[Oral erythroplakia and erythroleukoplakia: red and red-white dysplastic lesions of the oral mucosa--part 1: epidemiology, etiology, histopathology and differential diagnosis]

Oral erythroplakia (OE) and oral erythroleukoplakia (OEL; synonym: speckled leukoplakia) are working diagnoses for red and red-white lesions of the oral mucosa after exclusion of all other possible diagnoses for lesions with a similar clinical appearance. A good knowledge of oral medicine and possible differential diagnoses of oral mucosal pathologies is mandatory to correctly detect OE and OEL on this exclusion basis. In the present review article in a series of two, epidemiologic data, etiologic factors, possible differential diagnoses, and the histopathologic characteristics of OE and OEL will be presented and discussed regarding the current literature. A thorough histopathologic examination of these epithelial precursor lesions is mandatory to recognise the presence and the severity of epithelial dysplasia, which is a decisive factor for the subsequent treatment planning.

Dose-response relationships of oral habits associated with the risk of oral pre-malignant lesions among men who chew betel quid

Betel quid, cigarettes and alcohol are well-recognized risk factors for oral cancer. However, the combined effect of the frequency and duration of these oral habits on the risk for developing oral pre-malignancies among betel quid users has not been fully addressed. In this study, an oral screening programme for men chewing betel quid was carried out by well-trained dentists for early detection of oral pre-malignancy lesions. Using generalized logit model and proportional odds model, we found that, compared with the occasional user, the adjusted odds ratios of developing leukoplakia for men chewing one to 10 pieces of betel quid, 11-20 pieces, and more than 20 pieces per day were estimated as 2.14 (95% confidence interval [CI] 1.62-2.81), 2.99 (95% CI 2.06-4.27), and 5.37 (95% CI 3.76-7.47), respectively. The corresponding figures for erythroleukoplakia were 3.69 (95% CI 1.55-8.79), 13.78 (95% CI 5.76-32.98), and 36.64 (95% CI 15.94-84.16), respectively. Similar results were found while the duration was considered. The dose-response relationships were not as noteworthy for cigarette and alcohol drinking.

Oral cancer

Five percent of all tumors occur in the head and neck, and approximately half of those occur specifically in the oral cavity. Of the 615,000 new cases of head and neck [corrected] tumors reported worldwide in 2000, 300,000 were primary oral cavity squamous cell carcinomas. Recent data from the Surveillance, Epidemiology, and End Results Program suggest that 28,900 new cases of oral cancer will be identified and 7400 deaths attributed to oral cancer each year in the United States. The sixth leading cause of cancer-related mortality, oral cancer accounts for 1 death every hour in the United States. However, despite advances in screening tools, imaging technology, and access to primary care physicians, a considerable percentage of patients present with advanced-stage disease. Clinical signs and symptoms of head and neck tumors are often nonspecific and may be mistaken for other common ailments. Primary care physicians must be aware of the possibility of oral cancer, particularly the increasing incidence in young patients without traditional risk factors of alcohol and tobacco abuse. To improve survival, all patients should be routinely and vigilantly screened for oral mucosal lesions.

Oral lesions in HIV-positive dental patients--one more argument for tobacco smoking cessation

OBJECTIVE

To determine the prevalence of oral lesions associated with human immunodeficiency virus (HIV) in a population of dental patients and analyze its association with psycho-social variables and biological markers.

STUDY DESIGN

The dental charts of 415 dental patients consecutively treated between May and July 2005 in a dedicated HIV dental clinic were reviewed. Oral soft tissue examinations, psycho-social and medical variables were extracted and recorded for each patient. Ethnicity, gender, HIV treatment, peripheral CD(4) counts and tobacco usage were analyzed in correlation with oral lesions associated with HIV.

RESULTS

Fifty-five percent of all subjects had at least one oral lesion associated with HIV, with oral candidiasis, salivary gland enlargement and oral hairy leukoplakia being the most commonly observed conditions. Gender and ethnicity did not correlate with a higher prevalence in lesions. However, tobacco smoking correlated significantly with a higher prevalence of oral lesions, independent of CD(4) counts.

CONCLUSIONS

These findings suggest that oral lesions remain commonly observed morbidities among HIV-infected dental patients independent of gender and ethnicity and that tobacco usage is a major and often underestimated risk factor for those lesions.

