Endoscope-assisted intraoral approach for masseteric hypertrophy

Although conventional intraoral surgery for masseteric hypertrophy is a useful technique, it is considerably difficult to resect the mandibular angle due to the narrow visual field. For the purpose of compensating for the drawbacks of this procedure, we performed endoscope-assisted intraoral surgery on 5 patients with bilateral masseteric hypertrophy, who were successfully treated. The use of an endoscope offers a clear view of the mandibular angle region, thus facilitating accurate and easy resection of the spur.

[A rare case of angiolymphoid intramasseteric hyperplasia]

A white caucasian male 38-year-old has come to our Department with an intramasseterin neoformation. The histopathological report has been angiolymphoid hyperplasia. Surgical approach is discussed considering at the same time the peculiarity of this rare type of intervention.

Open reduction and internal fixation of condylar fractures via an extended bicoronal approach with a masseteric myotomy

Although condylar fractures of the mandible may be treated by closed reduction and appropriate physiotherapy, open reduction and internal fixation is indicated in specific circumstances. We report 25 cases of a previously unreported method of exposure of condylar fractures using an extended bicoronal approach combined with myotomy of the masseter muscle. Acceptable reduction and fixation was achieved in all cases with an early return to function. The incidence of complications was low, with three mild temporary facial palsies which had resolved by the sixth postoperative week and one haematoma beneath the bicoronal scalp flap. A cosmetically acceptable scar was produced in all cases. The excellent surgical exposure and protection of the facial nerve, combined with cosmetically acceptable scars, commend the use of this technique.

Changes in mandibular rotation after muscular resection. Experimental study in rats

The purpose of this study was to evaluate the effect of bilateral muscular resection on the rotational pattern of the rat mandible. The specific aim of the study was to seek possible changes in "articular growth" in the posterior (ramus and condyle of the mandible), and in the anterior part of the face (upper viscerocranium, and maxillary and mandibular dentoalveolar processes). The masseter, temporal, and suprahyoid muscles were bilaterally resected in three experimental groups of 21-day-old female Wistar rats. Another group of rats served as control. The results were evaluated at 42 (prepubertal) and 60 days after birth (pubertal rats). The craniofacial growth pattern, ramus dimension, condylar growth direction, histologic evaluation of condylar cartilage, and dentoalveolar processes height changes were studied. Two mandibular rotational patterns were found: one inferior after masseter muscles resection (MR), and the other superior after temporal muscles resection (TR). A less intense superior rotational pattern, after suprahyoid muscles resection (SR), was found also. Morphologic changes were more intense in older rats. On the contrary, more intense condylar histologic changes were found in younger rats. Changes in "articular growth" primarily take place at maxillary and mandibular dentoalveolar processes. Condylar growth amount could be modified to a limited extent. More important were the changes in condylar growth direction. An upward rotational pattern of the upper viscerocranium was detected when the inferior mandibular rotation pattern was produced.

Essentials of surgical treatment for intramasseteric hemangioma

Although rare, surgical treatment may become necessary for patients with intramasseteric hemangiomas. Possible bleeding, neural injury or postoperative dysfunction are factors limiting surgical approaches. We present the following surgical highpoints for tumors involving the masseter muscles. These include careful preoperative planning with computed tomography and magnetic resonance imaging, as well as a surgical approach that provides adequate exposure for optimal tumor resection and identification of vital anatomic structures. In particular, care must be taken to preserve branches of the facial nerve. In certain cases, preoperative embolization or ligation of vessels feeding tumor helps to minimize blood loss. Whenever possible, complete tumor should be adequately resected with a surrounding margin of normal muscle. Postoperative lymphedema can be minimized by preserving the mandibular periosteum and oral or parenteral use of medication with anti-inflammatory agents. At the University of Tokyo, continuous suction is preferred with a fenestrated drain or pressure dressing with a Penrose drain should be applied to prevent hematoma. Postoperative dysfunction, such as trismus, is prevented by supportive measures.

Role of periosteum in the formation of jaw bone. An experiment in the rat

The aim of the present investigation was to evaluate the bone-forming capacity of the outer (fibrous) and inner (cambium) layer of the mandibular periosteum in skeletally mature rats. The experiment was carried out in 25 rats. The mandibular ramus was exposed on one side (experimental side) after elevation of a muscle-periosteal flap. A teflon capsule was placed with its opening facing the periosteum at the subsurface of the raised muscle-periosteal flap after suturing. In the contralateral side serving as control, the periosteum of the lateral aspect of the mandibular ramus was left intact. This time the teflon capsule was placed with its opening facing the periosteum left behind at the ramus. The histological analysis demonstrated that in all experimental and control specimens, some bone was produced at 7 days after operation. In the experimental specimens, however, both the incidence and the amount of newly-formed bone in the teflon capsules gradually decreased from 7 to 120 days, while increasing in the control capsules placed over the periosteum. At 120 days, the mean amount of new bone produced in the experimental capsules was 3% (range 0-15%) of the total space created by the capsule, while it was 68% (range 41-85%) for the control capsules. The results demonstrated that substantial amounts of bone can be produced predictably by the placement of an occlusive teflon capsule facing mandibular covered with periosteum. Bone produced from the periosteum and without continuity with existing bone becomes resorbed with time.

