Thomas W. Braun

Abundant expression of myosin heavy-chain IIB RNA in a subset of human masseter muscle fibres

Type IIB fast fibres are typically demonstrated in human skeletal muscle by histochemical staining for the ATPase activity of myosin heavy-chain (MyHC) isoforms. However, the monoclonal antibody specific for the mammalian IIB isoform does not detect MyHC IIB protein in man and MyHC IIX RNA is found in histochemically identified IIB fibres, suggesting that the IIB protein isoform may not be present in man; if this is not so, jaw-closing muscles, which express a diversity of isoforms, are likely candidates for their presence. ATPase histochemistry, immunohistochemistry polyacrylamide gel electrophoresis and in situ hybridization, which included a MyHC IIB-specific mRNA riboprobe, were used to compare the composition and RNA expression of MyHC isoforms in a human jaw-closing muscle, the masseter, an upper limb muscle, the triceps, an abdominal muscle, the external oblique, and a lower limb muscle, the gastrocnemius. The external oblique contained a mixture of histochemically defined type I, IIA and IIB fibres distributed in a mosaic pattern, while the triceps and gastrocnemius contained only type I and IIA fibres. Typical of limb muscle fibres, the MyHC I-specific mRNA probes hybridized with histochemically defined type I fibres, the IIA-specific probes with type IIA fibres and the IIX-specific probes with type IIB fibres. The MyHC IIB mRNA probe hybridized only with a few histochemically defined type I fibres in the sample from the external oblique; in addition to this IIB message, these fibres also expressed RNAs for MyHC I, IIA and IIX. MyHC IIB RNA was abundantly expressed in histochemical and immunohistochemical type IIA fibres of the masseter, together with transcripts for IIA and in some cases IIX. No MyHC IIB protein was detected in fibres and extracts of either the external oblique or masseter by immunohistochemistry, immunoblotting and electrophoresis. Thus, IIB RNA, but not protein, was found in the fibres of two different human skeletal muscles. It is believed this is the first report of the substantial expression of IIB mRNA in man as demonstrated in a subset of masseter fibres, but rarely in limb muscle, and in only a few fibres of the external oblique. These findings provide further evidence for the complexity of myosin gene expression, especially in jaw-closing muscles.

Subjective and objective assessment of the temporalis myofascial flap in previously operated temporomandibular joints

PURPOSEnThis study evaluated the subjective and objective findings in patients who had undergone temporomandibular joint (TMJ) reconstruction with a temporalis myofascial flap. All joints had previously been reconstructed with alloplastic, allogeneic, or autogenous material.nnnPATIENTS AND METHODSnTwenty-three consecutive patients who underwent 28 temporalis myofascial flap procedures were assessed subjectively and objectively preoperatively and at an average of 36 months postoperatively. Panoramic radiographs, magnetic resonance imaging (MRI), or coronal computed axial tomography scans (CT scans) were performed on all patients preoperatively to evaluate for joint disease. A visual analog scale (VAS) was used to assess pain preoperatively and postoperatively. Patients also reported their use of pain medication, ability to function, diet, complications, and overall satisfaction. Preoperative and postoperative objective assessment consisted of an evaluation of range of motion, deviation on opening, joint noise on function, and cosmesis.nnnRESULTSnOn preoperative radiographic examination, 24 of 28 joints showed signs of bony degeneration, including cortical erosion, condylar flattening, and joint space alterations. Four joints showed evidence of ankylosis. The average preoperative maximal interincisal opening (MIO) was 23.7 mm, and the postoperative average was 32.3 mm (P<.05). Preoperatively, all patients displayed one or more objective clinical signs of joint disease such as joint noise on function, deviation on opening, limited mouth opening (less than 20 mm), or limited excursions (less than 2 mm). Postoperatively, 65% displayed one or more of these signs, a significant reduction (P<.05). Preoperatively, the average pain score was 8.2 on the VAS, and postoperatively the average pain score was 3.4 (P<.0005). Fifteen patients used less pain medication postoperatively, 7 used the same amount, and 1 patient used more. Thirteen patients were very satisfied with the overall results of the surgery, 4 were satisfied, and 4 were not satisfied. Two patients were satisfied with their increased function but were not satisfied with their pain reduction. All were satisfied with their cosmetic appearance. Minor complications after the procedure included 3 patients who had preauricular paresthesia and 1 who had an intraoperative dura mater exposure without sequelae. Two patients had postoperative superficial suture infections, and 2 noted hearing changes that were found to be clinically insignificant by audiologic examination.nnnCONCLUSIONnThe temporalis myofascial flap is an autogenous graft that has the advantages of close proximity to the temporomandibular joint, minimal surgical morbidity, and successful clinical results. It was found to be a valuable option for TMJ reconstruction in joints in which alloplastic, allogeneic, or autogenous materials have previously been placed unsuccessfully.

PREOPERATIVE, INTRAOPERATIVE, AND POSTOPERATIVE MANAGEMENT OF PATIENTS WITH OBSTRUCTIVE SLEEP APNEA SYNDROME

The patient with untreated, obstructive sleep apnea may present difficult or potentially life-threatening challenges to the surgical team. This is true even if the anticipated surgery is remote to the upper airway. Preoperative recognition of the obstructive apnea is essential as the first step in preventing potential complications. When recognized, intraoperative and postoperative initiative can result in a satisfactory outcome.

Management of the oral and maxillofacial surgery patient with end-stage renal disease

Chronic renal failure (CRF) is the consequence of a multitude of diseases that cause permanent destruction of the nephron. Concurrent with renal failure are a host of changes affecting the homeostatic functioning of the individual. This report outlines the pathophysiology of CRF and highlights its effects on surgical manipulation of the oral and maxillofacial region in this patient population. In addition, some of the common physical findings and alterations in blood chemistries frequently observed in these patients are discussed.

