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A recent study reported that the mean density of periapical cysts was greater than that of periapical granulomas. This study, which used a larger sample size and a robust method for standardization of density and contrast between images, found no difference between the radiographic density of cysts and granulomas classified by microscopic evaluation. Cysts tend to be larger than granulomas, but there was wide variation in size of both types of lesions. There was no significant correlation between the density of a lesion and its size.

Dentigerous cysts most frequently arise around the crowns of mandibular third molars, followed in incidence by maxillary canines and maxillary third molars. t Unlike other odontogenic cysts, the epithelial cells that line the lumen of a dentigerous cyst are of reduced enamel epithelium origin and possessan unusual ability to undergo transition into other epithelial cell types (metaplasia)? Because of this unusual ability, the epithelial lining often contains focal areas of orthokeratinization or a mixture ofmucin-secreting and ciliated cells. On occasion, some cysts appear to progress to more aggressive lesions, such as an odontogenic keratocyst, and others to neoplastic lesions such as ameloblastoma and mucoepidermoid carcinoma. Of even greater importance, squamous cell carcinoma has been reported to arise within the lining ofa dentigerous cyst. The exact prevalence of this latter occurrence is still not clear. Over the years different criteria have been used to determine whether a case report is sufficiently documented to be included in this category. Because intraosseous squamous cell carcinoma of the maxilla and mandible also may originate from other sources such as surface epithelium, sinus lining, epithelial remnants of odontogenesis ("odontogenic rests"), odontogenic tumors, and metastatic lesions to the area;' some basis for designating a case as being ofdentigerous cyst origin is necessary. The purpose of this report is to describe a case of squamous cell carcinoma arising in a dentigerous cyst that produced extensive destruction of the mandible with accompanying pathologic fracture, to review its clinical features and management, and to suggest that the commonly accepted criteria for making such a di

Squamous cell carcinoma of the oral cavity is often preceded by clinically evident precancerous lesions. These lesions exhibit progressive cytomorphologic changes connoting cellular transformation to malignant neoplasia. Molecular events underlie the microscopically identifiable cytological changes that herald transformation. Various proto-oncogenes are activated, overexpressed or mutated in the process of transformation. This investigation was designed to determine whether the nuclear binding c-myc oncoprotein, an activator of cell division, parallels or precedes cytomorphological changes at various histologically defined stages in oral precancerous lesions. Employing immunohistological methods, it was determined that c-myc nuclear labelling paralleled the progressive histological changes among various stages of transformation. It was also noted that some, yet not all, instances of benign keratoses which lacked any cytologic evidence of atypia harboured c-myc oncoprotein positive nuclei. It is concluded that c-myc expression is correlated with progressive cell transformation in oral cancerous lesions.

Presently oral Kaposi's sarcoma is primarily treated with systemic and intralesional chemotherapy, immunotherapy, radiation, and occasionally lasers. Each of these modalities achieves varying degrees of success. In patients with acquired immunodeficiency syndrome, the traditional treatments are frequently accompanied by local and generalized side effects that are detrimental to an already compromised immune system. Experience using sclerosing agents to treat other oral vascular lesions in healthy patients is known to produce excellent results. To evaluate the use of this treatment method in patients with acquired immunodeficiency syndrome, 15 oral lesions in 12 patients were injected with 3% sodium tetradecyl sulfate (Sotradecol). Thirteen lesions were located on hard palate; nine were nodular, three papular, and three macular. One week after treatment, some degree of ulceration occurred in all lesions with healing beginning by the middle of the second week. Six lesions required a second treatment to completely resolve. In one patient, healing was delayed, and the patient encountered a period of discomfort as a result of superficial bone sequestration. All other lesions healed uneventfully without the major side effects encountered with the other commonly used methods. Patients were followed for recurrence until they died or moved away. No recurrences were noted, with many followed for 18 months or longer. It is suggested that for lesions 2.6 cm or less in size, a sclerosing agent may be a better treatment modality than those now commonly used for oral Kaposi's sarcoma.

