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Primary Sjögren's syndrome (pSS) has a strong female bias. We evaluated an X chromosome dose effect by analyzing 47,XXY (Klinefelter's syndrome, 1 in 500 live male births) among subjects with pSS. 47,XXY was determined by examination of fluorescence intensity of single nucleotide polymorphisms from the X and Y chromosomes. Among 136 pSS men there were 4 with 47,XXY. This was significantly different from healthy controls (1 of 1254 had 47,XXY, p=0.0012 by Fisher's exact test) as well men with rheumatoid arthritis (0 of 363 with 47,XXY), but not different compared to men with systemic lupus erythematosus (SLE) (4 of 136 versus 8 of 306, Fisher's exact test p=NS). These results are consistent with the hypothesis that the number of X chromosomes is critical for the female bias of pSS, a property that may be shared with SLE but not RA.

Introduction Most radiolucent jaw lesions are benign and resolve with proper diagnosis and treatment. However, a small percentage of radiolucent jaw lesions are malignant and more difficult to manage. Methods A biopsy of the radiolucent jaw lesion associated with swelling after nonsurgical root canal therapy was submitted. Results The lesion had the combined diagnosis of diffuse large B-cell lymphoma with cystic involvement. The patient has since undergone radiation and chemotherapy treatments. Recall appointments indicate healing of the lesion, and no other areas of lymphoma have been found. Conclusions The existence of a nonhealing radiolucent jaw lesion emphasizes the importance of an early, definitive diagnosis with biopsy.

Purpose The purpose of this study was to evaluate the effectiveness of using titanium screws in combination with particulate human mineralized allograft, in a “tenting” fashion, to augment large vertical alveolar ridge defects for implant placement. Materials and Methods This prospective case study evaluated augmentation in consecutive patients with large (>7 mm) vertical alveolar ridge defects. Vertical ridge augmentation was performed using mineralized allograft placed around titanium screws to tent out the soft tissue matrix. The ridges were clinically evaluated 4 to 5 months after augmentation, and implants were placed at that time. Bone cores were harvested from all patients for histologic evaluations. Results Fifteen patients were treated in this prospective case study, and the mean vertical augmentation was 9.7 mm. Two patients had wound dehiscence resulting in loss of graft and requiring secondary grafting before implant placement. Five patients required 2-stage grafting procedures to achieve ideal ridge height before implant placement. Clinical evaluation of the grafted sites upon re-entry revealed uniform ridge anatomy. Histomorphometric analysis of 7 specimens revealed a mean bone content of 43%. A total of 32 implants were placed into grafted sites in 15 patients. All implants were integrated and successfully restored. Mean follow-up was 16.8 months after implant placement. Conclusions Tenting of the periosteum and soft tissue matrix with titanium screws maintains space and minimizes resorption of mineralized particulate allograft. This technique offers predictable functional and esthetic reconstruction of large vertical defects without the use of autogenous bone and is capable of osseointegration. More studies are needed to evaluate the stability of vertically grafted bone after long-term loading.

Recent literature suggests that giant cell angiofibroma (GCAF) is a variant of solitary fibrous tumor (SFT) and not just a related lesion. Herein we present a case of apparent SFT with giant cells, including floret cells and focal pseudovascular areas, which are defining features of GCAF. The tumor occurred in the tongue of an 84-year-old female and depicted an encapsulated, patternless spindle cell proliferation in a fibromyxoid stroma with focal dense collagenous areas and scattered floret-type multinucleated giant cells seen primarily in the periphery, as well as pseudovascular spaces, numerous capillaries, and hemangiopericytomalike areas. Immunohistochemical investigation revealed positive staining for CD34 and positive immunoreaction for estrogen and progesterone receptors. We support the present notion that GCAF is a histologic subtype of SFT.

Calcifying epithelial odontogenic tumor (CEOT) is a benign, locally aggressive odontogenic neoplasm characterized by sheets and nests of epithelial cells with deeply eosinophilic or occasionally clear cytoplasm, calcifications, and eosinophilic amorphous material that stains positive for amyloid. Although many cases of CEOT are associated with impacted teeth and occasionally appear radiographically as dentigerous cysts, a true cystic variant has not been previously reported. We report a 15-year-old white male with a large cystic maxillary lesion that filled most of the left maxillary sinus. It deformed the medial wall, the inferior orbital floor, and caused narrowing of the left inferior meatus. Histologically, the cystic lining showed characteristics of CEOT. An intraluminal component that featured histologic characteristics of CEOT was identified during surgery. The lesion was enucleated and the postsurgical course of the patient was uneventful. Because follow-up has been for less than 1 year, a meaningful long-term prognosis cannot be determined at present. However, the patient has not reported any symptoms or signs of recurrence during the follow-up period.

