Expression of CLLD7 and CHC1L Proteins in Oral Epithelial Dysplasia in a Group of Thai Patients.

OBJECTIVES: Previous study showed aberrant CLLD7 and CHC1L protein expression in oral squamous cell carcinoma (OSCC) compared to normal oral mucosa (NOM). This study aimed to evaluate the expression of these proteins in oral epithelial dysplasia (OED). MATERIALS AND METHODS: Forty specimens of OED and 11 NOM were used. The expression of CLLD7 and CHC1L was determined by immunohistochemistry. In each case, at least 1000 cells were counted. Presence of nuclear, cytoplasmic, and/or membrane staining of CLLD7 and CHC1L were considered positive. Percentages of total positive cells and positive cells at different locations were recorded. SPSS version 18 was used to compare variation between groups with statistical significance at p<0.05. RESULTS: No significant differences in the percentages of total positive cells of CLLD7 and CHC1L were found between NOM and all grades of OED. Nevertheless, there were significant differences in subcellular staining of these two proteins. In CLLD7, the nuclear staining of the moderate and the severe OED groups was significantly lower than that of the NOM group (p<0.05). The percentages of membrane staining of CHC1L in moderate and severe OED were significantly higher than that of NOM (p<0.001). In addition, the nuclear staining of CHC1L in each grade of OED was significantly lower than that of NOM (p<0.05). CONCLUSION: The subcellular mislocalization of CLLD7 and CHC1L in OED suggests that the expression of these potential tumor suppressor proteins might be dysregulated during the dysplastic process. The distinct membrane staining of CHC1L observed in OED but not in NOM is a useful characteristic that can be used to separate OED from NOM. Thus, CHC1L may be a good marker to assist in the diagnosis of OED.

Distribution of Epstein-Barr virus in the oral cavity of Thais with various oral mucosal conditions.

Objectives: We aimed to examine the presence of EBV, EBV strains, and variants among 3 oral conditions including normal oral mucosa (NOM), oral potentially malignant disorders/oral cancer (OPMDs/OC) and non-OPMDs/OC in a group of Thais. Material and methods: Oral exfoliated cells were obtained from 315 participants living in the northeastern and central regions of Thailand. The participants were divided into 3 groups encompassing the NOM, the OPMDs/OC and the non-OPMDs/OC groups. The presence of EBV was first determined by PCR using primers for LMP1 gene. Subsequently, EBV strains of EBNA3c and variants based on LMP1 sequences were determined by real-time PCR. Results: The prevalence of EBV in OPMDs/OC, non-OPMDs/OC and NOM were 72.0 %, 56.2 %, and 27.2 % respectively. EBV type A, B and AB were found in 52.1 %, 32.1 % and 15.8 % of all positive samples, respectively. The percentage of participants with EBV type A was more prominent in the NOM group (72.0 %) compared to the non-OPMDs/OC (54.8 %) and the OPMDs/OC group (41.8 %) whereas EBV type B was higher in the OPMDs/OC group (35.8 %) compared to the non-OPMDs/OC (31.5 %) and the NOM (24.0 %) groups. Regarding EBV variants, 30-bp deletion LMP1 variant (del-LMP1) which is more associated with malignant transformation was predominately found in the OPMDs/OC (32.8 %) and the non-OPMDs/OC (38.4 %) groups compared to the NOM group (20.0 %). Conclusions: High frequency of EBV was demonstrated in the OPMDs/OC group. EBV type A was more predominant in the NOM group whereas EBV type B was more prevalent in the OPMDs/OC group. The del-LMP1 variant was more common in the OPMDs/OC and the non-OPMDs/OC groups.

Preliminary Study on the Expression of CLLD7 and CHC1L Proteins in Oral Squamous Cell Carcinoma.

