Leukoplakia, lichen planus, and other oral keratoses in 23,616 white Americans over the age of 35 years

This investigation provides the first detailed population-based reporting of white keratotic lesions of the oral mucosa in a United States population. More than 21% of 3,783 oral mucosal and connective tissue lesions reported from 23,616 white Americans, usually over 35 years of age, were keratotic lesions, representing 3.4% of the entire group of examinees. Leukoplakia was the most common of all lesions diagnosed and was the most common of the keratotic lesions (85.5% of the latter). The prevalence rate for leukoplakia was 28.9/1,000 white Americans over 35 years of age and was twice as high for males as for females (43.2/1,000 males versus 20.9/1,000 females). Age-specific leukoplakia prevalence rates demonstrated a tenfold increase for males from the third to the eighth decade of life, and twofold increase for females from the fourth to the seventh decade. Sites of leukoplakia involvement, in decreasing order of frequency, were lip vermillion, buccal mucosa, mandibular gingiva, tongue, oral floor, hard palate, maxillary gingiva, lip mucosa, and soft palate. Almost 7% of leukoplakias demonstrated carcinoma or severe dysplasia microscopically. Prevalence rates for other white oral mucosal lesions were tobacco/snuff pouch keratosis, 1.6/1,000; chronic cheek bite, 1.2/1,000; lichen planus, 1.1/1,000; palatitis nicotina, 0.7/1,000; and leukoedema, 0.3/1,000.     

Prevalence of oral leukoplakia in 1000 Berliners

OBJECTIVE: The aim of this study was to determine the prevalence of oral leukoplakia and other oral white lesions in an urban population of non-referred patients to a department of oral surgery in the city of Berlin.
DESIGN: A total of 1000 patients over the age of 16 were evaluated for oral leukoplakia and other oral white lesions. Age, sex, and smoking as well as alcohol habits were recorded.
RESULTS: Of 506 men (50.6%) and 494 women (49.4%), 0.9% showed oral leukoplakia. Men were more frequently affected (I.6%) than women (0.2%). Patients of older age groups were more frequently affected than younger patients. Other white oral lesions were recorded such as leukoedema (8.3%), smoker's palate (0.I%), frictional white lesions (2.6%) and lichen planus (0.6%) with equal distribution between men and women.
CONCLUSION: The prevalence of oral leukoplakia in this limited group of urban patients was low, however comparable to that of other neighbouring west European countries. Association with tobacco and alcohol consumption was demonstrated as in most other studies.     

Occurrence of oral mucosal lesions, the influence of tobacco habits and an estimate of treatment time in an adult Swedish population

A randomly selected sample of adult subjects living in a Swedish county was examined for the presence of oral mucosal lesions. Nine hundred twenty (920, 95%) of the selected sample of 967 subjects, comprising approximately 0.75% of the total adult population, were examined; lesions were registered in 596 of the 920. The registered prevalence levels were very similar to earlier reported data from Sweden. Further, the relationship between tobacco habits and mucosal lesions was analyzed and the time needed for treatment of the lesions was estimated. A positive correlation could be demonstrated between tobacco use and leukoplakia, frictional white lesion, coated tongue, hairy tongue and excessive melanin pigmentation, while a negative correlation was observed for geographic tongue and aphthous ulcers. Approximately 70% of the lesions were associated with local irritants (e.g. dentures, tobacco, cheek and lip biting etc.). The estimated mean time required for registration and management of oral mucosal lesions in the studied group of adults was 24 min per individual.     

