OBJECTIVE: To examine all studies reporting prevalences of oral lichen planus (OLP) for epidemiological validity and to extract prevalence data from the valid papers. DESIGN: Computer based literature searches were carried out using the MeSH headings 'lichen planus, oral and (prevalence or incidence)' and were supplemented by manual searching. MAIN OUTCOME MEASURES: Each paper was examined for five criteria: clinic-based or population study, adequate demographic description (by sex and age group) of the population, adequate demographic description of the sample (if the population was sampled), adequate demographic description of the OLP cases identified, and histological confirmation of the clinical diagnosis. RESULTS: Forty-five relevant papers were identified, 21 clinic-based and 24 population studies. All but one of the population studies was deficient. One study, while having some defects, was probably sufficiently valid to permit the findings to be regarded as useful. An overall age-standardized prevalence of 1.27% (0.96% in men and 1.57% in women) can be calculated from this study. CONCLUSIONS: There appears to be only one usable prevalence study of OLP. Other large-scale studies are required in other populations. Such studies need to distinguish between OLP and lichenoid reactions.

The reported prevalence of oral lichen planus: a review and critique

Matrix metalloproteinase-9 (MMP-9) is an inducible enzyme. Oral potentially malignant disorders (OPMDs) are considered as the early tissue changes that happen due to various habits such as smoking tobacco, chewing tobacco or stress. This alteration in the tissues alters the expression of MMP-9. The rationale of the review is to know the expression of MMP-9 in OPMDs. Hand searching and electronic databases such as PubMed and ScienceDirect were done for mesh terms such as OPMDs and MMP-9. Eight articles were obtained, after applying inclusion and exclusion criteria. These articles were assessed with QUADAS and data were extracted and evaluated. The included eight studies were done in 182 oral squamous cell carcinoma cases, 430 OPMDs (146 oral lichen planus, 264 leukoplakia and 20 oral submucous fibrosis) and 352 healthy controls evaluated for MMP-9. MMP-9 expression was found to be elevated in tissue, serum and saliva samples of OPMDs than in healthy controls. There is only one study in each serum and saliva samples to evaluate MMP-9. Saliva being noninvasive and serum being minimally invasive, more studies need to be done in both serum and saliva to establish MMP-9 as an early diagnostic marker in OPMDs to know its potential in malignant transformation.

Expression of matrix metalloproteinase-9 in oral potentially malignant disorders: A systematic review

Objective In a previous article, we reported the prevalence rates of oral mucosal lesions in this hospital from 1990-2001. This study was planned to study the spectrum of potentially malignant and malignant oral lesions in Allahabad, North India in the subsequent years till 2007 and to assess change in pattern of prevalence, if any. Materials and methods This is a single institutional retrospective study in and around Allahabad from 1990 to 2007. Data was collected year wise with reference to age, sex, site involved and histopathological findings. Results 1,151 oral biopsies were reviewed. Of these, 365 biopsies were benign, 344 were potentially malignant and 442 were malignant. The buccal mucosa was the most frequently involved site in benign and premalignant lesions, however in malignant lesions, the tongue was most common site. Oral submucous fibrosis constituted the highest number of patients in premalignant group, while in malignant group, squamous cell carcinoma was most prevalent. Conclusion This study showed that potentially malignant and malignant oral lesions were widespread in the patients visiting the hospital in this region.

