Eficacia clínica de la terapia fotodinámica por 5-ALA tópico en el manejo onco-preventivo de lesiones de leucoplasia oral. Una revisión sistemática / Clinical efficacy of topical 5-ALA photodynamic therapy in the onco-preventive management of oral leukoplakia lesions. A systematic review

Objetivo: La leucoplasia oral es el desorden maligno de la mucosa bucal más prevalente a nivel global y su manejo clínico sigue siendo un desafío. Se llevó a cabo una revisión sistemática para determinar la eficacia clínica de la terapia fotodinámica mediada por ácido 5-aminolevulínico tópico como una alternativa de quimio-prevención para las diferen- tes formas clínicas de la leucoplasia oral. Materiales y métodos: Empleando términos MeSH, se realizó una búsqueda exhaustiva en diferentes bases digi- tales de ensayos clínicos publicados en inglés en los últimos 30 años acerca del uso de la terapia fotodinámica mediada por ácido 5-aminolevulínico tópico como fotosensibilizador, y radiación láser de baja intensidad o luz LED como posibles fuentes de iluminación. Resultados: La revisión sistematizada que aplicó la guía PRISMA mostró una eficacia del 88,6% para este modo de fototerapia en el manejo de leucoplasias orales, con un 60,7% de respuesta completa y 27,9% de respuesta parcial. Además, el tamaño de efecto fue mayor para las formas clíni- cas homogéneas con cambios displásicos, independientemen- te del tipo de fuente de luz. La ausencia de respuesta fue del 11,4%, pero la evidencia empleada en este análisis fue mo- derada. Conclusión: La terapia fotodinámica mediada por áci- do 5-aminolevulínico tópico parece ser una alternativa útil en el manejo onco-preventivo de lesiones de leucoplasia oral. Sin embargo, es recomendable ejecutar ensayos clínicos controla- dos y aleatorizados con metodologías homogéneas que per- mitan generar un meta-análisis con un alto nivel de evidencia

Aim: Oral leukoplakia is globally the most prevalent ma- lignant disorder of the oral mucosa and its clinical manage- ment remains a challenge. A systematic review was carried out to determine the clinical efficacy of photodynamic therapy mediated by topical 5-aminolevulinic acid as an alternative for chemoprevention in the different clinical forms of oral leu- koplakia. Materials and methods: Using MeSH terms, an ex- haustive search was carried out in different digital databases of clinical trials published in English in the last 30 years on the use of photodynamic therapy mediated by topical 5-ami- nolevulinic acid as a photosensitizer, and low-intensity laser radiation or LED light as possible lighting sources. Results: The systematized review using PRISMA guide- lines showed an efficacy of 88.6% for this mode of photother- apy in the management of oral leukoplakias, based on 60.7% of complete response and 27.9% of partial response. In addi- tion, the effect size was larger in homogeneous clinical forms with dysplastic changes, regardless of the type of light source. There was an 11.4% of absence of response, but the evidence used in this analysis was moderate. Conclusion: Photodynamic therapy mediated by topical 5-aminolevulinic acid seems to be a useful alternative in the onco-preventive management of oral leukoplakia lesions. However, it is recommendable to perform controlled and ran- domized clinical trials with homogeneous methodologies that allow the generation of a meta-analysis with a high level of evidence (AU)

Inhibition of mTOR signaling and clinical activity of metformin in oral premalignant lesions.