Polymorphisms at XPD and XRCC1 DNA repair loci and increased risk of oral leukoplakia and cancer among NAT2 slow acetylators

Polymorphisms at N-acetyl transferase 2 locus (NAT2) lead to slow, intermediate and rapid acetylation properties of the enzyme. Improper acetylation of heterocyclic and aromatic amines, present in tobacco, might cause DNA adduct formation. Generally, DNA repair enzymes remove these adduct to escape malignancy. But, tobacco users carrying susceptible NAT2 and DNA repair loci might be at risk of oral leukoplakia and cancer. In this study, 389 controls, 224 leukoplakia and 310 cancer patients were genotyped at 5 polymorphic sites on NAT2 and 3 polymorphic sites on each of XRCC1 and XPD loci by PCR-RFLP method to determine the risk of the diseases. None of the SNPs on these loci independently could modify the risk of the diseases in overall population but variant genotype (Gln/Gln) at codon 399 on XRCC1 and major genotype (Lys/Lys) at codon 751 on XPD were associated with increased risk of leukoplakia and cancer among slow acetylators, respectively (OR = 4.2, 95% CI = 1.2-15.0; OR = 1.6, 95% CI = 1.1-2.3, respectively). Variant genotype (Asn/Asn) at codon 312 on XPD was also associated with increased risk of cancer among rapid and intermediate acetylators (OR = 1.9, 95% CI = 1.2-2.9). Variant C-G-A haplotype at XRCC1 was associated with increased risk of leukoplakia (OR = 1.7, 95% CI = 1.2-2.4) but leukoplakia and cancer in mixed tobacco users (OR = 3.1, 95% CI = 1.4-7.1, OR = 2.4, 95% CI = 1.1-5.4, respectively) among slow acetylators. Although none of the 3 loci could modulate the risk of the diseases independently but 2 loci in combination, working in 2 different biochemical pathways, could do so in these patient populations.

[Changes in oral mucosa of the partially edentulous who wear removable partial dentures ]

PURPOSE

to confirm or infirm structural modification of oral mycosis at the summit after fifteen days of wearing removable resin partial dentures.

METHODS

our study took place at the health center of Rufisque in Senegal from January to July 1998, involved fourteen patients divided into two groups according to sex: seven males and seven females who came for removable resin partial dentures. The macroscopic examination was conducted through to inspection and touching of mycosis at the level of toothless summit before the wearing of the denture. A biopsy was conducted on each patient before and after the wearing of the resin dentures. Tissue reaction was appreciated qualitatively through morphological analysis.

RESULTS

Before the wearing of the removable resin partial dentures 92.9% of patients had epithelial hyperplasia; 7.1% epithelial hypoplasia and 85.7% keratosis at the level of the chorion the number of collagen fibbers (28.6% discrete, 50% moderate, 21.4% important), fibroblasts (35.7% discrete; 42.9% moderate ; 21.4% important), inflammatory cells (71.4% discrete; 28.6% moderate; 0% important) and for blood vessels (64% discrete; 35.70% moderate; 0% important) after fifteen days of wearing partial denture. After fifteen days of the wearing removable resin partial dentures: 85.7% of patients had epithelial hyperplasia; 14.3% normal epithelial and 100% de keratosis at the level of the chorion the number of collagen fibbers (14.3% discrete; 21.4% moderate; 64.3% important), fibroblasts (42.9% discrete; 42.90% moderate; 14.3% important), inflammatory cells (50% discrete, 35.7% moderate: 14.3% important), blood vessels (43% discrete; 28.6% moderate; 28.6% important).

CONCLUSION

Biopsies of the summit are reliable contribution; they provide precise information on the quality of tissue supporting resin partial dentures. This tissues may seem healthy appearance (inspection and touching) but show sign of suffering at this anatomy-pathological examination.

A review of premalignant oral conditions

The value of mass oral cancer screenings has come under scrutiny, as a consequence of a lack of improvement in the long-term outcomes associated with oral carcinoma over the past several decades. However, it is generally accepted that most oral carcinomas are preceded by visible changes to the mucosa and certain high risk lesions have been identified. The responsibility to evaluate the mucosal tissues of the oral cavity clearly falls under the purview of the dentist. The dentist must clearly grasp the distinction between reactive lesions which usually change in 7 to 14 days and malignant and premalignant lesions which do not. Therefore, appropriate diagnostic procedures (i.e., biopsy of the lesion) must be implemented as a matter of course in the evaluation of any lesion that does not respond to usual therapy in 7 to 14 days.

