approximately 600 million people are aged 60 years and older , and this number will double by 2025 . by 2050 , this number will reach 2 billion , with 80% living in developing countries . as in other developing countries , elderly populations are mainly affected by non - transmissible diseases , which are quickly becoming the leading causes of disability and mortality , and many of these diseases share common risk factors with different oral diseases . in addition to dental caries and periodontal disease , oral mucosal disease is another significant problem found in elderly populations . the oral mucosa performs essential protective functions that significantly affect the general health of an individual . a decline in the protective functions of the oral mucosa could expose the aging individual to a variety of pathogens and chemicals that enter the oral cavity . as human beings age , the oral mucosa becomes more permeable to toxic substances and more vulnerable to external carcinogens . the oral epithelium has been reported to become thinner with age , and collagen synthesis by connective tissue decreases . as a result , , poor oral health of elders is evidenced by high levels of tooth loss , dental caries , and periodontal disease , accompanied by other conditions such as xerostomia , mucosal lesions , pre - malignant lesions , and oral cancer . the prevalence of lesions affecting the oral mucosa is an important parameter in evaluating the oral health of elders , and its assessment is important for government decisions regarding health programs . nevertheless , the information currently available about the oral health of elders is scarce , especially in yemen and other arab countries , where no research has been done on the subject . therefore , the aims of this study were to obtain baseline information on the prevalence of oral mucosal lesions ( omls ) in a population of elderly yemeni dental patients and to investigate differences in the presentation of these findings in relation to age , gender , education level , and the wearing of dentures . this cross - sectional study , conducted between january and june 2014 , included a sample of 310 elderly dental patients ( aged 60 years and older ) attending the outpatient dental clinics in sanaa university , yemen . the faculty of dentistry of sanaa university is the only public dental school in sanaa , and it offers free dental services to the general public . the minimum sample size for such a study was calculated to be 210 at 95% confidence level with an absolute precision of 5% and the expected prevalence rate of 83.6% . the study was approved by the research and ethics committee of the faculty of medicine and health sciences , sanaa university , and informed consent was obtained from the study participants . before clinical examination , demographic characteristics and clinical information including age , gender , education level , oral risk habits ( smoking and qat chewing ) , oral hygiene practices , systemic health , and past and current use of medications were obtained from all participants through interviews . participants were categorized into two groups according to their education status : illiterate ( those with no school education ) and literate ( those with any kind of formal education ) . extra- and intra - oral examination of the mouth was carried out by an oral pathologist from the department of oral medicine and pathology ( al - jamaei aa ) using an artificial light , dental mirror , tweezers , gauze , and a wooden tongue depressor . cotton swabs were used for removing debris and examining whether white lesions could be wiped off . any abnormality of the oral mucosa was diagnosed according to the diagnostic criteria described in the world health organization ( who ) guide to epidemiology and diagnosis of oral mucosal diseases . recurrent herpetic lesions and aphthous stomatitis were recorded only if observed at the time of the examination . no biopsies or laboratory tests were done in the present study . the number of natural teeth and the presence of dentures , either partial or complete , were also recorded . after the oral examination , participants who presented with lesions were referred for appropriate treatment . the 310 participants studied , 218 ( 70.3% ) were men and 92 ( 29.7% ) were women . the mean age of the participants was 64.77  6.38 years ( range 6086 ) , with 72.3% in the 6069-year - old age group . one - quarter of the participants had at least one systemic disease , and 19.7% reported consuming some type of drugs . the vast majority of the participants ( 72.6% ) were illiterate , and only 85 ( 27.4% ) had received a formal education . a total of 68.4% of the participants were qat ( or khat ) chewers and 38.4% were smokers . demographic characteristics of the study subjects the mean score of tooth loss was 13.91  9.15 ( range 028 ) , with 77.8% of the participants having lost at least six teeth . in the sample , 12 participants ( 3.9% ) were fully dentate , 255 ( 82.2% ) were partially edentulous , and 43 ( 13.9% ) were edentulous . a total of 239 participants ( 77.1% ) were diagnosed with at least one oml . the prevalence rate was significantly higher in men than in women ( 80.3% vs. 69.6% ; p < 0.05 ) . the diagnosed omls were categorized into seven main groups : tongue lesions , white lesions , denture - related lesions , ulcerative lesions , exophytic lesions , pigmentation lesions , and miscellaneous . the most prevalent lesions were fissured tongue ( 34.2% ) , benign tumors ( 17.1% ) , hairy tongue ( 16.5% ) , and qat - induced white lesions ( 12.6% ) [ table 2 ] . the frequency of omls according to gender and age groups , n ( % ) table 2 shows the distribution of various omls in relation to gender and age groups . hairy tongue , qat - induced white lesions , and shammah keratosis were associated with men ( p < 0.01 , p < 0.05 , and p < 0.05 , respectively ) , whereas geographic tongue was associated with women ( p < 0.05 ) . overall , the prevalence of omls was significantly higher in the 6069-year - old group than in the 70 years and older group ( 80.8% vs. 67.4% ; p < 0.05 ) . the frequencies of benign tumors and hairy tongue were significantly higher in the 6069-year - old group ( p < 0.01 ) . on the other hand , denture stomatitis was observed in 4.7% of the participants in the 70 