A family-based genome-wide association study of recurrent aphthous stomatitis.

OBJECTIVES: The aetiology of recurrent aphthous stomatitis (RAS) remains unknown. Individuals may share features of genetic susceptibility, and there may also be a hereditary component. The aim was to identify patterns of association and segregation for genetic variants and to identify the genes and signalling pathways that determine the risk of developing RAS, through a family-based genome-wide association study (GWAS). SUBJECTS AND METHODS: DNA was extracted from buccal swabs of 91 individuals in 16 families and analysed in an Illumina core exome single nucleotide polymorphism (SNP) array. A family-based association test (dFAM) was used to derive SNP association values across all chromosomes. RESULTS: None of the final 288,452 SNPs reached the genome-wide significant threshold of 5 × 10-8 . The most significant pathways were the Ras and PI3K-Akt signalling pathways, pathways in cancer, circadian entrainment and the Rap 1 signalling pathway. CONCLUSIONS: This confirms that RAS is not monogenic but results as a consequence of interactions between multiple host genes and possibly also environmental factors. The present approach provides novel insights into the mechanisms underlying RAS and raises the possibility of identifying individuals at risk of acquiring this condition.

Increased levels of calprotectin in the saliva of patients with geographic tongue.

OBJECTIVE: We investigated whether patients with geographic tongue have increased salivary levels of calprotectin and whether there is a correlation between the salivary levels of calprotectin and interleukin 8 (IL-8), which is another marker of inflammation. METHODS: Twenty-three patients diagnosed with geographic tongue and 32 control subjects without oral mucosal lesions were included in the study. The patients with geographic tongue were classified based on clinical appearance and number of oral lesions. ELISAs were used to determine the levels of calprotectin and IL-8 in whole saliva samples. RESULTS: There was a statistically significant increase in the salivary output of calprotectin in patients with geographic tongue compared with the healthy controls (62 ± 9,1 vs. 37,5 ± 4,7 µg/min; p = .0134). Furthermore, the levels of calprotectin correlated positively with the number of oral lesions in patients with geographic tongue. There was also a significant and positive correlation between the salivary levels of calprotectin and IL-8, both for the patients with geographic tongue and the controls. CONCLUSION: This study supports the notion that GT is an inflammatory disease, in which the activation of neutrophils and production of calprotectin in the saliva may play roles in its pathogenesis.

Cooling of the oral mucosa to prevent adverse effects of chemotherapeutic agents: An in vitro study.

BACKGROUND: The cytotoxic effect of chemotherapeutic agents to the oral mucosa, as a side effect of cancer treatment, is a major problem. Cooling the oral mucosa using ice chips in conjunction with chemotherapy is known to reduce the severity of oral mucositis. However, although the use of ice chips is of clinical value, this method of cooling has inherent problems including discomfort for the patient, non-uniformity and fluctuations in cooling temperature throughout the oral cavity. Furthermore, despite being used clinically, it is not known what reduction in temperature is required to prevent oral mucositis. The aim of this study was therefore to determine in vitro if the cytotoxic effect of 5-fluorouracil (5-FU) on the oral mucosa could be reduced by lowering the temperature during chemotherapeutic treatment. METHODS: Tissue-engineered oral mucosal (TEOM) models were incubated at 20, 25, 30 or 35°C for 30 minutes followed by exposure to a clinically relevant concentration of 5-FU (162 µg/mL) for 2 hours and compared with untreated models (35°C). Cell viability and inflammatory cytokine production (IL-6 and TNF-α) were measured using PrestoBlue® and ELISA, respectively. RESULTS: TEOM models incubated at 20°C showed an increased cell viability and had a reduced IL-6 and TNF-α production compared to models treated with 5-FU incubated at 35°C. CONCLUSION: This study demonstrates a reduced cytotoxic effect to the TEOM by reducing the temperature of the tissue during chemotherapy treatment and suggests that decreasing the temperature to 20°C could have clinical advantages.

Mutations in the genes for keratin-4 and keratin-13 in Swedish patients with white sponge nevus.