The prevalence of oral mucosal lesions in a population in Ljubljana, Slovenia

The purpose of the present study was to evaluate the prevalence of oral mucosal lesions and conditions in a population in Ljubljana, capital of Slovenia. A total 1609 subjects represented the study population in the survey about the periodontal treatment needs in a population in Ljubljana, conducted from 1983 to 1987. Ten years later the same 1609 subjects were invited to the second examination. Altogether, 555 (34.5%) of the invited subjects in the age range 25-75 years came for an interview and clinical examination at the Department of Oral Medicine and Periodontology of the Dental Clinic in Ljubljana. Oral mucosal lesions and conditions were evaluated according to the WHO Guide to Epidemiology and Diagnosis of Oral Mucosal Diseases and Conditions. The results showed the presence of one or more mucosal lesions in 61.6% of the population. Fordyce's condition was observed the most frequently (49.7%) followed by: fissured tongue (21.1%), varices (16.2%), history of herpes labialis (16.0%), history of recurrent aphthae (9.7%), denture stomatitis (4.3%), leukoplakia (3.1%), cheek biting (2.7%), lichen planus (2.3%), frictional keratosis (2.2%), geographic tongue (2.2%), geographic and fissured tongue together (1.1%), mucocele (0.9%), smoker's palate (0.5%) and angular chelitis (0.4%). In the population examined, no oral malignancies were observed. Mucosal lesions like whitish lesions, denture related lesions, fissured tongue, varices and mucocele were more prevalent with increasing age. Tobacco-related lesions (leukoplakia and smoker's palate together) were significantly more prevalent among men than among women (P<0.05), while lichen planus, denture stomatitis and herpes labialis occurred more frequently in the female population.     

The prevalence of oral mucosal lesions in patients visiting a dental school in Southern India.

The purpose of the present study was to evaluate the prevalence of oral mucosal lesions in Manipal, Karnataka State, India. A total of 1190 subjects who visited the department of oral medicine and radiology for diagnosis of various oral complaints over a period of 3 months were interviewed and clinically examined for oral mucosal lesions. The result showed the presence of one or more mucosal lesions in (41.2%) of the population. Fordyce's condition was observed most frequently (6.55%) followed by frictional keratosis (5.79%), fissured tongue (5.71%), leukoedema (3.78%), smoker's palate (2.77%), recurrent aphthae, oral submucous fibrosis (2.01%), oral malignancies (1.76%), leukoplakia (1.59%), median rhomboid glossitis (1.50%), candidiasis (1.3%), lichen planus (1.20%), varices (1.17%), traumatic ulcer and oral hairy leukoplakia (1.008%), denture stomatitis, geographic tongue, betel chewer's mucosa and irritational fibroma (0.84%), herpes labialis, angular cheilitis (0.58%), and mucocele (0.16%). Mucosal lesions like tobacco-related lesions (leukoplakia, smoker's palate, oral submucous fibrosis, and oral malignancies) were more prevalent among men than among women. Denture stomatitis, herpes labialis, and angular cheilitis occurred more frequently in the female population.     

The prevalence of oral mucosal lesions in adults from the Turin area

Aim:  To assess the prevalence of oral mucosal lesions (OML) and evaluate its association with tobacco and alcohol consumption and the wearing of removable dentures in an adult population from the Turin area, Italy.
Materials and methods:  A retrospective study, based on an invitational self-selected screening, was performed on 4098 subjects. It included clinical examination plus biopsies when necessary. Patient history included age, sex, denture wearing and risk habits. Internationally accepted criteria were adopted to classify the OMLs.
Results:  Males were observed to have more OMLs (557/2040; 27.3% vs 471/2058; 22.89%). Overall OML prevalence was linked to risk habits and age. Tobacco was linked to leukoplakia, melanin pigmentation, smoker's palate, frictional lesions and papilloma. It was negatively related to recurrent aphthous stomatitis and oral lichen planus. Alcohol was linked to leukoplakia, frictional lesions and median rhomboid glossitis. The tobacco–alcohol association was linked to frictional lesions, leukoplakia, melanin pigmentation and smoker's palate. Denture wearers had an overall higher prevalence of OMLs, in particular candidiasis, traumatic and frictional lesions.
Conclusions:  The prevalence of OMLs in Turin seems to be comparable to those in other European studies and emphasize that risk habits and denture wearing have some relationship with the presence of OMLs.     

