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Background: Oral and pharyngeal cancers constitute the sixth most common type of cancer globally, with high morbidity and mortality. In many countries, most cases of oral cancer arise from long-standing, pre-existing lesions, yet advanced malignancies prevail. A new approach to early detection is needed. We aimed to validate a model for screening so that only high-risk individuals receive the clinical examination.Methods: A community-based case-control study (n=1029) in rural Sri Lanka assessed risk factors and markers for oral potentially malignant disorders (OPMD) by administering a questionnaire followed by an oral examination. We then developed a model based on age, socioeconomic status and habits of betel-quid chewing, alcohol drinking and tobacco smoking, with weightings based on odds ratios from the multiple logistic regression. A total, single score was calculated per individual. Standard receiver-operator characteristic curves were plotted for the total score and presence of OPMD. The model was validated on a new sample of 410 subjects in a different community.Results: A score of 12.0 produced optimal sensitivity (95.5%), specificity (75.9%), false-positive rate (24.0%), false-negative rate (4.5%), positive predictive value (35.9%) and negative predictive value (99.2%).Conclusion: This model is suitable for detection of OPMD and oral cancer in high-risk communities, for example, in Asia, the Pacific and the global diaspora therefrom. A combined risk-factor score of 12.0 was optimal for participation in oral cancer/OPMD screening in Sri Lanka. The model, or local adaptations, should have wide applicability. [ABSTRACT FROM AUTHOR]

Objective: To investigate attitudes and opinions of the members of the British Dental Association towards implementing tobacco cessation strategies in dental practices. Design and Method: Questions about tobacco and tobacco cessation were asked on the September 2002 BDA Omnibus survey. The survey was sent out to a random sample of 1,500 BDA members, excluding retired members, overseas members and students. After two reminder circulations, 870 completed questionnaires were received, giving a response rate of 58%. Results: The survey results revealed good awareness amongst respondents of the health risks of tobacco. One fifth of respondents said that patients had asked them for advice on tobacco cessation. The majority (64%) of respondents stated that they gave advice on tobacco cessation 'fairly regularly' or 'always' (whether asked or not) and 37% of respondents recommended over-the-counter nicotine replacement therapy. Overall, 68% of respondents agreed that offering patients advice about tobacco cessation was the duty of every dentist. The most common barriers to a successful tobacco cessation campaign were perceived to be the amount of time required, lack of reimbursement, lack of training, lack of patient education materials and lack of knowledge of available referral resources. Nearly all respondents (92%) said that their practice was a completely smoke-free environment, and 66% of respondents had never used tobacco. The majority of respondents displayed patient education materials in their practice waiting/reception areas less than 60% of the time, and nearly a quarter (23%) never had them available. The survey revealed that most respondents did not feel particularly well prepared to assist patients in quitting tobacco, but 70% of respondents said they would be willing to cooperate with a campaign to inform all tobacco using patients about the advantages of tobacco cessation. Respondents felt that leaflets for patients, staff training and posters in the practice would contribute to the success of the campaign. Conclusion: Members of the dental team are very willing to implement tobacco cessation strategies in the dental practice. Most dentists feel that promotion of tobacco cessation is an important part of the duty of a dentist, but they feel inadequately prepared to deliver such advice. The major barriers to delivering successful tobacco cessation campaigns are the amount of time required, lack of reimbursement, lack of training, lack of patient education materials and lack of knowledge of available referral resources. The majority of dentists have received no training in tobacco cessation strategies. They feel that staff training and free availability of more patient education materials (leaflets, posters, etc) would help promote the success of such a campaign. [ABSTRACT FROM AUTHOR]

