Functional reconstruction of the masseter muscle by microvascular free gracilis muscle transfer: technique and outcome

Microvascular reconstruction of the cheek is most often performed using fasciocutaneous flaps and without functional reconstruction of the masseter muscle. This article reports a technique of masseter muscle resection, dissection of the masseteric nerve, and masseter muscle reconstruction with a functional gracilis muscle flap. The technique was applied in a 38-year-old man with recurrent intramuscular lipoma of the right masseter muscle. The flap was highly stable in form and showed good function. Bite force, electromyography results, and the radiological appearance of the gracilis muscle were similar to those of the contralateral masseter muscle at 12 months after surgery. In conclusion, full rehabilitation of masseter muscle function and good facial aesthetics were achieved by functional gracilis muscle reconstruction of the masseter muscle in a case of total resection.

Neurectomy of the Masseteric Nerve Using an Extra-Oral Approach to Treat Masseter Hypertrophy: Case Report and Literature Review

Masticatory muscle hypertrophy is a benign clinical anomaly which leads to facial asymmetry or a squared face appearance. We report a case of masticatory muscle hypertrophy, particularly on the right side, that was successfully treated by neurectomy of the right masseteric nerve through an extra-oral approach. Clinical examination showed significant aesthetic improvement of the facial symmetry with complete paralysis and atrophy of the right masseter muscle. The impaired postoperative function of the frontal branch of the right facial nerve was fully restored 10 weeks postoperatively. The patient no longer experiences headaches or discomfort with eating or sleeping on her right side.

Masseter idiopathic calcinosis circumscripta: A rare condition

Calcinosis is defined as a biomineralization occurring in soft tissues leading to ectopic calcification. Isolated and localised calcification in a muscle is rare, and it is called calcinosis circumscripta in opposition to calcinosis universalis wich is seen in juvenile dermatomyositis and polymyositis. According to laboratory findings and clinical history, calcinosis circumscripta can be metastatic, dystrophic or idiopathic. Masseter muscle is rarely involved. Pre-operative diagnosis of masseter idiopathic calcinosis is a challenge because of many differential diagnosis. Here, we report a case of 22 years old women presented with swelling over left middle third of her face. Clinical history, morphologic and laboratory examinations helped considering such a rare diagnosis.

Masseteric nerve position on the "temporomandibular joint-chin tip" artificial axis: an anatomical study

PURPOSE

The use of the masseteric nerve develops in the surgery of facial paralysis rehabilitation. The objective of this study was to determine the topography of the masseteric nerve and to deduce and predict a precise and reproducible anatomical cluster to facilitate its clinical identification during V-VII neurotization surgery.

METHOD

For the purpose of this work, a cadaveric study was performed on 31 hemi-faces. All dissections were performed bilaterally and comparatively, following steps aiming at simulating, as close as possible, the clinical conditions of a facial palsy rehabilitation by V-VII anastomosis.

RESULT

For the identification of the masseteric nerve, bony reference points were used, i.e., the temporomandibular joint (TMJ) and the chin point (CT). A virtual axis was drawn between the TMJ and the CT, and the distance [TMJ-MN] determining the smallest length h was then plotted against the distance [TMJ-CT] determining the largest length H, thus allowing the calculation of an h/H proportion ratio (PR) indicating the proximal part of the masseteric nerve from the TMJ. The average length h between the TMJ and the NM was 3.5 cm (± 0.1 cm) from the TMJ, i.e., an average ratio h/H [TMJ-MN]/[TMJ-CT] of 28.1% 4.0 and a median ratio of 28.6% of the distance [TMJ-CT].

CONCLUSION

Our study opens new perspectives for facilitating its identification and use, offering practitioners a tool to make V-VII the neurotization procedure less complex, with the eventual prospect of a minimally invasive procedure combining imaging, surgery, and augmented reality.

Reduction Mandibuloplasty Along with Partial Masseter Muscle Resection: Masseter Muscle Response and Bone Regeneration

OBJECTIVE

To compare the masseter muscle changes and bone regeneration between reduction mandibuloplasty along with partial masseter muscle resection and reduction mandibuloplasty alone.

METHODS

Forty-seven patients who complained of prominent mandibular angle and hypertrophy masseter muscles (MMH) were divided into group 1 treated with reduction mandibuloplasty along with partial masseter muscle resection, and group 2 treated with reduction mandibuloplasty alone. Pre-5 days and long-term postoperative computed tomography data were collected, and the masseter muscle volume, hemi-mandible volume, and unilateral lower face width were measured. Patient satisfaction and complication were also evaluated.

RESULTS

At long-term follow-up, group 1 showed a greater decrease in masseter volume (p < 0.001), and lower face width (p < 0.001), and less bone regeneration (p < 0.001) than group 2. Furthermore, patients in group 1 had higher satisfaction with the surgical outcome (p < 0.05).

CONCLUSION

Reduction mandibuloplasty along with partial masseter muscle resection can achieve a slender frontal appearance and significantly decrease bone generation. For patients with MMH, reduction mandibuloplasty along with partial masseter muscle resection is an effective and predictable lower face reshaping surgery.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266 .

The Masseteric-Facial Anastomosis With Intratemporal Translocation of the Facial Nerve: Step-by-Step Technique and Results

BACKGROUND

In the absence of a viable proximal nerve stump, damaged after surgical procedures around the skull base, numerous techniques for facial reanimation have been developed over time, aiming to restore baseline symmetry and active mimicry.

OBJECTIVE

To report experience using the masseteric nerve as a direct transfer to the facial nerve rerouted after intratemporal translocation. This paper illustrates the main steps of the technique and the quality of results.