Oral mucosal lesions in a representative cross-sectional study of aging Germans

OBJECTIVES: To determine prevalence of oral mucosal lesions in a cross-sectional study among aging Germans. METHODS: Three specially trained dental teams examined adults (35-44 yrs, Group 1) and senior individuals (65-74 yrs, Group 2) in 90 sample points of which 60 were located in the former West and 30 in the former East part of Germany. The spectrum comprised 28 different oral lesions with subforms. RESULTS: 655 individuals in Group 1 (35-44 yrs) and 1367 individuals in Group 2 (65-74 yrs) were studied. 33.8% (Group 1) and 33.9% (Group 2) were without any pathology of the oral mucosa. Several lesions were not recorded in both Groups like oral hairy leukoplakia and gingival hyperplasia (Group 1 and two) and xerostomia (Group 1). In Group 1 history for labial herpetic lesions (31.7%), Fordyce granules (26.6%), history for recurrent aphthous ulceration (18.3%) and lip and/or cheek biting (10.1%) were recorded. In Group 2 Fordyce granules (23.7%), history of labial herpes (20.0%), plicated tongue (19.0%) and denture stomatitis (18.3%) were those lesions most frequently recorded. Leukoplakia was seen in 1.8% (West) and 0.9% (East) respectively; men were more often affected than women (2.3% versus 0.0% P<0.05, Group 1; 2.3% versus 0.9%, Group 2. There was association between the prevalence of leukoplakia and a lower (3.3%) or higher educational level (0.5%). Denture associated lesions were seen in 18.3% (Group 2) compared to 2.5% (Group 1) (P<0.001). Other age-related lesions were lip and/or cheek biting being more prevalent in Group 1 10.1% versus 1.9% (P<0.001), plicated tongue 19.0% in Group 2 versus 3.8% in Group 1 (P<0.001). CONCLUSIONS: The present study has shown prevalence to be comparable to other relevant Western European studies. Since the spectrum of oral mucosal lesions changes with age and increases with general morbidity, routine examinations of oral cavities of the aging are mandatory particularly to detect early precancerous and other mucosal lesions.     

Nachweis von TP53-Mutationen mittels Exfoliativzytologie (brush biopsy) oraler Leukoplakien

Objective. The aim of this study was to determine the prevalence of mutations of the tumour suppressor gene TP53 in oral leukoplakias. Material and method. Brush biopsy specimens of 43 oral leukoplakias, 26 oral squamous cell carcinomas (OSCC) for reference, and the oral mucosa of 4 clinically normal volunteers were collected. DNA of the critical exons 5–8 was analysed by temperature gradient gel electrophoresis (TGGE). Results. The prevalence of mutations was 57.7% in OSCC, 39.5% in leukoplakias and 0% in controls. The highest frequency of mutations was found in exon 5 (46.2%) in OSCC and in exon 6 (23.3%) in leukoplakia. More than one mutation was detected in 26.9% of OSCC and 7% of leukoplakia specimens. At least one mutation was found in 37.5% of T1 OSCC and 100% of T4 OSCC specimens and in 37.1% of the L1 leukoplakia and 100% of L3 leukoplakia specimens. Conclusions. TP53 mutations could be a useful prognostic indicator in precancerous oral lesions. Although the brush biopsy technique appears simple clinically, further investigations are necessary to specify the implications of genetic analysis.     

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

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.     

Risk factors for oral soft tissue lesions in an adult Spanish population

OBJECTIVES: The aims of this study were (i) to determine the prevalence of oral lesions in adults over 30 years old in the city of Oviedo (Spain), and (ii) to analyze the relationship between the prevalence of oral lesions, toxic habits (tobacco and alcohol) and denture wearers in these patients. METHODS: A representative sample of the adult population in Oviedo (Spain) was obtained through randomized sampling (n = 753); a total of 308 (41%) subjects were finally included in the study. The observed oral pathology was classified according to the WHO criteria and earlier epidemiological studies. RESULTS: A little over half of all patients (51.1%) had oral lesions. The most frequent lesions were frictional lesion (7.5%), traumatic ulcer (7.1%), denture stomatitis and pseudomembranous candidosis (6.5%), followed by melanin pigmentation (5.8%) and denture-induced hyperplasia (5.2%), plicated tongue (3.9%), lichen planus and hemangioma (3.2%), angular cheilitis and cheek biting (2.9%), fibrous hyperplasia and coated tongue (2.6%), recurrent aphthae (1.9%) and oral leukoplakia (1.6%). In relation to leukoplakia, the odds ratio (OR) of heavy drinkers was 15.98 and the OR of heavy smokers was 12.37. The OR of heavy smokers or heavy drinkers diagnosed of frictional lesion was four times greater than that of nonsmokers or nondrinkers. The OR of heavy smokers with melanic pigmentations was 4.08. The OR of complete denture wearers with candidosis was 11.38. The OR of partial removable denture wearers with hemangioma was 5.01. CONCLUSIONS: This study shows the relation of heavy tobacco and heavy alcohol to traumatic keratosis and leukoplakia, and of complete dentures to pseudomembranous candidosis, fibrous hyperplasia and stomatitis. Programs designed to eradicate toxic factors (alcohol and tobacco) should, therefore, be implemented with adequate maintenance of dentures.     