Oral cancer education in dental schools: knowledge and experience of Nigerian undergraduate students

The objective of this study was to determine the knowledge and experiences of clinical dental students of the College of Medicine, University of Lagos, Nigeria related to the management and prevention of oral malignancy and premalignancy. A self-administered questionnaire was distributed to all clinical dental students. Most of the students (87.7 percent; n=57) had witnessed at least a patient with oral malignancy, while 61.5 percent (n=40) had witnessed or examined a patient with oral premalignancy. While 61.5 percent of the students had observed biopsies of malignant and premalignant lesions, only 13.8 percent (n=9) had ever performed one under supervision. All the respondents believed that oral malignancy is always or sometimes associated with pain, and most of the students were more familiar with the late signs of oral malignancy than the early signs. Almost two-thirds (64.6 percent) of the respondents believed that oral screening programs were effective for early diagnosis and management of oral malignancies. This study revealed a need for a more structured teaching program with increased emphasis on the early signs and symptoms of oral malignancies and involvement of the students in the examination and biopsies of malignant and premalignant lesions.

Long-term treatment outcome of oral premalignant lesions

The purpose of the present retrospective study was to learn the long-term outcome of oral premalignant lesions, leukoplakia and erythroplakia, with or without surgical intervention and to relate the outcome to factors supposed to be significant for malignant development including clinical type, demarcation, size, site, presence of epithelial dysplasia, smoking and surgery. A total of 269 lesions in 236 patients were included. Ninety-four lesions were surgically removed, 39 lesions (41%) being homogenous and 46 (49%) non-homogenous leukoplakias whereas nine (5%) were erythroplakias. Seventy-three percent of the lesions were associated with tobacco habits. The mean size of the lesions was 486 mm(2), and 71% of the lesions showed a degree of epithelial dysplasia. After excision the defects were closed primarily by transposition of mucosal flaps or they were covered by free mucosal or skin grafts. A few defects were left for secondary healing. After surgical treatment the patients were followed (mean 6.8 yrs, range 1.5-18.6 yrs), and new biopsies taken in case of recurrences. One hundred and seventy five lesions had no surgical intervention, 149 lesions (85%) being homogenous and 20 (11%) non-homogenous leukoplakias, and 6 (3%) erythroplakias. Eighty-one percent of the lesions were associated with smoking. The mean size of the lesions was 503 mm(2) and 21 of the lesions (12%) exhibited epithelial dysplasia. Sixty-five lesions were not biopsied. These patients were also followed (mean 5.5 yrs, range 1.1-20.2 yrs), and biopsies taken in case of changes indicative of malignant development. All patients were encouraged to quit smoking and candidal infections were treated. The possible role of different variables for malignant development was estimated by means of logistic regression analysis. Following surgical treatment 11 lesions (12%) developed carcinoma after a mean follow-up period of 7.5 yrs. Non-homogenous leukoplakia accounted for the highest frequency of malignant development, i.e. 20%, whereas 3% of the homogenous leukoplakias developed carcinomas. Surgically treated lesions with slight, moderate, severe and no epithelial dysplasia developed carcinoma with similar frequencies, i.e. 9-11%. Without surgical intervention 16% of the 175 lesions disappeared whereas seven lesions (4%) developed carcinoma after a mean observation period of 6.6 yrs. The highest frequency of malignant development (15%) was seen for non-homogenous leukoplakias, this figure being 3% for homogenous leukoplakias. Fourteen percent of lesions with slight epithelial dysplasia developed malignancy and 2% of lesions with no dysplasia showed malignant transformation. Logistic regression analysis showed a seven times increased risk (OR = 7.0) of non-homogenous leukoplakia for malignant development as compared with homogenous leukoplakia and a 5.4 times increased risk for malignant development for lesions with a size exceeding 200 mm(2). No other examined variables including presence of any degree of epithelial dysplasia, site, demarcation, smoking and surgical intervention were statistically significant factors for malignant development.

