Subgingival periodontal pathogens associated with chronic periodontitis in Yemenis.

BACKGROUND: Subgingival microbial profile associated with periodontitis has been reported to significantly differ by geographical location. The purpose of this study was to assess the association between a panel of putative periodontal bacterial pathogens and chronic periodontitis among Yemenis. METHODS: Subgingival DNA samples were obtained from diseased and healthy sites of 20 non-smoking, moderate to severe chronic periodontitis subjects. Absolute counts (bacterial DNA copies per sample) and relative counts (% total bacteria) of seven periopathogenic species/genera representative of the red and orange complexes were determined using Taqman q-PCR assays. RESULTS: The q-PCR assays showed excellent linearity (R2 > 0.99) and a sensitivity of 100 copies/sample. The detection rate was 100% for all tested species/genera except for P. gingivalis and A. actinomycetemcomitans that were detected at 97.5% and 67.5%, respectively. The median log absolute counts were in the range of 2.41-6.53 copies per sample while median relative counts were in the range of 0.001-0.77%, both being highest for fusobacteria and lowest for A. actinomycetemcomitans. Significant interspecies correlations were observed. Adjusting for multiple comparisons (P≤0.0063), only T. forsythia, T. denticola and P. micra maintained significant association with periodontal destruction. The latter species, however, showed the strongest association and was found in higher proportions at the periodontitis sites across all subjects (3.39 median fold increase). No significant differences were observed for P. gingivalis. CONCLUSIONS: P. micra rather than P. gingivalis appears as a keystone pathogen in this Yemeni Sample. However, these findings need to be validated in a larger-scale study before they can be claimed to represent ethnic variations in pathogens' association with periodontitis.

Histopathological changes in oral mucosa due to takhzeen al-qat: a study of 70 biopsies.

BACKGROUND: Chewing qat leaves (takhzeen al-qat) is a common habit in East Africa and Yemen. It has been reported to cause different systemic effects. At the oral mucosa, it causes clinical changes that appear as white lesions. The aim of this paper was to study the histopathological changes in the oral mucosa related to takhzeen al-qat. METHOD: Seventy biopsies were studied. Biopsies were divided into three groups: (G1) Forty biopsies were taken from the oral mucosa of the chewing side. (G2) Twenty biopsies were taken from the oral mucosa of the opposite side and (G3) 10 biopsies were taken from the oral mucosa of non-chewing volunteers. All biopsies were conventionally prepared, paraffin embedded and histopathological protocol was followed for each case to study the histopathological changes. RESULTS: Acanthosis appeared in 97.5% (G1) and 50% (G2), parakeratosis in 45% (G1) and 0% (G2), orthokeratosis in 25% (G1) and 10% (G2), abnormal rete ridges in 97.5% (G1) and 25% (G2), intracellular edema in 80% (G1) and 65% (G2), inflammatory infiltration in the subjacent connective tissue of 55% (G1) and 5% (G2), increased amount of collagenous fibers in 47.5% (G1) and 0% (G2), and mild epithelial dysplasia in 25% (G1) and 0% (G2). Biopsies taken from G3 showed no histopathological changes except one case with intracellular edema. Differences were statistically significant. CONCLUSION: Takhzeen al-qat caused histopathological changes in the oral mucosa at the side of chewing; however, these changes were innocuous and without any evidence of malignancy.

Expression of p53, cyclin D1 and Ki-67 in pre-malignant and malignant oral lesions: association with clinicopathological parameters.

In this study, a possible association was examined between the immunoexpressions of p53, cyclin D1, Ki-67 and tobacco exposure and the risk of oral cancer (OC) in premalignant and malignant formalin-fixed, paraffin-embedded oral mucosal tissue specimens from patients from Yemen (n=24, all were pre-malignant) and India (n=16, 11 were OCs). Overexpressions of p53, cyclin D1 and Ki-67 were found in 100%, 45.5% and 80% of the OCs, compared to 65.5%, 82.8% and 85.1% of the pre-malignant lesions, respectively. In the pre-malignant lesions, a statistically significant correlation was found between histopathological grading and expressions of cyclin D1 (p = 0.001) and Ki-67 (p = 0.03), and between anatomical site and expression of Ki-67 (p = 0.01). Coexpressions of the three proteins in the cases examined was found to correlate significantly to each other (cyclin D1: p53, r = 0.48, p = 0.002; p53: Ki-67, r = 0.41, p = 0.008) except for cyclin D1: Ki-67. These findings suggest that the expressions of p53, cyclin D1 and Ki-67 might contribute to OC susceptibility in oral mucosal lesions examined from Yemen and India. The importance of the three proteins examined as biomarkers in OC and pre-malignant lesions deserves particular attention because it might offer further understanding of the development of these lesions, particularly in populations heavily exposed to tobacco habits. Abnormalities of both cyclin D1 and Ki-67 might play an important role in the development of oral pre-malignant lesions and warrant further studies. Larger studies are, therefore, necessary in the two countries to examine the role of these biomarkers in OCs and premalignant oral mucosal lesions.

A study of 342 oral keratotic white lesions induced by qat chewing among 2500 Yemeni.

BACKGROUND: Qat chewing is a common habit in Yemen. Various studies demonstrated clear effects of this habit on the systemic organs of the human body. The lack of studies, however, on the effects of this habit on oral mucosa was the major motive of this study. METHODS: This cross-sectional study was made on 2500 Yemeni citizens (mean age 27 years, 1818 males and 682 females). Clinical protocol was made for all cases with a full intraoral examination. A new grading system was applied for each case with oral white lesion. RESULTS: Of our sample, 1528 cases (61.12%) were qat chewers; of them, 342 cases (22.4%) had oral keratotic white lesions at the site of qat chewing, while only 6 (0.6%) non-chewer cases had white lesions in their oral cavity (P < 0.000000, Odds ratio = 46.43, RR = 36.26). According to our grading system; 14, 5.9 and 2.4% were grade I, II and III. CONCLUSIONS: We conclude that qat chewing can provoke the development of oral keratotic white lesions at the site of chewing. The prevalence of these lesions and its severity increase as duration and frequency increase.