The gonial angle stripper: an instrument for the treatment of prominent gonial angle

In the Orient, a prominent gonial angle, so-called benign masseteric hypertrophy, is rather common and considered unattractive. Therefore, its surgical correction is one of the most popular forms of facial skeletal contouring. For accurate and safe osteotomy of the mandibular angle region, a gonial angle stripper was specially invented. It has a small projection that will ease identification of the osteotomy line in a narrow operative field. The tool has been clinically used in eight patients to prove its usefulness, especially for a posteriorly developed mandibular angle.

Changes in the temporomandibular joint caused by the vertical facial pattern. Study on an experimental model

An experimental model reproducing open bite or verticalized facial pattern was used to study its effect on the temporomandibular joints. 140 Wistar rats were used, divided into 3 groups: bilateral resection of the masseteric muscle, simulated muscular resection and control group. A series of radiological, morphological and histological tests were analyzed. The posterior rotation of the jaw caused by muscular resection although not producing a degenerative effect, did produce specific articular changes in the temporomandibular joint components.

Precise repair of orbital maxillary zygomatic fractures

OBJECTIVE

To demonstrate the techniques, advantages, indications, and potential pitfalls of the transconjunctival approach with lateral canthotomy, sublabial approach, and coronal approach in the treatment of complex trimalar fracture with associated blow-out fractures.

DESIGN

All patients diagnosed as having complex trimalar fractures with or without blow-out treated by either of us over a 2-year period were included. Follow-up ranged from a minimum of 6 months to 2 years.

SETTING

All patients were treated with December 1989 to December 1991 at either Louisiana State University Medical Center, Shreveport, or University of Kansas Medical Center, Kansas City.

PATIENTS

Eighteen patients with complex trimalar fractures were included in this study. Eight patients had associated orbital blow-out fractures. Simple isolated arch fractures were excluded.

INTERVENTION

All subjects underwent a transconjunctival approach with lateral canthotomy. Seven subjects also had associated sublabial flaps. Five patients required hemicoronal or coronal approaches.

RESULTS

There were seven minor complications. Ninety-three percent (14/15 [three didn't respond to the survey]) of patients surveyed were either very satisfied or satisfied with their functional and cosmetic results.

CONCLUSION

The management of complex trimalar fracture with blow-outs is greatly facilitated by the rational application of the described techniques.

Reanimation of the face after facial nerve palsy resulting from resection of a cerebellopontine angle tumour

Twenty-three patients with facial nerve paralysis following surgery for a cerebellopontine angle tumour had a facial-hypoglossal anastomosis and simultaneous anastomosis of the cervical ansa with the distal stump of the hypoglossal nerve. In 18 patients, simultaneously with the neural anastomoses, additional transpositions of the temporalis and masseter muscles were performed. At follow-up examination 3-87 months after reconstructive surgery, eight patients had House grade II, ten grade III and five grade IV outcome. The EMG evidence of reinnervation was observed 5-11 months after anastomosis. Combination of the facial-hypoglossal anastomosis with simultaneous myoplasty and with anastomosis of the distal hypoglossal nerve stump to the ansa cervicalis provides the advantage of immediate protection against ophthalmic complications, prevents hemiatrophy of the tongue and gives good functional results when reinnervation of the facial muscles takes place.

Pectoralis major muscle free flap in rat model

The rat pectoralis muscle can serve as a vascularized, innervated muscle flap model. The muscle, consisting of superficialis and profundus portions, is supplied by separate neurovascular systems. The vessels to pectoralis profundus (averaging 0.3 mm in diameter) can be taken in continuity with the axillary vessels (averaging 11 mm in diameter), which are used for transplantation. The profundus portion of muscle weighed an average of 1.8 g, and the average pedicle length was 0.9 cm. Nine of 11 transplanted muscles were viable, with intact circulation at 72 hours. An example of muscle transplantation for tissue defect coverage was attempted. The pectoralis profundus transplant was technically reliable, and the muscle bulk and contour could allow biochemical and functional studies.

End results of 114 extended "commando" operations for retromolar trigone carcinoma

Retromolar trigone carcinomas invade the mandible and the pterygoid and/or masseter muscles in a large number of cases. There is also a significant risk of ipsilateral lymph node neck metastasis. The purpose of this retrospective study was to report the survival results of 114 consecutive patients who underwent an extended "commando" operation (retromolar operation) from 1960 to 1991. The technique is a variation of a composite resection. The operation consists of hemimandibulectomy with resection of the pterygoid and masseter muscles, with an ipsilateral neck dissection (radical classical, modified, or supraomohyoid). The oral cavity and oropharyngeal defects were closed primarily in 83 patients. In the remaining 31 patients (27.2%), it was reconstructed by a tongue flap (12 patients), pectoralis major myocutaneous flap (10 patients), and other flaps (9 patients). There were 104 men and 10 women, with a median age of 55 years. All patients had squamous cell carcinoma. Tumor stages were T1 (5 patients), T2 (44 patients), T3 (24 patients), T4 (28 patients), and Tx (13 patients). The metastases were predominantly in levels I and II. Only patients with positive nodes at levels I and/or II had histologically positive nodes at levels IV or V. Complications occurred in 51.8% of the patients (wound infection in 21 patients, 18.4%). Sixty-six patients underwent postoperative irradiation (4 to 70 Gy, median: 50 Gy). To date, 41 patients have presented with 50 tumor recurrences: 31 local, 9 in the dissected neck, 3 in the contralateral neck, and 7 distant. The 5-year actuarial overall survival rate was 80.0% in patients with T1 tumors, 57.8% in those with T2 tumors, 46.5% in those with T3 tumors, and 65.2% in those with T4 tumors. In conclusion, the retromolar operation can be performed with acceptable morbidity, and it is effective (5-year overall survival rate of 55.3%). The rate of local recurrences (27.2%) suggests that radiotherapy as an adjunctive modality should be indicated in patients in whom recurrences are likely.