Oral cancer and pre-cancer in Myanmar: a short review

Cancer in Myanmar is one of the 10 leading causes of morbidity and mortality. In 1974, the Yangon Cancer Registry was established. From 1974 to 2001 a total of 85 298 cancer cases were registered. From 1963 to 1972 the average annual incidence rate of oral cancer was calculated to be 363 per 100 000 population. The tongue was mostly affected (31.2%). In one study, the prevalence of oral leukoplakia was 1.7%, erythroplakia 0.1%, and submucous fibrosis 0.1%. No epidemiologic studies of the prevalence of betel quid chewing (BQC) in Myanmar have been performed. One study showed that among 773 individuals over the age of 6 years, 46.4% were habitual smokers. A recent symposium on oral health stressed the necessity to introduce concepts of prevention, focusing on BQC habits and smoking as high-risk factors for oral cancer and pre-cancer in Myanmar.

Proliferative verrucous leukoplakia and field cancerization: report of a case

Proliferative verrucous leukoplakia (PVL) is a multi-focal oral pre-malignant lesion, proliferative in nature, with a tendency to recur despite adequate therapy, and a high rate of malignant transformation. The field cancerization phenomenon may explain the characteristic behaviour of PVL. A case of PVL is presented and the field cancerization concept is discussed.

Kindler syndrome

Kindler syndrome is a rare autosomal recessive disorder associated with skin fragility. It is characterized by blistering in infancy, photosensitivity and progressive poikiloderma. The syndrome involves the skin and mucous membrane with radiological changes. The genetic defect has been identified on the short arm of chromosome 20. This report describes an 18-year-old patient with classical features like blistering and photosensitivity in childhood and the subsequent development of poikiloderma. The differential diagnosis of Kindler syndrome includes diseases like Bloom syndrome, Cockayne syndrome, dyskeratosis congenita, epidermolysis bullosa, Rothmund-Thomson syndrome and xeroderma pigmentosum. Our patient had classical cutaneous features of Kindler syndrome with phimosis as a complication.

8-Nitroguanine formation in oral leukoplakia, a premalignant lesion

Oral leukoplakia is a premalignant lesion associated with development of oral cancer. To clarify the mechanism of development of oral carcinogenesis from leukoplakia, we examined DNA damage in oral epithelium of biopsy specimens of patients with leukoplakia by immunohistochemical methods. Histological changes, such as epithelial dysplasia and infiltration of inflammatory cells were observed in oral tissues of leukoplakia patients. A double immunofluorescence labeling study demonstrated that the accumulation of mutagenic 8-nitroguanine, an indicator of nitrative DNA damage, and 8-oxo-7,8-dihydro-2'-deoxyguanosine, an indicator of oxidative DNA damage, was apparently observed in the oral epithelium of patients with leukoplakia, whereas little or no immunoreactivity was observed in normal oral mucosa. Expression of inducible nitric oxide synthase (iNOS) was also observed in oral epithelium of leukoplakia patients. Immunoreactivity of 3-nitrotyrosine, an indicator of nitrative stress, was observed in oral epithelial cells and colocalized with 8-nitroguanine. Moreover, proliferating cell nuclear antigen and p53 were expressed in 8-nitroguanine-positive epithelial cells in the basal layer. These results suggest that iNOS-mediated nitrative stress contributes to development of oral carcinogenesis from leukoplakia through DNA damage as well as oxidative stress.

A stochastic model of cancer initiation including a bystander effect

A stochastic model of cancer initiation is considered. The model is used to evaluate whether a bystander effect may be important in the pre-malignant and malignant stages of carcinogenesis, and furthermore, on the basis of epidemiological data, to estimate the mutation rates of genes involved in the development of oral leukoplakias. The bystander effect is defined here as the capability of oncogenic mutations to increase the mutation probability of neighbouring (bystander) cells, thus leading potentially to a cascade of neighbouring mutated and neoplastic cells as a pre-stage in the development to leukoplakias and cancer. We find that incidence data for oral cancer are indeed in accordance with a significant bystander effect, operating either alone or in combination with genomic instability in the early stages of carcinogenesis, i.e. the development of neoplasia. Simulations performed gave a picture of how mutations and neoplasia may spread in a tissue, to form characteristic leukoplakias with a core of neoplastic cells. The model also showed that the probability of finding at least one neoplastic cell in the tissue after a given number of years is more sensitive to changes in genomic instability within the cell itself than to changes in a bystander effect. Based on epidemiological data we also calculate the maximum number of oncogenic genes that may be involved in the bystander effect and development of genomic instability. Even if capable of explaining the initial development of oncogenic mutations towards neoplastic cells, the bystander model could not reproduce the observed incidence rates of leukoplakia without assuming a carcinogen mutation probability per cell per year of neoplastic cells practically equal to one. This means that the bystander effect, to be of substantial importance in the final development of neoplastic cells towards leukoplakias, requires a very significant increase in mutation probabilities for bystanders to neoplastic cells. Alternatively, additional mechanisms such as abnormal cell differentiation and uncontrolled proliferation and apoptotis in the neoplastic stage may be of major importance during the development to cancerization.

