Dynamic reconstruction of eye closure by muscle transposition or functional muscle transplantation in facial palsy

For patients with facial palsy, lagophthalmus is often a more serious problem than the inability to smile. Dynamic reconstruction of eye closure by muscle transposition or by free functional muscle transplantation offers a good solution for regaining near-normal eye protection without the need for implants. This is the first quantitative study of three-dimensional preoperative and postoperative lid movements in patients treated for facial paralysis. Between February of 1998 and April of 2002, 44 patients were treated for facial palsy, including reconstruction of eye closure. Temporalis muscle transposition to the eye was used in 34 cases, and a regionally differentiated part of a free gracilis muscle transplant after double cross-face nerve grafting was used in 10 cases. Patients' facial movements were documented by a three-dimensional video analysis system preoperatively and 6, 12, 18, and 24 months postoperatively. For this comparative study, only the data of patients with preoperative and 12-month postoperative measurements were included. In the 27 patients with a final result after temporalis muscle transposition for eye closure, the distance between the upper and lower eyelid points during eye closing (as for sleep) was reduced from 10.33 +/- 2.43 mm (mean +/- SD) preoperatively to 5.84 +/- 4.34 mm postoperatively on the paralyzed side, compared with 0.0 +/- 0.0 mm preoperatively and postoperatively on the contralateral healthy side. In the resting position, preoperative values for the paralyzed side changed from 15.11 +/- 1.92 mm preoperatively to 13.46 +/- 1.94 mm postoperatively, compared with 12.17 +/- 2.02 mm preoperatively and 12.05 +/- 1.95 mm postoperatively on the healthy side. In the nine patients with a final result after surgery using a part of the free gracilis muscle transplant reinnervated by a zygomatic branch of the contralateral healthy side through a cross-face nerve graft, eyelid closure changed from 10.21 +/- 2.72 mm to 1.68 +/- 1.35 mm, compared with 13.70 +/- 1.56 mm to 6.63 +/- 1.51 mm preoperatively. The average closure for the healthy side was from 11.20 +/- 3.11 mm to 0.0 +/- 0.0 mm preoperatively and from 12.70 +/- 1.95 mm to 0.0 +/- 0.0 mm postoperatively. In three cases, the resting tonus of the part of the gracilis muscle transplant around the eye had increased to an extent that muscle weakening became necessary. Temporalis muscle transposition and free functional muscle transplantation for reanimation of the eye and mouth at the same time are reliable methods for reconstructing eye closure, with clinically adequate results. Detailed analysis of the resulting facial movements led to an important improvement of the authors' operative techniques within the last few years. Thus, the number of secondary operative corrections could be significantly reduced. These qualitative and quantitative studies of the reconstructed lid movements by three-dimensional video analysis support the authors' clinical concept of temporalis muscle transposition being the first-choice method in adult patients with facial palsy. In children, free muscle transplantation is preferred for eye closure, so as not to interfere with the growth of the face by transposition of a masticatory muscle. In addition, a higher degree of central plasticity in children might be expected.     

Free gracilis muscle transplantation, with microneurovascular anastomoses for the treatment of facial paralysis. A preliminary report.

A clinical operative technique for free muscle transplantation by microneurovascular anastomoses is presented. Two cases of free transfer of the gracilis muscle for dynamic reconstruction of facial paralysis are described, including a follow-up study with electromyography, light microscopy, and electron microscopy. We feel this new technique will have a wide range of application in reconstructive surgery.     

Neurovascularized free short head of the biceps femoris muscle transfer for one-stage reanimation of facial paralysis