OBJECTIVE: This study aimed to preliminarily evaluate the expression of two putative tumor suppressor proteins, including chronic lymphocytic leukemia deletion gene 7 (CLLD7) and chromosome condensation 1-like (CHC1L) proteins in oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Expression of CLLD7 and CHC1L proteins was analyzed in 19 OSCC and 12 normal oral mucosa (NOM) using immunohistochemistry. The percentage of positive cells and intensity of staining were semiquantitatively assessed and expressed with an immunoreactive score. The number of positive cells at various subcellular localizations was evaluated and presented in percentages. The immunoreactivity scores and percentages of positive cells at various localizations were compared between the normal and OSCC groups with statistical significance at p-value less than 0.05. RESULTS: According to immunohistochemical analysis, the immunoreactivity scores for both CLLD7 and CHC1L were higher in NOM than those of OSCC. Analysis of CLLD7 localization revealed predominant nuclear staining at basal and parabasal areas in NOM, whereas more cytoplasmic staining was observed in OSCC. For CHC1L, nuclear staining was prominent in NOM. In contrast, significantly increased plasma membrane staining was detected in OSCC. CONCLUSION: The expression of CLLD7 and CHC1L proteins was reduced in OSCC. Alterations in the subcellular localization of these two proteins in OSCC were also demonstrated. These preliminary results suggest that CLLD7 and CHC1L are aberrantly expressed in OSCC. The precise mechanisms of these putative tumor suppressor proteins in OSCC require future studies.

Presence of Candida and its associated factors in participants attending oral cancer screening in the lower northeastern area of Thailand.

BACKGROUND: Certain evidence indicated high prevalence of Candida in oral potentially malignant disorders (OPMDs) and oral cancer (OC). This study was aimed to investigate the presence of Candida and its associated factors in participants who attended the oral cancer screening program in the lower northeastern districts of Thailand. METHODS: Convenient participants residing in the lower northeastern districts of Thailand who attended the oral cancer screening were enrolled. A questionnaire retrieving demographic characteristics, risk factors of oral cancer, and risk of having Candida was completed. Oral examination was performed by oral medicine specialists or oral surgeons. The participants were categorized into 4 groups according to their clinical diagnosis, namely normal oral mucosa (NOM), OPMDs/OC, non-OPMDs/OC and clinically suspected oral candidiasis (CSOC). Stimulated saliva flow rate was measured. Dip-slide test was performed in each participant to evaluate the presence of Candida. The levels of Candida were categorized into high and low levels according to the score received from the dip-slide test. Factors associated with high levels of Candida were identified using multivariate logistic regression analysis. RESULTS: A total of 577 participants were recruited. High levels of Candida were found in 31.3%, 24.7%, 25.9% and 18.1% in the OPMDs/OC, the non-OPMDs/OC, the CSOC and the NOM groups, respectively. According to multivariate logistic regression analysis, age above 60 years, female gender, betel quid chewing habit, use of denture, hyposalivation, and being in the CSOC group were found to be significantly associated with high levels of Candida. CONCLUSION: Higher number of participants in the OPMDs/OC group was found to have high levels of Candida. Increasing age, female gender, betel quid chewing habit, use of denture, hyposalivation and having CSOC lesions were associated with high levels of Candida.

Epstein-Barr Virus Detection and LMP-1 Expression in Thai Patients with Oral Squamous Cell Carcinoma.

