Characterization of organotypic keratinocyte cultures on de-epithelialized bovine tongue mucosa.

Organotypic cultures have been used to study epithelial cell behavior for many years. The aim of this study was to develop an organotypic culture method that better mimics the three-dimensional morphology of interdigitating rete ridges and connective tissue papillae and that also conserves the basement membrane zone (BMZ). Bovine tongue mucosa connective tissue, separated from epithelium after 1 M NaCl incubation, was used as organotypic culture substratum for different human keratinocyte cell lines. Organotypic cultures were characterized by electron and immunofluorescence microscopy for expression of integrin subunits and extracellular matrix components. While spontaneously immortalized mucosal keratinocytes produced highly irregular stratified organotypic cultures, the normal human epidermal keratinocytes (NHEK) demonstrated culture morphology that resembled in vivo epidermis. However, in this model, the histomorphology, expression of differentiation markers involucrin, keratin 10 and 14, and integrins varied significantly between the cell lines. Some cultures appeared to have an extended survival since they were maintained up to 40 days without histological signs of degeneration. The ultrastructure of the BMZ including hemidesmosomes was similar to the normal dermo-epidermal junction. Extracellular matrix molecules, including tenascin, laminin-1 and -5, were expressed in the cultures demonstrating their secretion solely by keratinocytes. Distribution and expression of integrins in NHEK cultures was similar to that seen in vivo skin with the exception of additional expression of alpha5beta1 and alpha(v)beta6 integrins. Organotypic NHEK cultures show similarities to normal stratified epithelium and are potentially useful for multiple applications for studies on epithelial cell behavior in vitro.

Successful periodontal maintenance of a case with Papillon-Lefèvre syndrome: 12-year follow-up and review of the literature.

BACKGROUND: Various approaches to treating the periodontal condition associated with Papillon-Lefèvre syndrome have been reported. These include oral hygiene instruction, use of mouthrinses, frequent debridement, multiple antibiotic regimens, periodontal surgery, extraction of hopeless teeth, and extraction of all deciduous teeth. Because Papillon-Lefèvre syndrome is rare, most publications are case reports, and very few document long-term successful treatment of the periodontal condition. METHODS: In 1986, a 3.5-year-old Indo-Canadian male was diagnosed with Papillon-Lefèvre syndrome and began periodontal treatment. Initial therapy consisted of debridement every 3 weeks, a 0.12% chlorhexidine mouthrinse, 2 regimens of metronidazole, and oral hygiene instruction for his parents. After 10 months it became apparent that the treatment was having little beneficial effect, since the periodontal destruction continued and teeth 51 and 61 exfoliated. At age 4, all remaining deciduous teeth were extracted and complete dentures inserted for the following 2-year edentulous period; then a 3-month maintenance schedule was maintained. RESULTS: The patient is now 17 years old and all his adult teeth are present with the exception of the third molars. His oral hygiene varies between moderate and good, with his most recent plaque score at 80% effectiveness. There are no probing depths greater than 4 mm, with the exception of the distal of the lower second molars where opercula are present. CONCLUSIONS: Extraction of all the deciduous teeth followed by a period of edentulousness may partially explain the fact that there has been no recurrent attachment loss in the permanent teeth up to age 17. Other explanations are discussed as part of the literature review of Papillon-Lefèvre syndrome.

Naturally occurring periodontal bone loss in the wild deer mouse, genus Peromyscus.

BACKGROUND: Historically, animal models for the study of periodontal diseases have incorporated surgically created defects, plaque retentive ligatures, as well as soft and high-sucrose diets which may not accurately reflect progression of the natural disease. Spontaneous periodontal disease is seen in a few animal species, but these are often expensive to maintain and are unsuitable for manipulation using advanced molecular biology techniques. Mice are inexpensive, easy to maintain, and are routinely used for transgenic experiments and are therefore an optimal animal for research purposes. However, it is commonly accepted that mice do not spontaneously develop periodontal disease. The purpose of this study was to determine if a mouse population that exhibits periodontal breakdown in the wild could be found, allowing for genetic manipulation of naturally occurring periodontal disease. METHODS: We examined over 2,500 dry skulls of several Peromyscus species from various locations and habitats on the west coast of North America for periodontal bone loss in the molars, using furcation involvement as an indicator of disease severity. Alveolar bone loss was classified as Grade I) horizontal component of bone loss in the furcations; II) through-and-through furcations; and III) through-and-through furcations with alveolar bone loss into the apical third of the root. RESULTS: The proportions of individual mice experiencing bone loss were 3.8% for Class I-III involvement, 1.3% for Class II-III involvement, and 0.5% for Class III alone. Three subspecies of P. keeni and one subspecies of P. maniculatus had periodontal disease prevalences in 7% to 13.5% of their samples. Mice from isolated islands had 1.8- to 4.7-fold higher disease prevalence than those located on the mainland, with even greater prevalence on small islands. No statistically significant differences between genders were found. CONCLUSIONS: It appears that periodontal disease is far more common in this mouse genus than previously believed. Some of the subspecies demonstrated severe periodontal disease at a prevalence comparable to that found in humans.

The periodontal disease classification system of the American Academy of Periodontology--an update.