The single-stage technique for cross-face reanimation of the paralyzed face without nerve graft is an improvement over the two-stage procedure because it results in early reinnervation of the transferred muscle and shortens the period of rehabilitation. On the basis of an anatomic investigation, the short head of the biceps femoris muscle with attached lateral intermuscular septum of the thigh was identified as a new candidate for microneurovascular free muscle transfer. The authors performed one-stage transfer of the short head of the biceps femoris muscle with a long motor nerve for reanimation of established facial paralysis in seven patients. The dominant nutrient vessels of the short head were the profunda perforators (second or third) in six patients and the direct branches from the popliteal vessels in one patient. The recipient vessels were the facial vessels in all cases. The length of the motor nerve of the short head ranged from 10 to 16 cm, and it was sutured directly to several zygomatic and buccal branches of the contralateral facial nerve in six patients. One patient required an interpositional nerve graft of 3 cm to reach the suitable facial nerve branches on the intact side. The period required for initial voluntary movement of the transferred muscles ranged from 4 to 10 months after the procedures. The period of postoperative follow-up ranged from 5 to 42 months. Transfer of the vascularized innervated short head of the biceps femoris muscle is thought to be an alternative for one-stage reconstruction of the paralyzed face because of the reliable vascular anatomy of the muscle and because it allows two teams to operate together without the need to reposition the patient. The nerve to the short head of the biceps femoris enters the side opposite the vascular pedicle of the muscle belly, and this unique relationship between the vascular pedicle and the motor nerve is anatomically suitable for one-stage reconstruction of the paralyzed face. As much as to 16 cm of the nerve can be harvested, and the nerve is long enough to reach the contralateral intact facial nerve in almost all cases. The lateral intermuscular septum, which is attached to the short head, provides "anchor/suture-bearing" tissue, allowing reliable fixations to the zygoma and the upper and lower lips to be achieved. In addition, the scar and deformity of the donor site are acceptable, and loss of this muscle does not result in donor-site dysfunction.     

The pectoralis minor vascularized muscle graft for the treatment of unilateral facial palsy

A series of 10 pectoralis minor vascularized muscle transfers to reanimate the face in unilateral facial palsy are presented. The procedure is carried out in two stages. The first stage constitutes a nerve graft from the functional contralateral facial nerve to the preauricular region of the paralyzed side. Six months later, the pectoralis minor is transferred to the denervated side of the face with restoration of its neurovascular pedicle. The muscle is well suited to its new position with respect to length and bulk, as well as its fanlike shape. The diameter of its vascular pedicle is comparable with the facial vessels. The results demonstrate function in 8 of the 10 grafts, the two failures relating to early vascular thrombosis rather than an inability to reinnervate the muscle grafts.     

Results of management of facial palsy with microvascular free-muscle transfer

This paper reports our experience in facial reanimation using free innervated muscle transfer in 69 patients with long-term facial palsy. The majority of patients were treated in two stages with cross-facial nerve graft as the first stage and microvascular muscle transfer at the second stage. The gracilis muscle was used in 62 patients. A system of grading results has been utilized in the long-term evaluation. The overall final result was excellent or good in 51 percent of 47 patients who were available for follow-up. Although the results are not completely satisfactory, they justify the use of this approach to a difficult clinical problem. The results are improving as technical modifications to the procedure have evolved. The gracilis muscle is a reliable free transfer with internal anatomy conductive to use for reanimation of the paralyzed face. This type of transfer, in our experience, has proved superior to nonmicrosurgical methods for treatment of complete and severe incomplete facial palsy. The seventh cranial nerve is used in the innervation of the transferred muscle, the ipsilateral being preferable if available. The authors believe that use of the same cranial nerve is superior to methods that involve other cranial nerves, where spontaneity is often not achieved.     

The SOOF lift: its role in correcting midfacial and lower facial asymmetry in patients with partial facial palsy