Prevalence of Oral Pre-malignant and Malignant Lesions at a Tertiary Level Hospital in Allahabad, India

To date, the term oral leukoplakia (OL) should be used to recognize 'predominantly white plaques of questionable risk, having excluded (other) known diseases or disorders that carry no increased risk of cancer'. In this review, we addressed four controversial topics regarding oral leukoplakias (OLs): (i) Do tobacco and alcohol cause OLs?, (ii) What percentage of OLs transform into oral squamous cell carcinoma (OSCC)?, (iii) Can we distinguish between premalignant and innocent OLs?, and (iv) Is proliferative verrucous leukoplakia (PVL) a specific entity or just a form of multifocal leukoplakia? Results of extensive literature search suggest that (i) no definitive evidence for direct causal relationship between smoked tobacco and alcohol as causative factors of OLs, (ii and iii) the vast majority of OLs follow a benign course and do not progress into a cancer, and no widely accepted and/or validated clinical and/or biological factors can predict malignant transformation, and (iv) the distinction between multifocal/multiple leukoplakias and PVL in their early presentation is impossible; the temporal clinical progression and the high rate of recurrences and development of cancer of PVL are the most reliable features for diagnosis.

Urban legends series: oral leukoplakia.

Objective The aim of this study was to investigate the oral mucosal disorders associated with habitual gutka consumption. Methods Databases were searched from 1956 to June 2009 using the following terms: “gutka,” “gutkha,” “ghutka,” “guttkha,” “smokeless tobacco,” “areca nut,” “betel nut,” “slaked lime,” “dental,” “oral,” “periodontal,” “inflammation,” “submucous fibrosis,” “carcinoma,” and “cancer.” The eligibility criteria included: human and experimental studies, use of control subjects, and articles published in English. Unpublished data were not sought. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed. Results Twelve studies were included. Three studies associated gutka consumption with periodontal inflammation (ORs 1.64 [CI 1.2-2.1], 2.20 [CI 1.1-4.9], and 3.56 [CI 1.9-5.5]). Five studies showed a direct relationship between gutka usage and oral submucous fibrosis (ORs 1.65 [CI 1.2-2.3], 2.33 [CI 1.9-4.5], 2.98 [CI 1.5-3.9], 3.56 [CI 1.3-4.7], and 5.08 [CI 3.7-6.4]). An increased frequency of gutka usage was associated with malignant transformations in oral submucous fibrosis by 2 studies (ORs 4.59 [CI 2-5.6] and 18 [CI 5.8-61.6]). Two studies showed an extension of oral submucous fibrosis into the hypopharynx and esophagus in gutka users (ORs 4.59 [CI 2-5.6] and 33 [CI 2.2-46.6]). Conclusions Habitual gutka usage is associated with severe oral mucosal disorders, and the consequences may extend beyond the oral cavity.

Oral mucosal disorders associated with habitual gutka usage: a review.

BACKGROUND: Smoking, drinking and chewing tobacco product, common habits in India have been positively associated with oral lesions. No study has been conducted in this part of Tamilnadu regarding the prevalence of oral lesions in relation to habits. METHODS: A hospital based cross-sectional study was carried out at Ragas Dental College, Chennai. Already existing data of two thousand and seventeen consecutive patients from sub-urban areas of Chennai, who attended the outpatient department, at Ragas Dental College, for dental complaints during a period of three months in 2004, who underwent oral examination and interviewer based questionnaire was used. RESULTS: Oral soft tissue lesions were found in 4.1% of the study subjects. The prevalence of leukoplakia, OSF and oral lichen planus was 0.59%, 0.55%, and 0.15% respectively. The prevalence of smoking, drinking alcoholic beverages and chewing was 15.02%, 8.78% and 6.99% respectively. Smoking and chewing were significant predictors of leukoplakia in this population. DISCUSSION: The prevalence of leukoplakia, OSF and oral lichen planus in our study population is similar to those found in other populations. The prevalence of consumption of alcoholic beverages in our study population was higher when compared to the Indian National Sample Survey study. However the prevalence of smoking and chewing was found to be lower. Smokers were more likely to develop smoker's melanosis compared to other lesions. Among those who consumed alcoholic beverages alone, the prevalence of leukoplakia was higher compared to other lesions. OSF was the most prevalent lesion among those who chewed panmasala or gutkha or betel quid with or without tobacco.

Prem Deepa Narasimhan

Papers

Prevalence of oral lesions in relation to habits: Cross-sectional study in South India.