BACKGROUND: To date, high-risk human papillomavirus (HPV) is primarily linked to oropharyngeal carcinoma, but only a small subset of oral squamous cell carcinoma (OSCC) is truly driven by high-risk HPV. In addition, Epstein-Barr virus (EBV) is another potential oncogenic virus for OSCC development. This study aims to investigate the role of EBV infection in Thai patients with OSCC. METHODS: Forty-seven formalin-fixed paraffin-embedded specimens of OSCC were obtained. EBV DNA was detected by polymerase chain reaction analysis using primers for LMP-1 region of EBV. EBV-positive OSCC cases were subjected to LMP-1 immunohistochemical analysis and EBV-encoded small RNA (EBER) in situ hybridization to determine EBV cellular localization in OSCC. LMP-1 immunohistochemical analysis was also performed in all EBV-negative OSCC cases. RESULTS: Of the 47 OSCC specimens, ten (21%) exhibited EBV DNA by PCR analysis. Seven of ten (70%) EBV-positive specimens showed high-grade LMP-1 expression by immunohistochemistry. However, no EBER expression was detected in all EBV-positive OSCC specimens. In EBV-negative specimens, LMP-1 was also negative except in 3 specimens which showed low grade expression of LMP-1. CONCLUSION: The prevalence of EBV infection in OSCC in this group of Thai patients was 21%. Most of EBV-positive OSCC cases showed LMP-1 expression but a lack of EBER expression. From our findings, we presume that EBV may take some roles in OSCC development in this group of participants.

Histopathological and risk factor analyses of oral potentially malignant disorders and oral cancer in a proactive screening in northeastern Thailand.

BACKGROUND: Lip and oral cavity cancer has been reported as the 10th most common cancer in Thailand. Recently, a screening program for oral potentially malignant disorders (OPMDs) and oral cancer was conducted in the northeastern Thailand which took into consideration a total of 371,911 people who resided in the provinces of Buriram, Chaiyaphum, Nakhon Ratchasima, and Surin. METHODS: A total of 330,914 subjects were consecutively screened for risk factors of oral cancer by village health volunteers (VHVs) using a questionnaire (S1). Then, 186,710 subjects with one or more risk factors for oral cancer were referred for oral screening by dental auxiliaries or dentists at sub-district level hospitals (S2) where 86,941 subjects were subsequently screened. Afterwards, 1576 subjects with suspicious oral lesions for OPMDs or oral cancer attended local hospitals for further investigation and treatment. Oral medicine specialists, oral surgeons, and local dentists at the district level hospitals performed biopsies and the samples were sent for histopathological analysis. The objectives of the study were to report the histopathology findings from the biopsies obtained from these subjects and the associated risk factors. RESULTS: Out of 427 subjects who received biopsies, complete diagnostic results were obtained from 409 patients (462 specimens). The 5 most common histopathological results from these specimens were mild epithelial dysplasia (27.3%), fibroepithelial hyperplasia (14.5%), oral lichen planus/oral lichenoid reactions (11.5%), moderate epithelial dysplasia (8%), and acanthosis with or without hyperkeratosis (5%). Oral squamous cell carcinoma was detected in 14 subjects and 11 other forms of oral cancer were revealed. Among the analyzed risk factors, habitual betel quid chewing was established as a statistically significant risk factor associated with OPMDs and oral cancer. CONCLUSION: The most frequently observed histopathological results of clinically suspected oral cancer and OPMDs included mild epithelial dysplasia, fibroepithelial hyperplasia, oral lichen planus/oral lichenoid reactions, moderate epithelial dysplasia, and acanthosis with or without hyperkeratosis. Betel quid chewing habit was found to be associated with OPMDs and oral cancer.

Dentists' Attitudes toward Diabetes Mellitus Screening in Thai Dental Clinics.

Diabetes mellitus (DM), especially type 2 DM, has become a common problem worldwide. Previous studies have demonstrated that chairside screening can effectively identify undetected type 2 DM patients. This study was conducted to determine dentists' attitudes toward DM screening in dental clinics. A total of 632 currently active dentists with more than 1 year of working experience participated. The six-part (importance, barriers, willingness, readiness, knowledge, and routine management) anonymous, self-administered questionnaire of five-point response scales was then distributed. The results illustrated that most dentists (86.3%) realized the importance of DM screening and that patients' willingness was the main potential barrier (86.4%). Of the respondents, 98.1% and 82.4% were willing to measure blood pressure and weight and height for their patients, whereas only 45.4% and 38.8% were willing to collect blood from the fingertip or oral fluids for salivary diagnostics, respectively. Moreover, 73.7% of respondents were ready to refer patients to physicians, and 59.5% could explain the relationship between DM and oral diseases. However, only 44.3% and 27.9% were prepared to provide education about DM awareness or were able to perform screening, respectively. In addition, 67.2% and 65.8% knew the screening criteria and risk factors of DM, respectively, but only 45.1% knew what to do. The result of our study provided essential knowledge with respect to dentists' attitudes in the screening for DM in Thai dental clinics.