Subperiosteal face lifting has gained wide acceptance in aesthetic surgical practice. It may also have a role to play in patients with partial facial palsy. These patients demonstrate poor static position of the mouth but maintain some degree of facial movement. This study examined the role of subperiosteal facial suspension as an alternative treatment modality in this patient group. In this series, five patients with varying degrees of partial facial palsy underwent subperiosteal face lifting, including sub-orbicularis oculi fat elevation via a temporal, lower lid, and buccal approach, thereby mobilizing and elevating and suspending the zygomaticus major and levator labii superioris muscles on the facial skeleton. An attempt was made to categorize the patients according to overall House-Brackmann score. It was not possible to precisely classify the patients by this method, although the approximate scores were two patients scoring 3, two patients scoring 4, and one patient scoring 5. To overcome inconsistencies with this method, the degree of static and dynamic asymmetry of the mouth and also the excursion of the mouth were graded separately. Four patients with mild to moderate dynamic and static asymmetry (House-Brackmann score of approximately 3 and 4) who maintained excellent or good excursion of the mouth achieved excellent or good results. One patient with poor excursion and severe partial facial palsy (House-Brackmann score of 5) was improved but remained markedly asymmetric (follow-up, 4 months to 1 year). Subperiosteal face lifting is a useful therapeutic modality for management of selected patients with mild partial facial palsy. These patients demonstrate asymmetric static position but maintain some degree of muscle excursion. Patients with severe facial palsies with poor muscle excursion continue to require muscle transfer or sling procedures. The authors hope that long-term follow-up will confirm the sustained effect of midfacial suspension in this selected patient group.     

Neurovascular free-muscle transfer to treat facial paralysis associated with hemifacial microsomia

Despite the wide spectrum of hemifacial microsomia manifestations, treatment mainly focuses on mandible and ear abnormalities, rather than on facial paralysis. In fact, the surgical treatment of facial paralysis associated with hemifacial microsomia is quite underdeveloped, because the degree of paralysis is frequently incomplete or partial. Timing and type of surgery are also difficult to determine. Neurovascular free-muscle transfer is now a standard procedure for the dynamic smile reconstruction of longstanding facial paralysis. This type of strategy has considerable potential in the treatment of facial paralysis in patients with hemifacial microsomia. We present here our experience with neurovascular free-muscle transfer for smile reconstruction in eight patients with facial paralysis associated with hemifacial microsomia. The age of the patients at the time of surgery ranged from 7 to 28 years old, (average, 13.9 years). Six were male patients and two were female patients. The two-stage method combining gracilis muscle transfer with cross-face nerve grafting was performed in three patients, whereas the one-stage transfer of the latissimus dorsi muscle was performed in five. To construct a natural or near-natural smile, the muscles were transferred into the paralyzed cheek in all except one patient, in whom the latissimus dorsi muscle was transferred into the sublabial area to reconstruct a paralyzed lower lip. A dermal flap segment vascularized with perforating vessels from the latissimus dorsi muscle was simultaneously inserted into the underdeveloped cheek for soft-tissue augmentation in this patient. Muscle contraction was evident in all patients between 4 and 8 months after muscle transfer. Our present series revealed that neurovascular free-muscle transfer is a good option not only for smile reconstruction but also for restoration of the facial contours of patients with hemifacial microsomia. Compared with the two-stage method combining gracilis muscle transfer with cross-face nerve grafting, the one-stage method using the latissimus dorsi muscle has some advantages, including a one-stage operation, a shorter recovery period, and the absence of sequelae that occur after harvesting a sural nerve.     

Facial animation in children with Möbius syndrome after segmental gracilis muscle transplant

M?bius syndrome is a complex congenital anomaly involving multiple cranial nerves, including the abducens (VI) and facial (II) nerves, and often associated with limb anomalies. Muscle transplantation has been used to address the lack of facial animation, lack of lower lip support, and speech difficulties these patients experience. The purpose of this study was to investigate the results of bilateral, segmental gracilis muscle transplantation to the face using the facial vessels for revascularization and the motor nerve to the masseter for reinnervation. The outcome of the two-stage procedure was assessed in 10 consecutive children with M?bius syndrome by direct interview, speech assessment, and oral commissure movement. Preoperative data were collected from direct questioning, viewing of preoperative videotapes, notes from prior medical evaluations, and rehabilitation medicine and speech pathology assessments. All of the patients developed reinnervation and muscle movement. The children who described self-esteem to be an issue preoperatively reported a significant posttransplant improvement. The muscle transplants produced a smile with an average commissure excursion of 1.37 cm. The frequency and severity of drooling and drinking difficulties decreased postoperatively in the seven symptomatic children. Speech difficulties improved in all children. Specifically, of the six children with bilabial incompetence, three received complete correction and three had significant improvement. Despite the length and complexity of these procedures, complications were minimal. Muscle transplantation had positive effects in all problematic areas, with a high degree of patient satisfaction and improvement in drooling, drinking, speech, and facial animation. The surgical technique is described in detail and the advantages over regional muscle transfers are outlined. Segmental gracilis muscle transplantation innervated by the motor nerve to the masseter is an effective method of treating patients with M?bius syndrome.     

