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Sjögren's syndrome (SS) is an autoimmune disease characterized by lymphoplasmacytoid focal adenitis leading to mucosal dryness, with 9:1 female dominance and peak incidence at menopause. Due to autoimmune adenitis it can be speculated that the normal epithelial cell renewal has failed, possibly as a result of local intracrine failure to process dehydroepiandrosterone (DHEA) to dihydrotestosterone (DHT). Local intracrine/-cellular DHT deficiency seems to predispose to SS if estrogens are low, in menopausal women and in men. This intracrine failure could be the initial noxious stimulus, factor X, initiating the development of SS. Abnormal release and presentation of exocrine gland-derived antigens (Ag-epitopes), in a complex with major histocompatibility complex class II (MHC II), by migratory dendritic cells (DC) activates T-cells in the regional lymph nodes. B-cells with the same specificity capture and present self-Ag to Th-cells which provide T-cell help. B-cells transform to plasma cells and start to produce autoantibodies (Ab) against these T-cell-dependent Ag. Ab against SS-A/Ro and SS-B/La ribonucleoproteins occur only in HLA-DQw2.1/DQw6 heterozygous individuals, but hY-RNA and RNA polymerase III transcripts in these Ag may in all SS patients stimulate toll-like receptors (TLR) 7 and 9 of the plasmacytoid DCs, because IFN-α and IFN-signature are produced. CD8+αEβ7+cytotoxic T-cells activated via cross-presentation recirculate to attack intracrine-deficient, apoptotic epithelial cells expressing self-Ag on their surface. Exocrine glands fall into the sphere of mucosal/gut-associated lymphatic tissue. This together with immune complexes spreads the immunological memory/aggression to extra-glandular sites explaining the systemic nature of the syndrome. Secondary SS could be explained by disturbed lymphocyte recirculation. There is no conclusive evidence that SS in those few men affected is more severe than in women, suggesting that sex steroid endo-/intracrinology has its major impact on the target tissue, not on immune modulation. This article is part of a Special Issue entitled 'Essential role of DHEA'.

In Scandinavia, as in many European countries, most patients consult their general dentist once a year or more. This gives the dentist a unique opportunity and an obligation to make an early diagnosis of oral diseases, which is beneficial for both the patient and the society. Thus, the dentist must have knowledge of clinical symptoms, local and systemic signs and clinical differential diagnoses to make an accurate diagnosis. The dentist must be competent in selecting appropriate diagnostic tests, for example, tissue biopsy and microbiological samples, and conducting them correctly, as well as in interpreting test results and taking appropriate action accordingly. Furthermore, the dentist must be aware of diseases demanding multidisciplinary cooperation and be able to recognise his/her professional limitation, and to refer to other specialists when required. The dental curriculum changes over time as new approaches, treatments and diagnostic possibilities develop. Likewise, the role of the dentist in the community changes and may vary in different countries. As members of the Scandinavian Fellowship for Oral Pathology and Oral Medicine and subject representatives of oral pathology and oral medicine, we feel obliged to contribute to the discussion of how the guidelines of the dental curriculum support the highest possible standards of dental education. This article is meant to delineate a reasonable standard of oral pathology and oral medicine in the European dental curriculum and to guide subject representatives in curriculum development and planning. We have created an advisory topic list in oral pathology and oral medicine.

J Oral Pathol Med (2012) 41: 158–164 Background: Recurrent aphthous ulcer (RAU) is characterized by acute and painful inflammatory ulcerations, which heal spontaneously but tend to recur. Many pathogens have been proposed as causative agents, but none has been consistently proven. According to our hypothesis, RAU is an autoinflammatory disorder triggered by pathogen-associated molecular patterns (PAMPs) shared by different pathogenic and commensal microbes. Methods: PAMP-reactive Toll-like receptors (TLRs) were mapped in oral epithelium in healthy controls compared to RAU. Results: In controls, the superficial epithelium formed a TLR−, a PAMP non-reactive physical barrier zone, but all TLRs were found deeper in the epithelium, usually restricted to suprabasal and basal cell layers. In RAU, the epithelial TLR polarity was lost: TLRs 1, 2, 5, 7, and 8 were found throughout the epithelium, but also TLRs 4, 6, and 10 extended higher up than normally, whereas TLR-3 was almost lost in RAU. In RAU lesions, connective tissue stroma was heavily infiltrated by TLR+ inflammatory cells. Conclusions: Normal TLR architecture prevents inflammatory responses against normal microbes but still contains a deep TLR+, PAMP-reactive dormant defense zone. In RAU, the TLR+, PAMP-reactive zone extends to surface or subsurface exposed to microbial PAMPs. TLR reactivity is further enhanced by recruitment of inflammatory leukocytes forming a new deep line of defense. The organization of the TLR system in healthy mucosa and its changes in RAU are compatible with active pathogenic involvement of TLRs, which together with the typical clinical picture and course suggest that RAU is a TLR-mediated disease.

AIMS: T lymphocyte-antigen-presenting cell (APC) interaction plays a central role in T lymphocyte activation and APC maturation. We therefore studied the CD1a-positive Langerhans cells with respect to receptor activator of nuclear factor kappa B ligand (RANKL)-positive cells in chronic hyperplastic candidosis (CHC). MATERIALS AND METHODS: Tissue sections of CHC were compared with leukoplakia and healthy oral mucosa using RANKL and CD1a monoclonal antibodies in an avidin-biotin peroxidase complex protocol. Two different antigen-retrieval protocols, pepsin preincubation and Tris-EDTA heat treatment, were used. RESULTS: CD1a-positive Langerhans cells were in healthy and leukoplakia epithelium found in the middle layer, but in CHC in all layers of the epithelium, at the basement membrane and as mononuclear round cells in the lamina propria. Use of pepsin digestion enabled studies of mast cells and their activation in the form of degranulation of RANKL. CONCLUSIONS: The numerical, morphological and topographical versatility of the CD1a-positive Langerhans cells in CHC can be clarified by dendritic cell (DC) recruitment into the epithelium. RANK-positive and RANKL-sensitive DCs have ample opportunity to interact with local T lymphocytes. Use of an optimized antigen-retrieval protocol enabled demonstration of an active engagement (degranulation) of mast cells, which represent a rapidly available source of soluble RANKL.

Previous studies on the frequency of mast cells (MCs) in recurrent aphthous ulcers (RAU) have yielded conflicting results. Monoclonal antibodies specific for tryptase (AA1) and anti-IgE (polyclonal antibody) were used to identify density and distribution of MCs in an immunohistochemical study of RAU (n=15), induced oral traumatic ulcers (TUs) (n=9), and control clinically healthy oral mucosa (n=15). Results were quantified by means of a VIDAS image analyzer. In all sections studied, IgE-positive cells showed similar frequency and distribution to tryptase-positive MCs. In RAU lesions, numerous tryptase-positive MCs were found in the sub-epithelial lamina propria, but MC numbers in the epithelium were low and present only in some RAU biopsies. MCs were also more numerous in RAU-inflammatory infiltrates (118+/-31 cells/mm2) than those seen in TU-inflammatory infiltrates (75+/-18 cells/mm2, P

