESULTS

A total of 64 charts were reviewed. The most important findings were eye abduction limitation (100%), facial palsy (100%), esotropia (54%), epicanthus (51.5%), entropion (22%), and history of use of abortion inducers in the mother in the first trimester of pregnancy (28%). We also found exotropia and hypertropia in some cases.

CONCLUSIONS

Mobius syndrome has a wide spectrum of ophthalmological manifestations that are important to detect early in order to improve function and esthetics.

Oral motor assessment in individuals with Moebius syndrome

BACKGROUND

Moebius syndrome (MS) is a rare congenital condition that is characterised by facial hypomimia and congenital strabismus caused by complete or partial impairment of the 6th and 7th cranial nerves. MS may be further associated with other nerves or malformations, mainly involving the extremities. The objective of this study was to quantify the decrease in oral motor performance in people with MS compared with normoreactive individuals using the Oral Motor Assessment Scale (OMAS).

METHODS

The study group comprised 33 subjects between the ages of 2 and 20 years (average age: 10 ± 5 years) with MS along with 46 age- and gender-matched control subjects.

RESULTS

The study group displayed a lower average functional score than the control group (P < 0.0001). A significant lack of lip closure (P = 0.03) and anterior lingual seal during swallowing (P = 0.03) occurred in the study group; in most cases, the individuals with MS were classified as 'subfunctional'. In addition, individuals with MS in the older age group displayed better functional scores than those in the younger group (P = 0.05).

CONCLUSIONS

Functional damage to oral motor function in individuals with MS is evident, but differs among patients with respect to severity and the movements that are compromised. However, overall, improvements in the functional patterns of these individuals can be observed as they mature in age.

Treatment of severe skeletal open bite deformity in patients with Möbius syndrome: a report of 3 cases

PURPOSE

To investigate the treatment of severe skeletal open bite deformities in Möbius syndrome patients.

MATERIALS AND METHODS

Three patients aged 17 to 24 years (2 male patients and 1 female patient) with Möbius syndrome were evaluated and treated with preoperative orthodontics, orthognathic surgery, and postoperative orthodontic management. One patient was treated by bilateral V osteotomies of the mandibular body and one patient with bilateral V osteotomies of the mandibular body plus a Le Fort I osteotomy. The third patient had bilateral mandibular ramus sagittal split osteotomies in combination with maxillary osteotomies. Two of the patients had preoperative electromyographic studies on the temporalis and masseter muscles.

RESULTS

Postoperative and post-orthodontic stability was good in 2 cases, whereas a 5-mm anterior open bite developed after treatment in 1 case and additional orthodontic management was required to re-establish good occlusion. Potential to redevelop anterior open bites may likely be related to the functional deficiencies of the muscles of mastication and facial paralysis. Two patients who had electromyographic studies to evaluate muscle function showed lower-than-normal function of the temporalis and masseter muscles. Lower lip ptosis remained a significant esthetic issue in 2 of 3 patients.

CONCLUSIONS

Patients with Möbius syndrome with severe skeletal open bite deformities can be treated with combined orthodontic and orthognathic surgery; however, there is a tendency for redevelopment of an anterior open bite with the surgical and orthodontic techniques used in these cases.

Upper lip augmentation with double-row subcutaneous pedicled V-Y flaps in Möbius syndrome

Treatment of open-mouth deformity and augmentation of the upper lip were performed using a combination of double-row V-Y mucosal advancement flaps and a V-Y skin advancement flap in 2 cases with Möbius syndrome. The mucosal V-Y advancement flaps were consisted for 2 rows of flaps. The first row was placed near the labial sulcus, including 3 V-Y advancement flaps. These flaps equally provided 3 directional augmentation for each segment of the upper lip. Second row V-Y mucosal advancement flap was used for the augmentation of the vermilion tubercle. In our cases, V-Y advancement flaps were used as subcutaneous based flaps unlike other distally based V-Y flap techniques for the upper lip. Postoperative complications such as scar formation, sensation problems, severe pain, and edema were decreased because of subcutaneous pedicled V-Y flaps. In addition, the relationship between mucosa and orbicularis oris muscle, which is responsible for the fine balance of the vermilion, was maintained with subcutaneous-based flaps. The skin V-Y advancement flap was used both to lengthen the upper lip and to create philtral columns on the upper lip.