Risk of oral nonmalignant lesions associated with human papillomavirus infection, betel quid chewing, and cigarette smoking in Taiwan: an integrated molecular and epidemiologic study

CONTEXT

In contrast to previous studies about the association of oral squamous cell carcinoma with human papillomavirus (HPV) 16/18, the associations between nonmalignant oral lesions (chronic inflammation, submucous fibrosis, leukoplakia, and squamous papilloma) and HPV are much less well understood.

OBJECTIVE

We conducted this study using an in situ polymerase chain reaction in situ hybridization assay, which is one of the most sensitive methods for in situ viral detection. Other known oral cancer risk factors, including betel quid chewing and cigarette smoking, were also analyzed.

DESIGN

Oral specimens from 23 patients with submucous fibrosis, 36 patients with leukoplakia, 22 patients with squamous papilloma, and 21 patients without significant lesions were analyzed for the presence of HPV DNA. Their betel quid chewing and cigarette smoking histories were reviewed.

RESULTS

HPV-16 and HPV-18 were frequently identified in all 3 oral lesions (61.5% and 42.1%), while HPV-6 and HPV-11 were seen only in squamous papilloma (21.1% and 5.0%). HPV-18, betel quid chewing, and smoking were significantly associated with leukoplakia and squamous papilloma, while only betel quid chewing and smoking were significantly associated with submucous fibrosis. Multivariate analysis showed that the betel quid chewing habit remained an independent factor for leukoplakia and squamous papilloma.

CONCLUSIONS

Our data indicated that betel quid chewing and smoking habits are 2 important risk factors for these nonmalignant or premalignant oral lesions, while for high-risk HPV, only HPV-18--not HPV-16--is a significant risk factor for leukoplakia and squamous papilloma.

Carcinoma and dysplasia in oral leukoplakias in Taiwan: prevalence and risk factors

OBJECTIVES

The issue of existence of malignancy within oral leukoplakia has seldom been addressed in Taiwan. The aims of this study were to investigate the prevalence of carcinoma and dysplasia within oral leukoplakia at the time of clinical diagnosis and to identify the associated risk factors in Taiwan.

STUDY DESIGN

The prevalence rate of malignancy and dysplasia in 1046 oral leukoplakias at a university hospital was calculated. Univariate and multivariate analyses by the Mantel-Haenszel method and multiple logistic regression model were performed to examine risk factors associated with the presence of carcinoma and dysplasia within the lesions.

RESULTS

The prevalence rate of carcinoma was 12.9%. The relative risks for the presence of malignancy in leukoplakias on the tongue/floor of mouth and with nonhomogeneous appearance were 2.72- and 28.13-fold by multivariate logistic regression analysis, when compared with those on buccal mucosa and lesions having homogeneous surface (both P < .05). In contrast, patients who both smoked and chewed betel quid had a significantly lower risk for carcinoma than the abstainers (P < .05). A synergistic effect between the 2 major risk factors of clinical appearance and lesion site was evident. Nonhomogeneous leukoplakia on tongue/floor of mouth had a 43.10-fold higher risk compared to homogeneous lesions located on buccal mucosa or other sites (P < .05). However, homogeneous leukoplakia in buccal mucosa or other sites of the oral cavity still had the possibility of having carcinoma within the lesion. The prevalence of dysplasia was 45.6% among the noncancerous leukoplakias with risk factors similar to those for carcinoma.

CONCLUSIONS

Our results demonstrate that some leukoplakias contain a malignant component. Lesions with certain features are more prone to carcinoma, but no clinical attributes can bring certitude. Therefore, all oral leukoplakias should be submitted to microscopic analysis before any definite treatment or long-term follow-up.