METHODS

Eleven patients were treated with a masseteric direct transfer to the facial nerve. Its extratemporal rerouting toward the zygoma allowed tension-free coaptation between donor and recipient nerves.

RESULTS

Of the 11 patients, 8 had a good to excellent recovery, showing different patterns of time and scores, according to age, surgical timing, and masseteric nerve function quality. The return of activity in the frontalis muscle, never obtained after reinnervation via the hypoglossal nerve, is of particular interest. The quality of the smile can be improved with re-education and practice but remains under volitional control. A true emotional response is still lacking.

CONCLUSION

The masseteric nerve is an excellent alternative to the hypoglossal nerve and can reinnervate the whole territory of the facial nerve rerouted after intratemporal translocation. The overall results are remarkable, but the low quality of the trigeminal nerve, eventually affected by the first surgery, may be an important limitation. Even if the patients appear more at ease in re-education than with other techniques, a fully natural facial expression remains impossible to obtain.

Dual Innervation of Free Functional Muscle Flaps in Facial Paralysis

Dual innervation in free muscle flap facial reanimation has been used to create a functional synergy between the powerful commissure excursion that can be achieved with the masseter nerve and the spontaneity that can be derived from a cross-face nerve graft. The gracilis has been the most frequently used muscle flap, and multiple combinations of neurorrhaphies have been described, including the masseter to the obturator (end-to-end) combined with a cross-face nerve graft to the obturator (end-to-side) and vice versa. Single and staged approaches have been reported. Minimally, dual innervation is as effective as using the motor nerve to masseter alone.

Rehabilitation and functional recovery after masseteric-facial nerve anastomosis

BACKGROUND

After masseteric-facial nerve (V-VII) anastomosis, a new neurological circuit oversees the facial muscles and patients should learn to activate the facial movements using the masseteric function.

AIM

To monitor the rehabilitative protocol of facial muscles activation through teeth clenching and to assess the clinical evolution after V-VII anastomosis in terms of facial symmetry and functional recovery.

DESIGN

Case series.

SETTING

Outpatients clinic.

POPULATION

Eleven patients undergone V-VII anastomosis for complete unilateral facial palsy.

METHODS

After surgery, patients underwent a needle electromyography (EMG) and a rehabilitative training with mirror feedback to learn how to reach the symmetry at rest and during facial movements through teeth clenching. The rehabilitative protocol at the first clinical evaluation has been monitored through the Italian version of Sunnybrook Facial Grading System (SFGS) and the Software Facial Assessment by Computer Evaluation (FACE). Functional limitations and quality of life have been evaluated using the Italian version of Facial Disability Index (FDI). The clinical evolution at 18 months was evaluated with EMG, SFGS, biting evaluation and FDI.

RESULTS

At the first clinical evaluation after reinnervation, through teeth clenching patients displayed an improvement of symmetry at rest, symmetry of voluntary movement, symmetry of smile and composite score of SFGS. Objective measurement of facial structures with FACE system demonstrated an improvement of symmetry at rest and during smile through teeth clenching. At 18 months patients displayed a good reinnervation with a further improvement of SFGS scores and reduction of functional disability. No biting deficit has been observed.

CONCLUSIONS

After V-VII anastomosis, at the first rehabilitative visit, patients learn to activate the reinnervated facial muscles through teeth clenching. Eighteen months after the anastomosis, patients display a further improvement of voluntary control on facial symmetry and smile and a reduction of disability.

CLINICAL REHABILITATION IMPACT

Our study illustrates the rehabilitative protocol after V-VII anastomosis and analyzes the clinical evolution after this intervention in terms of recovery of facial symmetry and reduction of disability. This will be instrumental to standardize the rehabilitative protocol among different centers and to choose the best patient-tailored surgical approach for subjects affected by complete facial palsy.

Masseter flap for reconstruction of defects after excision of buccal mucosa cancers with intact mandible

Among the reconstructive options available for buccal mucosa defects with an intact mandible, free flap with microvascular anastomosis is the best option. However, in the developing world, with poor resources, limited infrastructure, and high patient load, this cannot be offered to all patients. We report on the success of the masseter flap for reconstruction of such defects in carefully selected patients. Despite some known limitations, this flap is easy to learn and carries acceptable complications. The results of this flap may not be comparable to those of microvascular reconstructions, but they are better than those from other options such as skin graft, nasolabial flap, submental flap, etc., in terms of surgical time required, no donor site morbidity, and minimal aesthetic deformity.

[DIAGNOSTICS OF POSITION OF THE MOTOR AND TRIGGER POINTS: OF THE CHEWING MUSCLES FOR ZYGOMATIC COMPLEX FRACTURES]

Existing treatment methods of zygomatic complex fractures, which are complicated by contrac- ture of the masseter as a result of displaced bone fragments, have to be improved. Lack of muscle relaxation leads to the formation of local hypertonicity. In spasmodic muscle fibers varies perfusion and hypoxia occurs, which is accompanied by the release of inflammatory mediators and activation of pain receptors. Over time, areas formed local hypertonicity specific trigger points that contain multiple sensory loci and include one or more sensitive nerve endings. A device for the effective electromyographic study of masseters as a source of their condition and the dynamics of changes in masticatory muscles during patient treatment by improving the fixation system on the face of the patient and the introduction of more perfect spatial coordinate system for mathematical calculations masseter motor position (or triggered) point. Patients were examined before and in the dynamics of treatment according to our methodology, which included proper masseter relaxation, reposition and fixation of bone fragments and further medical therapy.