The etiology and pathogenesis of traumatic bone cyst are still far from being conclusively established with multiple theories, names, and forms of management being proposed and used. The rarity of these lesions in the older age groups suggests that self-healing can occur. This article presents two well-documented cases of what clinically and radiographically were consistent with so-called “traumatic bone cyst” of the mandible, which have appeared to heal without surgical intervention, thus providing additional information to our understanding of the biologic nature of this entity. Case 1 involved a 14-year-old boy with a lesion of the anterior left mandible that was monitored for 7 years and 5 months. Case 2 involved a 19-year-old female patient with a lesion of the right mandible that was monitored for 2 years and 9 months. In both cases, intraosseous biopsy or other surgical procedures were not undertaken. By the time both patients approached age 22, their lesions had resolved and the trabecular bone pattern radiographically approached normal.

This full colour, simple, interesting and easy to understand textbook introduces the novice dental student to the many oral disease processes. For the practising specialist and general dentist it provides a review of processes fundamental to clinical problems and an understanding of recent developments and changing concepts. The chapters are organised to coincide with the more recent trends in dental education where students are seeing patients earlier and therefore requiring immediate knowledge of some of the more common and less complicated aspects of oral pathology. To accommodate this trend the subjects that are less difficult conceptually and require fewer prerequisites science courses are in the earlier chapters with more complex topics to be found in later chapters. Each chapter includes an outline of the topics, an introduction to the disease processes, followed by a thorough discussion of the common disorders, organised by aetiology, pathogenesis, clinical and radiographic features, histopathology, differential diagnosis, treatment and prognosis. Each chapter concludes with a short bibliography of the most recent and pertinent review articles and classic publications.

Pooled serum from subjects with active recurrent aphthous ulceration (RAU) and from control subjects was tested against indigenous surface mucosal material from subjects with active RAU, remission RAU subjects, and normal subjects. IgM antibody reactivity in both sera was significantly higher to material from remission RAU subject mucosa than to material from control subjects or subjects with active RAU. IgG antibody activity in both sera was significantly lower to material from active RAU subject mucosa than to material from control subjects or subjects whose RAU was in remission. These results suggest that the character and amount of antigen on mucosa may differ during the pathogenesis of RAU.

Spherical granular and filamentous intranuclear bodies were found in the marginal epithelial cells of recurrent aphthous ulcers with a herpetiform pattern. They ranged from 0.8 to 1.2 μ in size with one to four bodies being present in any one nucleus. Because of their size and the demonstrated lack of DNA or RNA, it was thought that they were not viral in nature, as has been previously reported. It is hypothesized that intranculear bodies of the type found in this study represent a common manifestation of altered cellular metabolism produced by several etiologic factors.

The amorphous areas, which are gray in sections stained with hematoxylin and eosin and which are a prominent feature in the coronal dentin of the more severely affected cases of regional odontodysplasia, were studied ultrastructurally and with an electron probe and a Vickers microhardnesss tester. The ultrastructural findings confirmed previous histochemical evidence that the amorphous material consists of glycosaminoglycans and represents collagen-free dentinal matrix, that is, ground substance. Phosphoproteins may also present. The ultrastructural examination of nondecalcified material and electron-probe and microhardness tests supported previous microradiographic evidence that the amorphous areas are more heavily mineralized than normal dentin. The boundaries of the amorphous areas were found on ultrastructural examination to be distinct but very irregular.

Four cases of peripheral giant cell reparative granuloma (PGCRG) of the jaws were studied by electron microscopy to investigate the histogenesis and nature of the basic tissue component and to compare these findings with the ultrastructural features of intra-osseous benign giant cell tumors of bone. Histologically, the PGCRG of jaw were only found to differ from giant cell tumors by being surfaced by a stratified squamous epithelium and by usually containing dense fibrous connective tissue bands which separated the nodular masses of giant cell tissue and fused with the periosteum of the alveolar bone. Ultrastructurally, the multinucleated giant cells and stromal cells were identical to those found in the benign giant cell tumors of other bones. The multinucleated cells were felt to contain a sufficient number of features in common with osteoclasts to represent a slightly modified form of that cell. The ultrastructure of the stromal cells was compatible with the various stages of differentiating osteoprogenitor cells. The PGCRG is felt to be of osseous origin and to represent the periosteal counterpart of the central giant cell lesions of bone.