Detection of Human Papillomavirus and p16INK4a Expression in Thai Patients with Oral Squamous Cell Carcinoma.

This study investigated the prevalence of human papillomavirus (HPV) infection in oral squamous cell carcinoma (OSCC) cases, as well as the association between HPV presence and p16INK4a expression, in Thai patients with OSCC. Eighty-one formalin-fixed paraffin-embedded specimens of OSCC were obtained. DNA extraction was performed; this was followed by nested polymerase chain reaction analysis to determine HPV DNA status, using consensus primers for the L1 region of HPV. HPV subtypes were determined by DNA sequencing. HPV-positive specimens and HPV-negative specimens from age- and sex-matched patients were subjected to immunohistochemical analysis to determine p16INK4a expression status. Of the 81 OSCC specimens, eight (9.9%) exhibited HPV DNA; DNA sequencing confirmed that the viral subtype was HPV-18 in all eight specimens. These eight HPV-positive specimens, as well as eight HPV-negative specimens from age- and sex-matched patients, were subjected to immunohistochemical analysis to determine p16INK4a expression status. Three of eight (37.8%) HPV-positive specimens and three of eight (37.8%) HPV-negative specimens showed positive p16INK4a expression findings. However, we did not find a significant association between HPV status and p16INK4a expression status in our OSCC samples. In conclusion, the prevalence of high-risk HPV was low in this group of OSCC patients; no association between HPV status and p16INK4a expression status was identified.

Erratum: Suwattipong et al. Comparison of Point-of-Care Testing and Hospital-Based Methods in Screening for Potential Type 2 Diabetes Mellitus and Abnormal Glucose Regulation in a Dental Setting. Int. J. Environ. Res. Public Health 2021, 18, 6459.

In the original article [...].

Pilot Model for Community Based Oral Cancer Screening Program: Outcome from 4 Northeastern Provinces in Thailand.

Management of advanced-stage oral cancer adds a great burden to individuals and health care systems. Community-based oral cancer screening can be beneficial in early detection and treatment. In this study, a novel oral cancer screening program was conducted utilizing an existing network of health care personnel, facilities, and digital database management for efficient coverage of a large population. The screening program considered 392,396 individuals aged ≥40 from four northeastern provinces in Thailand. Three levels of screening were performed: S1 by village healthcare volunteers to identify risk groups, S2 by dental auxiliaries to visually identify abnormal oral lesions, and S3 by dentists for final diagnosis and management. A total of 349,318 individuals were interviewed for S1, and 192,688 were identified as a risk group. For S2, 88,201 individuals appeared, and 2969 were further referred. Out of 1779 individuals who appeared for S3, oral potentially malignant disorders (OPMDs) were identified in 544, non-OPMDs in 1047, doubtful lesions in 52, and no results in 136 individuals. Final treatment was carried out in 704 individuals that included biopsies of 504 lesions, exhibiting 25 cancerous lesions and 298 OPMDs. This study is so far one of the largest oral cancer screening programs conducted in Thailand and showed effective implementation of community-based oral cancer screening.

The Relationship of Tobacco, Alcohol, and Betel Quid with the Formation of Oral Potentially Malignant Disorders: A Community-Based Study from Northeastern Thailand.