Liquid nitrogen cryotherapy has been advocated as an adjunct in the enucleation and curettage of locally aggressive lesions of the jaws. Simultaneous autogenous bone grafting has also been advocated to accelerate bone formation and reduce morbidity. There is, however, relatively little scientific basis for either of these hypotheses. In this study, nine Yucatan minipigs had artificial defects created in the mandible, which were treated with liquid nitrogen spray. Half of the defects were grafted with autogenous bone from the chin and half were closed primarily. Two animals were sacrificed 3 days postoperatively to measure the width of necrosis and the rest were sacrificed at 3 months to assess healing and new bone formation. It was found that drilling the artificial defects alone caused bone necrosis for a mean depth of 0.09 mm. Liquid nitrogen cryospray caused a mean depth of bone necrosis of 0.82 mm (range 0.51-1.52 mm). The defects that were bone grafted healed well clinically. Defects not bone grafted showed a 50% rate of wound breakdown and sequestrum formation with delayed healing. Vital staining showed a non-significantly greater rate of bone formation in the grafted defects. Digitally superimposed radiography showed a non-significantly greater bone density in the non-grafted defects at 3 months postoperatively. It appears that liquid nitrogen cryospray does devitalize an area of bone around defects in the mandible. The width of necrosis is usually less than 1 mm and subsequent healing is enhanced by autogenous bone grafting. This has clinical implications.

Because of the limited observations of published studies, the condition of hydroxyapatite after a long period of intraoral function remains a concern. This clinical report describes the histologic evaluation of a 9 year-old hydroxyapatite specimen retrieved from a human subject. The residual hydroxyapatite particles showed no sign of resorption, and tight contact with the surrounding bone was observed.

A workshop to discuss primary oral melanomas was convened at the annual Western Society of Teachers of Oral Pathology meeting in Bannf, Alberta, Canada. Fifty oral melanomas, identified from the files of the participants, were reviewed in order to better understand the clinical features, histologic spectrum, and natural history of these perplexing lesions. Results confirmed that oral melanomas occur in adults almost three times more frequently in men than women and have a decided predilection for the palate and gingiva. Some lesions exhibit a clinically detectable and prolonged in situ growth phase, whereas others seem to lack this property and exhibit only or predominantly invasive characteristics. Recurrences, metastases, and death from tumor were characteristic of the follow-up of a limited number of patients. Until definitive prospective data are collected that elucidate natural history, oral mucosal melanomas should be tracked separately from cutaneous lesions. All oral pigmented lesions that are not clinically diagnostic should be biopsied. Lesions with equivocal histopathologic features might be referred to as "atypical melanocytic proliferation" and should be excised. Recognition of lesions in an early in situ phase and aggressive treatment should have a favorable effect on prognosis. To enhance future or prospective study of these rare neoplasms, guidelines for reporting oral melanomas are suggested.

During the debonding of ceramic orthodontic brackets, there is a risk of causing fractures, cracks, or flaking of enamel or of the bracket itself. Preliminary work on the resin-enamel interface under bonded brackets with the indirect (modified Thomas) or the thermal-cured indirect bonding techniques revealed an interlayer of unfilled resin formed between the filled resin and the enamel surface. The direct bonding technique, on the other hand, showed no such layer. This study was designed to determine the effect of the interlayer on conventional debonding techniques for polycrystalline ceramic orthodontic brackets. Variables examined were bracket failure or fracture (BF), amount of remnant adhesive (ARI), and enamel damage. Brackets were bonded to 90 fresh bovine teeth. These were divided into three groups of 30 each, based on three methods of bonding, i.e., direct, indirect (modified Thomas), and an indirect technique that used a thermal-cured resin. Each bonding group was further divided into three groups of 10 each, based on the type of debonding technique used, i.e., lift off, delamination, and twisting. Brackets bonded by the indirect (modified Thomas, BF mean = 0.27, ARI mean = 0.93) and the indirect technique that used a thermal-cured resin (BF mean = 0.03, ARI mean = 0.43) resulted in an overall significantly lower failure (p < 0.01) and ARI score on debonding (p < 0.0001) compared with those bonded by the direct technique (BF mean = 1.03, ARI mean = 1.97). Specimens evaluated under the stereomicroscope revealed that the brackets bonded with the indirect techniques debonded at the filled-unfilled resin interface or within the interlayer of unfilled resin.(ABSTRACT TRUNCATED AT 250 WORDS)