BACKGROUNDThe aberrant activation of the PI3K/mTOR signaling circuitry is one of the most frequently dysregulated signaling events in head and neck squamous cell carcinoma (HNSCC). Here, we conducted a single-arm, open-label phase IIa clinical trial in individuals with oral premalignant lesions (OPLs) to explore the potential of metformin to target PI3K/mTOR signaling for HNSCC prevention.METHODSIndividuals with OPLs, but who were otherwise healthy and without diabetes, underwent pretreatment and posttreatment clinical exam and biopsy. Participants received metformin for 12 weeks (week 1, 500 mg; week 2, 1000 mg; weeks 3-12, 2000 mg daily). Pretreatment and posttreatment biopsies, saliva, and blood were obtained for biomarker analysis, including IHC assessment of mTOR signaling and exome sequencing.RESULTSTwenty-three participants were evaluable for response. The clinical response rate (defined as a ≥50% reduction in lesion size) was 17%. Although lower than the proposed threshold for favorable clinical response, the histological response rate (improvement in histological grade) was 60%, including 17% complete responses and 43% partial responses. Logistic regression analysis revealed that when compared with never smokers, current and former smokers had statistically significantly increased histological responses (P = 0.016). Remarkably, a significant correlation existed between decreased mTOR activity (pS6 IHC staining) in the basal epithelial layers of OPLs and the histological (P = 0.04) and clinical (P = 0.01) responses.CONCLUSIONTo our knowledge this is the first phase II trial of metformin in individuals with OPLs, providing evidence that metformin administration results in encouraging histological responses and mTOR pathway modulation, thus supporting its further investigation as a chemopreventive agent.TRIAL REGISTRATIONNCT02581137FUNDINGNIH contract HHSN261201200031I, grants R01DE026644 and R01DE026870.

PD-1 blockade prevents the progression of oral carcinogenesis.

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies in the head and neck with a poor prognosis. Oral cancer development is a multistep process involving carcinogenesis. Though significant advances in cancer immunotherapy over the years, there is lack of evidence for T-cell exhaustion during oral carcinogenesis. Clinical specimens from healthy donors and patients diagnosed with oral leukoplakia (OLK) or OSCC were collected for immunohistochemical staining with PD-L1, CD86, CD8, PD-1 and CTLA-4 antibodies. Meanwhile, chemically induced mouse models of oral carcinogenesis were constructed with 4-nitroquinolone-N-oxide induction. Exhaustion status of T cells was measured by flow cytometry for spleens and by multiplex immunohistochemistry for formalin-fixed paraffin-embedded lesions in multiple stages of oral carcinogenesis. The efficacy of PD-1 blockade with or without cisplatin treatment was evaluated on the mice in precancerous and OSCC stages. We observed higher expression of PD-1 in the human OLK and OSCC tissues compared with the normal, while low expression CTLA-4 in all oral mucosa tissues. Animal experiments showed that the exhausted CD4+ T cells existed much earlier than exhausted CD8+ T cells, and an increased ratio of stem-like exhausted T cells and partially exhausted T cells were detected in the experimental groups. Besides, the expression of immune checkpoint markers (PDCD1, CTLA4 and HAVCR2) was strongly positively correlated with cytokines (IFNG and IL-2). In summary, T-cell exhaustion plays a vital role in oral carcinogenesis, and PD-1 blockade can prevent the progression of oral carcinogenesis.

Leukoplakia and Immunology: New Chemoprevention Landscapes?

Oral potentially malignant disorders (OPMDs) comprise a range of clinical-pathological alterations frequently characterized by an architectural and cytological derangements upon histological analysis. Among them, oral leukoplakia is the most common type of these disorders. This work aims to analyze the possible use of drugs such as immunochemopreventive agents for OPMDs. Chemoprevention is the use of synthetic or natural compounds for the reversal, suppression, or prevention of a premalignant lesion conversion to malignant form. Experimental and in vivo data offer us the promise of molecular prevention through immunomodulation; however, currently, there is no evidence for the efficacy of these drugs in the chemoprevention action. Alternative ways to deliver drugs, combined use of molecules with complementary antitumor activities, diet influence, and better definition of individual risk factors must also be considered to reduce toxicity, improve compliance to the protocol treatment and offer a better individualized prevention. In addition, we must carefully reconsider the mode of action of many traditional cancer chemoprevention agents on the immune system, such as enhancing immunosurveillance and reversing the immune evasion. Several studies emphasize the concept of green chemoprevention as an alternative approach to accent healthy lifestyle changes in order to decrease the incidence of HNSCC.

Met Receptor Tyrosine Kinase and Chemoprevention of Oral Cancer.