Oral lesions of 500 habitual psychoactive substance users in Chennai, India

The aim of this study was to ascertain the prevalence of oral lesions among 500 psychoactive substance users in a hospital-based population. The study group consisted of 500 consecutive patients attending TTK Hospital, a non-governmental organisation involved in rehabilitation of substance users. Patient history was recorded in a pre-determined format and clinical findings were recorded by a trained physician and dental surgeons. Psychoactive substances used by the patients were alcohol (97%), tobacco (72%), arecanut (57.2%), narcotics (6.8%), cannabis (3.2%) and benzodiazipines (1.8%). Ninety-one percent of patients had one or more oral lesions: dental caries (39%), gingivitis (37.6%), extrinsic stains (24%), oral submucous fibrosis (OSF) (8%), periodontitis (7.4%), leukoplakia (6.6%), melanosis (5.2%), nicotina palatini (2.2%) and erythroplakia (0.6%). For OSF, those using arecanut and alcohol had an odds ratio (OR) of 2.4 [95% confidence intervals (CI) 1.23-4.69, P=0.009], smokers using arecanut products and alcohol had an OR of 3.07 (95% CI 1.59-5.91, P=0.000), and smokers who chewed arecanut products and used drugs had an OR of 23.1 (95% CI 2.05-260, P=0.001) compared with the general population. Those who smoked and used alcohol, arecanut and drugs had a 20.67-fold higher risk of developing leukoplakia compared with those who did not engage in these habits. In conclusion, 91% of patients had one or more oral lesions that needed dental treatment, and most patients were not aware of their oral lesions. The high prevalence of OSF and leukoplakia in substance abusers compared with the general population emphasises the need for regular dental assessments in these patients.

Association between diabetes mellitus and pre-malignant oral diseases: A cross sectional study in Kerala, India

Recent studies have suggested role of diabetes mellitus in the development of periodontal diseases, oral inflammatory and neoplastic lesions. We analysed data from randomised oral cancer screening trial in Kerala, India, to study the association between chronic diseases in general, diabetes mellitus in particular, and pre-malignant oral lesions and conditions. A total of 927 subjects with oral leukoplakia, 170 with oral submucous fibrosis, 100 with erythroplakia lesions and 47,773 apparently healthy subjects constituted the cases and controls respectively for our present study. The odds ratio (OR) for oral leukoplakia among women with a history of diabetes mellitus was found to be 2.0 (95% confidence interval (CI) = 1.4-2.9) whereas that for erythroplakia was 3.2 (95% CI = 1.3-7.9), after adjusting for potential confounders. No statistically significant association between diabetes mellitus and oral submucous fibrosis and pre-cancerous lesions/conditions in men was found. An association between diabetes mellitus and pre-malignant oral lesions among women has been observed in our study, although the underlying mechanisms are not clear. This needs to be further evaluated in other settings.

[Tobacco-associated lesions of the oral mucosa]

Consumption of tobacco can result not only in a multitude of different general health problems like carcinoma of the lung, ischaemic cardiac diseases, peripheral vascular diseases, stroke, chronic-obstructive pulmonary diseases or peptic ulcers, but also in pathologic lesions of the oral mucosa. Benign oral lesions from smoking or consumption of smokeless tobacco are the so-called smoker's palate and smoker's melanosis. On the other hand, tobacco-associated lesions like oral leukoplakia or oral squamous cell carcinoma are already potentially life-threatening diseases that in general require active treatment. The following review article will present and discuss the typical lesions of the oral mucosa that result from chronic tobacco consumption. The aim of this article is to demonstrate dental health care providers the needs and benefits of tobacco use cessation in a dental setting, especially regarding stomatologic sequelae and consequences. The present article is the first in a series of articles from the Swiss task force "Smoking - Intervention in the private dental office" on the topic "tobacco use and dental medicine".

Oral precancerous disorders associated with areca quid chewing, smoking, and alcohol drinking in southern Taiwan

OBJECTIVE

To investigate the prevalence and the associated risk factors of oral precancerous disorders in southern Taiwan.