BACKGROUND: White sponge nevus is a rare autosomal dominant disorder that affects the non-keratinised stratified squamous epithelium. Mutations in the genes that encode mucosa-specific keratin-4 and keratin-13 are strongly linked to the manifestation of white sponge nevus. This study involved mutational analysis of the genes encoding keratin-4 and keratin-13 in two Swedish families with white sponge nevus. METHODS: The diagnosis of white sponge nevus was based on disease history, clinical characteristics of the lesions and, in the majority of the cases, histopathological examination. Samples were collected from the affected buccal mucosa using buccal swabs. DNA was subsequently extracted and amplified using touchdown-PCR. The keratin-4 and keratin-13 genes were sequenced, and a genetic analysis was performed. RESULTS: A novel heterozygous missense mutation was identified in exon 1A of the keratin-4 gene in Family 2. In addition, previously reported heterozygous missense mutations were identified in the keratin-4 (E449K, A72V, Q156R, R208H) and keratin-13 (L115P) genes in both families. CONCLUSION: We describe a novel heterozygous missense mutation in the keratin-4 gene of a Swedish family with white sponge nevus. Our results support the notion that mutations in keratin-4 and keratin-13 are the underlying cause of white sponge nevus.

Saliva on the oral mucosa and whole saliva in women diagnosed with burning mouth syndrome.

OBJECTIVE: The aim of the study was to examine mucosal saliva and unstimulated (UWS) and stimulated (SWS) whole saliva secretion rates and associated factors, in 56 female patients diagnosed with BMS and age-matched control women. MATERIAL AND METHODS: Mucosal saliva was assessed using the Periotron® method and blood flow using laser Doppler flowmetry. Diseases, drug usage and xerostomia were registered using questionnaires. RESULTS: The patients with BMS displayed less lingual and whole saliva, and more hyposalivation, xerostomia diseases/disorders and drug usage, compared to the controls. Only a low SWS and xerostomia differed after adjusting for drugs and systemic diseases. Regression analyses suggested an importance of saliva affecting drugs for saliva on the tongue and for SWS, and the total number of drugs used for UWS. Lingual saliva and UWS were also associated with systemic diseases in the patients. Xerostomia was significantly associated with drug use and whole saliva for all subjects but not in separate analyses of the groups. CONCLUSION: Less saliva in patients with BMS could be related to more systemic diseases and medication and not to the syndrome per se. Xerostomia in the patients was not related to any of these factors.

Clinical characterization of women with burning mouth syndrome in a case-control study.

OBJECTIVE: Burning mouth syndrome (BMS) is a chronic orofacial pain disorder that is defined by a burning sensation in the oral mucosa. The aim of this study was to investigate the underlying factors, clinical characteristics and self-reported oral and general health factors associated with BMS. MATERIAL AND METHODS: Fifty-six women with BMS (mean age: 67.7) and their age-matched controls were included in the study. A general questionnaire, an OHRQL index and BMS-specific questionnaires were used. Each subject underwent an oral examination. RESULTS: The mean severity of the BMS symptoms (VAS, 0-100) was 66.2 (SD 19.7). Overall, 45% of the patients reported taste disturbances. More of the patients than the controls rated their general health, oral health and life situation as 'less satisfactory'. The patients also reported more frequently on-going medications, diseases/disorders, xerostomia, allergy and skin diseases. Except for more bruxofacets among the patients, there were no significant differences regarding signs of parafunction. In a multiple logistic regression analysis, xerostomia and skin diseases showed the strongest prediction for BMS and no significant effect was found for medication, allergy or bruxofacets. CONCLUSIONS: Skin diseases and xerostomia but not parafunction were strongly associated with BMS. Our findings provide the basis for additional studies to elucidate the causal factors of BMS.

The engagement of oral-associated lymphoid tissues during oral versus gastric antigen administration.