Objective Sjogren's syndrome (SS), an autoimmune disease of exocrine glands, typically starts at the time of adrenopause. We undertook this study to test the hypothesis that SS is characterized by an insufficient androgen effect at the target tissue level. Methods We searched for androgen response elements (AREs) in the cysteine-rich secretory protein 3 (crisp-3) gene. Dehydroepiandrosterone (DHEA) responsiveness was experimentally studied using quantitative reverse transcriptase–polymerase chain reaction and immunofluorescence staining of human submandibular gland–derived acinar cells and labial salivary gland explants with or without DHEA. Finally, glandular and salivary CRISP-3 in healthy controls and SS patients was analyzed using immunohistochemistry, in situ hybridization, and enzyme-linked immunosorbent assay. Serum DHEA sulfate (DHEAS) and salivary DHEA levels were measured using a radioimmunometric method. Results Literature analysis and a search for AREs in gene banks suggested androgen dependency of human CRISP-3, and this was verified by studies of human submandibular gland acinar cells cultured with or without DHEA, in which DHEA increased CRISP-3 messenger RNA (mRNA) levels (P = 0.018). This finding was confirmed by the results of DHEA stimulation of labial salivary gland explants. Glandular CRISP-3 mRNA and protein labeling was weak and diffuse, coupled with low secretion in saliva (mean ± SEM 21.1 ± 2.7 μg CRISP-3/15 minutes in SS patients versus 97.6 ± 12.0 μg CRISP-3/15 minutes in healthy controls; P < 0.0001). Compared with healthy controls, SS patients had low serum levels of DHEAS (P = 0.008) and also low salivary levels of DHEA (mean ± SEM 224 ± 33 pmoles versus 419 ± 98 pmoles; P = 0.005). Conclusion CRISP-3 pathology was seen in acini remote from lymphocyte foci and is apparently not secondary to local inflammation, but may represent some systemic effect in SS. Indeed, androgen deprivation in the salivary glands of SS patients is evidenced both by low salivary levels of DHEA and by low levels of DHEA-regulated CRISP-3. This may explain some of the characteristic features of SS.

A recurrent aphthous ulcer (RAU) is a common inflammatory ulcerative lesion affecting oral mucosa. We studied the eventual apoptosis of epithelial cells from the point of view of ulcer and inflammation. RAU lesions and healthy mucosa samples were immunostained for caspase-3 and high-mobility group box 1 (HMGB1). DNA nicks were identified using TUNEL staining. We studied the effects of tumor necrosis factor α (TNFα) and interferon γ (IFNγ) on the toll-like receptor 2 and 4 (TLR2 and TLR4) expression of human oral SCC-25 keratinocytes. We also studied the effects of self-DNA, all-thiol-HMGB1, and disulfide-HMGB1 on epithelial cells, with or without IFNγ. At the edge of RAU lesions, all epithelial cell layers were caspase-3+, TUNEL+, and HMGB-1+ and had widened intercellular spaces. In contrast, healthy epithelial cells were negative for caspase-3 and TUNEL staining. HMGB1 was seen in only the basal cell layers, and the cells retained close cell-to-cell contacts. Self-DNA increased TNF-α mRNA ( P = 0.02) in SCC-25 cells. Both TNFα and IFNγ ( P = 0.01) increased TLR2. Upon TNFα stimulation, SCC-25 cells lost their nuclear HMGB1 staining. HMGB1 did not increase IL-8, IL-6, or TNF-α mRNA in SCC-25 cells, which was unaffected by the presence of IFNγ. We conclude that in healthy epithelium, the most superficial cells at the end of their life cycle are simply desquamated. In contrast, RAU is characterized by top-to-bottom apoptosis such that dead cells may slough off, leading to an ulcer. Because of a lack of scavenging anti-inflammatory macrophages, apoptotic cells probably undergo secondary necrosis releasing proinflammatory danger signals, which may contribute to the peripheral inflammatory halo. This is supported by self-DNA-induced TNFα synthesis. In contrast to TLR4- and TLR2-binding lipopolysaccharide used as a positive control, disulfide-HMGB1 did not stimulate proinflammatory cytokines.

INTRODUCTION: Neutrophils are the main opponents of Candida albicans in chronic hyperplastic candidosis. They migrate from the circulation to the epithelium where they form microabscesses. We therefore hypothesized that the neutrophil chemokine interleukin-8 (IL-8) might play a role in the neutrophil-Candida interaction. METHODS: Biopsies from patients with chronic hyperplastic candidosis (n = 10) were stained using the avidin-biotin-peroxidase complex protocol for IL-8 and IL-8 receptor A and were compared to healthy control mucosa (n = 3). A set of C. albicans agar sections was similarly analysed. RESULTS: In chronic hyperplastic candidosis lesions IL-8 was strongly expressed in both vascular endothelium and mucosal epithelium. Many resident and immigrant inflammatory cells, including intraepithelial neutrophils, were IL-8 receptor A positive. In addition, IL-8 (or an analogue) was found in the candidal mother cell in chronic hyperplastic candidosis and in agar, whereas the tips of the hyphae expressed IL-8 receptor A (or an analogue). CONCLUSION: IL-8 may play a role in the recruitment of neutrophils from the vascular compartment to the epithelial microabscesses. C. albicans may have developed an ability to sense IL-8. The IL-8 ligand-receptor interaction may help to direct the growth of the IL-8-receptor-containing tips of the hyphae away from the IL-8-producing candidal cell body (a centrifugal growth pattern to facilitate host tissue penetration). Later, this ability might help to keep the vulnerable hyphal tips away from areas with high concentrations of host IL-8 and candidacidal neutrophils. We suggest that this phenomenon, in contrast to chemotropism, is named chemophobia.

Central intraosseous adenoid cystic carcinoma (ACC) of the mandible, formerly known as cylindroma, is a rare neoplasm with only 16 cases reported in the literature. We describe the diagnosis, etiology, and treatment of a central ACC located in the mandibular premolar region. We also review the literature. This case illustrates 2 key facts regarding the diagnosis and etiology of ACC. First, central salivary gland tumors should be considered in the differential diagnosis of cystic lytic lesions in the mandible. Second, even though the origin of this type of tumor is still unknown, the presence of ectopic tissue anterior to the submandibular gland in the submandibular area indicates that this tumor might be made up of ectopic embryogenic inclusions.

In the field of craniomaxillofacial and orthopaedic surgery there is a constant need for bone or bone substitute. At the present, the most effective way to enhance bone healing clinically is to use autogenous bone grafts. The problems associated with the use of these autografts are donor site morbidity, limited supply and need for a second operative site. Currently there are several different synthetic products commercially available in the market; nevertheless, none of them is ideal for filling bone defects. Therefore, search for new synthetic materials for bone replacement is necessary. A mixture of tricalcium phosphate (TCP) and epsilon-caprolactone-lactide copolymer P(epsilon -CL/DL-LA) was prepared and implanted in critical size mandibular bone defects in twelve sheep. Contralateral side was used as a control. Follow-up times for histological and radiological studies were 9, 14, 24 and 52 weeks. We found that the implanted material did not enhance bone formation compared to control site. We also confirmed that defect size was of critical size, since there was no complete healing of the control site either. The results do not encourage us to continue our studies with the mixture of TCP and P(epsilon-CL/DL-LA) as a filling material for bone defects. Therefore the search for the ideal material is still ongoing.

The frequency of Candida infection in periodontal tissues of chronic periodontitis (CP) patients and the extent of candidal penetration into gingival tissues was studied. Tissue specimens collected from 25 CP patients during periodontal flap operations of initial periodontal therapy were examined by immunohistochemistry using Candida albicans-specific antibodies. Sections were also stained with periodic acid-Schiff (PAS) and subgingival plaque samples from 17 patients were cultured. Immunoreactivity for Candida was present in four of the 25 CP specimens (16%). Only one yeast-positive specimen was found when PAS-staining was used (4%) and two yeast-positive specimens were found with plaque culture (8%). Hyphal formation seemed essential and candidal hyphae were found to extend into the periodontal connective tissue. The degree and type of inflammation adjacent to the hyphae varied from a site and a patient to another. The sensitivity of specific antibodies was superior to PAS-stain or plaque culture in detection of Candida in tissues.