This study's objective was to describe the relationship between the main risk factors for oral cancer, including tobacco (in the form of cigarettes, smokeless tobacco (SLT), secondhand smoking (SS)), alcohol, and betel quid (BQ), and the occurrence of oral potentially malignant disorders (OPMDs). A community-based case-control study was conducted with a population of 1448 adults aged 40 years or above in northeastern Thailand. Patients aged 60 years or above (OR 1.79, p < 0.001) and female patients (OR 2.17, p < 0.001) had a significant chance of having OPMDs. Our multivariate analysis showed that the most potent risk factor for OPMDs occurrence was betel quid (BQ) (adjusted OR 4.65, p < 0.001), followed by alcohol (OR 3.40, p < 0.001). Even former users were at risk of developing OPMDs. The synergistic effect between these main risk factors was significantly shown in the group exposed to SLT, SS, BQ, and alcohol. The most potent synergistic effect was found in the group exposed to SLT, BQ and alcohol with the OR = 20.96.

Oral Bacterial Microbiomes in Association with Potential Prediabetes Using Different Criteria of Diagnosis.

This study aimed to find a potential biomarker that can be used to diagnose prediabetic condition by comparing the salivary bacterial microbiomes between Thai dental patients with normoglycemia (NG) and those with potential prediabetes (PPG) conditions. Thirty-three subjects were randomly recruited. Demographic data were collected along with oral examination and unstimulated salivary collections. The salivary bacterial microbiomes were identified by high-throughput sequencing on the V3-V4 region of the bacterial 16S rRNA gene. Microbiomes in this study were composed of 12 phyla, 19 classes, 29 orders, 56 families, 81 genera, and 184 species. To check the validity of the selection criterion for prediabetes, we adopted two separate criteria to divide samples into PPG and NG groups using glycated hemoglobin A1c (HbA1c) or fasting plasma glucose (FPG) levels. Using the HbA1c level resulted in the significant reduction of Alloprevotella, Neisseria, Rothia, and Streptococcus abundances in PPG compared with those in NG (p-value < 0.05). On the other hand, the abundance of Absconditabacteriales was significantly reduced whereas Leptotrichia, Stomatobaculum, and Ruminococcaceae increased in the PPG group when the samples were classified by the FPG level (p-value < 0.05). It is implied that the group classifying criterion should be carefully concerned when investigating relative abundances between groups. However, regardless of the criteria, Rothia is significantly dominant in the NG groups, suggesting that Rothia might be a potential prediabetic biomarker. Due to the small sample size of this study, further investigation with a larger sample size is necessary to ensure that Rothia can be a potential biomarker for prediabetes in Thai people.

Comparison of Point-of-Care Testing and Hospital-Based Methods in Screening for Potential Type 2 Diabetes Mellitus and Abnormal Glucose Regulation in a Dental Setting.

This study aimed to compare the screening methods between point-of-care (POC) testing and hospital-based methods for potential type 2 DM and abnormal glucose regulation (AGR) in a dental setting. A total of 274 consecutive subjects who attended the Faculty of Dentistry, Mahidol University, Bangkok, Thailand, were selected. Demographic data were collected. HbA1c was assessed using a finger prick blood sample and analyzed with a point-of-care (POC) testing machine (DCA Vantage®). Hyperglycemia was defined as POC HbA1c ≥ 5.7%. Random blood glucose (RBG) was also evaluated using a glucometer (OneTouch® SelectSimple™) and hyperglycemia was defined as RBG ≥ 110 mg/dl or ≥140 mg/dl. The subjects were then sent for laboratory measurements for fasting plasma glucose (FPG) and HbA1c. The prevalence of AGR (defined as FPG ≥ 100 mg/dl or laboratory HbA1c ≥ 5.7%) and potential type 2 DM (defined as FPG ≥ 126 mg/dl or laboratory HbA1c ≥ 6.5%) among subjects was calculated and receiver operating characteristic (ROC) analysis was performed using FPG and HbA1c for the diagnosis of AGR and potential type 2 DM. The prevalence of hyperglycemia defined as POC HbA1c ≥ 5.7%, RBG ≥ 110 mg/dl, and RBG ≥ 140 mg/dl was 49%, 63%, and 32%, respectively. After the evaluation using laboratory measurements, the prevalence of AGR was 25% and 17% using laboratory FPG and HbA1c criteria, respectively. Based on the ROC curves, the performances of POC HbA1c and RBG in predicting FPG-defined potential type 2 DM were high (AUC = 0.99; 95% CI 0.98-0.99 and AUC = 0.94; 95% CI 0.86-1.0, respectively) but lower in predicting AGR (AUC = 0.72; 95% CI 0.67-0.78 and AUC = 0.65; 95% CI 0.59-0.70, respectively). This study suggested that POC testing might be a potential tool for screening of subjects with potential type 2 DM in a dental setting.

