Emad S. Helmy

Osteoarthrosis of the temporomandibular joint following experimental disc perforation in Macaca fascicularis.

The aim of this experiment was to study the sequela of experimental temporomandibular joint (TMJ) disc perforation. Each TMJ of four Macaca fascicularis adult monkeys was surgically exposed, and a 4- to 6-mm perforation at the posterolateral portion of the avascular disc was produced by electrosurgery. Four monkeys were used as controls. The animals were killed 11 weeks (two experimental and two controls) or 12 weeks (two experimental and two controls) after disc perforation. The perforations were increased in size in five joints, and healed in one joint. In addition, two joints of one animal showed complete loss of the disc, denudation of articular surfaces, and bone-to-bone contact. In contrast to control joints, the experimental joints exhibited the following changes histopathologically: thick, highly cellular and fibrillated fibrous coverings of articular surfaces (five joints); marked hyperplasia of synovial membrane; migration of synovial cells on the surfaces of the disc and margins of perforation; multiple adhesions of disc to articular surfaces; increase in cellularity and vascularity of discs; and chondrocytic clustering in temporal fibrous covering; and osteophytes of condylar and temporal components and focal or complete denudation of articular surfaces (2 joints). Most of these changes were consistent with the diagnosis of osteoarthritis. From this study, one can conclude that disc perforation can lead to osteoarthritis.

Management of frontal sinus fractures: Review of the literature and clinical update

The purpose of this article is to discuss and analyze the controversial treatment protocols that are currently recommended in the management of frontal sinus fractures. Embryology, anatomy, and diagnostic radiology of the frontal sinus are also discussed.

Synovial chondromatosis with intracranial extension: A case report

A case of unilateral synovial chondromatosis of the temporomandibular joint with intracranial extension is presented. Extracapsular extension of these lesions is rare, and few cases have previously been reported. The case presentation will also reflect the inadequacy of routine preoperative temporomandibular joint x-ray films to reflect the extent of the lesion. Despite the benign nature of the lesion, excision was done because of the clinical aggressive behavior.

Histopathological study of human TMJ perforated discs with emphasis on synovial membrane response

Fifteen perforated TMJ discs from human cadavers were studied histologically to examine the synovial membranes and to compare the findings with previous experimental results in monkeys. There were four with perforations in the bilaminar zone (these four discs were displaced anteriorly), three in the medial third of the disc, and eight in the lateral third of the disc. Histopathologically, there was an increase in vascularity and strong methyl pyronine-positive cellularity around the margins of the perforations. A young, loose, collagenous tissue lined the lateral margins of the perforated discs. Increased fibrous tissue content of the synovial subintimal territorial matrix and osteochondroid metaplasia were also seen. Severe synovial hyperplasia was visible in all joint recesses, but was greatest within those associated with displaced discs. There was patchy distribution of acidic glycoproteins, especially in the lateral parts of the perforated discs. As in the animal studies, human TMJ disc perforation was associated with a vigorous synovial reaction that was seen to form lateral bridges along the margins.

Synovial chondromatosis associated with experimental osteoarthritis in adult monkeys

This report describes the synovial response to temporomandibular joint disc perforation in an experimental animal model. Histologic examination revealed the presence of marked synovial membrane hypertrophy in all experimental joint recesses. Gradual transformation of synovial islands from a cellular to a metaplastic stage, with chondroid or even osteochondroid-containing tissue also was seen. The cartilage was arranged in a lobular pattern with intervening fibrous septae within the synovial islands. These synovial islands were observed in the anterior recess of three joints and in the posterior recess of another joint. The experimental findings suggest a relation between synovial chondromatosis and osteoarthritis.

Repair of temporomandibular joint disc perforation using a synovial membrane flap in Macaca fascicularis monkeys: Light and electron microscopy studies

Previous studies have demonstrated that experimentally produced perforations in the discs of Macaca fascicularis monkeys lead to osteoarthrosis. Synovial membrane hyperplasia also was demonstrated in monkey and human joints with disc perforations. The hypothesis was advanced that a synovial flap obtained from within the affected joint would be the most appropriate tissue to repair chronic disc perforation. To test this hypothesis, four adult M fascicularis monkeys were anesthetized and 4- to 6-mm perforations were made in the posterolateral aspects of the avascular discs bilaterally. The wounds were sutured leaving the perforations open, and the animals were fed their normal diet. After 4 weeks, one joint in each monkey was reopened and a repair was performed using a double-layered flap from the synovial lining of the superior and inferior recesses. Four weeks after repair, the animals were killed and the temporomandibular joints (TMJs) were removed en bloc and decalcified. The joints were sectioned into lateral, middle, and medial sections and were photographed using a stereomicroscope and then processed for light and electron microscopy. The same processing was done to four intact joints that were used as controls. Eight weeks following perforation, the joint components showed degenerative changes consistent with osteoarthritis. Close to the perforations the disc showed loss of collagen, vacuolation of extracellular matrix, accumulation of dense proteoglycan-like material, and the appearance within the disc of type A or macrophage-like cells of the synovium. The discal tissue away from the perforation showed high cellularity and vascularity. The temporal and condylar surfaces showed denudation, fibrillation, osteophytes, and chondrocytic clustering, all characteristics of osteoarthrosis. The surgically repaired discs were intact and the articular surfaces showed no degenerative changes. Discal collagen was restored and appearance of myofibroblasts and elastogenesis were a consistent feature of the repaired disc. The vascularity of the condylar cartilage of the repaired joints appeared similar to that of embryonic cartilage. The reversibility of the degenerative alterations following discal repair in this experimental model should provide the basis for a rational and useful method for surgical repair of TMJ disc perforation using intraarticular synovial tissue.

Immune thrombocytopenia in AIDS patients: Case report

This article reports a case of an AIDS patient, with no history of platelet dysfunction, who developed late-onset thrombocytopenia which was not present 3 weeks before surgery

Carotid-cavernous sinus fistula accompanying an isolated mandibular fracture

A patient who developed carotid-cavernous sinus fistula associated with an isolated mandibular fracture is reported, and the etiology, diagnosis, and treatment of this condition and the associated abducens nerve palasy are discussed.