Squamous cell carcinoma (SCC) of the oral cavity is a highly invasive tumour of stratified squamous epithelium that spreads through degradation of the basement membrane (BM) and extracellular matrix (ECM). There are currently no reliable tissue or serum markers to predict whether the tumour has metastasized at the time of diagnosis. Verrucous carcinoma (VC) of the oral cavity is a rare low-grade variant of oral SCC that penetrates into the subepithelial connective tissue. Many matrix metalloproteinases (MMPs), such as MMP-1, -2, -7, -9, -13, and -14, as well as integrin receptors have been implicated in cancer invasion. Integrin alphavbeta6 is induced in SCC and appears to be involved in up-regulation of MMP-9 expression by oral keratinocytes and promotion of their migration. The aim of this study was to investigate whether the pattern of MMP expression or that of alphavbeta6 integrin contributes to the differences in the biological behaviour of oral SCC and VC. The results show that the less aggressive nature of oral VC may be connected to its MMP expression profile. Typically, VCs were devoid of epithelial MMP-3, -7, -9, -12 and -13 expression, compared with SCCs. MMP-19 was expressed by epithelial keratinocytes in hyperproliferative areas of verrucous hyperplasia, VC, and SCC, but was absent in the invasive cancer cell nests of SCC. MMP-26 was expressed by hyperproliferative keratinocytes in VC as well as by invasive cancer cells in SCCs. MMP-10 was expressed widely in the epithelium of all SCC specimens. alphavbeta6 integrin expression was also detected in some cases of epithelial hyperplasia but was significantly more abundant in cancers at the invasive front. The absence of MMP-7, -9 and -12 from epithelial cells may serve as a good prognostic marker of non-invasive oral carcinoma. Blocking the activity of invasion-specific MMPs or alphavbeta6 integrin might offer novel therapeutic modalities in early-stage oral carcinoma.

Biodegradable polymers, mainly derivates of α-hydroxy acids, are widely used today in oral- and maxillofacial surgery, orthopedics, and other fields of surgery. These biomaterials are well tolerated by living tissue and fracture fixation devices made of polylactic or polyglycolic acid are clinically widely used today. Still, there are some problems in application of biodegradable polymers. Abacterial inflammatory reactions have been noticed after the clinical introduction of these devices. Both swelling and pain at the site of implantation have also been reported. The etiology of this inflammatory reaction is still unknown, despite the numerous studies. Therefore, the aim of the present study was to further characterize this inflammatory reaction in detail, by electronmicroscopy. We prepared a mixture of e-caprolactone–lactide copolymer and tricalcium phosphate and placed it in the dermis in 12 sheep. Follow-up times were 9, 14, 24, and 52 weeks. We found that the mixture caused a mild inflammatory reaction. There were no signs of cell damage. Fibroblasts, macrophages, and eosinophils were found adjacent to the copolymer. The mixture is easy to handle and can be moulded into different shapes in room temperature. The results encourage us to continue our studies to develop a filling material for bone defects.

Background: Our previous findings in oral lichen planus (OLP) and lichenoid reactions (LR) raised the question whether the histopathological changes observed in sensory and autonomic innervation produce oral sensory disorders. Methods: Spontaneous pain was assessed using the Visual Analogue Scale (VAS). Thermal pain thresholds were measured with a contact thermostimulator and mechanical pain thresholds with an electronic algometer. Results: Patients with OLP reported a higher intensity of spontaneous pain than LR patients (P = 0.001). Even erosive LRs were relatively painless. No thermal or mechanical hyperalgesia was detected in oral lesions. Highest separate cold pain threshold was measured in lesions affected by intense Candida growth. Conclusion: Together with previous histological findings, the present data suggest that increased somatic innervation and sympathetic denervation do not promote clinical pain sensitivity or hyperalgesia in oral mucosa and that these sensory functions are not affected by OLP and LR. Candida growth may function as secondary irritant modulating the pain responses.

Dextran sulfate sodium-induced inflammatory bowel disease in mice resembles human ulcerative colitis. In inflammatory bowel diseases matrix metalloproteinases contribute to tissue degradation. Laminin-5 is an anchoring filament protein in the basement membrane area that can be cleaved by matrix metalloproteinases. We investigated the expression of matrix metalloproteinases-2 and -8 and laminin-5 γ2-chain in dextran sulfate sodium-induced mice by immunohistochemistry and in situ hybridization. Matrix metalloproteinase-8 expression was evidenced in the colon surface epithelial cells and the protein was more abundant in dextran sulfate sodium-induced mice colon. Matrix metallproteinase-2 and laminin-5 γ2-chain colocalized in the colon surface epithelial cells and in the basement membrane zone as demonstrated by double immunostaining. In dextran sulfate sodium-induced colon, matrix metalloproteinase-2 immunoreactivity was detected in epithelial cells in the lower parts of the crypt and surrounding the degraded crypts. Matrix metalloproteinase-2 and -8 could participate in the local epithelial inflammatory processes and tissue destruction. The presence of laminin-5 γ2-chain indicates alternative anchoring mechanisms in the colon, a compartment devoid of hemidesmosomes.

Objectives It was hypothesized that beta 2 defensin (BD-2) is increased in RAU lesions compared with healthy controls to promote anti-microbial host defence. Methods RAU and control mucosa samples were subjected to quantitative real-time PCR and immunostained for BD-2, CD68, mast cell tryptase and 4-hydroxynonenal (4HNE). The effect of tumour necrosis factor-α (TNF-α) ± interleukin-17C (IL-17C), without and with vitamin K3, was studied on BD-2 expression in epithelial SCC-25 cells. Results Although BD-2 mRNA did not differ between healthy and RAU mucosa, BD-2 stained strongly in acute-phase RAU epithelium (P = 0.001). In controls, subepithelial BD-2+ cells were mast cells and macrophages, whereas in RAU, most infiltrating leucocytes were BD-2+ (P = 0.004). In cell culture, BD-2 was increased 124-fold by TNF-α (P

Objective: Mechanisms of the dentigerous cyst formation from the normal eruption follicle is unknown but disturbances in the proteolytic activity have been suspected, since the growth of these cysts is accompanied by local bone destruction. The aim of the present study was to evaluate the expression of matrix metalloproteinases (MMP) in human dental dentigerous cysts and healthy dental follicles. Materials and Methods: We studied 10 patients with dentigerous cysts and 10 healthy dental follicles from the lower jaw in respect to their immunoexpression of MMPs -8, -9, -25, and -26 and tissue inhibitor of metalloproteinases -1 (TIMP-1). Results: MMP-8 was expressed slightly more in cyst epithelium than in odontogenic epithelium of healthy controls dental follicle but the difference lacked statistical difference. Other MMPs and TIMP-1 did not differ regarding the studied specimens. Conclusion: Differences in MMP expression cannot solely explain the cyst expansion suggesting the potential involvement of other osteolytic mechanisms.

Objectives Oral lichen planus (OLP) is an autoimmune disease characterized by a band-like T-cell infiltrate below the apoptotic epithelial cells and degenerated basement membrane. We tested the hypothesis that the high-affinity histamine H4 receptors (H4Rs) are downregulated in OLP by high histamine concentrations and proinflammatory T-cell cytokines. Materials and Methods Immunohistochemistry and immunofluorescence staining, image analysis and quantitative real-time polymerase chain reaction of tissue samples and cytokine-stimulated cultured SCC-25 and primary human oral keratinocytes. Results H4R immunoreactivity was weak in OLP and characterized by mast cell (MC) hyperplasia and degranulation. In contrast to controls, H4R immunostaining and MC counts were negatively correlated in OLP (P = 0.003). H4R agonist at nanomolar levels led to a rapid internalization of H4Rs, whereas high histamine concentration and interferon-γ decreased HRH4-gene transcripts. Conclusion Healthy oral epithelial cells are equipped with H4R, which displays a uniform staining pattern in a MC-independent fashion. In contrast, in OLP, increased numbers of activated MCs associate with increasing loss of epithelial H4R. Cell culture experiments suggest a rapid H4R stimulation-dependent receptor internalization and a slow cytokine-driven decrease in H4R synthesis. H4R may be involved in the maintenance of healthy oral mucosa. In OLP, this maintenance might be impaired by MC degranulation and inflammatory cytokines.