Reanimation of the middle and lower face in facial paralysis: review of the literature and personal approach

Facial paralysis refers to a condition in which all or portions of the facial nerve are paralysed. The facial nerve controls the muscles of facial expression, paralysis which results in a lack of facial expression which is not only an aesthetic issue, but has functional consequences as the patient cannot communicate effectively. The treatment of long-standing facial paralysis has challenged plastic surgeons for centuries, and still the ultimate goal of normality of the paralysed hemi-face with symmetry at rest as well as the generation of a spontaneous symmetrical smile with corneal protection has not yet fully been reached. Until the end of the 19th century, the treatment of this condition involved non-surgical means such as ointments, medicines and electrotherapy. With the advent and refinement of microvascular surgical techniques in the latter half of the 20th century, vascularised free muscle transfers coupled with cross-facial nerve grafts were introduced, allowing the possibility of spontaneous emotion being restored to the paralysed face became reality. The aim of this article is to revisit the surgical evolution and current options available as well as outcomes for patients suffering from facial paralysis concentrating on middle and lower face reanimation.

Facial animation in children with Moebius and Moebius-like syndromes

BACKGROUND

Moebius syndrome, a rare congenital disorder of varying severity, involves multiple cranial nerves and is characterized predominantly by bilateral or unilateral paralysis of the facial and abducens nerves. The paralysis of the VI and VII cranial nerves leads to a lack of function in the muscles they supply. Facial paralysis often causes bilabial incompetence with speech difficulties, oral incompetence, problems with eating and drinking, including pocketing of food in the cheek and dribbling, as well as severe drooling.

METHODS

In this study, we report on pediatric patients with Moebius and Moebius-like syndromes seen and treated surgically from 2003 to September 2007 at the Operative Unit of Maxillofacial Surgery, Head and Neck Department, University of Parma, Italy.

RESULTS

Twelve patients underwent microsurgical reconstruction for restoration of facial movement. The contralateral facial nerve was used as a motor donor nerve in 4 procedures, the motor nerve to the masseter muscle was used in 8 patients, and the gracilis muscle was used in all operations, with a total of 17 free-muscle transplantations. All free-muscle transplantations survived transfer, and no flap was lost. We observed a significant improvement in drooling, drinking, speech, and facial animation with a high degree of patient satisfaction.

CONCLUSIONS

The gracilis muscle free transfer is a surgical procedure well tolerated by the young patients and well accepted by their families. We consider it a safe and reliable technique for facial reanimation with good aesthetical and functional results in children with Moebius and Moebius-like syndromes.

The "babysitter" procedure: minihypoglossal to facial nerve transfer and cross-facial nerve grafting

BACKGROUND

In 1984, Terzis introduced the "babysitter" procedure, a new concept in facial reanimation. It involves two stages, with coaptation of ipsilateral 40 percent hypoglossal to facial nerve on the affected side, performed concomitantly with cross-facial nerve grafting and secondary microcoaptations 8 to 15 months later. This article presents the senior author's (J.K.T.) experience with the original procedure.

METHODS

Of 75 patients who had minihypoglossal nerve transfer, 20 fulfilled the selection criteria for the original babysitter procedure. All patients' records, photographs, videotapes, and needle electromyography studies were reviewed. The clinical results were scored using Terzis' Grading Scale. Eye closure, smile, and lower lip depression were each assessed separately. Functional and aesthetic outcomes and preoperative and postoperative electromyography results were analyzed.

RESULTS

Seventy-five percent of patients achieved excellent and good results, 15 percent had moderate results, and 10 percent had fair results. The difference between preoperative and postoperative eye closure was statistically significant (t test, p < 0.001). Symmetrical smile and full contraction (excellent result) was achieved in two patients (10 percent), 13 patients (65 percent) had nearly symmetrical smile (good result), and five patients (25 percent) had a moderate result. Two patients (10 percent) had full lower lip depression (excellent result) and 15 (75 percent) had good results. In three patients (15 percent), subsequent digastric or platysma muscle transfer was performed because of inadequate depression and symmetry (moderate result). A statistically significant difference was observed between preoperative and postoperative electromyography results, in eye closure, smile, and lower lip depression.