years and older group compared with 2.2% in the 6569-year - old group ; however , the difference was not significant ( p > 0.05 ) . table 3 illustrates the distribution of the most frequent omls in relation to various clinical and demographic variables . the presence of one or more lesions was significantly associated with low education level ( p < 0.05 ) . white lesions , hairy tongue , and benign tumors were significantly associated with qat chewing ( p < 0.001 , p < 0.001 , and p < 0.01 , respectively ) . likewise , the presence of one or more lesions , white lesions , hairy tongue , and benign tumors was significantly associated with smoking ( p < 0.05 ) . there was no significant association between the occurrence of omls and denture wearing , systemic diseases , or medication consumption ( p > 0.05 ) . disease prevalence is usually determined by cross - sectional studies . to the best of our knowledge , this is the first study to provide data on the prevalence and characteristics of omls among an elderly population in yemen . in our study , the prevalence of omls was 77.1% , which is slightly lower than that reported among elderly patients in thailand ( 83.6% ) and iran ( 86.1% ) . however , this rate is much higher than the results of other epidemiological studies , where investigators recorded a prevalence of 15.567% . it is important to mention that it is difficult to compare results with those of other studies because of the methodological variability and sociocultural and demographic differences present in the studied populations . the present authors observed that omls were more common among men than women , which is in accordance with several studies . this finding is possibly because men are more exposed to risk habits than are women . also , women in our community are usually more meticulous than men regarding their oral hygiene . the present authors found a decrease in the incidence of omls with advancing age , which is a finding consistent with other studies . in which the prevalence increases with age , although we must consider that the population of the latter study consisted of institutionalized elders . in the present study , the highest prevalence of omls was in the 6069-year - old group ( 80.8% ) as compared with the older group ( 67.4% ) . decrease in the incidence of omls with advancing age can be attributed to the fact that older people usually , due to certain medical reasons , quit oral risk habits such as smoking and habitual qat chewing with advancing age . several previous studies have shown that tongue lesions constitute a considerable proportion of omls , and their prevalence varies in different parts of the world . our study supports these findings ; fissured tongue and hairy tongue were among the most prevalent lesions that we identified . the prevalence of fissured tongue ( 34.2% ) was higher than that reported among the elderly populations in thailand ( 28% ) , brazil ( 6.6% ) , and germany ( 19.0% ) , whereas it was lower than that described by mozafari et al . tongue fissuring is suggested to be genetically determined , and this could be the reason for such prevalent variability worldwide . hairy tongue was observed in 16.5% of our study population , which is much higher than that reported in previous studies in germany ( 1.8% ) and thailand ( 6% ) . similar to most published studies , our study also found hairy tongue to be more frequent in men and in tobacco users . in addition to tobacco use , hairy tongue has also been associated with poor oral hygiene . therefore , dentists should identify and eliminate the predisposing factors and advise regular brushing of the tongue and maintaining proper oral hygiene . the prevalence of geographic tongue in the present study was 3.5% , a percentage similar to the 3.0% prevalence reported by banoczy et al . in a hungarian population . the most frequent white lesions were qat - induced white lesions ( 12.6% ) , leukoedema ( 6.8% ) , and shammah keratosis ( 3.9% ) . qat - induced lesions are keratotic white lesions associated with the habit of qat chewing ( a widespread social habit in yemen ) and are strictly confined to the site of chewing . these lesions are confined primarily to the buccal mucosa and , to a lesser extent , to the vestibular and mucobuccal fold mucosa . suggested that such lesions are related to the combination of mucosal dryness and exposure to chemical and mechanical irritation . our findings are in accordance with previous studies , which reported these lesions as a common finding in populations where qat chewing is a popular habit . also , similar to previous researchers , the present authors found these lesions to be more frequent in men than in women , probably because of the higher practice of qat chewing among yemeni men . although not significant , leukoedema was found to be more common among men than women in our study population . this higher prevalence among men supports previous findings by reichart , jainkittivong et al . , and vieira - andrade et al . regarding ulcerative lesions , traumatic ulcers were the most common ( 6.5% ) , followed by herpes labialis ( 0.6% ) . this finding is in line with those of earlier studies which reported traumatic ulcers as the most common type of ulcerative lesions . the traumatic ulcers in this study population were most commonly located on the buccal mucosa and lateral surface of the tongue , and were mainly caused by trauma from ill - fitting dentures , fractured restorations , and sharp edges of broken teeth . in the present study , traumatic fibroma was found to be the most common type of exophytic lesions , which is in agreement with earlier reports . the major cause of irritation fibroma is mechanical irritation from dentures , lip biting , calculus deposition , sharp margins of teeth , and long - standing cheek biting and tongue thrusting . the most common location for traumatic fibromas in our study population was the tongue dorsum , followed by the buccal mucosa and lips . denture - related lesions were not a common finding in our study population , as only 2.9% of the participants had denture stomatitis . this low rate contradicts the findings from most of the previous studies in which denture stomatitis was reported to be one of the most common lesions in elderly populations . this is possibly due to non - usage or usage limited