A clinical and epidemiologic study morsicatio buccarum/labiorum

abstract – A study of habitual self mutilation of the buccal and/or labial mucosa by biting was conducted on 8,589 persons attending the Royal Dental College, Copenhagen. Forty-two cases were found. The youngest patient was 5 years old and the oldest was 47. The condition occurred most frequently (1.77%) among persons aged 15–19 years. There was no difference in prevalence between males and females. Combined mutilation of cheek(s) and lip(s) was more frequent (62%) than isolated mutilation of the cheek(s) (24%) or isolated mutilation of the lip(s) (14%). Bilateral biting of the cheeks was more frequent than unilateral biting, and biting of the lower lip was more frequent than biting of the upper lip. Ninety-three per cent of the patients were aware of their habit, and most of them stated that they had been biting for years. Twenty patients were re-examined; in all but one patients the biting persisted but in 7 patients the location of the lesions had changed. In several cases a link could be traced to personal problems and mental stress. It was further noticed that many patients were students and white-collar workers, suggesting that "intellectual" work may predispose for the habit.     

The prevalence of oral mucosal lesions in U.S. adults: data from the Third National Health and Nutrition Examination Survey, 1988-1994

BACKGROUND: Most reports of oral lesion prevalence are based on studies of atypical populations. There are no published studies on oral mucosal lesion prevalence in U.S. adults that are based on a national probability sample. METHODS: The Third National Health and Nutrition Examination Survey, or NHANES III, employed a complex, multistage sample of 33,994 civilian, noninstitutionalized people from 19,528 households. Dentist examiners were trained to recognize, classify and record in a standardized manner the clinical characteristics of each of the 48 conditions of interest to include diagnosis, size, location, surface morphology, color consistency, pain, duration and history using procedures based on the World Health Organization's Guide to Epidemiology and Diagnosis of Oral Mucosal Diseases. RESULTS: Examinations were performed on 17,235 people aged 17 years and older, of whom 4,801 (27.9 percent) had a total of 6,003 lesions. Denture-related lesions (stomatitis, hyperplasia, ulcers, inflammation and angular cheilitis) composed 8.4 percent and tobacco-related lesions (smokeless tobacco-related and nicotinic stomatitis) composed 4.7 percent of all lesions. Discounting denture-related lesions, amalgam tattoos were the most prevalent lesions (3.30 percent), followed closely by cheek/lip bites (3.05 percent) and frictional white lesions (2.67 percent). Smokeless-tobacco users (odds ratio, or OR, = 3.90) and removable denture wearers (OR = 3.57) had the highest odds of having a lesion. CONCLUSION: Lesion prevalences differed significantly by age, sex, race/ethnicity, denture wearing and tobacco use. When lesion-specific prevalences are cited in the literature, they should be stratified by covariates known to be associated with them.     

Oral habits in children--a prevalence study

This epidemiological study was conducted upon 4,590 school children to find the prevalence of oral habits in Mangalore in relation to their age and sex and to find the correlation, if any, between the habits and the malocclusion status. We noted that 29.7% of the population had habits of which 3. 1% had digit sucking, 4.6% mouth breathing, 3.02% tongue thrusting, 6.2% bruxism, 6% lip/cheek biting, 12.7% nail biting, 9.8% pencil biting and 0. 09% masochistic habits respectively. Digit sucking, pencil biting and tongue thrust were highly prevalent among Group 1 (3-6 years) children. Mouth breathing and bruxism were significant in Group 2 (7-12 years) cases whereas lip/cheek biting and nail biting were more common in Group 3 (13-16 years) cases. Digit sucking, tongue thrust, mouth breathing and bruxism were more prevalent among the boys whereas lip/cheek biting, nail biting and pencil biting were more prevalent among the girls. 28.95% of the children in Group 2 and 3 with habits had malocclusion. There was a significant correlation between class I type 2, class II div 1 and tongue thrust and mouth breathing whereas children with digit sucking showed a high correlation with class I type 2 malocclusion.     