Background: We have previously shown that gene expression profiles of oral leukoplakia (OL) may improve the prediction of oral cancer (OC) risk. To identify new targets for prevention, we performed a systematic survey of transcripts associated with an increased risk of oral cancer and overexpressed in OC vs normal mucosa (NM). Methods: We used gene expression profiles of 86 patients with OL and available outcomes from a chemoprevention trial of OC and NM. MET expression was evaluated using immunohistochemistry in 120 OL patients, and its association with OC development was tested in multivariable analysis. Sensitivity to pharmacological Met inhibition was tested invitro in premalignant and OC cell lines (n = 33) and invivo using the 4-NQO model of oral chemoprevention (n = 20 mice per group). All statistical tests were two-sided. Results: The overlap of 693 transcripts associated with an increased risk of OC with 163 transcripts overexpressed in OC compared with NM led to the identification of 23 overlapping transcripts, including MET. MET overexpression in OL was associated with a hazard ratio of 3.84 (95% confidence interval = 1.59 to 9.27, P = .003) of developing OC. Met activation was found in OC and preneoplastic cell lines. Crizotinib activity in preneoplastic and OC cell lines was comparable. ARQ 197 was more active in preneoplastic compared with OC cell lines. In the 4-NQO model, squamous cell carcinoma, dysplasia, and hyperkeratosis were observed in 75.0%, 15.0%, and 10.0% in the control group, and in 25.0%, 70.0%, and 5.0% in the crizotinib group (P < .001). Conclusion: Together, these data suggest that MET activation may represent an early driver in oral premalignancy and a target for chemoprevention of OC.

Factores de riesgo asociados con leucoplasia bucal en pacientes del consultorio 43. Ciro Redondo. Bayamo. 2017 / Risk factors associated with oral leucoplakia in patients from doctor office 43. Ciro Redondo. Bayamo. 2017

Introducción: la prevalencia del cáncer bucal, varía según los diferentes países, y se reconoce entre las seis causas de muerte más frecuente entre todos los cánceres del mundo. Método: se realizó un estudio observacional analítico de caso control para determinar qué factores de riesgo influyen en la aparición de leucoplasia en pacientes de 15 a 59 años del consultorio 43 de Ciro Redondo, Bayamo, Granma en el período 2016-2017. Resultados: la leucoplasia, se localizó con mayor frecuencia en mucosa del carrillo. Se obtuvo como resultado que los pacientes más afectados por leucoplasia estuvieron en el grupo de 45 a 59 años, predominó el sexo masculino. Los factores de riesgo que predispusieron a la leucoplasia fueron la higiene bucal deficiente, el tabaquismo y los irritantes traumáticos y térmicos. Conclusiones: se demostró asociación directa entre los factores de riesgo y la aparición de la leucoplasia(AU)

Introduction: the prevalence of oral cancer varies according to the different countries, and it is recognized among the six most frequent causes of death among all cancers in the world. Method: an observational, analytical, case-control study was conducted to determine which risk factors influence the appearance of leukoplakia in patients aged 15 to 59 years from the 43rd office of Ciro Redondo, Bayamo, Granma in the 2016-2017 period. Results: leukoplakia was most frequently located in the mucosa of the cheek. It was obtained as a result that the patients most affected by leukoplakia were in the group of 45 to 59 years, the male sex predominated. The risk factors that predisposed to leukoplakia were poor oral hygiene, smoking and traumatic and thermal irritants. Conclusions: a direct association between risk factors and the appearance of leukoplakia was demonstrated(EU)

p53 and ki67 as biomarkers in determining response to chemoprevention for oral leukoplakia.

BACKGROUND: We performed a randomized controlled chemoprevention trial of oral leukoplakia by administrating a low dose of beta-carotene and vitamin C supplements. 17% of subjects in the experimental arm (4/23) demonstrated clinical remission (complete or partial response) at completion of the trial. The objective of this study was to determine whether baseline expression of p53 and ki67 demonstrated any differences between those responding or not responding to our intervention. A secondary objective was to elucidate any relationship between dietary factors and clinical responses. METHODS: For this biomarker study, we included all subjects in the experimental group (n = 23) who were non-smokers. Among 16 who completed the trial for 1 year of supplementation, there were four responders and 12 non-responders at 1-year follow-up. Following immuno-staining for p53 and ki67, the percentage of positive cell nuclei were analyzed as labeling index (LI). RESULTS: Expression of p53 was greater in basal layers than in para-basal layers. Mean para-basal LI of p53 was higher in non-responding (26.0) than in responding subjects (11.2) (P = 0.028). ki67 LIs were not significantly different in the two groups. CONCLUSIONS: Expression of p53 was inversely related to clinical response to the supplements. Other biomarkers that may recognize subject's responsiveness to chemoprevention require further study.