Surgical consideration of the anatomic origin of the risorius in relation to facial planes

BACKGROUND

Confusion exists as to the plane of the risorius with respect to the superficial musculoaponeurotic system (SMAS), the parotid fascia, and the masseteric fascia, which generally are considered origins of the risorius.

OBJECTIVES

The authors attempted to clarify the origin of the risorius by topographic examination and dissection, which would provide valuable anatomic information for flap dissection in facelift surgery.

METHODS

Detailed dissection was performed in the perioral region of 46 cadaveric specimens to discern the origin of the risorius in relation to the fascial layer. The anatomic aspects of the muscular arrangement and origin of the risorius were classified according to the location of attachment.

RESULTS

The risorius originated solely from the fascial layer superficial to the SMAS in 27 specimens (58.7%; type A). It originated solely from the masseter tendon in 3 specimens (6.5%; type B) and from the fascial layers, both superficial and deep to the SMAS, in 16 specimens (34.8%; type C).

CONCLUSIONS

The patterns of risorius origination identified in this study represent important anatomic reference information for flap dissection in facelift surgery.

Circumscribed myositis ossificans of the masseter muscle: report of a case

Myositis Ossificans (MO) is an unusual pathological entity still largely unknown, characterized by dystrophic calcification leading to heterotopic ossification of intramuscular connective tissue. The masticatory muscles are exceptionally involved. Four distinct types of myositis ossificans have been described: MO Progressiva, which is a genetic disorder involving several muscular groups; MO Circumscripta, limited to a single muscle and generally due to calcification of an intramuscular haematoma following severe trauma and progressive ossification; MO Pseudo-malignant limited to soft tissue and not associated to any trauma; MO associated to paraplegia. A case of circumscribed myositis ossificans of the masseter muscle in a 62 years-old woman is reported.

Recurrent keratocystic odontogenic tumor in the masseter muscle overlying the boney perforations: a case report

Keratocystic odontogenic tumor (KCOT) is a benign intraosseous neoplasm of odontogenic origin with high recurrence rates and tendency to invade adjacent tissue. Most recurrences occur in the first 5 years after surgery and are usually located at the site of the primary tumor in the jaws. We report a rare case of KCOT which recurred in the masseter muscle 14 years after segmental mandibulectomy and autogenous frozen lesional mandible reimplantation. The patient had undergone enucleation of KCOT in the right mandible 20 years before segmental mandibulectomy. This case could further demonstrate the aggressive behavior of KCOT.

A phlebolith in the anterior portion of the masseter muscle

The differential diagnosis of a buccal soft tissue mass containing calcified bodies includes a phlebolith associated with a vascular lesion, such as a hemangioma with a calcified intravascular thrombus, and diseases such as sialolithiasis, traumatic myositis ossificans, calcified acne lesion, neoplasm, and calcified lymph nodes, including tuberculosis. The appearance of the calcified bodies on plain radiographs may help to differentiate these entities. Computed tomography, magnetic resonance imaging, and ultrasonography are also useful for differentiating the soft tissue lesions. We report a 17-year-old girl with a small mass containing a calcified body in the anterior portion of the masseter muscle. The mass was resected surgically and evaluated histologically, confirming the diagnosis of phlebolith. We also discuss the differential diagnosis of a buccal soft tissue mass containing calcifications and suggest that the immunolocalization of CD31 at capillaries in the mass may help to diagnose as a phlebolith.

Percutaneous approach to the foramen ovale: an anatomical study of the extracranial trajectory with the incorrect trajectories to be avoided

OBJECTIVE

Meckel's Cave may be accessed percutaneously through the foramen ovale (FO). Detailed knowledge of the region's anatomical surroundings is invaluable in improving target accuracy and preventing complications with this approach. The approach has been used in the treatment of trigeminal neuralgia as well as in performing biopsies of lesions located in the parasellar region, described formerly by the senior author (M.S.). A comprehensive cadaveric study of the region traversed by needle is thus presented.

MATERIALS AND METHODS

Three cadaveric heads (six sides) were fixed in formaldehyde and injected with latex. A detailed description of the regional anatomical needle trajectories was performed.

RESULTS

An "inverted pyramid" subdivided into three segments is described. The inferior third begins at cutaneous penetration and ends at the parotid duct (PD). The middle third extends from the PD to the lateral pterygoid muscle (LPM). The superior third starts from the LPM and ends at the FO. The main vascular anatomical variation was with regard to the maxillary artery (MA). In half of the cases, the MA traveled though the middle of the pyramid and in the other half through the upper third.

CONCLUSIONS

Although widely used, the FO approach carries risks. Special attention is warranted when the needle traverses the upper third of the pyramid to avoid the variant course of the MA. Image-guided techniques and detailed anatomical knowledge are necessary to expand the use of this route not just for approach to lesions within the parasellar and upper third of the petroclival region but also to lesions invading the infratemporal fossa.

Intramuscular myxoma of the masseter muscle. A case report

PURPOSE

Myxomas are benign, locally infiltrative, connective tissue tumors that rarely occur in the head and neck region. The purpose of this paper is to describe a very rare case of an intramuscular myxoma of the masseter muscle.

METHODS

A 74-year-old man presented with a 2-year history of a painless swelling over his left preauricular region. Computed tomography scan showed an intramasseter well-defined soft tissue mass. After a preauricular approach, a circumscribed solid gelatinous tumor was excised with thin margins including adjacent muscle tissue.