Prevalence of oral mucosal lesions in a representative population.

OBJECTIVE: The aim of this study was to assess the prevalence and intraoral distribution of oral mucosal lesions in a representative adult population (Study of Health in Pomerania/Germany). METHOD AND MATERIALS: The study sample comprised 6267 randomly selected subjects who were scheduled for examination from 1997 to 2001 (population-based cross-sectional study; response rate: 69%; age range 20 to 81 years). RESULTS: The prevalence of oral mucosal lesions was age dependent (5.56% in 20- to 29-year-olds to 19.55% in 70- to 81-year-olds) with an overall prevalence of 11.83%. The prevalence in men (12.20%) was slightly higher than in women (11.40%). Exophytic neoplasia was the most prevalent alteration (3.00%), followed by leukoplakia simplex (prevalence 2.85%). Premalignant lesions were found in 0.57% of the participants, with lichen ruber mucosae contributing the major part (0.48%). Exophytic neoplasia was most often situated in the buccal mucosa, the hard palate, or the mucosa of the lower lip. CONCLUSION: These data stress the importance of screening for oral mucosal lesions, especially because of a predicted increase in the number of elderly persons in industrialized countries.     

Leukoplakia and carcinoma in situ synchronously associated with invasive oral/oropharyngeal carcinoma in Rochester, Minn., 1935-1984

Previous investigations into the association between oral/oropharyngeal carcinoma and clinical white patches (leukoplakia) have noted that the latter lesion is found adjacent to malignancies in 10% to 100% of all carcinomas of this site. This is an unacceptable variation in results and probably relates more to the referral biases inherent in hospital-based studies than to any other factor. The present population-based study, which is relatively free of selection bias, demonstrates that 62%, 36%, and 18% of invasive carcinomas of the labial vermilion, oral cavity proper, and oropharynx, respectively, have leukoplakia lesions of immediately adjacent mucosal surfaces. Only 7% of invasive carcinomas have juxtaposed carcinoma in situ, whereas another 2% have severe epithelial dysplasia. Mucosal carcinomas associated with leukoplakias appear to be smaller, more mature histologically, and more likely to be only superficially invasive; such carcinomas present with fewer metastases at diagnosis and provide a better prognosis than similar carcinomas not associated with leukoplakia.     

Effect of cessation of tobacco use on the incidence of oral mucosal lesions in a 10–yr follow-up study of 12 212 users

OBJECTIVE: To study the effect of cessation of tobacco use on the incidence of lichen planus, leukoplakia and other oral mucosal lesions.
DESIGN: A 10–yr cohort study in a rural population of Ernakulam district, Kerala, India.
MATERIAL AND METHODS: Some 12 212 tobacco users were interviewed and examined in a basetine survey and re-examined annually for 10 years. At each examination they were exposed to health educational programs to encourage them to quit their tobacco use. The incidence rates were calculated using person-years method among those who stopped their tobacco use and all others.
RESULTS: A total of 77 681 person-years of observation accrued among men and 32 544 among women. Among men 6.5% of these and among women 14.4% were in the stopped category. The incidence of oral lichen planus did not show any consistent association with cessation of tobacco habits (incidence ratio I.35) but for leukoplakia there was a substantial drop in the incidence after cessation (incidence ratio 0.3I). Several other tobacco-associated oral mucosal lesions such as oral lichen planus-like lesion, smoker's palate, preteukoplakia, central papillary atrophy of the tongue and leukoedema showed either zero, or very small incidence, after cessation. CONCLUSION: The reported association between tobacco use and lichen planus appears to be indirect but for all other lesions it is direct. The cessation of tobacco use led to a substantial fall in the incidence of leukoplakia and other lesions implying a reduced risk for oral cancer after cessation of tobacco use.     