Salivary and serum interleukin-17A and interleukin-18 levels in patients with type 2 diabetes mellitus with and without periodontitis.

OBJECTIVE: Interleukin (IL)-17A and IL-18 have been proposed to play important roles in periodontitis and type 2 diabetes mellitus (DM), but human data are conflicting. The present study aimed to investigate the roles of IL-17A and IL-18 in periodontitis and DM by measuring salivary and serum levels, respectively. MATERIALS AND METHODS: A total of 49 participants with type 2 DM and 25 control subjects without type 2 DM were recruited. A periodontal screening and recording (PSR) index (0, 1-2, 3, and 4) was used to classify whether these subjects had periodontitis. Salivary and serum IL-17A and IL-18 levels were measured by enzyme-linked immunosorbent assay. Multiple linear regression analyses were used to evaluate the associations between these cytokines and clinical parameters. RESULTS: Salivary IL-17A levels were not significantly different between patients with DM and controls, however, the levels were significantly higher in controls with periodontitis than those without periodontitis (p = 0.031). Salivary IL-17A levels were significantly associated with the PSR index (ß = 0.369, p = 0.011). Multiple linear regression analyses revealed the association of salivary IL-18 levels and fasting plasma glucose (ß = 0.270, p = 0.022) whereas serum IL-18 levels were associated with HbA1C (ß = 0.293, p = 0.017). No correlation between salivary and serum levels of IL-17A and IL-18 was found. CONCLUSION: Salivary IL-17A was strongly associated with periodontitis, whereas salivary IL-18 was associated with FPG and serum IL-18 was associated with HbA1C. These results suggest the role of these cytokines in periodontal inflammation and DM.

Salivary and serum cystatin SA levels in patients with type 2 diabetes mellitus or diabetic nephropathy.

OBJECTIVE: To investigate putative salivary biomarkers for screening and diagnosis of type 2 diabetes mellitus and diabetic nephropathy. DESIGN: Saliva and serum samples were collected from 29 patients with type 2 diabetes, 20 patients with diabetic nephropathy, eight patients with non-diabetic induced nephropathy, and 25 healthy subjects. Initially, pooled unstimulated saliva samples from six sex- and age-matched healthy subjects and six patients with type 2 diabetes were subjected to two-dimensional gel electrophoresis, followed by mass spectrometry. Protein expression of cystatin SA in the saliva of patients with type 2 diabetes was further examined in saliva and serum using enzyme-linked immunosorbent assay (ELISA). RESULTS: Two-dimensional gel electrophoresis revealed upregulation of salivary cystatin SA in patients with type 2 diabetes. ELISA showed a weak trend of increasing salivary cystatin SA levels in patients with type 2 diabetes, compared with those levels in healthy subjects. When patients were stratified according to periodontal status, linear regression analyses revealed that salivary cystatin SA levels were associated with Periodontal Screening and Recording (PSR) index (ß = 0.297, p < 0.05) when the analysis was adjusted for age, sex, HbA1C, estimated glomerular filtration rate (eGFR), and number of teeth. Serum cystatin SA levels were negatively associated with eGFR (ß = -0.534, p < 0.0001) when the analysis was adjusted for age, sex, HbA1C, number of teeth, and PSR index. CONCLUSIONS: Salivary cystatin SA was associated with periodontal disease severity; moreover, serum cystatin SA levels could reflect kidney function.