METHODS

We conducted a cross-sectional community survey interviewing 1075 adult subjects, 15 years of age and over, gathered from randomly selected 591 households, and spanning five villages in southern Taiwan. The study protocol included a visual oral soft tissue examination and a questionnaire-based interview. The chi-square test was used to test the differences in prevalence of oral precancerous lesions and conditions by different "life styles" relating to current risk habits of current areca quid chewing, smoking, and alcohol drinking. To control for possible confounding, a logistic regression model was used to estimate the Odds Ratios (OR) for leukoplakia and oral submucous fibrosis (OSF).

RESULTS

136 precancerous lesions and conditions were detected among 1075 subjects (12.7%). The analysis of the spectrum of oral precancerous disorders detected, leukoplakia (n = 80), OSF (n = 17) and verrucous lesions (n = 9), demonstrated an association with gender (P < 0.001). There were statistically significant associations among leukoplakia (P < 0.01), OSF (P < 0.0001), and verrucous lesions (P < 0.0001) and the life style of current areca quid chewing, smoking, and alcohol drinking. The synergistic effect of smoking and areca quid chewing habit on leukoplakia and OSF was demonstrated.

CONCLUSION

This study reinforces the association of current areca quid chewing without tobacco, cigarette smoking, and alcohol drinking to leukoplakia, OSF, and verrucous lesions in Taiwan.

Increased Risk of Oral Leukoplakia and Cancer Among Mixed Tobacco Users Carrying XRCC1 Variant Haplotypes and Cancer Among Smokers Carrying Two Risk Genotypes: One on Each of Two Loci, GSTM3 and XRCC1 (Codon 280)

An individual's susceptibility to oral precancer and cancer depends not only on tobacco exposure but also on the genotypes/haplotypes at susceptible loci. In this hospital-based case-control study, 310 cancer patients, 197 leukoplakia patients, and 348 controls were studied to determine risk of the disease due to polymorphisms at three sites on XRCC1 and one site on XRCC3. Independently, variant genotypes on these loci did not modulate risk of leukoplakia and cancer except for the XRCC1 (codon 280) risk genotype in exclusive smokeless tobacco users with leukoplakia [odds ratios (OR), 2.4; 95% confidence intervals (CI), 1.0-5.7]. But variant haplotypes, containing one variant allele, on XRCC1 increased the risk of leukoplakia (OR, 1.3; 95% CI, 1.0-1.7). Among stratified samples, mixed tobacco users, carrying variant haplotypes, also had increased risk of both leukoplakia (OR, 2.2; 95% CI, 1.3-3.9) and cancer (OR, 1.9; 95% CI, 1.2-3.1). In a previous study on this population, it was shown that the GSTM3 (A/A) genotype increased the risk of oral leukoplakia and cancer among smokers, which has also been substantiated in this study with expanded sample sizes. The simultaneous presence of two risk genotypes in smokers, one on each of two loci, GSTM3 and XRCC1 (codon 280), increased the risk of cancer (OR, 2.4; 95% CI, 1.0-5.8). Again, smokers carrying two risk genotypes, one on each of two loci, GSTM3 and XRCC1 (codon 399), were also overrepresented in both leukoplakia and cancer populations (P(trend) = 0.02 and 0.04, respectively) but enhancement of risks were not observed; probably due to small sample sizes. Therefore, the presence of variant haplotypes on XRCC1 and two risk genotypes, one on each of two loci, GSTM3 and XRCC1, could be useful to determine the leukoplakias that might progress to cancer in a group of patients.

Tobacco cessation for the dental team: a practical guide part I: background & overview

Dental professionals are strategically placed to be the leaders in tobacco prevention and cessation as they provide preventive and therapeutic services to a basically healthy population on a regular basis. By expanding the dental exam, diagnosis, and treatment to include tobacco cessation, a potentially life saving element of care is added to an established service. In addition periodontal disease and the potential for oral cancer mandate the inclusion of tobacco cessation services into dental care. Though dental professionals are aware of the health issues associated with tobacco use, they often feel ill prepared or uncomfortable presenting patients with a clear cessation message. In this, the first of a two-part article, the purpose is to provide dental professionals with the foundational knowledge necessary to provide effective tobacco cessation as a normal part of patient care.

Dyskeratosis congenita: its connections with oral and maxillofacial surgery

Dyskeratosis congenita is characterised by abnormal pigmentation of skin, dystrophy of nails, and mucosal leukoplakia mainly on the tongue. Bone marrow failure, pulmonary complication, and premalignant leukoplakia of the tongue are serious complications of the disease.