OBJECTIVES—To investigate the occurrence of and risk factors for focal sialadenitis in patients with rheumatoid arthritis (RA), mixed connective tissue disease (MCTD), ankylosing spondylitis (AS), and spondyloarthropathy (SpA). METHODS—A total of 85 patients (25 with RA, 19 with MCTD, 19 with AS, 22 with SpA) participated in the study. Each patient filled out a questionnaire for eye and oral symptoms and for the use of medication, and was interviewed; other tests included Schirmer's test, laboratory tests, collection of unstimulated and stimulated whole saliva, and minor salivary gland biopsy. A focus score of ⩾1 was regarded as an indicator of focal sialadenitis. RESULTS—Focal sialadenitis was observed in 68% (57/84) of all patients. It affected 80% (20/25) of the patients with RA, 94% (17/18) of those with MCTD, 58% (11/19) of those with AS, and 41% (9/22) of those with SpA (χ2 test, p=0.0013). Salivary secretion correlated negatively with the focus scores—that is, severity of focal sialadenitis. Patients with focal sialadenitis had both decreased salivary secretion and decreased tear secretion significantly more often than did patients without (χ2 test, p=0.0074 and p=0.048 respectively). Patients with positive rheumatoid factor (RF), antinuclear antibodies (ANA), or SSA or SSB antibodies had sialadenitis significantly more often than did patients with negative antibodies. In the subgroup of patients with AS or SpA, no associations were found between focal sialadenitis and the presence of these antibodies. CONCLUSION—In addition to patients with RA or MCTD, focal sialadenitis also affects a very high proportion of patients with AS or SpA. Focus scores are significantly higher in patients with RA or MCTD than in those with AS or SpA. A significant association exists between focal sialadenitis and RF, ANA, SSA and SSB. However, in the subgroup of patients with AS or SpA, no associations were found between focal sialadenitis and serological markers or clinical symptoms.

Tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine, can stimulate matrix metalloproteinase synthesis and osteoclastic bone resorption. We hypothesized that elevated expression of TNF-alpha and its p55 and p75 receptors (TNF-R) in gingival tissue might associate with periodontitis. Immunohistochemistry was used for the study of the localization of TNF-alpha and its p55 and p75 TNF-R in adult periodontitis (AP) gingival tissue, in comparison with that in healthy control specimens. TNF-alpha and p55 TNF-R were detected in sulcular epithelial basal cells and in monocyte/macrophages, fibroblasts, and endothelial cells in the AP gingival tissue specimens, but mainly in fibroblasts and endothelial cells in control specimens. P75 TNF-R was occasionally found in monocyte/macrophage-like cells in gingival tissue specimens. The percentage of TNF-alpha-containing cells was not increased in AP compared with controls (13.2%+/-6.1% vs. 12.8%+/-7.6%), but, due to the increased cellularity of AP samples, the number of TNF-alpha positive cells/mm2 was clearly increased (1621+/-663 vs. 664+/-191, p0.001). Thus, AP gingival tissue has an elevated expression of TNF-alpha and especially its p55 receptor, suggesting that TNF-alpha may contribute to tissue degradation in periodontitis.

Matrix metalloproteinases (MMPs) collectively degrade extracellular matrix and basement membrane proteins in chronic inflammation and bone-destructive lesions. This study examined the ability of immunoglobulin-producing plasma cells, typically present in sites of chronic inflammation, to express collagenases (MMP-8 and -13) in vivo and in vitro. Phorbol-12-myristate-13-acetate, interleukin-6, and tumour necrosis factor-alpha and heparin with the tumour promoter or cytokines potently enhanced (up to nine-fold) MMP-8 and -13 expression by the RPMI 8226 myeloma cell line, as evidenced by western blotting and semi-quantitative reverse transcriptase-polymerase chain reaction. Immunohistochemical analysis and in situ hybridization revealed that plasma cells expressed MMP-8 and -13 focally in periapical granulomas, odontogenic cysts, and malignant plasmacytomas. MMP-8 and MMP-13 from plasma cells can participate in bone organic matrix destruction at sites of chronic inflammation and neoplastic growth. Since MMP-13 was more frequently expressed than MMP-8 in plasma cells of strongly recurring keratocysts and malignant plasmacytomas, it is concluded that plasma cell MMP-13 has a particularly important role in benign and malignant bone-destructive lesions.

Lymphocytes bearing the T-cell receptor (TCR) gamma/delta are increased in the peripheral blood of patients with recurrent aphthous ulcers (RAU) and Behcet's disease. In this study, we examined whether the density of TCR-gamma/delta bearing lymphocytes was also increased locally in RAU lesions. Ten RAU lesions from ten patients were compared with ulcer-free mucosa from sites contralateral to the lesions, and with 10 samples of clinically healthy oral mucosa taken from 10 healthy volunteers. Samples were labeled with a panel of monoclonal antibodies specific to CD3, alpha/beta TCR and gamma/delta TCR in avidin-biotin-peroxidase complex (ABC) staining. Lymphocytes expressing gamma/delta TCRs were very low in non-lesional mucosa and clinically healthy mucosa. By contrast, gamma/delta T-cells were numerous and observed in all RAU lesions especially within the epithelium, inflammatory infiltrates and at perivascular locations. The count of gamma/delta T-cells was high in connective tissue of RAU (200 +/- 126 cells/mm2) compared with connective tissue of controls (4+/-4 cells/mm2; P

The peripheral nervous system was analysed in the oral mucosa of eight patients with oral lichen planus (OLP), five with a lichenoid reaction (LR) and three with mild chronic inflammation (MCI), by morphometric analysis of nerve fibres containing immunoreactive PGP 9.5, substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP), or C-flanking peptide of neuropeptide Y (CPON). Overall nerve fibre density was higher in OLP (P=0.039) and LR (P=0.026) compared with healthy oral mucosa and was compatible with sprouting and collateral formation. In contrast to the innervation visualized with structural nerve fibre-marker PGP 9.5, the densities of neuropeptide-immunoreactive nerves were low in inflamed tissue. This is consistent with depletion via local release. Retraction and local loss of innervation were found in areas coinciding with the most severe inflammation and basal membrane (BM) damage. Interestingly, LR showed a twenty-eight-fold loss of post-ganglionic CPON-ir sympathetic nerve fibres (P=0.044). In LR, CPON-ir innervation was markedly lower than in OLP. Finally, the pattern of innervation in relation to inflammatory cell infiltrates and tissue structures differed between OLP and LR. In conclusion, the peripheral nervous system is implicated in the immunopathogenesis of lichen planus and lichenoid reactions, with a disorder-specific difference in this involvement.