CONCLUSIONS

The original babysitter procedure offers significant improvement in selected patients with facial paralysis. Symmetry and coordinated movements can be restored, with satisfying aesthetic and functional outcomes.

Spatial statistics of gaze fixations during dynamic face processing

Social interaction involves the active visual perception of facial expressions and communicative gestures. This study examines the distribution of gaze fixations while watching videos of expressive talking faces. The knowledge-driven factors that influence the selective visual processing of facial information were examined by using the same set of stimuli, and assigning subjects to either a speech recognition task or an emotion judgment task. For half of the subjects assigned to each of the tasks, the intelligibility of the speech was manipulated by the addition of moderate masking noise. Both tasks and the intelligibility of the speech signal influenced the spatial distribution of gaze. Gaze was concentrated more on the eyes when emotion was being judged as compared to when words were being identified. When noise was added to the acoustic signal, gaze in both tasks was more centralized on the face. This shows that subject's gaze is sensitive to the distribution of information on the face, but can also be influenced by strategies aimed at maximizing the amount of visual information processed.

Anesthetic implications of Möbius syndrome

Möbius syndrome is a rare disorder characterized by unilateral or bilateral facial paralysis and defective extraocular eye movements secondary to congenital paresis of the facial (VII) and abducens (VI) cranial nerves. Associated dysfunction of other cranial nerves, orofacial abnormalities, and skeletal muscle hypotonia are common accompanying features. Given the multisystem involvement of Möbius syndrome, there are several potential perioperative concerns. Of primary importance to the anesthesia provider are the propensity for postoperative respiratory failure due to several pathological mechanisms, associated orofacial abnormalities that may make routine airway management difficult, the presence of gastroesophageal reflux and other factors that increase the risk of perioperative aspiration, and associated hypotonia of the skeletal musculature. The authors present a 10-month-old infant with Möbius syndrome who required anesthetic care during a Nissen fundoplication. The potential anesthetic implications of this syndrome are discussed.

Congenital unilateral multiple cranial neuropathy: an etiology shared with Mobius syndrome?

Mobius syndrome was originally described as bilateral 6th and 7th cranial nerve palsy and has since been expanded to include involvement of nearly all cranial nerves, limb deformities, orofacial anomalies and deficits in intellectual function. The etiology of Mobius syndrome remains elusive. Here we present a case with unilateral 5th, 7th, 9th, 10th and 12th cranial nerve palsy along with MRI evidence of ipsilateral brainstem hypoplasia. We propose the unilateral pathology supports the theory that vascular malformation in utero, which can be due to various etiologies, leads to brainstem ischemia and is the key factor in development of Mobius syndrome.

Obstetrical and Pediatric Anesthesia Anesthetic management of children with Moebius sequence

BACKGROUND

Moebius sequence is a rare congenital absence of the sixth and seventh cranial nerves, although there may be additional congenital cranial neuropathies. Developmental delay, cardiac and musculoskeletal abnormalities may also co-exist. Oro-facial manifestations include bilateral facial nerve palsy resulting in a mask like facies, drooling, incomplete eye closure, and strabismus secondary to the extra-ocular muscle imbalance. This condition has multiple implications for anesthetic care.

METHODS

We reviewed 111 anesthesia records of 46 patients with Moebius sequence for anesthesia technique and related complications.

RESULTS

Facial nerve palsy was universally present and bilateral in 44 (93.6%) patients. Thirty-two (68%) had concomitant sixth nerve palsy. Oro-facial and limb abnormalities were present in 16 (35%) and 18 (39%) of patients respectively. Endotracheal intubation, when attempted, was easy in 76 of 106 cases. Tracheal intubation was consistently difficult in seven patients and intubation failure occurred in a single patient only. Statistically significant factors associated with difficult tracheal intubation included structural abnormalities of the mandible and palate and abnormalities of four cranial nerves (IX, X, XI, XII).

CONCLUSION

We confirm that tracheal intubation may be difficult in patients with Moebius sequence. We identify disease features that might predict a difficult tracheal intubation and thus allow the anesthesiologist an opportunity to plan accordingly.