Adult monkey coronoid process after resection of trigeminal nerve motor root.

A smaller or absent coronoid process has been reported, by some investigators but not by others, in growing animals following resection of the temporalis muscle. The trauma of resection, altered function, hemorrhage, scar tissue, and changes in vascularity may have influenced the results. The purpose of this experiment was to observe in adult Macaca mulatta the fully grown coronoid process after decreasing or eliminating neurofunctional activity of the temporalis muscle unilaterally without the trauma of local resection. In two males and three females the motor root of the trigeminal nerve which innervates the temporalis muscle was resected intracranially. In three control animals of both sexes the same surgical procedure was performed except for resection of the nerve. At postmortem, one year later, the temporalis muscle mass was atrophic on the resected side. There were no significant morphological differences, however, between the right and left sides of the mandible, including the coronoid process, regardless of which motor root of the fifth nerve had been resected, which side had been sham-operated, or sex. An extensive deposit of calculus on the buccal surfaces of the teeth on the operated nerve side was a consistent, conspicuous finding.     

The temporalis myo-osseous flap: an experimental study

The present paper investigates the anatomy and vascularization of the temporalis myo-osseous flap. This is a calvarial bone flap that employs temporalis muscle and its distal pericranial extension as a pedicle. In six human cadavers the flap was raised as an island on the anterior deep temporal artery after transecting the zygomatic arch and coronoid process. Maximal mobilization was thus obtained, allowing rotation of the flap into the mouth for intraoral reconstruction. The arc of rotation and potential surgical applications were noted. A comparative study of the temporalis myo-osseous flap and free calvarial bone graft was then conducted in a rabbit model. Vascularization of the calvarial bone flap was confirmed by technetium scintigraphy performed on the first postoperative day. The uptake of fluorochrome labels immediately after transfer verified the adequacy of the periosteal circulation in maintaining viability and new osteoid formation throughout the full thickness of calvarial bone. The transplantation of free calvarial bone grafts was followed by necrosis of most cellular elements. This was demonstrated by an absence of fluorochrome uptake up to 19 days postoperatively and a predominance of empty lacunae and nonviable marrow.     

Free proximal gracilis muscle and its skin paddle compound flap transplantation for complex facial paralysis

Gracilis functioning free-muscle transplantation for the correction of pure facial paralysis has been a preferred method used by many reconstructive microsurgeons. However, for complex facial paralysis, the deficits include facial paralysis along with soft-tissue, mucosa, and/or skin defects. No adequate solution has been proposed. Treatment requests in those patients are not only for facial reanimation but also for correction of the defects. Of 161 patients with facial paralysis treated with gracilis functioning free-muscle transplantation from 1986 to 2002, eight patients (5 percent) presented with complex deficits requiring not only facial reanimation but also aesthetic correction of tissue defects. The tissue defects included an intraoral defect created following contracture release (one patient), infra-auricular radiation dermatitis with contour depression (one patient), temporal depression following a temporalis muscle-fascia transfer (one patient), ear deformity (two patients), and infra-auricular atrophic tissue with contour depression (three patients). A compound flap, consisting of a gracilis muscle with its overlying skin paddle separated into two components, was transferred for simultaneous correction of both problems. The blood supply to the gracilis and to the skin paddle originated from the same source vessel and therefore required the anastomosis of only one set of vessels. The versatility of this compound flap allows for a wide arc of rotation of the skin paddle around the muscle. All flaps were transferred successfully without complications. Satisfactory results of facial reanimation were recorded in five patients after all stages were completed. The remaining three patients are undergoing physical therapy and waiting for revision of the skin paddle.     

Use of the temporalis muscule flap in blanking out orbits.

We report the use of the temporalis muscle as a transposition flap to obliterate the orbit in 5 patients. In 4 of the cases we split the muscle coronally and passed the anterior part through a window in the lateral orbital wall. In two of these patients, skin grafts were put on both sides of the temporalis muscle-fascia flap, to restore nasal lining and to cover the facial surface simultaneously. In the remaining patients, the muscle was split sagittally to provide a large surface for coverage. The temporalis muscle flap is a versatile one for filling orbits after exenteration.     

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.     