The role of oral-associated lymphoid tissues during induction of oral tolerance still remains elusive. Therefore, the aim was to compare T-cell activation and induction of tolerance to ovalbumin (OVA) presented through either of two routes; deposited into the oral cavity, or the stomach, thereby bypassing the oral cavity. OVA was administered by the oral or gastric route to BALB/c mice that had received OVA-specific DO11.10+ CD4(+) T cells, stained with CellTrace(™) Violet dye, through intravenous injection. Proliferating OVA-specific T cells were detected in the nose-associated lymphoid tissues (NALT) and the cervical, mesenteric and peripheral lymph nodes at different time-points following OVA exposure. OVA-specific T-cell proliferation was initially observed in the NALT 1 hr after oral, but not gastric, administration. However, at day 1, proliferation at this site was also detected after gastric administration and profound proliferation was observed at all sites by day 4. For the oral route the degree of proliferation observed was lower in the peripheral lymph nodes by day 4 compared with the other sites. These results demonstrate a similar activation pattern achieved by the two routes. However, the NALT distinguishes itself as a site of rapid T-cell activation towards fed antigens irrespective of feeding regimen. To evaluate induction of tolerance a semi-effective OVA dose was used, to detect differences in the degree of tolerance achieved. This was performed in a model of OVA-induced airway hypersensitivity. No differences in tolerance induction were observed between the two administration routes.

Factors associated with geographic tongue and fissured tongue.

OBJECTIVES: The primary objective of this study was to investigate the association of systemic diseases, use of medications, allergies and tobacco habits with geographic tongue (GT) and fissured tongue (FT) lesions. The secondary objectives were to evaluate the clinical characteristics of tongue lesions and to compare the overall results for referred and non-referred patients. METHODOLOGY: Non-referred patients with GT (GTgp; n = 130) and FT (FTgp; n = 62) were examined by general practitioners (gp) and compared to a control group without oral mucosal lesions (C; n = 1029). Referred patients with GT (GTs; n = 166) and FT (FTs; n = 15) were examined by oral medicine specialists (s) and compared to GTgp and FTgp. Statistical analyses were performed using unpaired t-test or Fisher's exact test. A multiple logistic regression model was developed to control for age and gender as confounders. RESULTS: Compared to the C group, GTgp patients used more anti-hypertensive medications and Swedish snus (p < 0.01). The GTgp group consisted of older males (p < 0.001) compared to C. Compared to the GTgp group, the GTs group was younger, more likely to have symptomatic lesions (p < 0.0001) and comprised of more females. Among the groups examined, FT patients had the highest mean age. CONCLUSION: This study identified an association between GT and anti-hypertensive medications, as well as the use of Swedish snus. It also found differences in the activities and symptoms of the lesions between referred patients and their counterparts who were seen in general dental practice; these parameters influenced the results when these conditions were taken into account.

Salivary mucin MUC7 oligosaccharides in patients with recurrent aphthous stomatitis.

OBJECTIVES: The aetiology of recurrent aphthous stomatitis remains unknown. In this study, we investigate the composition of oligosaccharides from mucin MUC7 in recurrent aphthous stomatitis as these heavily O-glycosylated mucins confer many of saliva's protective properties such as defence against mucosal pathogens. MATERIALS AND METHODS: Unstimulated whole saliva samples were collected from six individuals, three with recurrent aphthous stomatitis and three corresponding sibling, without this condition. Oligosaccharides from salivary MUC7 were isolated and analysed by liquid chromatography-tandem mass spectrometry. RESULTS: The types of oligosaccharides identified in the patients and control subjects were similar; however, statistical evaluation indicated semi-quantitative differences between specific oligosaccharide classes. These changes focused on a reduction in terminal glycan residues including fucosylation, sialylation and sulfation on galactose. CONCLUSIONS: This study was able to show differential MUC7 glycosylation in the patients suggesting functional changes to salivary mucins in this condition. The terminal glycans altered in disease have been shown to be important for a range of immunological and bacterial binding roles. Further investigation of these epitopes in a larger study may provide critical insights into the pathology of recurrent aphthous stomatitis. CLINICAL RELEVANCE: MUC7 glycosylation is altered in recurrent aphthous stomatitis. This may change the protective properties of this mucin against mucosal pathogens, which may effect this condition.

Immunophenotype in orofacial granulomatosis with and without Crohn's disease.