Problem: Hundreds of primary salivary neoplasms have been found to be completely enclosed within the marrow spaces of the maxilla and mandible, yet nonneoplastic salivary tissue has never been convincingly identified within marrow, either separately or adjacent to such neoplasms. This situation has forced the acceptance of an inherently awkward odontogenic origin for all intramedullary salivary carcinomas and adenomas. Objective: The purpose of this study was to microscopically evaluate a large number of maxillofacial marrow samples for the presence of intramedullary salivary tissue. Study Design: We microscopically reviewed 5034 maxillofacial bone samples from the Latvala Inflammatory Bone Registry for evidence of heterotopic salivary inclusions within the marrow tissues. Contributing surgeons were contacted for each identified case of intraosseous salivary tissue to assure that all submitted tissue was removed from within the marrow spaces rather than from overlying soft tissue. Results: Thirteen of 5034 marrow samples (0.3%) contained heterotopic acinic hamartomas, salivary choristomas, embryonic salivary rests, or entrapped surface glands. Four additional hamartomas of the condyle are described. We report also the chance finding of incipient odontogenic epithelial neoplasms (n = 6) and odontogenic epithelial rests (n = 84) within the fatty marrow and outside the periodontal ligament spaces, confirming that not all odontogenic neoplasms are necessarily of periodontal ligament origin. Conclusion: The frequency rate for salivary choristomas, hamartomas, embryonic rests, and displaced surface glands within alveolar bone is no less than 2.6 of 1000 biopsied marrow samples. This provides an additional and quite logical histogenetic explanation for the presence of intraosseous salivary neoplasms. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;90:205-17)

Mast cells (MCs) have been implicated in many immune-inflammatory disorders. Deranged mast cell distribution and function may contribute to the local pathomechanisms in the labial salivary glands (LSG) in Sjogren's syndrome (SS). Evidence for MC presence, localization, frequency, subtype, and degree of activation was sought by using reverse transcriptase-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC)/image analysis, transmission electron microscopy, Western blotting, spectrophotometric activity assay, and radioimmunoassay. The overall expression (densitometric units) of MC tryptase mRNA (1483 +/- 228 vs 1044 +/- 308) did not differ between SS and control LSGs. However, IHC disclosed an uneven distribution of MCs in SS with an absence in lymphocyte foci and increased numbers (cells/mm2 77 +/- 7 vs 38 +/- 4, P < 0.01) elsewhere. Absence of MCs in the lymphocyte foci was not a fixation artefact and was not explained by the presence of "phantom" MCs in these areas. In both SS and controls, 80% of all MCs were chymase containing, but the typical lattices/gratings characteristic for connective tissue MCs (CTMCs) were not found. Instead, MC granules had mostly a homogeneous, finely granular substructure characteristic of "new" granules subjected to a continuous, low-grade release. 32 kDa MC tryptase was found in saliva and its activity/concentration was comparable to that found in controls. However, tryptase output was low in SS (1.30 +/- 0.30 microg/min vs 3.49 +/- 0.66 microg/min, P < 0.001). Normal LSGs contain mostly CTMCs, in close contact with various resident and immigrant cells, characterized by a low-grade release of MC mediators. In SS this normal pattern is disturbed so that MCs are absent in lymphocyte foci (but increased elsewhere in the glands). The net salivary output of MC mediators is low in SS. This derangement of MCs may contribute to the pathogenesis of SS via multiple mechanisms.

Solitary fibrous tumour (SFT) is an uncommon mesenchymal neoplasm rarely located in the oral cavity. To characterize further oral SFT, we describe three new cases. Each tumour originated in the buccal mucosa of a middle-aged/elderly patient. Histological examination showed well-circumscribed tumours with densely cellular areas alternating with hypocellular areas in a variedly collagenous, vascular stroma. Mast cells were abundant. The spindle-shaped, neoplastic cells immunostained strongly for CD34 antigen and vimentin and weakly for bcl-2, but not for epithelial cell markers, alpha-smooth muscle actin, or neurofilament or S-100 proteins. Compatible with the virtual absence of mitoses and of marked nuclear atypia, the overall frequency of proliferating cells expressing Ki-67 was low. The expression of CD34 was useful in the differential diagnosis. The consistent location in the cheek and expansion of one tumour after local trauma does not preclude a traumatic element in the development of oral SFT.

Tumor necrosis factor (TNF)-alpha is a pro-inflammatory cytokine and crucial mediator in many aspects of immunity. Although several studies have shown that recurrent aphthous ulcers (RAU) can be prevented by treatment that prevents the synthesis of endogenous TNF-alpha little is known about the location and distribution of TNF-alpha-expressing cells at disease sites. The aim of the present work is, therefore, to investigate TNF-alpha and its cellular distribution in RAU lesions compared with those in induced oral traumatic ulcers (TUs). Twelve biopsies of RAU lesions of oral mucosa were obtained from 12 patients with RAU. They were compared to a control group consisting of ten samples of induced TUs. All samples were analyzed for TNF-alpha expression by using monoclonal mouse anti-human TNF-alpha antibody in avidin-biotin-peroxidase complex (ABC) staining. Results were quantified by a semi-automatic VIDAS image analysis system. TNF-alpha immunoreactivity was contained mainly in monocyte/macrophages and lymphocytes within the mononuclear inflammatory infiltrates. TNF-alpha was often seen in mast cells and vascular endothelial cells in connective tissue lateral to the inflammatory infiltrates. Interestingly, 32%-60% of the mononuclear cells were found to be TNF-alpha immunoreactive in RAU lesions. TNF-alpha containing cells were more numerous in aphthae (188+/-46 cells/0.2 mm2) compared with controls (52+/-14 cells/0.2 mm2, P

In previous studies, epsilon-caprolactone-lactide copolymer in solid form has been used in experimental animals as suture material, and as a biodegradable nerve guide. The aim of the study reported here was to assess tissue reactions to epsilon-caprolactone-lactide copolymer in paste form, histologically, and to compare bone healing at the sites of implantation versus that at control sites. The other purpose of the study was to evaluate the properties of the implanted material as a filling material for bone defects. Resorption time and intensity of inflammatory reaction were also evaluated. Material was implanted into the abdominal walls and femurs of 34 rats. Follow-up times were from 2 weeks to 1 year. The results showed that epsilon-caprolactone-lactide copolymer in paste form induces a severe inflammatory reaction when placed in muscle, and moderate inflammation when implanted into bone. The resorption time was more than 1 year. Bone healing at sites of implantation was slower than at control sites.

Objectives. Inflammatory arthritides/synovitides such as psoriatic (PsA), reactive (ReA) and rheumatoid (RA) arthritis share numerous immunopathological features, but develop diVerent patterns of joint involvement. To investigate whether distinctive cell apoptosis may play a role in this context, we have assessed synovial cell apoptosis in situ in PsA and ReA, and compared it with RA and ‘non-inflammatory’ controls. Methods. TdT-mediated dUTP nick end-labelling ( TUNEL) of DNA breaks complemented immunoperoxidase staining for CD68 or LCA as the specific cell markers. Results. The proportion of apoptotic synovial lining cells was high in PsA, ReA and RA compared to values in controls (P< 0.05). No diVerences existed between these inflammatory arthritides in numbers or type of apoptotic lining cells. In RA, however, in contrast to PsA and ReA, apoptotic lining cells were clustered or, in a small subset of samples, were very low in number. Prominent apoptosis of inflammatory cells in the sublining in ReA has accounted for higher overall apoptotic cell numbers in synovial stroma (sublining+ perivascular inflammatory cell infiltrates) in this condition than in RA or PsA (P< 0.05). Conclusions. No disease-specific pattern in the phenotype of apoptotic synovial lining cells could be suggested in any of the inflammatory arthritides studied. However, topological diVerences in the lining and quantitative diVerences in the inflammatory cell apoptosis in synovial stroma may in part explain the occurrence of the prominent synovial lining cell hyperplasia distinguishing RA from ReA and PsA. On the other hand, relatively frequent inflammatory cell apoptosis may contribute both to the downregulation of synovial inflammation and to the control of synovial lining hyperplasia in ReA.

Oral lichen planus (OLP) carries a very small probability of becoming malignant. Our Finnish series comprised eight patients suffering from OLP and concurrent or subsequent oral squamous cell carcinoma over a 10-year period. The mean interval between the histologically suggested initial diagnosis of OLP and carcinoma was 3.4 years. An oral ulcer as a clinical manifestation of malignant change appeared in seven of these eight patients; five of the eight died of carcinoma on average 13 months (range 7–20) after the final squamous cell carcinoma diagnosis. These eight patients were compared to eight control OLP patients without malignant transformation matched as to follow-up time, age, gender, sites of the lesions, etc. We could discover no histological features leading to malignant development. However, the clinically unilateral atrophic/erosive type of OLP more often preceded the malignant change, compared to the situation for control patients, in whom the most prevalent type was the bilateral reticular OLP. However, the probability seems to be very small.