RESULTS

Histopathology revealed an intramuscular myxoma, completely resected. The patient made an uneventful recovery, and there were no signs of recurrence 26 months after surgery.

CONCLUSIONS

Intramuscular myxoma of the masseter is an extremely rare entity, but it must be considered in the differential diagnosis of the swellings of the preauricular region.

The premasseteric branch of facial artery: its importance for craniofacial surgery

AIM

The masseter muscle is often exploited by craniofacial surgeons in transposition operations to correct facial palsy, benign masseteric hypertrophy; or neurectomy-induced atrophy of the muscle. A clear understanding of the course of the premasseteric branch of the facial artery and its relations with adjacent structures is essential in maneuvering the masseter muscle safely. In the present study the premasseteric branch was analyzed in details.

MATERIAL AND METHODS

Neurovascular and anatomical features and relations of the premasseteric branch and its branches were evaluated according to location, origin, diameter, length and course by bilateral meticulous anatomic micro dissection under 4x loop magnification in formalin fixed 14 adult preserved cadavers.

RESULTS

The premasseteric branch originated separately from the facial artery in all cases. The course of the branch was observed to the upper anterior border of the masseter muscle. The diameter of the premasseteric branch was 1.12 mm (mean) at the level of origin. The diameter of the premasseteric branch was larger than the facial artery in 3% of cases. The location of the branch was defined according to body of the mandible. Branches and anastomoses of the premasseteric branch were also represented.

CONCLUSION

Anatomical data of the premasseteric branch will help craniofacial surgeons elevate flaps safely.

Securing the coronoid process during a coronoidotomy

Sagittal application of a titanium mini screw in the coronoid process at the time of coronoidotomy is a very efficient method for easy removal.

Changes in the masseter muscle after curved osteotomy of the prominent mandibular angle

BACKGROUND

This study aimed to explore the changes in the masseter muscle after curved osteotomy of the prominent mandibular angle and to supply guidance for resection of the mandibular angle.

METHODS

Ultrasonography was used to assess changes in the thickness of the masseter muscle after curved osteotomy for 10 patients (20 hemimandibles) at the 6-month following-up assessment. The measurements were performed under both relaxing and maximal clenching positions through three cross sections of the masseter muscle (planes A, B, and C). Plane A contains the line from the mouth angle to the ipsilateral ear lobe. Planes B and C are parallel planes above and below plane A with a distance of 1 cm between them.

RESULTS

No significant difference between the preoperative and postoperative thicknesses of the masseter muscle for planes A and B (p > 0.05) was found, but there was a significant difference (p < 0.05) for plane C. The postoperative thickness of the masseter muscle in plane C was reduced by 0.244 +/- 0.121 cm in the relaxing position and by 0.244 +/- 0.142 cm in the clenching position, which were respectively 19.22% +/- 7.785% and 15.404% +/- 7.648% of its original thickness. There was no significant difference in the contraction amplitude of the masseter muscle under maximal clenching (p > 0.05) for any of the three cross sections postoperatively.

CONCLUSIONS

The masseter muscle around the mandibular angle becomes atrophied but without functional defect after curved osteotomy. Patients with prominent mandibular angles can be treated simply with curved osteotomy instead of masseter excision.

Malignant fibrous histiocytoma of the bucca: a case report

Malignant fibrous histiocytoma (MFH) is the most common soft-tissue sarcoma, but is relatively uncommon in head and neck area. Histologically, it is difficult to distinguish this tumor from other sarcomas and carcinomas. Surgery is the most reliable treatment for MFH, but the 5-year survival rate for cases of this tumor in the head and neck is low in comparison with MFH of the extremities and trunk. In the case reported here, the patient was a 61-year-old man who presented with swelling and pain of the left bucca. A CT scan demonstrated a 2.5 cm x 5.0 cm inhomogeneous lesion. In MRI, the tumor displayed an inhomogeneous isointense signal on T1-weighted images and a high-intensity signal on T2-weighted images. Fine-needle aspiration (FNA) was performed twice but we were unable to reach a definitive diagnosis histologically. MFH was subsequently diagnosed by open biopsy, and external radiotherapy with 38 Gy of radiation was performed. However, the tumor enlarged after this therapy, and therefore CyberKnife therapy was performed twice, after which the tumor gradually reduced in size. The patient is alive after a follow-up period of 22 months, and therefore we suggest that CyberKnife treatment may be useful for head and neck MFH.

Bipaddled radial forearm flap for the reconstruction of bilateral buccal defects in oral submucous fibrosis

Oral submucous fibrosis can result in progressive closure of the mouth. A total of 10 patients with advanced oral submucous fibrosis were surgically treated. The procedure consisted of (1) release of all the intraoral fibrotic tissue, (2) masticatory muscle myotomy and coronoidotomy, and (3) reconstruction with a bipaddled radial forearm flap. Preoperative mouth opening was 0-5mm (mean 2.3mm). The intraoperative mouth opening was 12-20mm (mean 16 mm) after submucous release, and 32-42 mm (mean 35.5mm) after further release via myotomy and coronoidotomy. The proximal flap included one perforator in four patients and two perforators in the remaining six patients. The flaps were 8-9 cm in length and 2-2.5 cm in width. Nine flaps survived uneventfully. Arterial thrombosis was noted in one flap, which was successfully salvaged. Temporomandibular joint subluxation developed in one patient. Two patients needed flap revision due to bulkiness. The postoperative mouth opening was 18-38 mm (mean 28.2mm) after a mean of 21 months' follow-up, and the mean increase was 25.9 mm. A bipaddled radial forearm flap, using a single donor site, can cover two separate buccal defects after release of oral submucosal fibrosis and obviate the need for a second free flap.