OBJECTIVES: The aim of this investigation was to characterise and compare the inflammatory infiltrates in patients with orofacial granulomatosis solely (OFG-S) and OFG with coexisting Crohn's disease (OFG+CD). STUDY DESIGN: Biopsy specimens with granulomas were obtained from patients with OFG-S (n=11) and OFG+CD (n=11) and immunostained with antibodies against CD1a, CD3, CD4, CD8, CD11c, CD20, CD68 and mast cell tryptase, followed by quantitative analysis. RESULTS: Analyses of the connective tissue revealed a significantly higher number of CD3-expressing T cells and CD11c-expressing dendritic cells in the connective tissue of patients with OFG-S compared to patients with OFG+CD. Mast cells displayed a high level of activation, although no significant difference was detected when comparing the two groups. CONCLUSIONS: The results show a different composition of the inflammatory infiltrate in patients with OFG-S compared to patients with OFG+CD. The present observations support that partly-divergent immune mechanisms are involved in these two different subcategories of OFG.

The morbidity of oral mucosal lesions in an adult Swedish population.

OBJECTIVE: To study the severity of symptoms and estimate the prevalence of oral mucosal lesions in a non-referral adult Swedish population, as registered by general dental practitioners. This study also aims to evaluate the possibility of dental practitioners collecting large quantities of reliable and accurate clinical data on oral mucosal lesions. STUDY DESIGN: Data from 6,448 adult Swedish patients were collected by general dental practitioners using a standardized registration method. A correlation analysis between a group with oral mucosal lesions and a control group, with no oral mucosal lesions, was performed for various parameters such as symptoms from the oral mucosa, systemic diseases, medication, allergy history, tobacco habits and the patient's own assessment of their general health. In addition, clinical photos were taken of all oral mucosal lesions in order to determine the degree of agreement between the diagnoses made by general dental practitioners and those made by oral medicine specialists. RESULTS: A total of 950 patients (14.7%) presented with some type of oral mucosal lesion and of these, 141 patients (14.8%) reported subjective symptoms. On a visual analogue scale, 43 patients (4.5%) scored their symptoms <30, 65 patients (6.8%) scored their symptoms ≥30, and 28 patients (2.6%) scored their symptoms ≥60. The most debilitating condition was aphthous stomatitis and the most common oral mucosal lesion was snuff dipper's lesion (4.8%), followed by lichenoid lesions (2.4%) and geographic tongue (2.2%). There was agreement between the oral medicine specialists and the general practitioners over the diagnosis of oral mucosal lesions on the basis of a clinical photograph in 85% of the cases (n=803). CONCLUSIONS: Nearly 15% of the patients with oral mucosal lesions reported symptoms. General practitioners could contribute significantly to the collection of large quantities of reliable and accurate clinical data, although there is a risk that the prevalence of oral mucosal lesions may be underestimated.

Efficacy of a novel device for cryoprevention of oral mucositis: a randomized, blinded, multicenter, parallel group, phase 3 trial.

Cryoprevention (CP) using ice (IC) is an effective strategy to prevent chemotherapy-induced oral mucositis (OM). However, the use of IC may cause adverse reactions and requires water of safe quality to minimize risk of serious infections. This randomized, blinded, parallel group, phase 3 trial was conducted in five Scandinavian centers. Eligible patients were diagnosed with multiple myeloma or lymphoma, scheduled to receive conditioning with high-dose chemotherapy prior to autologous hematopoietic stem cell transplantation (ASCT). Patients were assigned to cooling with IC or a novel intraoral cooling device (ICD). The primary outcome was the highest OM score during the study period, expressed as peak value on the Oral Mucositis Assessment Scale (OMAS-total). When the entire study population (n = 172) was analyzed for peak OMAS-total, the two cooling methods were equally effective. However, when the lymphoma group was analyzed separately, the ICD significantly reduced the peak OMAS-total score to a greater extent compared to IC (x̄ ± SD; 1.77 ± 1.59 vs. 3.08 ± 1.50; p = 0.047). Combined with existing evidence, the results of the present trial confirm that CP is an effective method to prevent OM. ClinicalTrials.gov. NCT03203733.

Orofacial granulomatosis in childhood-a clinical entity that may indicate Crohn's disease as well as food allergy.

