Resection of the buccal fat pad in the treatment of hypertrophy of the masseter muscle

Partial resection of the buccal fat pad added to the resection of the masseter muscle clearly improves the results in hypertrophy of these muscles.

Jaw protruder muscles and condylar cartilage growth in the rat

Many studies have explored the role of the protrusive musculature in promoting growth at the condylar cartilage and the overall lengthening of the lower jaw, with emphasis on the lateral pterygoid muscle (LPM). The largely anteroposterior orientation of the superficial part of the masseter muscle (SM) in the rat suggests that it may also function as a protruder of the lower jaw. Accordingly, it is possible that the action of the SM may play a part in the regulation of growth of the condylar cartilage and the lower jaw. To examine this hypothesis, bilateral resection of the superficial portion of the masseter muscle was performed in male Sprague-Dawley rats at 26 days of age. At 5 days after surgery, [3H]-thymidine incorporation in the condylar cartilage was increased (F = 6.93, p less than or equal to 0.01) in the SM myectomy group relative to the surgical control and unoperated control groups. However, by 20 days after surgery no differences were present. At this sacrifice interval, lower jaw dimensions relating to areas of muscle attachment, as well as ramus height, were significantly reduced in the SM myectomy group, but overall jaw length (mental foramen to condyle) was unaffected. In contrast, myotomy of the LPM resulted in a significant decrease in mitotic activity of the cartilage 4 days after surgery. This decrease was present, but not more pronounced, in animals subjected to both SM myectomy and LPM myotomy. Hence, myotomy or myectomy of these two muscles, each with a protrusive orientation, produces opposite effects on proliferative activity at the condylar cartilage.

Bicoronal flap approach to the temporomandibular joints

The bicoronal scalp flap provides an excellent approach to the temporomandibular joint, particularly in cases where bilateral operation is required. It is also indicated when wide exposure is required and when previous surgery may make more conventional techniques difficult. In this report, the anatomy and indications for this approach are reviewed, the operative technique is described and complications are discussed.

A modified surgical approach for parapharyngeal space tumours: use of the inverted 'L' osteotomy

Removal of tumours from the parapharyngeal space is often difficult because of limited surgical access. Mandibulotomy has proved useful for improving access but may cause damage to the inferior dental and lingual nerves. Use of the inverted 'L' osteotomy provides excellent access avoiding damage to the nerves and the technique is illustrated with three surgical cases.

Simultaneous 'dual system' rehabilitation in the treatment of facial paralysis

Simultaneous dual system rehabilitation of facial paralysis involves using two independent reanimation techniques to optimize facial movement in both a quantitative and qualitative manner. These techniques involve the use of nerve grafting or crossover procedures combined with a dynamic muscle transfer. A group of 37 patients who underwent five different combinations of reanimation was analyzed. The techniques were evaluated using a standard rating scheme for judging success of reanimation procedures. The combination of a masseter muscle transfer to the lower region of the face and a cable graft of the upper facial nerve division appeared to offer excellent results in terms of independent motion of the upper and lower regions of the face and good eye closure, while allowing spontaneous mimetic function in 50% of cases. The advantages and disadvantages of the other techniques are described. The clinical situations in which these techniques have advantage over single reanimation techniques are outlined.

[Biprotrusion]

The clinic characteristics of the biprotrusion are here of described together with the associate alterations, the maseteric an gonic hyperplasia, and the corresponding treatment. As an example what has been previously said is illustrated with the excellent result shown in a patient.

Fibrodysplasia ossificans progressiva

A 14-yr-old boy with fibrodysplasia ossificans progressiva (FOP) presented for surgery for bilateral division of his ossified masseter muscles. Patients with FOP may present problems to the anaesthetist, including difficulties with tracheal intubation, restrictive pulmonary disease and abnormalities of cardiac conduction. With our patient sedated the trachea was intubated using a fibrescope and anaesthesia was induced and maintained with nitrous oxide and enflurane in oxygen. Ventilation was controlled throughout surgery and recovery was uneventful.

[Hypertrophy of the masseter muscle. Clinical aspects--etiology--therapy]

Masseteric muscle hypertrophy is a problem occurring in daily practice. Main complaints are isolated swelling of the masseteric muscle, myalgia, and functional disturbances of the parotid gland. Diagnosis is effected by inspection, palpation and anterior posterior radiograph. Sialography, CT, EMG are rarely used. Main points in the discussion of the aetiology are congenital genesis, the psychological factor, habits and occlusal disorders. The therapy consists of surgical reduction of the hypertrophied muscle as well as of conservative methods.

[Split line patterns in the mandible after transposition of the insertion of the masseter muscle in the adult rabbit]

With the aim of studying in the fibrous structure of the compact bone, as revealed by the split-line technique, unilateral surgical transposition of the masseter muscle from the masseteric fossa to the central area of the mandibular body below the molar teeth was performed in seven adult rabbits. Six months later the animals were killed, their mandibles were removed, cleaned and then decalcified. Split-lines were made on the lateral surface of both the control and the operated side of the mandible. Myotransposition induced alterations in the split-line patterns; they showed to be entangled and disorganized, which mean structural changes in the bone itself.

Experimental studies on masseter muscle grafts in rats: comparison of donor muscles

Experimental studies were performed in rats to explore the feasibility of using limb muscles to replace masticatory masseter muscles. The results showed that if several small fusiform muscles such as the extensor digitorum longus (EDL), soleus (SOL) and plantaris (PLT) were used for the grafting, the graft regenerated and matured fully in the masseter bed, although the weights were lower than those of contralateral control masseter muscles. If a multipennate muscle such as the gastrocnemius was used for the grafting, the graft also regenerated but later degenerated due to the lack of innervation. This is probably due to the excessive amount of connective tissue in the multipennate muscle. The connective tissue proliferates faster than the regeneration of muscle fibres and, thus, renders the innervation of muscle fibres difficult. Other factors pertinent to the possible clinical application of muscle transplantation in oral region are discussed.