Ectopic bone formation as a complication of surgical rehabilitation in patients with Moebius’ syndrome

PURPOSE

Treatment of facial paralysis by muscular neurotization resulted in ectopic ossification in 1 of 134 cases in this department. That patient suffering from Moebius syndrome (MS) is presented. Reviewing the literature concerning MS, Hox genes and bone morphogenetic protein dysregulation, a pathogenesis of ossification in MS is suggested.

PATIENT

The MS patient exhibited a congenital facial nerve palsy, which was treated by muscular neurotization (Lexer-Rosenthal). Because of postoperative ossification of scarred areas, osteotomy of the processus muscularis and mobilization of the masseter muscle was performed. Nevertheless, further ossification occurred at the interface between the mandible and zygoma and in two masticatory muscles. So, the construction of a neoarthrosis became necessary. Three years later, the iatrogenic bone defect had reossified despite of an active opening therapy.

CONCLUSIONS

Ectopic ossification after muscular neurotization seems to be restricted to patients with MS and is triggered by trauma. Molecular pathogenesis: facial malformations in MS are caused by disturbances in embryonic patterning. Failure in the development of the second pharyngeal arch leads to a spatial BMP-4 dysregulation responsible for ossification after wounding of muscle fascia. Therefore, surgical rehabilitation of facial function by muscular neurotization is contra indicated in MS patients.

The influence of masseter activity on rat mandibular growth

Many studies have shown that mandibular and condylar growth is affected by compressive forces on mandibular bone and the condyle. It has been reported that chondroblastic differentiation and proliferation in chondrocytes play important roles in condylar growth. However, the influence of reduced compressive force on chondroblastic proliferation and mandibular bone formation is not fully understood. Thirty-six 3-week-old male Wistar rats were used in this study. In the experimental group, the masseter muscles were bilaterally resected to evaluate the influence of masticatory force on mandibular and condylar bone morphology. Six weeks after the operation, while the rats were in the pubertal growth stage, lateral X-rays were taken to analyze the skeletal pattern of the mandible. The form of the condyle and the thickness of the chondroblastic layers were evaluated by toluidine blue staining. Chondroblastic proliferation was identified by insulin-like growth factor-1 receptor (IGF-1r) immunostaining and bone resorption of the condyle was assessed by measuring tartrate-resistant acid phosphatase (TRAP) activity. Lateral X-rays of the mandible showed that rats in the experimental group tended to have large mandibular plane angles. The chondroblastic layer in the condyles of the experimental group rats was thinner than in the control group. The expression of IGF-1r immunopositive cells in the experimental group was significantly lower than in the control chondrocytes, and the number of TRAP-positive cells was significantly higher in the condylar bone of the experimental group. We conclude that masseter muscle activity is closely related to mandibular morphology during growth.

[Plastic surgery in patients with facial palsy]

In short-term irreversible paralysis caused by facial nerve problems the aim is to re-innervate the paralysed facial musculature. Whenever a paralysis remains untreated for longer than 12-18 months successful re-innervation is unlikely. In longer-term paralysis the symmetry of the face at rest can be restored by a static procedure, a skin resection or a fascial suspension for example. Restoration of movement in the paralysed side of the face is possible by means of a dynamic procedure. For many years the temporal muscle and the masseter muscle have been used to improve the position of the mouth and closure of the eye. Spontaneous laughter can again be made possible by using a muscle from elsewhere in the body (e.g. the gracilis or possibly pectoralis minor) and attaching it to the nerve supply of the opposite side of the face.

An unrecognized foreign body in the parotid gland after trauma

OBJECTIVE

Foreign bodies within the parotid gland retained after trauma are rarely observed, due in part to ease of detection. Few, however, particularly wooden foreign bodies, may not be identified clinically and radiologically.

CASE

A 44-year-old male was admitted complaining of recurrent swelling and pain in the left parotid gland with recent history of penetrating parotid trauma and foreign body removal. Ultrasonography revealed a high degree of parenchymal heterogeneity and an 18 x 5.7 mm linear mass shadow. Following superficial parotidectomy, an approximately 1 x 2 cm wooden fragment that was buried in the masseter muscle and surrounded by granulation tissue was palpated and extracted.

CONCLUSION

Any suspicion of a residual foreign body after penetrating parotid gland trauma can be clarified with a detailed radiological examination, which may provide further guidance for treatment. The treatment modality of parotid foreign bodies is early surgical exploration, and in delayed cases, superficial parotidectomy may be needed.

Radiofrequency volumetric reduction for masseteric hypertrophy

Masseteric hypertrophy occurs frequently among Asians, including Koreans, because of racial characteristics and dietary habits. It is thought to be an unpleasant feature, especially because of its strong and masculine impression. Recently, the authors developed a method for the volumetric reduction of hypertrophied masseter muscles using radiofrequency energy to correct the squared facial appearance caused by the hypertrophy. This study was performed to investigate the effects of radiofrequency applied to reduce hypertrophied masseter muscles of patients who sought an aesthetic alternative for a slim, smooth, and feminine-looking lower facial contour. A total of 340 patients were treated. The patients usually recognized the volume change 3 to 6 weeks after treatment, and an objective volume reduction was observed within 3 months of the operation. The range of the reduction in the masseter thickness, as measured by ultrasonic examination at a 6-month postoperative follow-up visit, was 10% to 60% (mean, 27%). Most of the patients could eat a nearly normal diet after 4 weeks and were satisfied with the improved aesthetic contour lines of their lower face. Radiofrequency-induced coagulation tissue necrosis of the masseter did not cause any infections or limitations of mouth opening, and the clinical improvement was well maintained after the treatment.