A case of osteomyelitis of the mandible in a patient with extensive Paget's disease of bone is presented. The changes in the bone with Paget's disease makes the diagnosis, clinical assessment and management of the osteomyelitis in such patients a difficult task.

The ultrastructural characteristics of the superficial cells of the epithelial lining of odontogenic keratocysts were studied. Examples of both the parakeratinized type and the less common orthokeratinized variant were examined. Scanning electron microscopy reveals that the morphology of the two cyst types is distinctly different. In parakeratinized cysts the transition of the epithelial cells into parakeratin is readily apparent and the epithelial surface is sparsely covered with parakeratin squames. In the orthokeratinized type the surface morphology is more uniform and is entirely covered with a leafy layer of keratin squames. The morphologic differences between the parakeratinized and orthokeratinized cysts may reflect differences in their biologic behavior.

The vacuum effect of a surgical suction tip can induce significant artifactual alterations in the connective tissue of specimens removed for diagnostic or therapeutic purposes. The alterations described in this article consist of a surgical suction artifact characterized by the formation of numerous, pleomorphic vacuoles that, on casual microscopic examination, resemble the morphology of traumatized adipose tissue. This artifact occurs when a vacuum draws air into connective tissue and mobilizes connective tissue mucins (acid mucopolysaccharides) that localize within the vacuoles that are formed.

The calcifications associated with the epithelium of the calcifying odontogenic cyst and odontoma were studied ultrastructurally and found to be of three types: (1) spherical calcifications which form on ghost cells and which therefore are dystrophic, (2) spherical calcifications which appear to be dysplastic enamel, and (3) irregularly shaped, diffuse calcifications which form on a collagenous matrix and appear to by dysplastic dentin or cementum.

Sera from subjects with recurrent aphthous ulceration (RAU) and control subjects were tested for relative levels of IgM, IgG, and IgA antibodies against eight selected laboratory-maintained bacteria, including Streptococcus sanguis which has been implicated in the etiopathogenesis of RAU. There were no differences in relative serum antibody levels for any isotype against any bacteria between control and RAU groups. RAU subjects with active lesions were then paired with control subjects, and each serum was tested against sedimentable material derived from the oral mucosa of each pair member. The analysis of data indicated that RAU and control subjects had similar levels of serum antibodies to indigenous mucosal antigens, but RAU subjects had significantly less antigenic material than control subjects.

A review of the literature and the addition of two new cases have revealed that according to a histologic criterion there are presently twenty reported cases of osteochondroma of the jaws located outside the condyles. Although most of the extracondylar lesions have occurred on the coronoid process, cases are now reported on the maxilla and the body of the mandible. The clinical features of these lesions are compared with those located in the condyle, and the radiographic and surgical approaches of the extracondylar lesions are discussed.

Xeroradiography and D-speed and E-speed film radiography were evaluated for the radiographic interpretation of periapical disease. Fifty-six consenting dental patients, either with or without periapical disease, were studied. Each patient received two radiographic examinations, one using xeroradiography and the other using either D-speed or E-speed film. Each tooth in the study population was evaluated independently relative to its history, clinical appearance, and clinical test results. Diseased teeth were endodontically treated. Teeth judged to be normal were followed for 1.5 yr to verify a clinically asymptomatic state. In both cases clinical assessments determined the true presence or absence of disease. Ten dentists scored the radiographic images for the presence of periapical disease and changes of various anatomical structures. Receiver-operating-characteristic (ROC) analysis of the three imaging techniques demonstrated no statistical difference in the diagnostic utility of xeroradiography (0.842 receiver-operating characteristic value) versus conventional radiography (0.843 receiver-operating characteristic value). In terms of radiation dose, xeroradiographic and E-speed film images required about one half the patient radiation exposure of D-speed film radiography. Therefore, xeroradiography or E-speed film techniques are preferred over conventional D-speed film radiography for the interpretation of periapical structures.