The prominent mandibular angle: preoperative management, operative technique, and results in 42 patients

A prominent mandibular angle is considered to be unattractive in the Orient because it gives the face a square and muscular appearance. While described infrequently in the United States, this entity is commonly encountered in the Orient owing to different facial characteristics and different aesthetic sensibilities. We present a retrospective study of 42 female patients who presented requesting the reduction of a prominent mandibular angle for cosmetic reasons. We describe our approach, which utilizes formal planimetry, cephalometric tracings, and Panorex mandibular radiographs. We utilize the intraoral approach and use an oscillating saw to resect the predetermined segment of bone. In 18 of the 42 patients, we resected muscle as well. We also describe using the preauricular incision in a patient undergoing a concomitant rhytidectomy. Our cosmetic results have been generally satisfactory, with only one inaccurate osteotomy. We had three infections which resolved without sequelae.

Bilateral hyperplasia of the mandibular coronoid processes: a report of two cases

Two cases of bilateral coronoid hyperplasia of the mandible are presented. Consistent with other reported cases, the patients were men whose onset of symptoms correlated with the onset of puberty. One case was unusual in that bilateral coronoidectomies did not relieve the restriction of mandibular movement. Additional masseter muscle and fascial surgery was required to provide unrestricted mandibular motion.

Masseter muscle cross over flap in primary closure of oral-oropharyngeal defects

A new technique of closure of the oral-oropharyngeal defects after tumour surgery in selected cases, using the masseter cross-over flap, has been described.

Masseter muscle hypertrophy. Aetiology and therapy

Masseter muscle hypertrophy (MMH) is most probably a congenital, genetically determined anomaly. Thus we should refer to it as hyperplasia rather than hypertrophy of the masseteric muscle. Excision of the internal layer of the masseter muscle and reduction of the thickened bone in the region of the mandibular angle, via an intraoral approach, is the treatment of choice. Immediately after surgery it is necessary to apply a fixed compression bandage to the masseteric region in order to obliterate dead space which would otherwise be filled by a haematoma which in turn leads to prolonged postoperative trismus. After removal of the bandage it is necessary to institute mouth opening exercises. Very good esthetic and functional results were achieved.

Adaptations in the temporalis muscles of rabbits after masseter muscle removal

Masseter muscles were surgically removed in six young female rabbits so that we could study adaptations of the superficial temporalis muscles (ST) to increased functional requirements. Eight weeks following surgery, we used morphological measurements, histochemistry, contractile properties in situ, and occlusal force in vivo to compare the muscles in the experimental animals and six control rabbits. Analysis of the results demonstrated a decrease in fatigability of ST after masseter myectomy. Incisal occlusal force decreased by 65% during the first two weeks, and no recovery was observed during the following six weeks. At eight weeks post-surgery, the mass, twitch tensions, and tetanic tensions of ST were not significantly different from those of the controls. An increase in the percent of the cross-sectional area composed of fast fatigue-resistant fibers, a slower time-to-peak twitch tension, and a decrease in fatigability suggest an increase in oxidative metabolism. Analysis of these results suggests that muscles used for highly repetitious activities with submaximal loadings adapt to increased functional requirements by increasing fatigue-resistant properties.

Pseudotumor of the pterygomaxillary space presenting as anesthesia of the mandibular nerve

Pseudotumor is a term used to describe a space occupying inflammatory lesion which mimics a true neoplastic process in its clinical presentation. In this paper, we report a pseudotumor of the pterygomaxillary space that presented with anesthesia and paralysis of the mandibular nerve. The importance of this case is to call attention to pseudotumors as a clinical entity and to document a case of an extraordinarily aggressive variant that required a surgical approach usually reserved for malignant tumors.

Reanimation of lower lip reconstructed by flaps

This paper describes a technique of reanimating the reconstructed lower lip. For this the complete masseter on both sides has been used in order to obviate the danger of damaging the motor nerve supply to the muscle. The technique has been suitably modified to use the remaining musculature of the lips (i.e. orbicularis and the levators of the angle and upper lip) to improve the overall efficiency of the remaining upper lip function.

Changes in distribution of some crucial elements in masseter myofibers following surgically induced trauma

Experimentally induced surgical trauma of the masseter muscle in rats led to changes in the distribution of some crucial intracellular elements as determined by microprobe analysis. Sulfur, phosphorus, and potassium values were lowered while sodium and chlorine levels were elevated. These changes were accompanied by increased formation of ice crystal artifacts in myofibers. The findings suggest that trauma causes alterations in cytoplasmic macromolecules and in the state of water in the cells. The method of analysis provides a means for the further evaluation of antiinflammatory drugs.

An introduction to ultrasonography in oral surgery

The examination of postsurgical facial swelling is restricted largely to clinical techniques of evaluation, such as palpation. In experienced hands, such evaluation provides an understanding of the gross changes occurring as a result of oral surgery. However, a more detailed anatomic assessment was considered beneficial. High-resolution gray-scale ultrasonography was therefore employed in the examination of facial tissues before and after the standard surgical approach to removal of impacted third molar teeth. This study revealed that information concerning the site and dimensions of postsurgical edema and hematoma was readily obtainable with the techniques used.