Putative salivary protein biomarkers for the diagnosis of oral lichen planus: a case-control study.

BACKGROUND: Salivary protein biomarkers for screening and diagnosis of oral lichen planus (OLP) are not well-defined. The objective of this study was to identify putative protein biomarkers for OLP using proteomic approaches. METHODS: Pooled unstimulated whole saliva was collected from five OLP patients and five healthy control participants. Saliva samples were then subjected to two-dimensional gel electrophoresis, followed by mass spectrometry to identify putative protein biomarkers. Subsequently, a subset of these putative biomarkers were validated in 24 OLP patients and 24 age-matched healthy control subjects, using an enzyme-linked immunosorbent assay (ELISA). Immunoblotting analyses were then performed in 3 pairs of age- and sex-matched OLP patients and healthy controls to confirm results from the ELISA study. RESULTS: Thirty-one protein spots were identified, corresponding to 20 unique proteins. Notably, fibrinogen fragment D and complement component C3c exhibited increased expression in OLP patients, while cystatin SA exhibited decreased expression in OLP patients, compared with healthy control subjects. ELISA analyses indicated increased expression of fibrinogen fragment D and complement component C3c, and decreased expression of cystatin SA, in the saliva of OLP patients. Statistical differences in the expression of salivary complement C3c were observed between OLP patients and healthy control subjects. Immunoblotting analyses confirmed the results of our ELISA study. CONCLUSION: Complement C3c, fibrinogen fragment D and cystatin SA may serve as salivary biomarkers for screening and/or diagnosis of OLP.

Xerostomia, hyposalivation and oral microbiota in patients using antihypertensive medications.

OBJECTIVE: Oral dryness can contribute to several diseases in the oral cavity. The objective of the present study was to compare the subjective oral dryness, salivary flow rates, the number of oral microbiota, and the dental status between medicated hypertensive patients and control subjects. MATERIAL AND METHOD: Four hundred subjects including 200 ambulatory hypertensive patients who were taking antihypertensive medications and 200 control subjects were included. Each subject's medical history was reviewed. The subject's oral health status, salivary flow rate, and the number of oral microbiota were also evaluated. RESULTS: The prevalence rate of xerostomia in the medicated hypertensive group was 50% whereas only 25.5% of the control group had xerostomia (p < 0.05). Using modified Schirmer test (MST), the mean unstimulated salivary flow rate of the medicated hypertensive group (23.11 +/- 6.08 mm/3 min) was significantly lower than that of the control group (31.30 +/- 3.36 mm/3 min) (p < 0.05). In addition, the mean stimulated salivary flow rate of the medicated hypertensive group (0.73 +/- 0.30 ml/min) was also significantly lower than that of the control group (1.31 +/- 0.34 mi/min) (p < 0.05). The strongest associated factor for dry mouth was the use of antihypertensive medications (OR = 6.28). The mean levels of mutans streptococci, Lactobacilli spp. and Candida spp. in the medicated hypertensive group were significantly higher than in the control group (p < 0.05). Furthermore, medicated hypertensive patients were more likely to have missing teeth compared to control subjects. CONCLUSION: Xerostomia, hyposalivation, and increasing number of oral microbiota were more prevalent in hypertensive patients taking antihypertensive medications.

Overexpression of cdk4 and p16 in oral lichen planus supports the concept of premalignancy.