Structural fat grafting: more than a permanent filler

Grafted fat has many attributes of an ideal filler, but the results, like those of any procedure, are technique dependent. Fat grafting remains shrouded in the stigma of variable results experienced by most plastic surgeons when they first graft fat. However, many who originally reported failure eventually report success after altering their methods of harvesting, refinement, and placement. Many surgeons have refined their techniques to obtain long-term survival and volume replacement with grafted fat. They have observed that transplanted fat not only adjusts facial and body proportion but also improves surrounding tissues into which the fat is placed. They have noted not only the improvement in the quality of aging skin and scars but also a remarkable improvement in conditions such as radiation damage, chronic ulceration, breast capsular contracture, and damaged vocal cords. The mechanism of fat graft survival is not clear, and the role of adipose-derived stem cells and preadipocytes in fat survival remains to be determined. Early research has indicated the possible involvement of more undifferentiated cells in some of the observed effects of fat grafting on surrounding tissues. Of particular interest is the research that has pointed to the use of stem cells to repair and even to become bone, cartilage, muscle, blood vessels, nerves, and skin. Further studies are essential to understand grafted fat tissue.

Nodular fasciitis in the orofacial region

Nodular fasciitis (NF) is a benign, reactive proliferation of fibroblasts in subcutaneous tissues which commonly occurs in the deep fascia. It can only be diagnosed by histopathological examination of a biopsy. A total of 23 orofacial NF patients was analysed, including those reported in the English language literature and six new patients from the files of this hospital. All patients were treated between 1994 and 2005. The reported lesions were located in cheek masseter muscle, parotid gland, upper neck, upper gingiva and body of mandibular. The clinical and histological features and differential diagnoses are discussed. All lesions were removed under general or local anaesthesia and no recurrence of the lesions was found.

A comparison of commissure excursion following gracilis muscle transplantation for facial paralysis using a cross-face nerve graft versus the motor nerve to the masseter nerve

BACKGROUND

The microneurovascular transfer of a free muscle transplant is the procedure of choice for facial animation in a child with facial paralysis. One of the critical factors of this procedure is the selection of a motor nerve to innervate the transplanted muscle.

METHODS

From 1989 to 1999, 166 free segmental gracilis muscle transfers were performed in 121 children for facial animation. The cross-face nerve graft was used in 70 procedures (cross-face nerve graft group) to innervate the muscle by branches of the seventh nerve for the normal side. The ipsilateral masseteric nerve was used in 94 procedures (50 patients, masseter group) and the ipsilateral accessory nerve was used in two procedures (one patient). To compare the operative procedures between the first two groups, all charts were reviewed. The extent of oral commissure movement was determined by measurements taken from the tragion to the oral commissure, both at rest and with full smile. In the cross-face nerve graft group (n = 20), the extents were measured on both the normal side and the reconstructed side; in the masseter group (n = 16), they were measured on the left and right sides.

RESULTS

No significant difference was found between the two groups (p < 0.05) for the mean age at the time of muscle transplantation, for the total operation time for muscle transplantation, and for the length of the muscle used or for the fraction of circumference of the segment of gracilis muscle used. Although the operative variables were similar between two groups, the muscle excursion differed. Excursion in the cross-face nerve graft group was less than that on the right (p = 0.0006) or left (p = 0.0000) in the masseter group. It was also less than on the normal side (p = 0.0000) of the cross-face nerve graft group. Also, there was no significant difference between the left and right sides within the masseter group (p < 0.05). Furthermore, the extent of oral commissure movement in the masseter group was similar to that of the normal side in the cross-face nerve graft group (p = 0.35, p = 0.61).

CONCLUSION

These results indicate that segmental gracilis muscle transplantation using the motor nerve to the masseter nerve for facial animation in children is a very reproducible operation and provides a commissure excursion in the range of normal.

Reconstruction of #7 facial cleft with distraction-assisted in situ osteogenesis (DISO): role of recombinant human bone morphogenetic protein-2 with Helistat-activated collagen implant

A case involving concomitant presentation of a #7 lateral facial cleft with a complete cleft of the ipsilateral lip, alveolus, and palate is presented. The mandibular defect was Pruzansky III with a foreshortened body, absent ramus and absent masseter. Taking advantage of developmental field theory, reconstruction of the osseous defect was undertaken using the autogenous periosteum as a source of mesenchymal stem cells. Expansion of the periosteum was followed by implantation of Helistat (Integra Life Sciences, Plainsboro, NJ) collagen sponge saturated with recombinant human bone morphogenetic protein-2. Stimulation of this distraction-induced envelope by rhBMP-2 resulted in abundant production of bicortical membranous bone in situ within 12 weeks. The neoramus was subsequently suspended from the cranial base, and a temporalis muscle transfer was used to provide motor control of the jaw. Synthesis of bone in this manner is termed DISO (distraction-assisted in situ osteogenesis). The biologic rationale and clinical implications of DISO are discussed.