Avaliação clínica e histopatológica e hábitos associados ao surgimento de leucoplasias e eritroplasias orais / Clinical and histopathological evaluation and habits associated with the onset of oral leukoplakia and erythroplakia

Objective: This research aims to establish the prevalence, factors associated with the onset, and clinical and histopathological features of oral leukoplakia and erythroplakia, so that these data can contribute to the prevention of these lesions and, consequently, of oral cancer. Material and method: A retrospective study was conducted at a reference service of Universidade Federal do Rio Grande do Norte (UFRN) from 2000 to 2012. To verify the association of variables, Pearson's chi-squared test and Fisher's exact test (p ≤ 0.05) were used. Results: Among 6,560 investigated records, 54 cases were selected, of which 44.4% were male and 55.6% female, with mean age of 56.93 years. Regarding habits, 72.2% were smokers and 25% were alcohol users; 17.9% showed association of both habits. Oral leukoplakia lesions were the most prevalent (0.65%) and oral erythroplakia showed greater association with malignancy in the histopathological presentation (p = 0.001). Most lesions showed no symptoms (p = 0.004). The most frequent was oral leukoplakia in smoking women, with mean age of 57 years. Conclusion: Knowledge of associated factors and clinical characteristics of oral leukoplakia and erythroplakia is essential for establishing the correct diagnosis and treatment...

Objetivo: Esta pesquisa objetiva estabelecer a prevalência, os fatores associados ao surgimento e as características clínicas e histopatológicas das leucoplasias e eritroplasias orais, a fim de que estes dados possam contribuir na estratégia de prevenção ao desenvolvimento dessas lesões e, consequentemente, do câncer oral. Material e método: Foi realizado estudo retrospectivo em um serviço de referência da Universidade Federal do Rio Grande do Norte (UFRN) no período de 2000 a 2012. Para verificar a associação das variáveis foi utilizado o teste qui-quadrado e o exato de Fisher (p ≤ 0,05). Resultados: Foram investigados 6.560 prontuários, tendo sido selecionados 54 casos, dos quais 44,4% do sexo masculino e 55,6% do feminino, com idade média de 56,93 anos. Com relação aos hábitos, 72,2% eram fumantes e 25% usuários de álcool, sendo que 17,9% exibiam associação dos dois hábitos. As leucoplasias orais foram as lesões mais prevalentes (0,65%), e as eritroplasias orais apresentaram maior associação com apresentação maligna no diagnóstico histopatológico (p = 0,001). A maioria das lesões não apresentou sintomatologia (p = 0,004). A leucoplasia oral foi mais frequente em mulheres fumantes com média de idade de 57 anos. Conclusão: O conhecimento dos fatores associados e das características clínicas das eritroplasias e leucoplasias orais é essencial para o estabelecimento do correto diagnóstico e tratamento...

Mucosal disorders with oral epithelial dysplasia risk--development of a simple screening tool for general health care setting.

OBJECTIVES: Oral visual screening can avert oral cancer mortality. Oral premalignancies are currently considered as separate, individual disorders. The objective was to develop a simple clinical screening tool to detect oral premalignancies in general health care setting and validate diagnostic accuracy against Oral Medicine specialist examination as gold standard. MATERIALS AND METHODS: All steps in development of new tool, from item generation to item selection and item reduction were carried out. Item generation was done using qualitative methods. After pre-testing and piloting, junior dental house surgeon administered the refined tool, to patients attending dental outpatient department (n=255). Subsequent evaluation by an Oral Medicine specialist using consensus clinical criteria, detected 59 screen positive cases. Each case was recoded as per scores assigned by binary logistic regression coefficients and total score computed. The Receiver Operator Characteristic (ROC) was performed against specialist examination as gold standard. Performance ability and reliability coefficient of final tool was assessed. A simple score was assigned to indicate stage and clinical severity. RESULTS: Screening Tool for Oral Premalignancies (STOP) has sensitivity 96.6%, specificity 99.0% and accuracy 98.4% with reliability coefficient 0.874. Scores detect clinical signs and staging reflect clinical severity alerts. CONCLUSION: Oral Potentially Malignant Disorders need to be evaluated as single entity, under a common umbrella - Mucosal Disorders with Oral Epithelial Dysplasia risk (MD-OEDr). STOP is a simple tool for opportunistic general health care screening of MD-OEDr.