BACKGROUND: Cell cycle arrest and increased cell proliferation have been demonstrated in oral lichen planus (OLP). This study evaluated the expression of cdk4, cdk6 and p16, important proteins in the G1 phase, in OLP and compared the expression of these proteins of OLP with those of normal mucosa. METHODS: Expression of cdk4, cdk6 and p16 were investigated in 23 OLP and 10 normal mucosae using immunohistochemistry technique. Positive cells were counted and presented as a percentage of positive cells. RESULTS: Expression of cdk4, cdk6 and p16 was observed in 3/10 (30%), 1/10 (10%) and none of normal mucosa, respectively. Expression of cdk4, cdk6 and p16 was detected in 18/23 (78.3%), 8/23 (34.8%) and 15/23 (65.2%), of OLP, respectively. The numbers of cdk4 and p16 positive cases of OLP were significantly higher than normal mucosa. In normal mucosa, the averages of the percentage of positive cells for cdk4 and cdk6 staining were 1.48 and 0.18, respectively. In OLP, the averages of the percentage of positive cells for cdk4, cdk6 and p16 staining were 2.73, 1.06 and 2.24, respectively. The percentage of cdk4-positive cells of OLP was significantly higher than those of normal mucosa group. CONCLUSION: Oral lichen planus demonstrated overexpression of cdk4 and p16, but not cdk6, suggesting that epithelial cells in OLP are in the hyperproliferative state and in cell arrest. Altered expression of cdk4 and p16 provides evidence of the malignant potential in OLP.

In vitro study of the effects of plaunotol on oral cell proliferation and wound healing.

Plaunotol is an acyclic diterpene alcohol extracted from a medicinal plant called plau-noi, Croton stellatopilosus Ohba, and has been widely used for the treatment of gastric ulcers in Japan. The aim of this study was to examine the effects of plaunotol on human gingival fibroblasts (HGFs) and human oral keratinocytes (HOKs). To assess the cytotoxic effect, HGFs and HOKs were treated with plaunotol. Subsequently, the morphology of cells was recorded and cells were subjected to MTT assay. To investigate cell proliferation effect, cells were treated with plaunotol and counted with a haemocytometer. To determine wound healing effect, the number of cells repopulated into the wounded areas in monolayer culture and in fibroblast-populated collagen lattice (FPCL) was measured. The results showed that 10 and 1 µg/ml (33 and 3.3 µmol/l) plaunotol induced toxicity in HGFs and HOKs, respectively. However, 0.1 µg/ml (0.33 µmol/l) plaunotol promoted HGF proliferation and wound healing in monolayer and FPCL models. In contrast, 0.1 µg/ml plaunotol could not induce HOK proliferation nor in vitro wound healing using monolayer culture, but it induced wound healing in a modified FPCL model. Our data suggested that plaunotol could promote oral cell proliferation and wound healing in vitro and may have an implication on oral wound healing.

Xerostomia, hyposalivation, and oral microbiota in type 2 diabetic patients: a preliminary study.

BACKGROUND AND OBJECTIVE: Mouth dryness is one of the major problems that can lead to several oral diseases such as dental caries, periodontitis and oral infection. Mouth dryness has also been associated with type 2 diabetes mellitus (DM). The objective of the present study was to investigate the prevalence of xerostomia (feeling of mouth dryness), hyposalivation (the reduction of saliva), and oral microbiota in Thai patients with type 2 DM. MATERIAL AND METHOD: One hundred and fifty-four ambulatory patients with type 2 DM and 50 non-diabetic control subjects were interviewed for symptoms of xerostomia. The medical records of these subjects were reviewed for pertinent medical history and laboratory investigations regarding their diabetic control. Oral examination and measurement of hyposalivation using a modified Schirmer test (MST) were performed The presence of oral microbial flora was investigated using a modified dip-slide test. RESULTS: The prevalence of xerostomia was 62% in patients with type 2 DM compared with 36% in the nondiabetic control group (p = 0.001). The prevalence of hyposalivation (defined as MST values < or = 25 mm at 3 min) was 46% in the patient group, whereas only 28% of the control group had hyposalivation (p = 0.03). Patients with hyposalivation had significantly higher numbers of mutans streptococci, Lactobacillus spp., and Candida spp. in the saliva compared with those without hyposalivation. CONCLUSION: These results suggested that xerostomia and hyposalivation were prevalent in patients with type 2 DM and were associated with higher numbers of oral pathogens in the saliva.