to eating and on social occasions among our study population . moreover , it is of interest to note that the percentage of denture wearers in the present study population was 37.4% , which was very much lower as compared with the data from the aforementioned studies , where 5094.3% of the elders used dentures . another possible reason could be the non - inclusion of ulcers caused by dentures under this category of lesions in the present study . melanin pigmentation was found to be more prevalent in this study than in the study among the malaysian elderly . it is expected to be mainly ethnical in predisposition in this part of the world , although there may be a small possibility for pigmentation to be due to smoking , which has been indicated as an important etiologic factor . premalignant lesions were not a common finding , and the incidence was similar to other reports . the 0.3% prevalence of leukoplakia in our study population was lower than that reported among german ( 1.2% ) , thai ( 4.8% ) , and chilean ( 1.7% ) elders . according to epidemiological data from different countries over the past 30 years , the prevalence of leukoplakia varies from 1 to 13% , with a mean value of 3% . lichen planus was observed in 1.6% of our study population , a finding similar to the ones reported by reichart and shet et al . no oral cancer cases were identified in this study , indicating rarity of this lesion in the oral cavity . nevertheless , dental practitioners should remain alert for any suspicious lesions encountered in the oral cavity . also , no difference was found in the prevalence of omls among denture wearers as compared with non - denture wearers ( p > 0.05 ) [ table 3 ] . this finding is different from those of other authors , where a higher prevalence of omls was correlated with denture wearing . our results showed a significant association between tobacco habits and the presence of one or more lesions , white lesions , hairy tongue , tumors , and tumor - like lesions . also , the results showed a significant association between qat chewing and the occurrence of certain oral lesions : white lesions ( p < 0.001 ) , hairy tongue ( p < 0.001 ) , and oral tumors ( p < 0.05 ) . the role of qat chewing in causing white lesions has been extensively studied and well established in the literature . regarding hairy tongue , the exact mechanism by which qat chewing may affect the tongue is still unclear . there are no available data in the literature about the subject , which indicates a need for further investigations . however , a high prevalence of hairy tongue among qat chewers might be attributed to xerostomia induced by qat , which is one of the contributory factors for causing tongue conditions . in our study , the presence of one or more lesions was associated with low education ; the lower the education level , the higher prevalence of one or more oral lesions . the reduction in salivary flow is common in elderly people and can be related to systemic diseases , sometimes because of medicine use , causing oral side effects such as mucosal burning , pain , or burning mouth sensation , interfering in the deglutition , speaking , and mastication , as well as in the taste , prosthesis adherence , and also contributing for the emergence of oral lesions . in the present study , however , the occurrence of omls was not associated either with systemic diseases or with medication use [ table 3 ] . although the most common omls seen in this study were benign , several participants had premalignant lesions . thus , a periodic oral checkup for the detection of precancerous and cancerous lesions is mandatory , especially in elderly populations . the main limitation of the study is the fact that data regarding oral hygiene practices , duration of prosthesis , night use of dentures , and the socio - economic status of the participants were not obtained . such data might have revealed some correlation between the study findings and the socio - demographic data of the subjects . another limitation is the lack of blood and/or salivary analyses to investigate the etiology of oral lesions among this population . these investigations could have objectively explained the results and might have shed some light on the etiopathogenesis of these lesions among this elderly population . in conclusion , this study demonstrated a high prevalence of omls among elders in yemen . also , the current results support those of other investigators who have shown that the presence of omls in elders is related to age , gender , low education level , and practicing oral habits . however , no association was found between the occurrence of oral lesions and denture wearing .
objectives : with aging , the oral mucosa becomes more susceptible to external stimuli . 
 the aims of this study were to obtain baseline data on the prevalence of oral mucosal lesions ( omls ) in a population of elderly yemeni patients and to investigate differences in the presentation of these findings in relation to age , gender , education level , and the wearing of dentures.patients and methods : the prevalence of omls was assessed by clinical examination of a sample of 310 elderly yemeni patients aged 60 years and older . 
 a single examiner performed detailed oral examinations of the oral cavity according to international criteria and the world health organization codes.results:the overall prevalence of omls was 77.1% , with a significant difference ( p < 0.05 ) between men ( 80.3% ) and women ( 69.6% ) . 
 the prevalence rate of omls indicated a significant decrease with advancing age . 
 the most frequently observed lesions were fissured tongue ( 34.2% ) , benign tumors ( 17.1% ) , hairy tongue ( 16.5% ) , and qat - induced white lesions ( 12.6% ) . 
 hairy tongue , qat - induced white lesions , and shammah keratosis were associated with men ( p < 0.01 , p < 0.05 , and p < 0.05 , respectively ) , whereas geographic tongue was associated with women ( p < 0.05 ) . the presence of one or more lesions was significantly associated with low education level ( p < 0.05 ) . 
 certain omls showed a significant association with smoking and qat chewing ( p < 0.05 ) . 
 no association was found between the occurrence of omls and denture wearing ( p > 0.05).conclusions : the present study has shown a high prevalence of oral lesions among yemeni elders .