Oral mucosal lesions associated with betel quid, areca nut and tobacco chewing habits: consensus from a workshop held in Kuala Lumpur, Malaysia, November 25-27, 1996.

A variety of betel/areca nut/tobacco habits have been reviewed and categorized because of their possible causal association with oral cancer and various oral precancerous lesions and conditions, and on account of their widespread occurrence in different parts of the world. At a recent workshop in Kuala Lumpur it was recommended that "quid" be defined as "a substance, or mixture of substances, placed in the mouth or chewed and remaining in contact with the mucosa, usually containing one or both of the two basic ingredients, tobacco and/or areca nut, in raw or any manufactured or processed form." Clear delineations on contents of the quid (areca nut quid, tobacco quid, and tobacco and areca nut quid) are recommended as absolute criteria with finer subdivisions to be added if necessary. The betel quid refers to any quid wrapped in betel leaf and is therefore a specific variety of quid. The workshop proposed that quid-related lesions should be categorized conceptually into two categories: first, those that are diffusely outlined and second, those localized at the site where a quid is regularly placed. Additional or expanded criteria and guidelines were proposed to define, describe or identify lesions such as chewer's mucosa, areca nut chewer's lesion, oral submucous fibrosis and other quid-related lesions. A new clinical entity, betel-quid lichenoid lesion, was also proposed to describe an oral lichen planus-like lesion associated with the betel quid habit.

A national epidemiological survey of oral mucosal lesions in Malaysia.

The prevalence of oral mucosal lesions in Malaysia was determined by examining a representative sample of 11,707 subjects aged 25 years and above throughout the 14 states over a period of 5 months during 1993/1994. A two-stage stratified random sampling was undertaken. A predetermined number of enumeration blocks, the smallest population unit in the census publication, was selected from each state. With the selected enumeration block, a systematic sample of living quarters was chosen with a random start. The survey instrument included a questionnaire on sociodemographic characteristics and a clinical examination. The clinical examination was carried out by 16 specially trained dental public health officers and the diagnosis calibrated with a final concordance rate of 92%. The age in the sample ranged from 25 to 115 years with a mean of 44.5+/-14.0. The sample comprised 40.2% males and 59.8% females; 55.8% were Malays, 29.4% Chinese, 10.0% Indians and 1.2% other ethnic groups. Oral mucosal lesions were detected in 1131 (9.7%) subjects, 5 (0.04%) had oral cancer, 165 (1.4%) had lesions or conditions that may be precancerous (leukoplakia, erythroplakia, submucous fibrosis and lichen planus) and 187 (1.6%) had betel chewer's mucosa. The prevalence of oral precancer was highest amongst Indians (4.0%) and other Bumiputras (the indigenous people of Sabah and Sarawak) (2.5%) while the lowest prevalence was amongst the Chinese (0.5%).

Prevalence study of oral mucosal lesions in a selected Cambodian population.

The aim of this study was to investigate the epidemiology of oral mucosal lesions in a selected Cambodian population to obtain pilot data useful in planning an oral health data base for the country. Due to unstable conditions in Cambodia, the validity of population data related to present census information is highly questionable. Therefore, prior to this investigation a census registration was carried out using local health workers as registrars in nine villages of a commune. In the period July 4-31, 1991, a total of 1319 individuals (953 women, 366 men, 15-99 yr) were examined by one oral surgeon in the nine villages of Kok Trop Commune, Kandal Stung District, southwest of the capital Phnom Penh. Clinical diagnoses were based on WHO criteria. Information on smoking habits, betel nut chewing habits, and alcohol use was collected by 4 Khmer dental personnel. In total, 71 lesions were recorded in 64 (4.9%) individuals. Leukoplakia was found in 1.1%, lichen lesions in 1.8%, candidosis in 1.4%, submucous fibrosis in 0.2%, cancer in 0.1% and other diagnoses in 0.8%. The prevalence of leukoplakia was 2.2% and 0.6% among men and women respectively, a statistically significant difference (P < 0.05). There were significantly more smokers (P < 0.01) among subjects with leukoplakia (64.3%) than among those without this lesion (28.6%). All subjects with lichen lesions were women. The age-adjusted relative risk for developing lichen among betel nut chewers as compared to non-chewers was 3.3.(ABSTRACT TRUNCATED AT 250 WORDS)

Oral melanin pigmentation in 467 Thai and Malaysian people with special emphasis on smoker's melanosis.

At the faculties of dentistry in Chiang Mai, Thailand (CM), and Kuala Lumpur, Malaysia (KL), 234 and 233 consecutive out-patients were interviewed concerning tobacco and chewing habits and examined for the presence of oral melanin pigmentation. Tobacco was regularly used by 32% and 28% of the studied populations in CM and KL. Cigarette smoking was the predominant habit, but the chewing of betel and tea leaves (miang) and the smoking of banana leaf cigars (khi yo) was also registered. The genetically acquired pigmentation dominated. Although nearly all non-tobacco users in the Malay and Indian populations had oral melanin pigmentation, it was found that tobacco smokers had significantly more oral surfaces pigmented than non-tobacco users. Among Thais, the percentage of pigmented individuals was significantly higher among tobacco smokers. It was concluded that tobacco smoking stimulates oral melanocytes to a higher melanin production also in dark-skinned ethnic groups.

Prevalence of oral soft tissue lesions in out-patients at two Malaysian and Thai dental schools.

At the Faculties of Dentistry in Chiang Mai, Thailand (CM), and Kuala Lumpur, Malaysia (KL), 234 and 233 consecutive out-patients of mean ages 33.8 and 31.0 yr, respectively, were examined for the presence of oral mucosal lesions. Tobacco in some form was regularly used by 31.7% and 27.5% of the study populations in CM and KL, respectively. Cigarette smoking was the predominant habit. In CM three persons chewed betel quids and nine smoked banana leaf cigars daily. In addition, there were 24 habitual chewers of tea leaves (miang). In KL six persons chewed betel quids daily. In CM and KL three cases each (1.3%) of tobacco-associated leukoplakias were found. In KL an additional idiopathic leukoplakia was registered. One and three cases of betel related lesions were found in CM and KL, respectively. One case of a squamous cell carcinoma was found in a 45-yr-old Indian woman in KL who had been chewing betel with tobacco daily for many years. High prevalence figures were found for lichen planus, 3.8% in CM and 2.1% in KL, and an extremely high one, 48.3%, in CM for episodes of aphthous ulcers experienced during the last 2 yr. Comparatively low prevalence figures were found for herpes labialis. As could be expected melanin pigmentation was prevalent while only low figures were encountered for denture-related lesions and amalgam tattoos.