Neurovascular free-muscle transfer for the treatment of established facial paralysis following ablative surgery in the parotid region

Neurovascular free-muscle transfer for facial reanimation was performed as a secondary reconstructive procedure for 45 patients with facial paralysis resulting from ablative surgery in the parotid region. This intervention differs from neurovascular free-muscle transfer for treatment of established facial paralysis resulting from conditions such as congenital dysfunction, unresolved Bell palsy, Hunt syndrome, or intracranial morbidity, with difficulties including selection of recipient vessels and nerves, and requirements for soft-tissue augmentation. This article describes the authors' operative procedure for neurovascular free-muscle transfer after ablative surgery in the parotid region. Gracilis muscle (n = 24) or latissimus dorsi muscle (n = 21) was used for transfer. With gracilis transfer, recipient vessels comprised the superficial temporal vessels in 12 patients and the facial vessels in 12. For latissimus dorsi transfer, recipient vessels comprised the facial vessels in 16 patients and the superior thyroid artery and superior thyroid or internal jugular vein in four. Facial vessels on the contralateral side were used with interpositional graft of radial vessels in the remaining patient with latissimus dorsi transfer. Cross-face nerve grafting was performed before muscle transfer in 22 patients undergoing gracilis transfer. In the remaining two gracilis patients, the ipsilateral facial nerve stump was used as the primary recipient nerve. Dermal fat flap overlying the gracilis muscle was used for cheek augmentation in one patient. In the other 23 patients, only the gracilis muscle was used. With latissimus dorsi transfer, the ipsilateral facial nerve stump was used as the recipient nerve in three patients, and a cross-face nerve graft was selected as the recipient nerve in six. The contralateral facial nerve was selected as the recipient nerve in 12 patients, and a thoracodorsal nerve from the latissimus dorsi muscle segment was crossed through the upper lip to the primary recipient branches. A soft-tissue flap was transferred simultaneously with the latissimus muscle segment in three patients. Contraction of grafted muscle was not observed in two patients with gracilis transfer and in three patients with latissimus dorsi transfer. In one patient with gracilis transfer and one patient with latissimus dorsi transfer, acquired muscle contraction was excessive, resulting in unnatural smile animation. The recipient nerves for both of these patients were the ipsilateral facial nerve stumps, which were dissected by opening the facial nerve canal in the mastoid process. From the standpoint of operative technique, the one-stage transfer for latissimus dorsi muscle appears superior. Namely, a combined soft-tissue flap can provide sufficient augmentation for depression of the parotid region following wide resection. A long vascular stalk of thoracodorsal vessels is also useful for anastomosis, with recipient vessels available after extensive ablation and neck dissection.     

Three-dimensional video analysis of facial movements: a new method to assess the quantity and quality of the smile

The results of neuromuscular reconstructions of the paralyzed face are difficult to assess. Very sophisticated methods are necessary to measure the motor deficits of facial paralysis or the functional recovery in the face. The aim of this development was a relatively simple system for data acquisition, which is easy to handle and which makes it relatively cheap to delegate data acquisition to centers all over the world, which will not be able to derive a data analysis on their own, but will send their data to a center with specialized equipment. A complex mirror system was developed to get three different views of the face at the same time on the video screen. At each investigation, a digital video is taken from a calibration grid and from standardized facial movements of the patient. Secondary analysis of the digital videofilm is made possible at any time later on by the support of a computer program, which calculates distances and movements three-dimensionally from the frontal image and the right and left mirror images. Pathologies of the mimic movements can be identified as well as improvements after surgical procedures by this system. The significant advantage is the possibility to watch the same movement on the video which is under study and to apply any kind of study later on. Taking the video needs only a few minutes, and fatigue of the patient's mimic system is prevented. Measurements usually at the endpoints of the movements give excellent information on the quantity of the movement or the degree of the facial palsy, whereas the video itself is very informative regarding the quality of the smile. Specific computer software was developed for standardized three-dimensional analysis of the video-documented facial movements and for data presentation. There are options like two-dimensional graphs of single moving points in the face or three-dimensional graphs of the movements of all measured points at the same time during a standardized facial movement. By a comparison of the right- and left-sided alterations of specific distances between two points during the facial movements, the degree of normal symmetry or pathologic asymmetry is quantified. This system is more suitable for detailed scientific multicenter studies than any other system previously established. A very sensitive instrument for exact evaluation of mimic function is now available.     