Summary This study evaluated early changes in full-thickness (FT) and partial-thickness (PT) articular cartilage defects created by arthroscopic surgery. The defects were of various configurations in a model (horse) that was weight-bearing immediately after surgery. The objectives were to evaluate recellularization and to examine the effect defect configuration had on adjacent cartilage cellularity and proteoglycan content. Thirty-six PT lacerations, FT lacerations, PT scrapes, PT craters, and FT craters were created in the antebrachiocarpal and intercarpal joints of eight adult horses. The configurations were lacerations by knife blade, scrapes by a curette, and craters created by motorized burr. Horses were euthanized one, three, and eight weeks after surgery. Histologic examination was performed using hematoxylin and eosin and safranin-O staining. All FT craters showed evidence of early repair. None of the lacerations showed evidence of early repair. One PT scrape and four PT craters bad fibrous tissue within the defect. All defects had degenerative changes in adjacent cartilage. Craters and scrapes had significantly worse degenerative changes than lacerations. Patients undergoing arthroscopic surgery who will be weight-bearing immediately after surgery should have full thickness crateriform debridement if a healing response is desired. Partial thickness debridement does not show evidence of repair. Degenerative changes in adjacent cartilage occurred in all defects and they are directly proportional to the amount of trauma and instrumentation used at surgery. Full thickness (FT) cartilage defects that penetrate the zone of calcified cartilage rely on hemorrhage from subchondral bone and the resultant fibrin clot to initiate repair. The fibrin clot acts as a matrix for cellular repair that results in formation of fibrous tissue. The quality of repair (i.e. fibrous tissue, fibrocartilage, or hyaline cartilage) relies on metaplasia of fibrous tissue. This mechanism of articular cartilage healing, referred to as extrinsic repair 1,2 occurs after subchondral abrasion with motorized instrumentation; 3,4,5 however, the quality and durability of repair tissue has been questioned. 5,6,7 Partial thickness (PT) cartilage defects do not penetrate the zone of calcified cartilage and do not bleed. Healing of PT defects relies on mitotic activity of chondrocytes and increased metabolic activity adjacent to the defect to create intrinsic repair. 2 Many investigators have shown the inability of PT defects to heal. 3,8,9,10,18 It has recently been shown that PT defects may undergo further degeneration. 3 The fibrin clot and other extrinsic factors released during hemorrhage in FT defects are reported to be important in initiating repair of articular cartilage. 5 Mesenchymal cells from the subchondral bone initiate the recellularization process in FT defects. 11,12,13 If PT defects are to heal with any degree of consistency then a “modified” extrinsic repair must occur or blood clot must attach to the defect and recellularization from synovial cells within the joint must take place. Early reparative changes in articular cartilage of other species have been documented. Most studies investigating articular cartilage healing in the horse are long-term studies evaluating the quality and durability of repair tissue. The purpose of this study was to investigate early recellularization of FT and PT defects created by arthroscopic surgery in articular cartilage located within the same joint surface in a model in which the operated horse was weight-bearing immediately after surgery. The objectives were to evaluate early recellularization and to examine the effect various types of defects had on adjacent cartilage cellularity and proteoglycan content at one, three, and eight weeks after surgery.

An improved technique for histologic sectioning of hard tissues is described. Thin sections (5 to 15 μm) of undecalcified tissues such as bones with ceramic and metallic implants as well as teeth with enamel and fillings can be produced. Implant-tissue and hard tissue-soft tissue interfaces are well preserved. Because of the development of equipment and materials designed specifically for this technique, consistently good results are obtained. Most stains used in the paraffin technique may also be used in these sections.

In this paper, we formulate a mathematical model for the evaluation of parameters responsible for the retardation and eventual acceleration of bone regeneration on the contralateral side of the mandible of experimental animals, following the discovery of a new mechanism of bone regeneration called the osteobstruction mechanism (a negative mechanism of bone regeneration as opposed to the well established and extensively documented positive mechanisms such as osteogenesis, osteoinduction and osteoconduction). This osteobstructive mechanism was demonstrated by episodes of overtaking and reovertaking on single photon emission computed tomography (SPECT) following evaluation of osteoblastic activities in a sequential animal experiment to validate both the Ogunsalu sandwich technique (a double guided tissue technique; D-GTR) and the interceed membrane technique (a single guided tissue regeneration technique; S-GTR) utilizing SPECT, histological and histomorphometric evaluation. This work is now given special attention in terms of mathematical analysis because of limited experimental observations since experiments cannot be observed infinitely. Mathematical modelling is as such essential to generalize the results of this osteobstructive mechanism in bone regeneration. We utilize the Fisher's equation to describe bone cell mobilization during bone regeneration by two different techniques: the Ogunsalu sandwich bone regeneration technique (D-GTR) and the S-GTR.