Different CO2 laser vaporization protocols for the therapy of oral precancerous lesions and precancerous conditions: a 10-year follow-up.

Use of the CO(2) laser (λ = 10.6 µm, continuous wave, defocused) is an established procedure for the treatment of premalignant lesions. Through employment of the sp-mode as well as scanners, thermal laser effects can be reduced but, on the other hand, a lesser degree of destruction of dysplastic cells could lead to an increased recurrence rate. The purpose of this study was to prospectively evaluate the recurrence rates resulting from different methods of CO(2) laser vaporization. From May 1995 to May, 2005, 145 patients with a total of 148 premalignant lesions of the oral mucosa were treated in a prospective clinical study. Sixty-two lesions in 62 patients were vaporized with the defocused CO(2) laser (group 1). In a further 45 lesions (43 patients, group 2), a scanner was additionally employed. In the remaining 41 lesions (40 patients, group 3), vaporization was carried out in the sp-mode in which the scanner was also used. In September, 2005, recurrence rates in the three groups were evaluated. Use of the scanner in sp-mode resulted in the most irregular tissue vaporization. This can be accounted for by the irregular paths of the laser beam and the pulsed delivery of the laser energy. Statistically significant lowest recurrence rates were yielded by the defocused cw-technique followed by the cw-scanner and the sp-mode. These results indicate that for CO(2) laser treatment of premalignant lesions of the oral mucosa, the best results can be achieved with the defocused technique. It may be assumed that other methods with lesser penetration of thermal effects (e.g. sp, scanner) do not reach the deeper-lying cells and, consequently, render higher rates of recurrence.

Lycopene: features and potential significance in the oral cancer and precancerous lesions.

Data from epidemiological studies have indicated that diets rich in fruits and vegetables are likely to benefit many aspects of the prevention of oral malignancy. Lycopene is a red-coloured carotenoid predominantly accumulated in tomatoes as well as other fruits and vegetables. It has been claimed to alleviate chronic diseases such as cancers and cardiovascular disease. Hence, the aim of this review is to summarize the features and its potential significance of lycopene in the development, prevention and treatment of oral premalignant lesions and oral cancer. Studies showed that lycopene might have beneficial effects in the management of some premalignant lesions in the oral cavity including oral submucous fibrosis and oral leukoplakia and may be an adjunct in the prevention and therapy of oral cancer. However, more mechanistic studies and randomized controlled trials of large sample size are necessary to further confirm these effects and to eventually make lycopene to be used in the community prevention and clinically routine management of these diseases.

Oral health risks of tobacco use and effects of cessation.

The purpose of this paper is to review the epidemiologic evidence for the effects of tobacco use and tobacco use cessation on a variety of oral diseases and conditions. Exposures considered include cigarette and bidi smoking, pipe and cigar smoking, and smokeless tobacco use. Oral diseases and disorders considered include oral cancer and precancer, periodontal disease, caries and tooth loss, gingival recession and other benign mucosal disorders as well as implant failure. Particular attention is given to the impact of tobacco use cessation on oral health outcomes. We conclude that robust epidemiologic evidence exists for adverse oral health effects of tobacco smoking and other types of tobacco use. In addition, there is compelling evidence to support significant benefits of tobacco use cessation with regard to various oral health outcomes. Substantial oral health benefits can be expected from abstention and successful smoking cessation in a variety of populations across all ages.

The effectiveness of chemoprevention agents is underestimated when lesion sizes are rounded.