Transplantation and transposition of skeletal muscles into the faces of monkeys

Restoration of normal facial movement after long-term facial paralysis with muscle atrophy has not yet been achieved reliably by either free grafts, in which fibers degenerate and regenerate, or by grafts made with microneurovascular repair, in which most fibers survive. Our purpose was to compare the structural and functional properties of free muscle grafts and continuously perfused muscle flaps transplanted into the faces of monkeys. In adult monkeys, the facial muscles were replaced by either a free graft of a donor muscle from the lower limb or a denervated flap of ipsilateral temporalis muscle. Each graft or flap was reinnervated with the preserved buccal branch of the facial nerve. The control muscles, grafts, and flaps were examined 90 days later for gross appearance, contractile properties, and fiber areas. Compared with muscle flaps, free grafts showed greater adaptability to the new location and innervation and a closer approximation to the structural and functional properties of the original facial musculature.     

Anatomy of emotion: a 3D study of facial mimicry

Alterations in facial motion severely impair the quality of life and social interaction of patients, and an objective grading of facial function is necessary. A method for the non-invasive detection of 3D facial movements was developed. Sequences of six standardized facial movements (maximum smile; free smile; surprise with closed mouth; surprise with open mouth; right side eye closure; left side eye closure) were recorded in 20 healthy young adults (10 men, 10 women) using an optoelectronic motion analyzer. For each subject, 21 cutaneous landmarks were identified by 2-mm reflective markers, and their 3D movements during each facial animation were computed. Three repetitions of each expression were recorded (within-session error), and four separate sessions were used (between-session error). To assess the within-session error, the technical error of the measurement (random error, TEM) was computed separately for each sex, movement and landmark. To assess the between-session repeatability, the standard deviation among the mean displacements of each landmark (four independent sessions) was computed for each movement. TEM for the single landmarks ranged between 0.3 and 9.42 mm (intrasession error). The sex- and movement-related differences were statistically significant (two-way analysis of variance, p=0.003 for sex comparison, p=0.009 for the six movements, p<0.001 for the sex x movement interaction). Among four different (independent) sessions, the left eye closure had the worst repeatability, the right eye closure had the best one; the differences among various movements were statistically significant (one-way analysis of variance, p=0.041). In conclusion, the current protocol demonstrated a sufficient repeatability for a future clinical application. Great care should be taken to assure a consistent marker positioning in all the subjects.     

Automated tracking of facial features in patients with facial neuromuscular dysfunction

Facial neuromuscular dysfunction severely impacts adaptive and expressive behavior and emotional health. Appropriate treatment is aided by quantitative and efficient assessment of facial motion impairment. We validated a newly developed method of quantifying facial motion, automated face analysis (AFA), by comparing it with an established manual marking method, the Maximal Static Response Assay (MSRA). In the AFA, motion of facial features is tracked automatically by computer vision without the need for placement of physical markers or restrictions of rigid head motion. Nine patients (seven women and two men) with a mean age of 39.3 years and various facial nerve disorders (five with Bell's palsy, three with trauma, and one with tumor resection) participated. The patients were videotaped while performing voluntary facial action tasks (brow raise, eye closure, and smile). For comparison with MSRA, physical markers were placed on facial landmarks. Image sequences were digitized into 640 x 480 x 24-bit pixel arrays at 30 frames per second (1 pixel congruent with0.3 mm). As defined for the MSRA, the coordinates of the center of each marker were manually recorded in the initial and final digitized frames, which correspond to repose and maximal response. For the AFA, these points were tracked automatically in the image sequence. Pearson correlation coefficients were used to evaluate consistency of measurement between manual (the MSRA) and automated (the AFA) tracking methods, and paired t tests were used to assess the mean difference between methods for feature tracking. Feature measures were highly consistent between methods, Pearson's r = 0.96 or higher, p < 0.001 for each of the action tasks. The mean differences between the methods were small; the mean error between methods was comparable to the error within the manual method (less than 1 pixel). The AFA demonstrated strong concurrent validity with the MSRA for pixel-wise displacement. Tracking was fully automated and provided motion vectors, which may be useful in guiding surgical and rehabilitative approaches to restoring facial function in patients with facial neuromuscular disorders.     

