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.

Qat chewing as an independent risk factor for periodontitis: a cross-sectional study.

This study assessed the effect of qat chewing on periodontal health, independent of other risk factors. Four hundred qat chewers and 100 nonchewers (20-50 years) were included. Demographic data and detailed information about chewing and smoking were obtained. Periodontal status was assessed using Community Periodontal Index (CPI) and clinical attachment loss (CAL). The qat chewers were older, included more males and smokers, and had worse oral hygiene but higher education levels; the majority were heavy chewers (mean duration of 14.45 years and frequency of 6.10 days/week). Regression analysis identified age, oral hygiene, education level, and cigarette smoking as independent predictors of periodontal destruction. Adjusted for these, qat chewing showed marginally significant association only with CAL (OR = 4.7; P = 0.049). The chewing sides showed significantly higher scores than the nonchewing sides; however, equal scores on both sides or lower scores on the chewing sides (possibly no or beneficial effect) were still observed in 50% of the chewers. Heavy qat chewing is shown here as an independent risk factor for attachment loss. However, the possibility that the habit may have beneficial effects in a subset of the chewers cannot be excluded. A holistic model that resolves the existing contradiction is presented.

Effect of khat chewing on periodontal pathogens in subgingival biofilm from chronic periodontitis patients.

AIMS: Existing in vitro and in vivo data suggest that khat may have a favorable effect on periodontal microbiota. The purpose of this study was to assess the effect of khat chewing on major periodontal pathogens in subgingival plaque samples from subjects with chronic periodontitis. MATERIALS AND METHODS: 40 subgingival plaque samples were obtained from periodontitis and healthy sites of 10 khat chewers (40 y median age) and 10 khat non-chewers (37.5 y median age) with chronic periodontitis. Absolute and relative counts of 6 periodontal pathogens were determined in each sample using highly sensitive and specific Taqman real-time PCR assays. Data were analyzed using an ordinal regression model. RESULTS: Significantly more total bacteria were detected in samples from the periodontitis sites of the khat chewers (OR=20). Treponema denticola was present at significantly higher absolute counts at the healthy as well as periodontitis sites of the khat chewers (OR=3.13 and 13, respectively). However, the khat chewers harbored significantly lower absolute counts of Porphyromonas gingivalis at the healthy sites (OR=0.07). Furthermore, khat chewing was significantly associated with lower relative counts of Porphyromonas gingivalis, fusobacterium ssp., prevotella ssp. and Parvimonas micra-like species in subgingival plaque samples from both healthy and periodontitis sites (OR=0.11-0.33). Only Treponema denticola was found in higher relative counts at the healthy sites of the khat chewers (OR=2.98). CONCLUSIONS: Overall, there was a lower burden of pathogens in the khat chewers. Findings from the current study are suggestive of a potential prebiotic effect for khat on periodontal microbiota.

High relative frequency of oral squamous cell carcinoma in Yemen: qat and tobacco chewing as its aetiological background.

To study the association of qat chewing with the occurrence of oral cancer, the frequency of oral cancer among whole body cancers and the patients' histories of tobacco consumption and qat chewing were examined in Yemen where qat chewing has been most popular. All primary malignant tumors listed in the surgical pathology files at Al-Thawra Hospital, University of Sana'a, in the year 2004 were analyzed, and the patients' histories of tobacco consumption and qat chewing were examined. A total of 649 cases of primary malignant tumors (348, 53.6% males and 301, 46.4% females) were extracted. Oral cancer was the most frequent body cancer in both males (17.2%) and females (19.6%). Squamous cell carcinoma (SCC) was the most frequent oral cancer (84%), and the tongue (42%), gingiva (23%) and buccal mucosa (20%) were the most common sites. Among the 119 patients with oral cancer, information on chewing habits and smoking was obtained in 92 patients (77.3%). There were 70 tobacco chewers (76.1%), 55 qat chewers (59.8%), and 22 smokers (23.9%). Simultaneous chewing of tobacco and qat was found in 48 cases (52.2%). The present survey has disclosed for the first time that oral SCC is the most frequent cancer in this study area in Yemen, and that the high relative frequency of oral SCC may be related to the habits of chewing tobacco and qat.

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.