Intramuscular hemangiomas of the masseter and sternomastoid muscles

Two cases of hemangiomas involving the masseter and sternomastoid muscle are added to the English literature. Our limited experience with these cases confirms that preoperative diagnosis and planning can be difficult. Recurrences of tumors are related to incomplete excisions although their further treatments in the final analysis depend on the adjacent structures affected. Careful individualization of treatment is therefore a necessity. Embolization is not sufficient therapy if not followed by surgery.

[Hemangioma of the masseter: a rare location of a pathology not always accurately diagnosed]

The hemangiomas of the skeletal muscles are rare. The authors describe a case of masseter muscle hemangioma, dwelling upon the problems of differential diagnosis that are present for the straight rapport that the muscle contract with the parotid gland. Thus, the surgeon is led to confuse the malformation with a neoplasm of the parotid gland.

Intramuscular hemangioma of the head and neck

Intramuscular hemangiomas (IMH) are uncommon tumors in the head and neck region, occurring most often in the trunk and extremities. Preoperative misdiagnosis is common because of the deep location of these tumors. Ten recent cases of head and neck IMH are presented, five of which involve the masseter muscle--the most frequent site of involvement in the head and neck. Masseter IMH occurred almost exclusively in the pediatric age group. The clinical presentation, radiographic and histologic findings, treatment, complications, and outcome of these patients are presented. The vital role of preoperative diagnosis using magnetic resonance imaging (MRI) is discussed, as well as a review of the natural history of IMH and indications for surgical intervention.

Intraoral cheek transposition flap for primary reconstruction of the soft palate

A method for primary reconstruction of the soft palate following radical tumor resection is described. The resulting defects can be repaired with 2 layers of tissue by combination of a cranial pedicled pharyngeal flap and a cranial pedicled intraoral cheek transposition (IOCT-) flap. For additional resection of the lateral pharyngeal wall the technique can be combined with a masseter crossover flap. The method allows satisfying restoration of swallowing and speech with relatively small operative effort.

[Provocable tumor of the cheek as a manifestation of so-called "infiltrating lipoma" of the masseter muscle]

We report on a 29-year-old male patient, who presented at our outpatient clinic with a 6-year history of progressive swelling of the right cheek. Contraction of the masseter muscle increased the swelling. MR-Imaging revealed a tumor measuring 2 x 3 cm, which was located within the masseter muscle. The histological diagnosis was infiltrating lipoma, which to our knowledge has not been described in this area before. This particular type of lipoma is extremely rare in the head and neck. The diagnostic and therapeutic management of infiltrating lipoma is discussed, and guidelines for adequate follow-up suggested. In addition, the authors review other sites of this tumor and describe its histological characteristics and differential diagnosis.

Autologous facial fat transplantation: improved graft maintenance by microbead bioactivation

An alternative approach to the management of free fat transplantation resorption was evaluated in a rat facial model. Fat grafts obtained from the inguinal region were transferred to subcutaneous lateral facial sites in 20 animals. The grafts were mixed with either basic fibroblast growth factor (bFGF) alone or dextran beads that had been pretreated with bFGF. The grafts were then compared by weight and histology at 1 and 6 months postoperatively. Although graft weights were nearly comparable at 1 month, substantial differences were seen at 6 months, with the bead-containing grafts exhibiting near complete weight maintenance and better overall graft form. Histologically, the bead-containing grafts had extensive intercellular collagen formation and a heterogeneity of adipocyte cell sizes, particularly after 1 month. These findings suggest that the addition of cell-specific bioactive peptides that affect either the preadipocyte cell line and/or the fibroblastic components of the recipient site improve postoperative fat graft weight maintenance. Delivery of the biochemical agent appears to require a carrier system to exert its effects.

The combined masseter muscle/intraoral cheek transposition (IOCT) flap for primary reconstruction of the dorsal oral cavity

A method for primary reconstruction of the dorsal oral cavity after tumor resection of T2 or small T3 tumors is presented. By combination of the masseter muscle flap with a cranial pedicled intraoral cheek transposition (IOCT) flap, a reconstruction of the defects with two layers of tissue is possible. This easy and functional reconstruction method is especially useful for high-risk patients because of the markedly reduced operating time.