Until recently, the accepted standard for the classification of periodontal diseases was the one agreed upon at the 1989 World Workshop in Clinical Periodontics. This classification system, however, had its weaknesses. In particular, some criteria for diagnosis were unclear, disease categories overlapped, and patients did not always fit into any one category. Also, too much emphasis was placed on the age of disease onset and rate of progression, which are often difficult to determine. Finally, no classification for diseases limited to the gingiva existed. In 1999, an International Workshop for a Classification of Periodontal Diseases and Conditions was organized by the American Academy of Periodontology to address these concerns and to revise the classification system. The workshop proceedings have been published in the Annals of Periodontology. The major changes to the 1989 proceedings and the rationale for these changes are summarized here. In addition, the potential impact of these changes is discussed.

Abnormal deposition of type VII collagen in Kindler syndrome.

Kindler syndrome is an extremely rare genetic disorder with features of epidermolysis bullosa and poikiloderma congenitale. Approximately 70 cases have been documented in the past 50 years, but only a few investigations of the basement membrane components have been done on these patients. The aim of this study was to examine the components of the basement membrane zone in search of the pathobiological defect(s) responsible for the clinical findings from a female 16-year-old patient diagnosed with Kindler syndrome. This patient also suffered from advanced early-onset periodontal disease. Biopsies were taken from inflamed gingiva and noninflamed oral mucosa as part of periodontal treatment. The basement membrane zone was examined using immunofluorescence microscopy to bullous pemphigoid antigens 1 and 2, collagen types IV and VII, laminins-1 and -5, and integrins alpha3beta1 and alpha6beta4. The biopsies studied revealed blistering with trauma above the level of lamina densa based on distribution of type IV collagen and laminin-1 at the blister floor. In the noninflamed mucosa, discontinuous areas of the basement membrane zone were found. Expression of the basement membrane zone components and the integrins studied appeared otherwise normal with the exception of type VII collagen which was found in abnormal locations deep in the connective tissue stroma. Our results suggest that Kindler syndrome is associated with abnormalities in the construction of the basement membrane, especially in the expression of type VII collagen. These alterations are likely to play a role as etiological factors leading to blister formation and early onset periodontal disease.

Do mutations in the basement membrane zone affect the human periodontium? Review with special reference to epidermolysis bullosa.

Epidermolysis bullosa (EB) is a group of diseases characterized by the development of blisters or erosions following minor trauma to the skin. Oral findings that have been associated with EB include keratin-filled cysts; blistering of the mucosa, tongue, and lips; perioral carcinomas; ankyloglossia; lingual papilla atrophy; caries; enamel hypoplasia; rapid attrition of the teeth; and obliteration of the oral vestibule. Defects at the basal cell/basement membrane/connective tissue levels correspond to the mutations in basal cell keratins, hemidesmosome components, and type VII collagen, respectively. In a number of types of EB, structural defects in the skin have been shown and genetic mutations determined. Although there are no publications documenting the prevalence of periodontal diseases in patients with epidermolysis bullosa, it is likely that some molecular defects in the basement membrane zone could increase the susceptibility of a patient to periodontal disease, as this has been noted in the related disorder of Weary-Kindler syndrome. Early-onset periodontal disease can be expected to develop in some types of EB patients, even in the absence of common periodontal pathogens, because of a reduced resistance at the junctional epithelial complex.

An atlas of HIV-associated oral lesions: a new classification and diagnostic criteria.

Many oral lesions are strongly associated with HIV infection. Along with the HIV-infected individual's T helper cell count (CD4 + cell count), they indicate the severity of immune suppression. It is important for dental professionals to recognize these lesions early, as it alerts patients to their HIV status, and allows them to receive appropriate and prompt treatment for their HIV infection and related oral conditions. An atlas of the oral lesions commonly associated with HIV infection is presented. To update dental providers and assist them in the recognition and diagnosis of these conditions, the recent criteria for diagnosis suggested by the European Economic Community (EEC) Clearinghouse on Oral Problems Related to HIV Infection and the World Health Organization (WHO) Collaborating Centre on Oral Manifestations of the Immunodeficiency virus are also presented.

Early-onset periodontitis associated with Weary-Kindler syndrome: a case report.

Weary-Kindler syndrome is a rare and poorly understood genetic disorder that has manifestations of both epidermolysis bullosa and poikiloderma congenitale. There are approximately 70 cases documented in the past 40 years but no cases appear in the dental literature, although dental findings have been discussed superficially in dermatological and pediatric publications. This case reports on the periodontal findings and treatment for a 16-year-old female diagnosed with the syndrome. Early exfoliation of deciduous teeth, severe periodontal bone loss around many permanent teeth, and fragile bleeding gingiva were key features. Microbiological testing revealed an absence of Actinobacillus actinomycetemcomitans and low levels of other commonly accepted periodontal pathogens. Tests for inflammation, including AST and elastase, were positive prior to therapy and greatly decreased after mechanical root instrumentation. A beneficial effect of non-surgical periodontal therapy was observed in the short-term follow-up.

Olfactory neuroblastoma invading the oral cavity in a patient with inappropriate antidiuretic hormone secretion.

Olfactory neuroblastoma is an uncommon intranasal neoplasm that has not been previously documented to invade the oral cavity. The tumor's variable clinical manifestations and microscopic features may create a diagnostic dilemma for the clinician. The neoplasm has been identified as a direct cause of ectopic arginine vasopressin production leading to inappropriate antidiuretic hormone secretion. An unusual case of olfactory neuroblastoma invading the oral cavity through the maxillary sinus in a patient with pathologic antidiuretic hormone secretion is reported.