A pathologic mandibular fracture in a 35-year-old woman 1 year after the attempted filling of a bone defect with particulate, dense hydroxyapatite resulted in a partial mandibular resection, allowing observation of cross sections of the mandible and associated soft tissue. Thin tissue sections were examined without decalcification. This permitted excellent observation of the hydroxyapatite particles, the bone, and the soft tissue. Osseointegration had occurred only in the areas closely associated with the bone. The immobility of the particles was a prerequisite for involvement with new bone formation. Hydroxyapatite particles in areas that allowed any mobility were surrounded by connective tissue with no bone formation evident. Heterogeneous particles were observed, indicating the possibility of a lack of purity in the hydroxyapatite ceramic, which may have contributed to the resorption of the particles. These findings, as well as other clinical and experimental findings, lead us to question the concept of hydroxyapatite as a bioactive ceramic that induces osteogenesis or osteoconductivity.

The effects of a high dose of cobalt-60 radiation on rhesus monkey mandibles have been studied with light microscopy. The radiation was similar in amount and method of delivery to that given human patients with cancer. Adult rhesus monkeys were irradiated with 4,500 rads of cobalt-60 radiation in 10 fractions over 12 days, the equivalent of 7,000 rads given in 35 fractions over 7 weeks. Observations ranged from 1 week to 6 months postirradiation. Clinical observations paralleled the signs and symptoms noted in human patients receiving radiation therapy to the head and neck. Osteocytes were killed only in the direct path of the radiation beam in the outer lamellar and Haversian bone. The medullary area of the irradiated mandibles underwent marked proliferation of new bone. The periodontal ligament became more densely collagenized, lost the organization of its principal fiber groups, and demonstrated changes in the vessels of the interstitial spaces. The Haversian canals showed changes ranging from obliteration of the blood vessels to complete plugging of canals with osteoid. Within the field of irradiation, the periosteum exhibited a loss of cellularity, loss of vascularity, loss of osteoid formation, and a tendency to be easily stripped from the bone during processing. A few areas showed exophytic bone growth and normal-appearing periosteum. The marrow of the irradiated animals showed striking changes, including fibrosis, proliferation of new bone, and obliterative endarteritis of many of the blood vessels.

Although there exists a desire to eliminate the possibility of cross-infection from microbial contaminated nitrous oxide nasal hoods, effective and practical methods of sterilization in a dental office are unsatisfactory. Microwaves have been used to sterilize certain contaminated dental instruments without damage. In this study nasal hoods contaminated with rhinovirus, parainfluenza virus, adenovirus, and herpes simplex virus were sterilized in a modified microwave oven. Ninety-five percent of the virus activity was destroyed after 1 minute of exposure of the contaminated nasal hoods to microwaves. By the end of 4 minutes, complete inactivation of all four viruses was found. Repeated exposure of the nasal hoods to microwaves resulted in no damage to their texture and flexibility. Microwave sterilization may potentially provide a simple and practical method of sterilizing nitrous oxide anesthesia equipment in a dental or medical practice.

The congenital epulis (gingival granular cell tumor) is a rare lesion of unknown origin found only in newborn infants. Remarkable similarities are noted between this lesion and the adult granular cell tumor (myoblastoma) by both light and electron microscopy. An electron microscopic study of a lesion from the anterior mandibular ridge in a newborn male infant was performed. No Schwann cells, axon fibers, odontogenic elements, or any muscle cells could be found. Cytoplasmic features were similar to those in adult granular cell tumors. Cells which appeared to be in a transitional state, not yet true granular cells, were found juxtaposed to the vessels in the position of pericytes. Fine-structure details of these cells were consistent with pericytes. Cells of this type found farther from the vessels appeared more like the typical granular cells. The cells were filled with structures of the autophagic type devoid of normal cell organelles. These findings support the theory that these are nonneoplastic, degenerative, or reactive lesions arising from a mesenchymal cell, possibly the pericyte.