Mandibular body osteotomies were fixed in nine sheep using new totally amorphous (70L:30DL), self-reinforced, polylactide (SR-PLA) lag screws and in nine sheep using standard stainless steel lag screws. No intermaxillary fixation was used. During follow-up, radiological, histological and microradiological studies were undertaken at 3, 6, 12 and 24 weeks. In both groups, all osteotomies consolidated at similar rates and no adverse reaction to the screws was seen. However, displacements of the fixed osteotomy fragments were common in both groups during the first 3 weeks. The biocompatibility of SR-PLA during the follow-up period was found to be good. Only initial signs of biodegradation were seen. The results of this study indicate that (70L:30DL) SR-PLA has potential for use as a fixation screw material in oral and maxillofacial surgery, and that further studies using this material are justified.

In cranio-maxillofacial surgery, bone transplantation is needed for treatment of bony defects. An autograft, allograft or biomaterial can be used. Autogenous bone grafts are considered to be the best materials available, but there are some disadvantages in their use including donorsite morbidity, need for a second operative site and limited graft supply. A search for new bone-graft materials therefore remains necessary. We prepared a mixture of tricalcium phosphate (TCP), which is a resorbable, non-toxic, osteoconductive ceramic material and e-caprolactone-lactide copolymer P(e-CL/DL-LA), a resorbable polymer, and placed it in the dermis and in mandibular bone defects in 13 rabbits. Follow-up times were two, three, seven, eight, 12, 15 and 18 weeks, tissue reactions were assessed, histologically and immunohistochemically. Times of resorption of the material from tissues were reported. We found that the mixture caused a mild inflammatory reaction when placed in bone and severe inflammation when placed in dermis. No highly fluorescent layer of tenascin or fibronectin was found surrounding the implant area. The mixture was excellent to handle and very easy to place into bone defects. The results are promising and have led us to continue development of the mixture. © 1999 Kluwer Academic Publishers

Purpose: The purpose of this study was to investigate the long-term tissue response and duration of degradation of self-reinforced poly-L-lactide (SR-PLLA) multilayer plates in vivo. Materials and Methods: Mandibular osteotomies in sheep were fixed with SR-PLLA multilayer plates. The animals were followed for 1, 2, 3, 4, and 5 years, after which histologic studies were performed. Results: The foreign-body reaction was mainly mild, and the osteotomies were well united. After 5 years in vivo, the material was almost completely resorbed, but small particles of polymer could still be detected at the implantation site. SR-PLLA plates were also incubated in vitro for 5 years. The material degraded considerably faster in vivo than in vitro. Molecular weight, melting temperature, and crystallinity of the plates remained at a constant level after 2 years in vitro, indicating very slow degradation of the oligomeric (molecular weight [Mw], 3500 daltons), highly crystalline (heat of fusion, 70 J/g), PLLA residue solely as a result of hydrolysis. Although the plates became increasingly fragile as they degraded, they retained their macroscopic form until the end of the 5-year follow-up. Loss of mass of the plates was 52% ± 8% after 5 years of incubation in vitro. Conclusions: Although the long degradation period may seem to be a minor drawback to the use of such plates, it does not appear to affect the healing process.

The extent of synovial cell proliferation in situ and its relationship to the destructive potential of rheumatoid arthritis (RA) is a matter of continuing debate. Notably, the situation has not been elucidated in other inflammatory arthritides [i.e. reactive (ReA) and psoriatic (PsA)], which, although they share some histopathological similarities with RA, develop different patterns of joint involvement. In order to estimate the proliferation of synovial cells in situ in PsA and ReA, and to compare this with RA and with 'non-inflammatory' joint lesions, we have utilized immunostaining of the Ki-67 antigen complemented with Ki-67/CD68 or Ki-67/leucocyte common antigen (LCA, clones 2B11 and PD7/26) double stainings to assess the extent of mononuclear inflammatory cell proliferation. Synovial samples analysed were from 33 patients: RA (n = 8), PsA (n = 13), ReA (n = 6) and six 'non-inflammatory controls' (degenerative or traumatic joint lesions). Thickening of the synovial lining (in particular in RA) and perivascular accumulations of mononuclear inflammatory cells, predominantly lymphocytes, were characteristic features in all synovitides. In contrast to the thickened avascular synovial lining in RA, in 5/13 cases with PsA, blood vessels were observed in the lining. The percentage of lining cells expressing Ki-67 antigen was higher in RA (median = 4.7, interquartile range [Q3-Q1] = 3.9, mean [95% CI] = 3.5 [1.7-5.2], P = 0.0063), PsA (median = 1.2, [Q3-Q1] = 1.9, mean [95% CI] = 1.6 [0.7-2.5], P = 0.007) and ReA (median = 1.4, [Q3-Q1] = 2.3, mean [95% CI] = 1.6 [0.1-3.1], P = 0.0235) than in controls (median = 0.1, [Q3-Q1] = 0.45, mean [95% CI] = 0.2 [0.07-0.5]). In this respect, the differences between different forms of the inflammatory arthritides were not statistically significant (P > 0.05). In RA, PsA and ReA, the percentage of labelled cells in the inflammatory mononuclear cell-rich areas was higher than in controls. The percentage of proliferating endothelial cells was also significantly higher in RA, PsA and ReA than in controls. However, in RA, endothelial expression of Ki-67 antigen was often seen in small blood vessels, whereas in PsA, Ki-67 antigen was preferably expressed in the medium to large blood vessels. Synovial lining cells of the monocyte/macrophage lineage (type A synoviocytes), but not stromal monocytes, demonstrated modest proliferation in situ. These results indicate that although proliferation of synovial lining fibroblasts is a prominent feature in RA, the extents to which this, or in situ proliferation of lymphocytes, contribute to the histopathology of PsA, ReA and RA are comparable. Vascular involvement is suggested by the proliferation of endothelial cells in RA, PsA and ReA in an overlapping manner, but, based on topological differences, such a response may represent diverse pathological features, such as angiogenesis, vascular enlargement and reparative responses to injury.

The histological features of recurrent aphthous ulcer (RAU) are consistent with increased number and activation of T cells in the diseased areas. A previous study suggested that 13-23% of the cells express IL-2 and transferrin receptors, which implies potential for local proliferation. The aim of the study was to to evaluate the proliferation activity in 10 RAU lesions compared to 9 oral traumatic ulcer (TU) lesions. Demonstration of proliferating cells was performed by application of affinity-purified rabbit anti-human Ki-67 antibodies in avidin-biotin-peroxidase complex (ABC) staining to both RAU and TU biopsies. We found that the basal/suprabasal layers of RAU epithelium away from the ulcer contained 30% more proliferating cells (127±24 vs 97±19 cells/0.2mm2, P

The factor XIIIa-positive (FXIIIa+) cell is a potent antigen-presenting cell, which has been described as increasing in numbers in various chronic inflammatory conditions. The purpose of this study was to investigate the distribution and frequency of FXIIIa+ cells in acute recurrent aphthous ulcer (RAU) lesions compared with induced traumatic ulcer (TU) lesions and with clinically healthy oral mucosa. Samples were labeled with polyclonal rabbit anti-human FXIIIa antibodies in avidin-biotin-peroxidase complex (ABC) staining. Most of the FXIIIa-immunoreactive cells in TUs and normal mucosa were spindle-shaped, whereas a relatively large, dendritic-like cell was predominant in RAU lesions. FXIIIa+ cells were quite frequent within mononuclear cell-rich inflammatory cell infiltrates and in perivascular areas in RAU lesions. In contrast, FXIIIa+ cells were not found in mucosal epithelium or in the neutrophil-rich areas. RAU mononuclear cell-rich inflammatory cell infiltrates appeared to have greater numbers of positively stained cells than the TU-inflammatory cell infiltrates (199 +/- 67 vs 110 +/- 31 cells/mm2, P < 0.001). Overall, FXIIIa+ dendrocytes were increased in numbers, and apparently also in size, in RAU lesions (274 +/- 68/mm2) as compared to controls (177 +/- 74/mm2, P < 0.01), and to TU lesions (183 +/- 50 mm2, P < 0.01). Interestingly, relatively high numbers of FXIIIa+ dendrocytes were also found in deep connective tissue in RAU sections compared with TUs (281 +/- 80 vs 166 +/- 57, P < 0.01). The characteristic changes in the size and shape of individual FXIIIa+ cells, their typical distribution and increase in frequency in RAU lesions indicate active involvement in the local pathogenic mechanisms. Localization to perivascular areas/inflammatory cell infiltrates would be compatible with a role in antigen presentation.