The inverted L osteotomy for treatment of skeletal open-bite deformities.

Numerous surgical procedures have been proposed for the correction of the skeletal open-bite deformity. Mandibular ramus procedures have not been uniformly successful due to the amount of observed relapse in both the horizontal and vertical dimensions. The authors studied 20 patients who underwent correction of an open-bite deformity using the inverted L ramus osteotomy technique. Results indicated that this procedure may have more stability in both the horizontal and vertical dimensions than previously reported ramus procedures.

Trismus and Preauricular Swelling in a 20-Year-Old Black Woman

A 22-year-old Haitian woman was referred to our institution with a 6-week history of trismus and preauricular swelling. The patient had initially presented to a dentist after experiencing pain and “stiffness” of her jaw on the left side. A diagnosis of myofascial pain syndrome was made, and the patient was treated with a soft diet and a nonsteroidal antiinflammatory agent. However, over the course of the next 3 weeks the pain and trismus progressively worsened and was now associated with a left preauricular swelling. The patient was referred to an otolaryngologist, who made the presumptive diagnosis of acute parotitis and placed the patient on a first generation cephalosporin. During the following 2 weeks, the left facial swelling and pain worsened significantly despite her compliance wilh the antibiotic regimen. At that time, she presented to our institution for further evaluation. The patient dcnicd any history of fever, chills, odynophagia, or recent trauma. Her medical history was unremarkable. She was born in Haiti and emigrated to the United States at the age of 6. Since then she has not traveled outside the United States. She denied owning any pets and did not abuse drugs. She was employed as a ward clerk in a New York City hospital The patient presented with normal vital signs and an oral temperature of 99.8”F. The clinical examination was significant for a large, tender, erythematous swelling of the left preauricular region extending from the zygomatic arch to the angle of the left mandible. Mandibular opening was limited to 10 mm and was associated with crepitus in the left temporomandibular joint. Thcrc was no cervical adcnopathy detected on palpation. Clear saliva flowed easily from the left Stenson’s duct. Results of an otoscopic examination of the left ear were normal. The oral mucosa, tongue, floor of

Indications for enteric tube feedings in oral and maxillofacial surgery

The catabolic effects of surgical trauma and sepsis have long been recognized. Oral and maxillofacial surgical patients represent a unique group in that their surgery and its effects on the stomatognathic system may adversely affect the ability to receive adequate nutrition. This article discusses some basic nutritional principles and describes the indications and guidelines for enteric tube feeding in this patient population.

Simultaneous reconstruction of maxillary and nasal deformity in a patient with Binder's syndrome (maxillonasal dysplasia)

Maxillonasal dysplasia, or Binder’s syndrome, a malformation characterized by midface hypoplasia and a flattened nasal profile, is one of the many facial deformities the oral and maxillofacial surgeon may encounter. Orthognathic surgical evaluation integrated with nasal reconstruction can enhance function and esthetics in such patients. Maxillonasal dysplasia was first described by Binder in 1962’ and further detailed by Gorlin2 and Holmstrom.3 The syndrome’s etiology, although unknown, has been postulated to be a congenital malformation3 or occur secondary to midface trauma.4 A hereditary association has been reported, but remains undefined.3 Hypoplastic nasomaxillary growth with degrees of severity may occur. The extent of reconstruction is tailored to the individual degree of deformity. The syndrome results in hypoplasia of the maxilla and nose while sparing the malar region. The flattened nasal profile is characteristic of the deformity. Associated with the nasal hypoplasia is an excessively obtuse or absent nasofrontal angle and a very acute nasolabial angle. The nasal alae are flattened, the nostrils are crescent shaped, and the columella is shortened. The upper lip is convex with a poorly developed, shallow philtrum. The anterior nasal spine (ANS) is hypoplastic or absent and the nostril sills are hypoplastic. The associated maxillary retrusion results in a class III deformity with relative mandibular prognathism. The sense of olfaction remains normal.2.3 A surgical-orthodontic coordinated treatment plan must assess the specific needs and extent of the defor

Nuclear dacryoscintigraphy : its role in oral and maxillofacial surgery

Obstruction of the lacrimal drainage apparatus may result in excessive tearing or epiphora. This may occur as a result of a traumatic injury or accumulation of debris, mucus, or pus. In nuclear dacryoscintigraphy, a radioactive solution is introduced into the conjunctival sac by pipette and allowed to follow the flow of the tear solution through the lacrimal drainage system. This article will review normal lacrimal anatomy and indications for nuclear dacryoscintigraphy in oral and maxillofacial surgery.

Economic analysis and its application to oral and maxillofacial surgery

PURPOSEnRecent clinical publications have increasingly emphasized comparison of cost with benefits in such areas such as drug therapies, surgical procedures, and prophylaxis regimes within certain populations. In the past, cost analysis was based principally on the comparative market price of new treatment compared with standard therapy. Benefits were assessed solely in terms of objective clinical and imaging improvement. Now, issues such as quality of life, early return to occupation, and subjective symptoms of pain and discomfort caused by a treatment are also being critically evaluated. Addressing these latter issues, however, is often complicated and expensive. This article reviews some terms and principles of cost analysis, cost effectiveness, and cost-benefit analysis. Examples are given of recent attempts to quantify costs and benefits for individuals, hospitals, health organizations, and society as a whole. Guidelines are suggested concerning how these studies can be applied to oral and maxillofacial surgery.