An impact of masticatory muscle function on IL-1beta and SOX9 expression in condyle

The importance of masticatory muscle function on the growth and differentiation of condyle was examined. The aim of this study was to investigate how reduced masticatory muscle function influences intrinsic regulatory factors which govern growth and differentiation of condylar cartilage. Masseter muscles of 3-week-old Wistar rats were resected bilaterally. Masseteric resected animals and corresponding control animals were sacrificed at 3, 6, 12 and 21 days post-resection. The condyles were then processed for histological and immunohistochemical analysis. The expression patterns of an inhibitory regulator (IL-1beta) and a master regulator (Sox9) of chondrogenesis in condylar cartilage of growing rats were investigated. Quantitative analysis shows that masseteric resection significantly increased the number of IL-1beta positive cells in proliferative layer. In contrast, the number of Sox9 positive cells was significantly decreased compared to the control animals. It can be concluded that the reduced articular function due to masseteric resection decreased condylar cartilage cell differentiation which led to the decrease in the thickness of condylar cartilage.

The role of imaging and surgery in the management of vascular tumors of the masseter muscle

PURPOSE

Intramuscular vascular malformations are uncommon lesions in the head and neck that may mimic salivary gland disease. This study reports on the use of various imaging modalities and recommends a surgical approach in the management of vascular malformations of the masseter muscle.

PATIENTS AND METHODS

This is a retrospective study of 7 consecutive patients with vascular tumors of the masseter muscle treated in one unit between 1995 and 2004. The age, gender, signs and symptoms, imaging methods, and surgical outcome are reported. A previously unreported surgical approach is described.

RESULTS

All patients had atypical swellings in and around the parotid region that were difficult to diagnose on plain radiography and computed tomography. Magnetic resonance imaging provides accurate three-dimensional images and provisional diagnosis of lesions within the masseter muscle. Six of the 7 patients underwent surgery by the recommended approach. No patients developed permanent facial weakness following modified parotidectomy. No recurrence of the vascular tumors occurred when the recommended approach is used.

CONCLUSIONS

Magnetic resonance imaging remains the imaging modality of choice for the management of tumors of the masseter muscle. The extended parotidectomy approach gives good and safe surgical access in the management of these uncommon lesions.

Transmasseteric antero-parotid approach for open reduction and internal fixation of condylar fractures

The morbidity that results from surgical approaches to the condylar neck, and the time-consuming nature of the operation inhibits many surgeons from using open reduction and internal fixation for the treatment of condylar fractures. The many approaches that have been described stand testimony to the disadvantages of the individual techniques. The most common problems are limited access and injury to the facial nerve. We describe the transmasseteric antero-parotid (TMAP) technique, which offers swift access to the condylar neck while substantially reducing the risk to the facial nerve and eliminating the complications associated with transparotid approaches.

Selective Neurectomy of the Masseteric Nerve in Masseter Hypertrophy

Asian women prefer to have more delicate and feminine features rather than prominent squared mandibular angles. It was proposed that a selective neurectomy of the masseteric nerve might result in muscular atrophy and subsequent reduction of the hypertrophic mass of the masseter muscle. This study is aimed at an elucidation of the precise course of the masseteric nerve and the impact of a neurectomy in case of masseter hypertrophy. Eleven heads of Korean cadavers were halved and dissected. The masseteric nerve and artery in the mandibular notch were clearly located. A selective neurectomy of the masseteric nerve was performed in four cases of masseter hypertrophy. The masseteric nerve and artery behind the temporalis muscle at the mandibular notch cross over to the masseter. The masseteric nerve was found 11.3 +/- 2.6 mm horizontally from the anterior border of the ramus and 11.3 +/- 2.6 mm above the mandibular notch and the superior masseteric artery, 25.6 +/- 3.7 mm from the ramus, and 7.8 +/- 2.6 mm above the notch. A neurectomy of the masseteric nerve can be used to reduce the hypertrophied masseter and as an ancillary procedure of mandibular angle ostectomy. One procedure can accompany another in the reduction of a prominent mandibular angle.

Endoscopic vertical ramus osteotomy: early clinical results

PURPOSE

The benefits of minimally invasive surgery have been well documented. The purpose of this report was to present early results in a series of patients who had endoscopic mandibular orthognathic surgery. Patients and methods This is a retrospective evaluation of 14 patients who underwent endoscopic vertical ramus osteotomy and rigid fixation for the treatment of mandibular prognathism (n = 9), malocclusion secondary to trauma (n = 3), or other pathology (n = 2). A 1.5-cm incision was made directly below the mandibular angle. The dissection was continued bluntly to the masseter muscle, which was incised using a needlepoint electrocautery. Then, with endoscopic elevators, an optical cavity was created for insertion of a Hopkins endoscope and visualization of the ramus/condyle unit. Anatomic landmarks were identified and the operation carried out with specially designed endoscopic equipment. Preoperative (T0), postoperative (T1), and follow-up (T2) clinical examinations; lateral cephalograms; and panoramic radiographs were used to evaluate the outcomes.

RESULTS

The procedures performed included: vertical ramus osteotomy (n = 13 patients, 23 sides) and condylectomy plus vertical ramus osteotomy (n = 1 patient, 1 side). Mean operating time was 37 minutes per side. One patient had temporary marginal mandibular nerve weakness. The occlusal result was as planned in all cases. Panoramic radiographs documented postoperative ramus/condyle unit position and lateral cephalograms documented mandibular position.

CONCLUSIONS

The results of this case series indicate that endoscopic vertical ramus osteotomy with rigid fixation is feasible for correction of a variety of mandibular deformities.

Paralyzed masseter muscle reinnervation by facial nerve implantation or anastomosis: a comparative study in rabbits

OBJECTIVE

To investigate the changes in the physiological and structural properties of the masseter muscle after reinnervation through different reinnervation methods.