Change in the area of premalignant lesions is an end point in estimating the efficacy of chemopreventive agents. When examiners round measurements of lesion length and width, they introduce variability, which perturbs the relative percent change in lesion area and, consequently, the percent of subjects showing a clinical response. We use simulations to illustrate the resulting bias when the agent under test is effective in reducing lesion area. We simulated 500 oral leukoplakia lesions per run, with 2,500 runs at each of five levels of agent effectiveness, namely, true relative percent reduction in area of 25%, 45%, 50%, 55%, and 75%. Realistic values of lesion lengths and widths were generated randomly and then rounded to the nearest multiple of five. The product is the distribution of mean relative percent change in lesion area and the corresponding percent of subjects showing a clinical response. Even the fifth percentile of the distribution of mean relative percent change in lesion area consistently underestimated the true value, by about 6 percentage points. The percent showing a clinical response was underestimated by 50%, 37%, and 11% for true values of reduction in lesion area of 50%, 55%, and 75%, respectively. This could easily double the required sample size for a modest phase II study. We suggest that it is cost-effective to train observers of lesion length and width to eschew rounding of measurements in the chemoprevention setting.

[Leukoplakia and erythroplakia--two orale precursor lesions]. / Leukoplakie und Erythroplakie--Zwei orale Präkursorläsionen.

The oral leukoplakia/erythroplakia is one of the most common epithelial precursor lesions of the oral squamous cell carcinoma. A clinical distinction is drawn between homogeneous and non-homogeneous as well as proliferative verrucous leukoplakia and erythroplakia. Due to the fact that the oral squamous cell carcinoma has a poor prognosis it is very important to decrease morbidity and mortality by systematic primary, secondary and tertiary prevention of the oral leukoplakia/erythroplakia. On the basis of histological classification systems the risk of malignant transformation can be evaluated, a defined therapy can be induced and the prognosis can be derived.

[Tobacco-associated lesions of the oral cavity and motivation for smoking cessation: a study of 121 cases]. / Lésions buccodentaires dues au tabac et motivation au sevrage : etude de 121 cas.

UNLABELLED: Tobacco use produces many changes to the oral cavity including non-malignant, precancerous, and malignant lesions. Most of these oral lesions and changes can be detected by a simple visual inspection of the oral cavity. METHODS: We evaluated the motivation for smoking cessation of patients with oral lesions. RESULTS: Visual inspection of the oral cavity in 121 patients made 58 % of them motivated to smoking cessation. DISCUSSION: Inspection of oral cavity showing lesions caused by tobacco is a good way to initiate tobacco cessation.

Lesões da mucosa oral em pacientes idosos: um problema pouco enfatizado por médicos e pesqisadores / Oral mucosa lesions in elderlly inpatients: a problem little emphasized by doctors and researchers

Objetivos: Estimar a freqüência de lesões da mucosa oral em idosos internados nas várias especialidades de hospital geral, em Belo Horizonte, Minas Gerais; determinar com qual freqüência as lesões detectadas pelos pesquisadores haviam sido identificadas também pelos médicos responsáveis pelos pacientes estudados e veridicar a possível associação dessas lesões com sexo, tabagismo, etilismo, edentulismo e uso de próteses dentárias. Pacientes e métodos: Os pacientes foram selecionados de acordo com a idade (60 anos e mais), a partir do prontuário médico, de onde também se extraíram informações sobre o sexo, realização do exame da cavidade oral pelo médico assistente e sobre a detecção de lesões da mucosa oral pelo mesmo. O diagnóstico das lesões baseou-se nas suas características clínicas. Resultados: Foram avaliados 198 pacientes, com idade média de 75 anos, sendo 116 do sexo feminino e 82 masculino. Foram detectadas lesões nas cavidades orais de 69 pacientes (34,8 por cento). Em apenas 13 pacientes (6,6 por cento) as lesões haviam sido detectadas também pelo médico assistente. As lesões mais freqüentemente encontradas foram candidíase (23 por cento), epulis fissuratum (11 por cento), hiperplasia inflamatória (11 por cento), afta recorrente (10 por cento), papiloma (10 por cento), queilite angular (7 por cento) e leucoplasia (3 por cento). Em relação à associação das lesões com sexo, tabagismo, etilismo, edentulismo e uso de prótese, encontrou-se que o uso de prótese esteve associado com maior número de lesões, especificamente, com hiperplasia inflamatória. Conclusões: Os dados ora apresentados são comparáveis aos observados em outros estudos, mas, diferentemente daqueles, demonstram o pequeno interesse dos médicos pelo exame da cavidade oral dos seus pacientes. Ressaltamos, portanto, a importância deste trabalho, cujos resultados alertam para a necessidade da realização do exame da cavidade oral por todos os profissionais que cuidam de pacientes idosos.