Diagnostic features of emotional expressions are processed preferentially

Diagnostic features of emotional expressions are differentially distributed across the face. The current study examined whether these diagnostic features are preferentially attended to even when they are irrelevant for the task at hand or when faces appear at different locations in the visual field. To this aim, fearful, happy and neutral faces were presented to healthy individuals in two experiments while measuring eye movements. In Experiment 1, participants had to accomplish an emotion classification, a gender discrimination or a passive viewing task. To differentiate fast, potentially reflexive, eye movements from a more elaborate scanning of faces, stimuli were either presented for 150 or 2000 ms. In Experiment 2, similar faces were presented at different spatial positions to rule out the possibility that eye movements only reflect a general bias for certain visual field locations. In both experiments, participants fixated the eye region much longer than any other region in the face. Furthermore, the eye region was attended to more pronouncedly when fearful or neutral faces were shown whereas more attention was directed toward the mouth of happy facial expressions. Since these results were similar across the other experimental manipulations, they indicate that diagnostic features of emotional expressions are preferentially processed irrespective of task demands and spatial locations. Saliency analyses revealed that a computational model of bottom-up visual attention could not explain these results. Furthermore, as these gaze preferences were evident very early after stimulus onset and occurred even when saccades did not allow for extracting further information from these stimuli, they may reflect a preattentive mechanism that automatically detects relevant facial features in the visual field and facilitates the orientation of attention towards them. This mechanism might crucially depend on amygdala functioning and it is potentially impaired in a number of clinical conditions such as autism or social anxiety disorders.     

Evaluation of a new measurement tool for facial paralysis reconstruction

Evaluation of facial movement, including distance and direction, is essential for anyone interested in facial paralysis reconstruction. The authors' goal was to develop a measurement system that is simple, uses commercially available equipment, takes little time, and provides meaningful and accurate measurements. This technique is called the facial reanimation measurement system. It involves placing dots around the patient's mouth and video recording the patient performing maximal effort smiles. Using a video editing program, one frame showing the patient at rest is overlaid with a second frame showing the patient's smile. This overlaid image is imported into Adobe PhotoShop, where measurements are obtained using tools available in the program. Twenty patients were used to test interrater and intrarater reliability of the facial reanimation measurement system. The accuracy of the measurement process was tested by comparing 10 known distances and angles with those obtained using the facial reanimation measurement system. Both intrarater and interrater reliability of the distance and angle measurements are highly accurate, with intraclass correlations greater than 0.9. The facial reanimation measurement system is accurate to within 0.6 mm and 2.0 degrees when compared with a "known" distance and angle. The facial reanimation measurement system has been used to measure smile movements of more than 200 patients and has been demonstrated to be valuable for detecting changes of facial movements over time. This system is simple and economical and only requires 20 minutes to perform. Although the authors demonstrated evaluation of smile movement, the system may be used to evaluate other movements, such as mouth puckering, eye closure, and forehead elevation.     