METHOD

Twenty-four adult rabbits were randomly divided into groups A and B (n=12) after the establishment of masseter muscle paralysis, followed by facial nerve anastomosis with the masseteric nerves in group A and facial nerve implantation into the masseter muscle in group B. At 1, 3 and 6 months after the operation, gross observation and wet weight measurement of the muscles were conducted along with myoelectric activity and enzyme- histochemical analyses and ultrastructural observation as well.

RESULTS

The reinnervation of the masseter muscle by both facial nerve anastomosis and implantation was confirmed and the muscles recovered their motion of contraction activity. Changes took place in the histochemical types of the muscle fibers, which tended to assume the properties typical of facial muscles. Three months after the operation, the muscle fiber conduction velocity recovery after the reinnervation by the two methods was significantly different (P<0.01), but not so till 6 months postoperatively (P>0.05).

CONCLUSION

This two methods are both effective in the reinnervation of the muscles, but in one-stage operation, intramuscular nerve implantation is relatively less complicated in operation and causes less damage while producing similar effects to that by nerve anastomosis.

[Expression of collagens in reattached masseter muscles to mandibles following a surgical detachment]

OBJECTIVE

The aim of this study was to investigate the expression of collagen in the process of masseter muscle reattachment to the cortical and cancellous bones of mandible.

METHODS

A total of nine adult goats were used in the study. One was the control. The other eight were treated with bilateral detachment of the masseter muscles. The biopsies of bone and muscle were taken at 2, 4, 8 and 12 weeks after the operation. The characteristics of the healing muscle-bone interfaces were examined using immunohistochemical techniques.

RESULTS

Immunohistochemical analysis illustrated that the locations of collagen type I, II and III were different during the healing process, but similar in the cortical and cancellous bones.

CONCLUSION

This study demonstrates that the distribution of the three types of collagens at the muscle-bone interfaces is associated with time, but not related with their locations.

False diagnosis caused by Warthin tumor of the parotid gland combined with actinomycosis

A case is reported in which a unilateral parotid gland cystadenolymphoma was combined with actinomycosis. A 48-year-old woman presented with a mass in the left parotid region and paresis of the lower left palpebra. The computed tomography, echography, and parotid radiographic findings did not exclude a neoplasm of the left parotid gland. The ramus of the mandible was involved in the process. Intraoperative freezing histology, total parotidectomy, and partial mandibulectomy were performed, with sacrifice of the facial nerve followed by nerve reconstruction. The final histological evaluation was Warthin tumor with actinomycosis. Four years after treatment, the patient is free of disease. No similar cases seem to have been reported thus far.

Intraoperative ultrasound imaging to aid abscess drainage--a technical note

Diagnostic ultrasound is used widely to identify the presence of fluid collections preoperatively. Although its role in other parts of the body is well established, this report describes the technique of using diagnostic ultrasound intraoperatively to aid drainage of a large fascial space abscess in the head and neck. Following previously inadequate drainage of a large superficial abscess from a blindly placed drain, a second procedure was carried out, using ultrasound imaging to locate the persisting abscess. Furthermore, ultrasound demonstrated the adequacy of drainage and helped the surgeon to position the drain in the correct tissue space. We consider that intraoperative use of ultrasound has a role as a guidance tool to drain superficial fascial space abscesses in the head and neck region.

A transparotid transcutaneous approach for internal rigid fixation in condylar fractures

Closed versus open reduction in condyle fractures is a dilemma that may torment the plastic surgeon. Although at present it is accepted that there are fractures that must be open reduced as when the middle cranial fossa or temporal fossa are involucrated, foreign body are in the joint capsule, lateral extracapsular deviation of condylar deviation, and open fractures. Risdon or retromandibular approaches are used for the treatment of fractures in the condyle neck and superior third of the lower ramus.When both approaches are used the correct placement of screws is very difficult for the following reasons: 1. Both drill and screwdrivers must be placed in an oblique direction to the bone surface; as a result, screws do not press the plate toward the bone and therefore a deficient stabilization results; 2. A distraction of too much soft tissue entrapped between the skin and mandibular bone is necessary for a good visual to surgical field and 3. The parotid tissue, the masseter muscle, and the facial nerve must be strongly distracted facilitating the nerve injury.A transcutaneous transparotid approach is the most appropriate for screws placement. By means of transbuccal set it is possible to reach the mandibular bone going through both the parotid tissue and the masseter muscle avoiding the injury the branches of the facial nerve.A case report illustrates the practical application of the above technique and it shows that as the lesion of branches of the facial nerve can be avoided.

[Ectopic parotid gland in the mandible and masseter muscle]

An unusual case of double salivary ectopy of parotid gland is described into the masseter muscle and the mandibular ramus in a 45 year-old patient. He first was seen for a slow course tumefaction of the cheek. Imaging demonstrated the intramasseteric localization of the tumefaction and revealed a bone defect in the upper medial part of the mandibular ramus. The intramasseteric salivary ectopy has been confirmed by histologic examination.

Open reduction of subcondylar fractures via an anterior parotid approach

Visualization of subcondylar fractures is limited, and rigid fixation technically difficult, employing standard open surgical techniques--especially when the condyle is displaced out of the glenoid fossa. The majority of condylar neck fractures are treated by closed reduction with maxillomandibular fixation, to obviate the potential for permanent injury to the facial nerve. The technique described employs an anterior parotid, two-layer, sub-SMAS (superficial musculo-aponeurotic system) approach via a rhytidectomy incision that reliably identifies and preserves the neural elements and provides direct access to the pericondylar region. The thirteen patients presented here exhibited satisfactory functional and aesthetic results. Complications included temporary nerve palsies, plate fractures, and a hematoma.