To characterize further the nature of calcifying odontogenic cyst (COC), we studied histologically and immunohistochemically an extraosseous and two intraosseous lesions. The extraosseous COC was in continuity with the stratified squamous epithelium of the alveolar mucosa. Immunostaining with monoclonal antibodies showed reactivity of both low- and high-molecular-weight cytokeratins, the degree of coexpression decreasing with the increasing morphological diversity of the cyst/tumour epithelium. Staining for the matrix glycoprotein tenascin-C was seen not only in the connective tissue, where its distribution patterns corresponded to the stage of hard tissue formation, but also in epithelial elements. The staining patterns were analogous to those described during normal tooth formation. Both the morphological characteristics and expression patterns of the various cytokeratin types and tenascin-C implied that COC represents a pathological counterpart of normal odontogenesis. In the case of the extraosseous COC, the correspondence could be traced back to early stages of tooth development.

Lymphocytes bearing T cell receptor (TcR) gamma/delta are increased in the jejunal mucosa of patients with dermatitis herpetiformis (DH) and coeliac disease. In this study, we examined whether increased numbers of gamma/delta TcR positive lymphocytes occur in the oral mucosa of patients with DH. Oral and jejunal mucosal biopsies were taken from 13 newly diagnosed and 13 gluten free diet (GFD)-treated patients with DH. Monoclonal antibodies and avidin-biotin peroxidase method was used for staining, and TcR positive cells were counted from the buccal and jejunal epithelium. Very few gamma/delta TcR positive lymphocytes were seen in the buccal epithelium of untreated or GFD-treated DH patients (median 0.4 and 0.3 cells/mm2), whereas alpha/beta TcR positive lymphocytes were frequent in both groups of DH patients (154 and 250 cells/mm2) and healthy controls (135 cells/mm2). The numbers of gamma/delta TcR positive intraepithelial lymphocytes were significantly increased in the jejunum of both untreated (43 cells/mm) and GFD-treated (27 cells/mm) DH patients compared to control patients (2.2 cells/mm). The present study did not, therefore, disclose any evidence for active recruitment of gamma/delta TcR positive lymphocytes in the oral epithelium, but showed substantial amounts of intraepithelial alpha/beta TcR positive lymphocytes both in DH patients and healthy controls.

Background Recurrent aphthous ulcer (RAU) is an ulcerative disease of non-keratinized oral mucosa. Colon and bronchial epithelial cells produce interleukin-17C (IL-17C) upon stimulation of Toll-like receptor 2 (TLR2), TLR3 and TLR5, which are highly expressed in epithelial cells in RAU lesions. We therefore investigated the eventual presence and function of IL-17C in cultured human oral keratinocytes (HOK) and control biopsies compared to RAU lesions. Methods Expression of IL-17A, IL-17C, IL-17RA and IL-17RE was analysed in cultured HOK cells using quantitative real-time polymerase chain reaction (qRT-PCR). HOK cells were stimulated with IL-17C and analysed for IL-8 and tumour necrosis factor-α (TNF-α) using qRT-PCR. Control mucosa (n = 5) was immunostained for IL-17A, IL-17C, IL-8, TNF-α and mast cell tryptase and compared with RAU lesions (n = 5) using the mean grey scale value. Results IL-17C, but no IL-17A, mRNA was found in cultured HOK cells. Components of the heterodimeric IL-17RA/IL-17RE receptor for IL-17C were also highly expressed. Stimulation of HOK with IL-17C increased TNF-α mRNA (P = 0.03; IL-8 increase was not statistically significant). HOK in RAU lesions stained intensively for IL-17C compared to controls (P = 0.006). This was associated with increased epithelial immunostaining of TNF-α (P = 0.04) and IL-8 (P = 0.02). Most of the inflammatory cells which stained for IL-17A in control mucosa and RAU lesions were also mast cell tryptase positive. Conclusion IL-17C is highly expressed in epithelial cells in RAU lesions, where it seems to stimulate oral keratinocytes via IL-17RA/IL-17RE to produce pro-inflammatory cytokines. Human oral epithelial cells are probably important inflammatory cells in RAU.

The expression of tenascin was assessed immunohistochemically. In normal oral mucosa, immunoreactivity for tenascin was seen either as a delicate line underlining the epithelium or in the stromal papillae. In oral lichen planus, a marked enhancement of tenascin immunoreactivity in the lamina propria was associated with focal infiltrates of inflammatory cells and seemed to reflect the intensity of inflammation. In lichenoid reactions in which only a sparse inflammatory infiltrate was present a band-like tenascin reactivity was seen. Oral psoriform reactions and chronic hyperplastic candidosis showed a prominent tenascin reaction in the connective tissue papillae among infiltrates of inflammatory cells. The results show that tenascin content is increased in oral mucocutaneous diseases and related lesions and that the abundance of tenascin reflects the intensity of the inflammatory reaction.

The molecular mechanisms of jaw cyst expansion probably involve interactions of matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs). In this study, molecular species of gelatinases present in neutral salt extracts of cyst walls and cyst fluids were characterized by functional activity measurements (type I gelatin and α-casein zymography) and immunologically (Western-blotting). The effects of various protein thiol-group or cysteine-switch reactants involved in the activation of collagenases were studied on cyst gelatinases and a gelatinases purified from human gingival fibroblasts (72 kD MMP-2), gingival keratinocytes (92 kD MMP-9) and polymorphonuclear neutrophilic leukocytes (92 kD MMP-9). Western-blottings revealed the presence of both 92 kD (MMP-9) and 72 kD (MMP-2) gelatinases in cyst wall extracts and cyst fluids. Western-blot studies further suggested that jaw cyst gelatinases were only in part complexed with and thus inhibited by TIMP-1 or TIMP-2, suggesting that both MMP-9 and MMP-2 may participate in cyst expansion. MMP-2 was also partially fragmented to a 68 kD form and additional lower molecular weight proteinases (

Recurrent aphthous ulcer (RAU) is characterized by acute and painful inflammatory ulcerations, which heal spontaneously but tend to recur. Many pathogens have been proposed as causative agents, but none has been consistently proven. According to our hypothesis, RAU is an autoinflammatory disorder triggered by pathogen-associated molecular patterns (PAMPs) shared by different pathogenic and commensal microbes.PAMP-reactive Toll-like receptors (TLRs) were mapped in oral epithelium in healthy controls compared to RAU.In controls, the superficial epithelium formed a TLR(-), a PAMP non-reactive physical barrier zone, but all TLRs were found deeper in the epithelium, usually restricted to suprabasal and basal cell layers. In RAU, the epithelial TLR polarity was lost: TLRs 1, 2, 5, 7, and 8 were found throughout the epithelium, but also TLRs 4, 6, and 10 extended higher up than normally, whereas TLR-3 was almost lost in RAU. In RAU lesions, connective tissue stroma was heavily infiltrated by TLR(+) inflammatory cells.Normal TLR architecture prevents inflammatory responses against normal microbes but still contains a deep TLR(+) , PAMP-reactive dormant defense zone. In RAU, the TLR(+), PAMP-reactive zone extends to surface or subsurface exposed to microbial PAMPs. TLR reactivity is further enhanced by recruitment of inflammatory leukocytes forming a new deep line of defense. The organization of the TLR system in healthy mucosa and its changes in RAU are compatible with active pathogenic involvement of TLRs, which together with the typical clinical picture and course suggest that RAU is a TLR-mediated disease.