Primary neoplasms of the facial nerve

A series of 30 primary facial nerve tumors is reviewed. Most of them were benign (n = 26); there were four malignant tumors. Neoplasms originating within the temporal bone were found to have preoperative facial paralysis in 84 percent of cases; the extracranial tumors had a 35 percent incidence of preoperative facial paralysis. All tumors in this series were treated surgically--by means of a middle fossa or transmastoid approach for the intratemporal group of tumors; the extracranial tumors were removed by the technique of parotid tumor surgery with complete facial nerve dissection. All the patients with preoperative facial weakness required facial nerve transection. Facial paralysis was rehabilitated with nerve grafts, hypoglossal crossover, or muscle transfers. Because "normal" facial expression is still not attainable following repair of complete facial nerve transection, an early diagnosis, hopefully prior to total neurotmesis, is essential. All patients with unexplained facial weakness, especially that which is progressive and persistent, should have the entire course of the facial nerve investigated for the possibility of treatable etiology.     

Botulinum toxin: a treatment for facial asymmetry caused by facial nerve paralysis

Injury to the frontal or other facial nerve branches can result in an asymmetry that can be very distressful to both patient and surgeon. This is especially true following cosmetic procedures such as rhytidectomy. We propose a means to create temporary symmetry while awaiting the possible return of nerve function. Botulinum neurotoxin causes a muscle paralysis lasting for approximately 3 months, and it is well established as the preferred treatment for blepharospasm. A case is presented in which botulinum toxin type A was injected into the opposite functioning frontalis muscle of a patient with unilateral frontal nerve paralysis. The patient experienced satisfactory relief of the asymmetry caused by onesided forehead wrinkling and brow elevation. Botulinum toxin therapy should be considered for both temporary and permanent facial asymmetries due to facial nerve paralysis as well as spasm.     

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.     

The blood supply of the reverse temporalis muscle flap: anatomic study and clinical implications

Although the reverse temporalis muscle flap has been used clinically, the exact vascular connection between the superficial and deep temporal vessels has not been clearly defined. The purpose of this study was to investigate the vascular territory of the reverse temporalis muscle supplied by the superficial temporal vessels. Six cadaver heads were studied using a colored lead oxide injection through the superficial temporal artery. The specimens were examined macroscopically and radiographically. The reverse temporalis muscle flap was then applied to a clinical case presenting with traumatic anterior skull base defect communicating with the nasal cavity. The cadaver specimens demonstrated that the superficial temporal artery formed an average 1.3 +/- 0.2 cm in width of dense vascular zone, which was located within 1.8 cm below the superior temporal line. The dense vascular network further perfused the anterior and posterior deep temporal arteries and the muscular branch of the middle temporal artery to supply the temporalis muscle. The mean perfused area of the temporalis muscle was 83 percent, ranging from 79 to 89 percent, in five cadaver heads. One cadaver revealed only 55 percent of perfused area in the absence of the muscular branch of the middle temporal artery. The consistent area without perfusion was located in the distal third of the posterior portion of the reverse temporalis muscle. In clinical cases, the reverse temporalis muscle flap was used successfully to obliterate the anterior skull base defect without evidence of muscle flap necrosis. The exact blood supply to the distal third of the posterior portion of the reverse temporalis muscle flap needs to be investigated further in vivo. Particular attention was paid to the inclusion of the muscular branch of the middle temporal artery in this flap to augment the blood supply to the temporalis muscle.     

Quantifying facial asymmetry. A method for objective assessment of impairments of facial motoricity; a pilot study]

The aim of this study was to develop a method of objectively evaluating the results of a dynamic reconstruction of facial nerve paralysis by means of nerve transplants with a view to reinnervating a free muscle transplant. The Vicon 3 D motion analysis system was used to measure the distances and movements of marker points on the face of the patient. This objective technique permits evaluation of the operation as well as the results of treatment.     

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.     

The functional relationship between feeding type and jaw and cranial morphology in ungulates