AIM: Orofacial granulomatosis (OFG) is a rare clinical entity with orofacial swelling in association with oral lesions such as mucosal oedema, ulcerations and mucosal tags. The aim of this prospective study was to evaluate the connection between OFG in childhood and systemic disease. METHODS: During a 3-year period, eight children (9-16 years old) who had been referred to the clinic of oral medicine were diagnosed solely with OFG. Thus, none of them had any known systemic disease or gastrointestinal symptoms at the time of referral. The children were then medically examined and followed up for 6-8 years at the department of paediatrics for systemic disease with specific emphasis on inflammatory disorders elsewhere in the gastrointestinal tract. RESULTS: During follow-up, four patients were diagnosed with Crohn's disease (CD). Further, one girl was found to have a food allergy-induced OFG, with delayed-type hypersensitivity to oats. One boy developed both diabetes and celiac disease during the follow-up. Only two patients had no diagnosis of systemic disease at the end of the observation period. CONCLUSION: OFG in childhood seems to be frequently related to systemic disease, and children with OFG should be referred to a paediatrician for examination and follow-up.

Oral infections and their influence on medical rehabilitation in kidney transplant patients.

Infections seem to be the most common life-threatening complication of long-term immunosuppressive therapy following organ transplantation. Although sparse scientific evidence, potential oral infections are considered to contribute to these complications. The aim of this study was to examine whether there is an association between oral infections and rejections after kidney transplantation. A group of 46 kidney transplant candidates was enrolled. The patients were examined clinically and radiographically for dental caries, periodontal disease, mucosal lesions/infections, and general oral health problems. Examinations were conducted the day before transplantation, and one year post transplantation. Fifteen (32.6%) patients developed acute rejections during the first year. Six of these patients (40%) presented with oral opportunistic infections (candida or herpes infections of the oral mucosa). The number of dental infections and semi-impacted teeth were low. When rejections were related to probing pocket depths (PPDs) > or = 4 mm and apical lesions together, statistical significance was not reached (p=0.075, OR=3.17 [0.87; 11.55]). Similar results were obtained when PPDs > or = 4 mm, apical lesions, semi-impacted teeth, and opportunistic mucosal infections were compared to rejections. The results of the present study do not support that opportunistic oral mucosal infections or dental-related infections seem to increase the risk of rejection in kidney transplanted patients.

Reduced sialyl-Lewisx on salivary MUC7 from patients with burning mouth syndrome.

We analysed and compared MUC7 O-glycosylation and inflammatory biomarkers in saliva from female patients with burning mouth syndrome (BMS) and gender/age-matched controls. Oligosaccharides from salivary MUC7 from BMS and controls were released. Inflammatory mediators were measured by multiplex proximity extension assay. Presence of sialyl-Lewisx (Si-Lex) epitope on MUC7 was confirmed using Western blot. MUC7 O-glycans and measured inflammatory biomarkers were found to be similar between BMS and controls. However, oligosaccharides sialyl-Lewisx (Si-Lex) was found to be reduced in samples from BMS patients. Positive correlation (combined patients and controls) was found between levels of C-C motif chemokine 19 (CCL-19) and the amount of core-2 oligosaccharides on MUC7 as well as fractalkine (CX3CL1) and level of sialylation. Patients with BMS were shown to represent a heterogeneous group in terms of inflammatory biomarkers. This indicates that BMS patients could be further stratified on the basis of low-level inflammation. The results furthermore indicate that reduced sialylation of MUC7, particularly Si-Lex, may be an important feature in patients with BMS. However, the functional aspects and potential involvement in immune regulation of Si-Lex remains unclear. Our data suggests a chemokine driven alteration of MUC7 glycosylation.

Osteonecrosis of the jaw and bisphosphonate treatment for osteoporosis.

A potential side effect associated with bisphosphonates, a class of drugs used in the treatment of osteoporosis, Paget's disease and metastatic bone disease, is osteonecrosis of the jaw (ONJ). The incidence of ONJ in the general population is unknown; this rare condition also may occur in patients not receiving bisphosphonates. Case reports have discussed ONJ development in patients with multiple myeloma or metastatic breast cancer receiving bisphosphonates as palliation for bone metastases. These patients are also receiving chemotherapeutic agents that might impair the immune system and affect angiogenesis. The incidence or prevalence of ONJ in patients taking bisphosphonates for osteoporosis seems to be very rare. No causative relationship has been unequivocally demonstrated between ONJ and bisphosphonate therapy. A majority of ONJ occurs after tooth extraction. Furthermore, the underlying risk of developing ONJ may be increased in osteoporotic patients by comorbid diseases. Treatment for ONJ is generally conservative.