The topographical distribution and relation to mast cells of PGP 9.5 (protein gene product 9.5, a major cytoplasmic neuron-specific protein with ubiquitin C-terminal hydrolase activity) and neurofilament (intermediate neuron-specific cytoskeletal filaments) in normal human buccal mucosa was studied in five healthy volunteers. Morphometric analysis disclosed the densest innervation to be in the middle layers of the lamina propria, with a mean number of 5.9-6.1 PGP 9.5 and/or neurofilament-immunoreactive nerve fiber profiles per one mm2. In contrast, the mean mast cell number decreased from 110/mm2 to 46/mm2 from superficial to deep lamina propria, being 69-72/mm2 in the most densely innervated middle layers. Only 16-17% of all fiber profiles contained substance P and 51-54% calcitonin gene-related peptide (CGRP). Finally, analysis of the spatial relationship between nerve fiber profiles and mast cells in a double staining procedure disclosed no preferential neuron-effector associations. All these findings suggest that such a relationship does not exist between peripheral nerves and mast cells in normal buccal mucosa.

Surgical specimens from 16 nonirradiated patients with carcinoma of the mandibular region who had undergone resection of the mandible were investigated histologically to evaluate the presence, pattern and extent of bone involvement. Thirteen of the 16 carcinomas had invaded the mandibular bone. Two main patterns of growth were identified: seven carcinomas had infiltrated nonuniformly into the bone and six tumours had advanced as a compact front. Direct invasion from the oral mucosal tumour could be verified in 12 cases. Extension of four of these 12 tumours in bone clearly exceeded their dimension in the overlying mucosa. Carcinoma tissue in the mandibular canal, at a distance from the major tumour extension, was seen in two cases, whereas the periodontal ligament spaces were invaded only when there was a direct contiguous invasion by the tumour. The grade of histologic differentiation of the carcinoma did not definitely correlate with the frequency, pattern or extension of bone involvement. The results indicate that large tumour size, location on the mandibular alveolar ridge and clinical fixation to the mandibular bone predispose to, but are not prerequisites for bone invasion. Taken together, this study has shown that prediction of the presence and extent of bone involvement of the carcinoma located in the mandibular region is difficult on clinical grounds.

Oral lichen planus (OLP) is an oral counterpart or oral manifestation of the common skin disease lichen planus. Chronic junctional stomatitis (CJS) is a relatively unknown condition characterized by a stromal lymphocyte infiltrate, which is also a diagnostic feature of OLP. The differential diagnosis of OLP and CJS is unclear and they have been suggested to represent variants of the same disease.To investigate possible differences in lymphocyte (sub)populations between these two conditions, we immunostained 10 OLP and 10 CJS specimens for CD1-a, and the lymphocyte markers, CD3, CD4, CD5, CD8, and CD20. We scored the staining results by a four-step grading system and used the Fisher exact test to analyze them statistically.The proportional amount of (CD20 positive) B lymphocytes was higher in CJS than in OLP and the predominance of CD4 positive T lymphocytes over CD8 positive T lymphocytes was stronger in OLP than in CJS. The differences were statistically significant.The results reflect differences in the lymphatic infiltrate between OLP and CJS. Their significance needs further investigation.

Wegener's granulomatosis (WG) is a rare granulomatous necrotizing vasculitis of small vessels, affecting vascular structures having predilection for upper airways. If untreated WG can be lethal. WG is also known to cause oral mucosal lesions. We report a case of WG that was first diagnosed on oral gingival mucosa. A 51-year old woman was referred to a specialized dentist because of consistent irritative buccal gingival hyperplasia that did not react to conservative and microbial treatment. The lesion was biopsied and the diagnosis was suggestive for WG. Patient was further referred to the Department of Rheumatology and the diagnose of WG was confirmed and treated. The oral lesions cured totally. This case emphasizes the importance to recognize the oral manifestation of WG to get proper medication as soon as possible and avoid serious systemic tissue damage.

Tissue lesions from eight patients with recurrent oral ulcers (ROU) were subjected to detailed immunohistopathologic studies. In five patients, a specimen of an unaffected area from the opposite site was obtained. The main inflammatory cells in situ were CD3 positive T lymphocytes, with CD4 cells forming approximately half (range 30-60%) and CD8 cells 20% (range 10-30%) of all cells. CD19 positive B lymphocytes formed 5-12% of all cells. Furthermore, 45% (range 15-65%) of all lymphoid cells had signs of previous antigenous contact and had helper/inducer CDw29 type. Suppressor/inducer CD45R cells formed only about 20% (range 7-50%) of all cells. Although this observation suggests involvement of antigen as a causative and/or triggering stimulus, elements of a non-specific inflammatory response were observed as well. Endogenous peroxidase-positive neutrophils were present at the ulcer site, and were occasionally observed intravascularly and in the extracellular matrix in areas characterized by inflammatory mononuclear cell infiltrates. Although the proportion of endogenous peroxidase-positive, recently recruited monocytes was low, CD11b and nonspecific esterase-positive mature tissue macrophages formed about 14% (range 5-35%) of all inflammatory cells in situ, particularly at the periphery of the lymphoid cell infiltrates. Mast cells were also observed in all samples studied, forming 2-5% of inflammatory cells in the richly vascularized connective tissue beneath the basement membrane. In the specimens from clinically unaffected areas, inflammatory cells were rare. Our observations stress the multifaceted nature and participation of multiple effector systems in the local tissue pathogenesis of ROU.

Bone grafts are used for bone augmentation to ensure optimal implant placement. However, this procedure may sometimes cause sinusitis. The case of a 44-year-old woman with the diagnosis of recurrent and chronic sinusitis of her right maxillary sinus with a history of dental implant surgery is presented. After several attempts with normal standard sinusitis therapy, unrecognized bone substitute was removed from the sinus cavity, which finally led to resolution of the sinusitis. This case reiterates the importance of a careful examination, consultation, and second opinion for the selection of optimal treatment.

T lymphocyte-antigen-presenting cell (APC) interaction plays a central role in T lymphocyte activation and APC maturation. We therefore studied the CD1a-positive Langerhans cells with respect to receptor activator of nuclear factor kappa B ligand (RANKL)-positive cells in chronic hyperplastic candidosis (CHC).Tissue sections of CHC were compared with leukoplakia and healthy oral mucosa using RANKL and CD1a monoclonal antibodies in an avidin-biotin peroxidase complex protocol. Two different antigen-retrieval protocols, pepsin preincubation and Tris-EDTA heat treatment, were used.CD1a-positive Langerhans cells were in healthy and leukoplakia epithelium found in the middle layer, but in CHC in all layers of the epithelium, at the basement membrane and as mononuclear round cells in the lamina propria. Use of pepsin digestion enabled studies of mast cells and their activation in the form of degranulation of RANKL.The numerical, morphological and topographical versatility of the CD1a-positive Langerhans cells in CHC can be clarified by dendritic cell (DC) recruitment into the epithelium. RANK-positive and RANKL-sensitive DCs have ample opportunity to interact with local T lymphocytes. Use of an optimized antigen-retrieval protocol enabled demonstration of an active engagement (degranulation) of mast cells, which represent a rapidly available source of soluble RANKL.