Longitudinal studies in oral leukoplakias

Abstract. Follow-up examinations of 520 patients with oral leukoplakia during a 25-ycar period showed cancer development in 31 cases, i.e. 5.9 %. The mean observation period was 8.7 years. The age distribution of leukoplakia showed that the highest frequency occurred in the age group 51–60 years; carcinoma was most frequency in the age group 61–70 years. Females had a higher prevalence for malignant transformation of oral leukoplakia (7.2 %). The tongue was the site of predilection for malignant transformation (in 38.8 % of the eases). Among etiological factors, smoking, mechanical irritation, alcohol consumption and electrical potential differences could be correlated with oral leukoplakia. Certain factors seemed to favor the development of cancer. Carcinoma originated in 26 % of verrucous leukoplakias and in 74 % of erosive leukoplakias. The highest risk for malignant transformation of leukoplakia occurs in the erosive type, whereby 28 % of all eases developed into cancer.     

Yeast species and biotypes associated with oral leukoplakia and lichen planus

Of 36 patients, 17 had oral leukoplakia, including homogeneous and nonhomogeneous types, and 19 had reticular lesions of oral lichen planus. A sample of yeast flora in each patient was taken from the pathologic lesion as well as from normal-appearing mucosa. The isolated yeasts were identified according to species level, and identification was extended beyond the species level for one species, Candida albicans, to reveal the biotype by means of the Odds and Abbott procedure comprising tests for acid and salt tolerance, proteinase production, resistance to 5-fluorocytosine and safranine, and assimilation of urea, sorbose, and citrate. Yeasts were present in the lesions of 82% of leukoplakia patients, compared to 37% of lichen planus patients, a frequency of yeasts corresponding to that in healthy adults. C. albicans was the dominating species in lesions of both diseases, constituting 82% of all yeasts in the leukoplakia lesions. In addition, the following species were identified: Candida tropicalis, Candida pintolopesii, Torulopsis glabrata, and Saccharomyces cerevisiae. Eighteen biotypes of C. albicans were encountered, the most frequently occurring biotypes being 355 and 177. Differences between C. albicans biotypes isolated from pathologic and normal mucosa were encountered in five of eleven leukoplakia patients and in one of three lichen planus patients. This indicates that the oral cavity comprises several ecologic niches for yeasts. As nonhomogeneous leukoplakias are more likely to develop into carcinoma than are homogeneous leukoplakias, it is interesting to note that the C. albicans biotypes isolated from nodular lesions (one type of nonhomogeneous leukoplakia)--biotypes 145, 175, and 575--rarely occur.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevalence study of oral precancerous lesions within a complex screening system in Hungary

Previous epidemiological studies, performed in conjunction with compulsory lung screening examinations, showed good results in detecting oral lesions in Hungary, where the mortality rate of oropharyngeal cancer has increased by more than 30% in the past decade. Oral examinations were performed on a district population sample in Budapest, called regularly for X-ray lung examinations. Precancerous lesions and conditions were diagnosed and grouped according to internationally accepted criteria. Oral examinations of 7820 individuals were performed: 42.9% in men and 57.1% in women; 42% of all examined subjects were over 60 yr of age. Oral leukoplakia was diagnosed in 104 cases (1.3%). Histologic examination revealed squamous cell carcinoma in one case. About 70% of oral leukoplakias occurred in men and 30% in women. Oral lichen was diagnosed in six cases (0.08%). The prevalence of smokers was 86.5% in the leukoplakia group as compared with with 29% in the non-lesion group. The new organizational screening model seems to function well in the "risk group" of elderly persons, especially in the early diagnosis of oral cancer and precancerous lesions.     

Size of nucleus and nucleolus in quantitative electron microscopy on orthokeratinized leukoplakias

abstract — Eleven leukoplakias of the homogeneous orthokeratotic type and control areas in the same patient were studied by means of standardized electron microscopic preparations of biopsy material and by methods of stereology applied to electron micrographs. In leukoplakias, nuclei and nudeoli were consistently enlarged at three epithelial levels, nucleoli in the basal cells averaging twice the control size. Comparison with specimens of mucosa of the hard palate showed that the enlargement of nuclei and nucleoli in orthokeratinized leukoplakias was in excess of the normal size differential between inherently orthokeratinized and nonkeratinized regions of the human oral mucosa. This suggests an abnormal stimulation of proteinsynthetic activity even in this prognostically "benign" type of leukoplakia.