Aims: To estimate the prevalence of oral mucosa lesions in elderly inpatients admitted to different specialities of a general hospital, its possible association with gender, smoking habit, alcohol use, edentulis and dental prosthesis anda how often these lesions go unrecognizes. Patients and methods: The case notes of all patients 60 years of age and older of both sexes were analyzes in order to identify whether the oral cavity was examined by the responsible doctor and what kind of oral mucosa lesions were detected. Results: A total of 198 patients (median age: 75 years) (116 females; 82 males) were evaluated. Oral cavity lesions were detected in 69 patients (34,8 percent). In only 13 patients (6,6 percent) lesions were recognized by the responsible doctor. The most frequently found lesions were: candidiasis (23 percent), epulis fissuratum (11 percent), inflammatory hyperplasia (11 percent), recurrente aphthous ulcer (10 percent), papilloma (10 percent), angular chelilitis (7 percent) and leucoplakia (3 percent). The use of dental prosthesis was associated with a greater number of lesions specifically inflammatory hyperplasia. Conclusions: The prevalence and type of oral mucosa lesions found in our study is similar to other studies. Nevertheless, is was clear that routine examination of the oral cavity was not performed regularly. It's highlighted the importance of routine examination of elderly oral cavity.

Oral hygiene practices and risk of oral leukoplakia.

OBJECTIVE: To determine the influence of oral hygiene habits and practices on the risk of developing oral leukoplakia. DESIGN: Case control study. SETTING: Githongo sublocation in Meru District. SUBJECTS: Eighty five cases and 141 controls identified in a house-to-house screening. RESULTS: The relative risk (RR) of oral leukoplakia increased gradually across the various brushing frequencies from the reference RR of 1.0 in those who brushed three times a day, to 7.6 in the "don't brush" group. The trend of increase was statistically significant (X2 for Trend : p = 0.001). The use of chewing stick as compared to conventional tooth brush had no significant influence on RR of oral leukoplakia. Non-users of toothpastes had a significantly higher risk of oral leukoplakia than users (RR = 1.8; 95% confidence levels (CI) = 1.4-2.5). Among tobacco smokers, the RR increased from 4.6 in those who brushed to 7.3 in those who did not brush. Among non-smokers, the RR of oral leukoplakia in those who did not brush (1.8) compared to those who brushed was also statistically significant (95% CL = 1.6-3.8). CONCLUSION: Failure to brush teeth and none use of toothpastes are significantly associated with the development of oral leukoplakia, while the choice of brushing tools between conventional toothbrush and chewing stick is not. In addition, failure to brush teeth appeared to potentiate the effect of smoking tobacco in the development of oral leukoplakia. RECOMMENDATIONS: Oral health education, instruction and motivation for the improvement of oral hygiene habits and practices; and therefore oral hygiene status, should be among the strategies used in oral leukoplakia preventive and control programmes.

[Preventive effect of genistein on malignant transformation of oral leukoplakia].

OBJECTIVE: To investigate the preventive effect of genistein on the malignant transformation of oral leukoplakia in hamster cheek pouch. METHODS: Sixty male Syrian golden hamsters were randomly divided into 4 groups, with two of 20 and two of 10. DMBA solution (0.5% in acetone) was applied topically to the left cheek pouch of male Syrian golden hamsters in group A and B, while animals in group C were painted with acetone, 3 times a week for 6 weeks. For the next 12 weeks, animals in group B received genistein (10 mg.kg(-1).d(-1)) daily by gavage; animals in group A and C received same volume of saline; animals in group D serving as blank control. At the end of the experiment, animals were sacrificed and tissue samples were collected for histopathological examination. RESULTS: No significant differences in the tumor latency and tumor incidence were observed between the control and genistein treated group. CONCLUSIONS: No inhibitory effect of genistein on the transformation of oral leukoplakia was observed in hamster.