The relationship between jaw and skull morphology and feeding type (grazer, mixed feeder, browser, frugivorous, omnivorous) was analysed in 94 species of extant ungulates. A total of 21 morphological traits of the jaw and skull (17 and 4, respectively) were analysed using analysis of covariance, with body mass as covariate. To take into account the phylogenetic effect, simulations were generated under the Brownian motion model of character evolution. Analysis of covariance was applied to these simulations and the simulated F-ratios were used to assess the signification of the F-ratios for the real values of the traits. The feeding types had a weak effect on ungulate cranial and jaw morphology in comparison with the phylogenetic effect, since, before phylogeny correction, the analysis of covariance showed statistically significant differences associated with feeding type in 15 out of the 21 traits analysed. After controlling for phylogeny, only 2 significant traits remained, the length of the coronoid process and the occipital height. Omnivorous species had shorter coronoid processes than grazers or mixed feeders, and the occipital height was greater in the omnivorous species than in the grazers, mixed feeders or browsers. The coronoid process is involved in the generation of bite force, being the effective moment arm of the temporalis muscle, and occipital height is positively related to the force exerted by the temporalis muscle. This result matches the hypothesis that species with a toughness diet should show higher bite force (“toughness” describes the resistance of a material to being mechanically broken down). When the omnivorous species were excluded from the analysis, no differences in jaw and skull morphology were detected between the rest of the feeding types. Received: 1 September 1998 / Accepted: 2 November 1998     

A Novel Application of Musculoskeletal Ultrasound Imaging

Ultrasound is an attractive modality for imaging muscle and tendon motion during dynamic tasks and can provide a complementary methodological approach for biomechanical studies in a clinical or laboratory setting. Towards this goal, methods for quantification of muscle kinematics from ultrasound imagery are being developed based on image processing. The temporal resolution of these methods is typically not sufficient for highly dynamic tasks, such as drop-landing. We propose a new approach that utilizes a Doppler method for quantifying muscle kinematics. We have developed a novel vector tissue Doppler imaging (vTDI) technique that can be used to measure musculoskeletal contraction velocity, strain and strain rate with sub-millisecond temporal resolution during dynamic activities using ultrasound. The goal of this preliminary study was to investigate the repeatability and potential applicability of the vTDI technique in measuring musculoskeletal velocities during a drop-landing task, in healthy subjects. The vTDI measurements can be performed concurrently with other biomechanical techniques, such as 3D motion capture for joint kinematics and kinetics, electromyography for timing of muscle activation and force plates for ground reaction force. Integration of these complementary techniques could lead to a better understanding of dynamic muscle function and dysfunction underlying the pathogenesis and pathophysiology of musculoskeletal disorders.     

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.     

Ectopic bone formation after temporal muscle transposition for facial paralysis

This report describes the case of a patient with congenital bilateral facial paralysis in whom ectopic bone formation developed following temporal muscle transposition. Ectopic bone formation was first noticed 4 years after surgery. Whether the ossification is a result of the transfer of periosteum or the osteogenic capacity of muscular tissue is still unknown.     

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.     

On the surgical treatment of facial paralysis in the early nineteenth century

The treatment of facial paralysis is generally considered to have been nonsurgical until the end of the nineteenth century. However, the authors discovered recently that already in the 1840s the celebrated German facial reconstructive surgeons Dieffenbach and von Langenbeck applied the technique of subcutaneous myotomy to healthy facial muscles to reestablish balance in the chronically paralyzed faces of their patients. They performed their operations at a time when anesthesia, asepsis, antisepsis, and antibiotics had not yet been introduced into surgery. It is concluded that Dieffenbach and von Langenbeck were the first, in recorded history, to develop a surgical way to treat irreversible facial paralysis. As their principles are still being used in surgical practice, they cannot be regarded as antiquated, which illustrates the difficulties that reconstructive surgeons still experience in the treatment of irreversible facial paralysis.     

Endoscopically assisted facial suspension for treatment of facial palsy

Static suspension remains an option for certain patients with facial paralysis. Endoscopically assisted facial suspension obviates the need for a counter-incision at the oral commissure to distally inset the fascia lata graft as described in the standard technique. The endoscopic technique is simple, allows secure placement of perioral fascial strips, and can be performed as an outpatient.     

Reanimation of the long-standing partial facial paralysis

Those unfortunate people who suffer from permanent partial facial paralysis have great difficulty finding surgeons who can offer corrective operations. Improving their function is a most delicate procedure. Great care must be exercised to avoid injuring nerves and muscles which are still operating, although in a greatly diminished state. The pathogenesis must be understood before attempting any corrective procedure. Adequate time must elapse from the moment of injury to surgical intervention, thus allowing for maximal nerve and muscle regeneration. This paper describes techniques that could improve facial movements. The most frequently used procedure is shortening of the levator and/or the zygomatic muscles that are partially atrophied. It must be understood that total reanimation is impossible as of this time.