Amount and type of alcohol and periodontitis in the Copenhagen City Heart Study.

AIM: The aim of this study was to study the association between alcohol consumption and periodontitis assessed as clinical attachment loss (CAL) and bleeding on probing (BOP) in a cross-sectional design. MATERIAL AND METHODS: The study included 1,521 adults aged 20-95 years, who underwent an oral examination including full-mouth registration of CAL and BOP. Alcohol was ascertained using a food-frequency questionnaire. The association between total and type-specific alcohol and periodontitis was assessed by means of multivariate logistic regression. RESULTS: A lower odds ratio (OR) for CAL (defined as mean >or=3 mm) was observed in men consuming 21-34 [OR=0.51, 95% confidence interval (CI), 0.27-0.95] and 35+ drinks/week (OR=0.34, 95% CI, 0.15-0.79) compared with men drinking 1-13 drinks/week. Also, men with a weekly wine consumption of more than 14 drinks compared with men who reported no wine intake had lower OR for CAL (OR=0.24; 95% CI, 0.09-0.62). A higher OR for BOP (defined as >or=25%) among male abstainers was observed (OR=1.79, 95% CI, 1.03-3.12) compared with men in the light-drinking group (1-13 drinks/week). No significant association was observed for either CAL or BOP in women. CONCLUSIONS: The results indicate that higher alcohol consumption, particularly intake of wine, is inversely associated with CAL in men. Such an association is not found in women.

SOMWeb: a semantic web-based system for supporting collaboration of distributed medical communities of practice.

BACKGROUND: Information technology (IT) support for remote collaboration of geographically distributed communities of practice (CoP) in health care must deal with a number of sociotechnical aspects of communication within the community. In the mid-1990s, participants of the Swedish Oral Medicine Network (SOMNet) began discussing patient cases in telephone conferences. The cases were distributed prior to the conferences using PowerPoint and email. For the technical support of online CoP, Semantic Web technologies can potentially fulfill needs of knowledge reuse, data exchange, and reasoning based on ontologies. However, more research is needed on the use of Semantic Web technologies in practice. OBJECTIVES: The objectives of this research were to (1) study the communication of distributed health care professionals in oral medicine; (2) apply Semantic Web technologies to describe community data and oral medicine knowledge; (3) develop an online CoP, Swedish Oral Medicine Web (SOMWeb), centered on user-contributed case descriptions and meetings; and (4) evaluate SOMWeb and study how work practices change with IT support. METHODS: Based on Java, and using the Web Ontology Language and Resource Description Framework for handling community data and oral medicine knowledge, SOMWeb was developed using a user-centered and iterative approach. For studying the work practices and evaluating the system, a mixed-method approach of interviews, observations, and a questionnaire was used. RESULTS: By May 2008, there were 90 registered users of SOMWeb, 93 cases had been added, and 18 meetings had utilized the system. The introduction of SOMWeb has improved the structure of meetings and their discussions, and a tenfold increase in the number of participants has been observed. Users submit cases to seek advice on diagnosis or treatment, to show an unusual case, or to create discussion. Identified barriers to submitting cases are lack of time, concern about whether the case is interesting enough, and showing gaps in one's own knowledge. Three levels of member participation are discernable: a core group that contributes most cases and most meeting feedback; an active group that participates often but only sometimes contribute cases and feedback; and a large peripheral group that seldom or never contribute cases or feedback. CONCLUSIONS: SOMWeb is beneficial for individual clinicians as well as for the SOMNet community. The system provides an opportunity for its members to share both high quality clinical practice knowledge and external evidence related to complex oral medicine cases. The foundation in Semantic Web technologies enables formalization and structuring of case data that can be used for further reasoning and research. Main success factors are the long history of collaboration between different disciplines, the user-centered development approach, the existence of a "champion" within the field, and nontechnical community aspects already being in place.

Collaboration patterns in an online community of practice in oral medicine.

SOMWeb is an online collaboration system based on Semantic Web technologies, which is used for knowledge sharing and dissemination within an oral medicine community in Sweden. Based on a previous study of the use of SOMWeb, general patterns of interaction and communicative activities involved in community collaboration have been identified. The patterns for one such activity, distance consultation, are described and modeled using techniques from the Pragmatic Web. It is also shown how patterns could inform system design.