Upper labial deficiency in Mobius syndrome: a previously unreported feature and its correction

Bilateral facial palsy in M?bius syndrome remains one of the greatest challenges in reconstructive plastic surgery. Facial reanimation is an invaluable aid to such patients because it allows for greater social interaction by means of the ability to smile. In performing facial reanimation surgery on patients with M?bius syndrome, it is the observation of the senior author (Harrison) that upper labial deficiency is a consistent and previously unreported feature of the syndrome. It has been the practice of the senior author to perform upper labial augmentation on M?bius syndrome patients by insertion of a lipodermal autograft, in addition to facial reanimation. Nine patients with M?bius syndrome who presented to the Department of Plastic Surgery during an 8-year period were reviewed. All nine possessed bilateral facial palsy and upper labial deficiency in addition to other abnormalities consistent with M?bius syndrome. Six patients underwent bilateral facial reanimation and upper labial augmentation alone. One patient refused facial reanimation surgery but consented to upper labial augmentation. One patient, with concomitant micrognathia, underwent bilateral facial reanimation, upper labial augmentation, and insertion of a Silastic chin implant. In one patient, a child who also exhibited micrognathia, bilateral facial reanimation alone was carried out, with further procedures for upper labial and chin cosmesis being postponed until adulthood. The indication for performing upper labial augmentation was cosmetic. The procedure improved upper labial appearance and restored balance to the mouth. Patients also expressed higher satisfaction with eating and drinking, which they related to the improved fullness of the upper lip. This was before the facial reanimation had become functional. Upper labial deficiency warrants addition to the list of facial features of M?bius syndrome and is something that must be assessed in the context of facial reanimation surgery.     

三叉神经对去运动神经支配面肌肌萎缩的影响

本文用组织化学、电镜以及肌球蛋白和肌动蛋白电泳分析了在单纯性面神经切断和三叉神经、面神经同时切断后面肌萎缩的病理改变--肌纤维的显微结构改变以及面肌收缩蛋白质在手术后不同时期的降解变化。实验证明,面部肌肉在不同的神经切断情况下其病理改变不同,正常的三叉神经支配可以延缓面瘫后肌肉蛋白质的降解,减少胶原纤维结缔组织的增生,较好地保护肌纤维的显微结构,延缓和减轻去运动神经支配面肌肌萎缩。本研究结果可以为临床治疗面瘫提供一定的理论指导。     

Pseudo-paralysis of the mandibular branch of the facial nerve after platysmal face-lift operation.

With the increasing popularity of platysmal face lifts, the anatomy of the cervical branch of the facial nerve should be noted. The postoperative appearance of lack of ability to retrude the corner of the mouth, in someone who had a "full denture" smile preoperatively, could possibly be due to severance or stretching of the rami of the cervical branch of the facial nerve--rather than an injury of the facial nerve of the marginal mandibular branch.     

Robust Eye Center Localization through Face Alignment and Invariant Isocentric Patterns

The localization of eye centers is a very useful cue for numerous applications like face recognition, facial expression recognition, and the early screening of neurological pathologies. Several methods relying on available light for accurate eye-center localization have been exploited. However, despite the considerable improvements that eye-center localization systems have undergone in recent years, only few of these developments deal with the challenges posed by the profile (non-frontal face). In this paper, we first use the explicit shape regression method to obtain the rough location of the eye centers. Because this method extracts global information from the human face, it is robust against any changes in the eye region. We exploit this robustness and utilize it as a constraint. To locate the eye centers accurately, we employ isophote curvature features, the accuracy of which has been demonstrated in a previous study. By applying these features, we obtain a series of eye-center locations which are candidates for the actual position of the eye-center. Among these locations, the estimated locations which minimize the reconstruction error between the two methods mentioned above are taken as the closest approximation for the eye centers locations. Therefore, we combine explicit shape regression and isophote curvature feature analysis to achieve robustness and accuracy, respectively. In practical experiments, we use BioID and FERET datasets to test our approach to obtaining an accurate eye-center location while retaining robustness against changes in scale and pose. In addition, we apply our method to non-frontal faces to test its robustness and accuracy, which are essential in gaze estimation but have seldom been mentioned in previous works. Through extensive experimentation, we show that the proposed method can achieve a significant improvement in accuracy and robustness over state-of-the-art techniques, with our method ranking second in terms of accuracy. According to our implementation on a PC with a Xeon 2.5Ghz CPU, the frame rate of the eye tracking process can achieve 38 Hz.