This case–control study aimed to identify the risk factors for oral cancer in patients aged 45 years and under.Patients were recruited over a 3-year period between 1999 and 2001 from 14 hospitals in the southeast of England, UK.Fifty-three (80%) newly diagnosed patients with squamous cell carcinoma (SCC) of the oral cavity participated. The mean age of cases at diagnosis was 38.5 years (SD = 7.0) and 53% were male. Patients were interviewed about main risk factors of tobacco, alcohol, cannabis and their consumption of fresh fruit and vegetables in the past. Ninety-one matched control patients were also recruited. Odds ratios (ORs) and 95% confidence intervals (CI) were obtained from adjusted conditional logistic analyses. Significantly elevated ORs were evidenced amongst males who had started to smoke under the age of 16 years (OR = 14.3; 95% CI: 1.1–178.8). A significant reduction in risk was also shown for ex-smokers (OR = 0.2; 95% CI: 0.5–0.8). Consumption of alcohol in excess of recommended amounts also produced an eightfold risk in males (OR = 8.1; 95% CI: 1.6–40.1) and over a fourfold risk of oral cancer from the consumption of excessive amounts of alcohol and having ever smoked (OR = 4.4; 95% CI: 1.1–17.7).The study shows that the traditional behavioural risk factors are present in younger people diagnosed with oral cancer. The relatively short duration of exposure and the substantial number of cases without any known risk factors, particularly amongst females, however, suggest that factors other than tobacco and alcohol may also be implicated in the development of oral cancer in a proportion of these younger patients.J Oral Pathol Med(2004)33: 525–32 [ABSTRACT FROM AUTHOR]

The cell proliferation status of 60 oral squamous cell carcinomas from Sri Lankan subjects was examined by immunohistochemistry using the Ki-67 index. A comparison was made between the indices derived from the centre of the tumours and those derived from the invasive fronts of the same tumours. There was a positive correlation between the two indices suggesting a clonal expansion of malignant cells, but the mean index derived for the invasive fronts (29.75  11.64) was significantly higher than the mean index for the body of these tumours (25.65  11.64). Thus, at a given time, more peripheral cells at the invasive front are proliferating and this compartment is likely to be more informative in prognostic and other behavioural studies involving the cell cycle. In squamous carcinomas, increased and uncontrolled cell proliferation at the invasive front may be one feature contributory to the invasion. [ABSTRACT FROM AUTHOR]

The evidence base for head and neck cancers is low with relatively few randomized controlled trials of the two main treatments, surgery and radiotherapy. The aim of the study was to investigate the patterns of surgery and radiotherapy treatment for head and neck cancers in three large areas of England and to investigate their effects on survival. This was a retrospective study of 13510 cases of head and neck cancers (ICD10: C00-C14, C30-C32) diagnosed and treated from 1984 to 1992 in England. We undertook multivariate analyses of survival using a step-wise Cox proportional hazard model and Kaplan-Meier analysis. There were regional variations in the treatments given to patients. Four in ten patients did not receive currently recommended treatments. In multivariate analyses treatment content and timing had an independent effect on survival. Better survival was associated with surgery for mouth cancers, radiotherapy for laryngeal cancers and combined treatment for pharyngeal cancers independent of tumour and demographic factors. Further research is needed to investigate the findings of this study through large randomized controlled trials and multi-centre audits. [ABSTRACT FROM AUTHOR]

We have reviewed the recent literature on the humoral immune responses to a variety of subgingival plaque bacterial species in patients with destructive periodontal diseases. We do not feel that the information presently available on the specific antibody responses to proposed pathogens such as Bacteroides gingivalis and Actinobacillus actinomycetemcomitans allows antibody responses to be diagnostic. All control subjects without periodontal destruction have antibodies to candidate pathogens but the generally higher levels in patients are not sufficiently elevated to be diagnostic. Nor can they be used to predict the initiation of disease or the onset of new episodes of destruction where disease had previously occurred. Successful treatment of patients may lead to lower levels of antibodies to some organisms, including possible pathogens, and thus support a given species in the aetiopathogenesis of disease. It appears that unsuccessful treatment may be accompanied by continuing high antibody levels to some organisms and further studies may enable this observation to be used to monitor therapy. There is some evidence from serological studies that each destructive episode may be induced by a different bacterial species or consortium. The start of studies using single antigens and the techniques of molecular biology will provide not only antibody-based diagnostic methods but also allow us to determine which bacterial antigens are virulence factors and thus the role of the antibody responses, whether protective or damaging, in the periodontal diseases. [ABSTRACT FROM AUTHOR]

The histological evaluation of surgical biopsies from affected tissues is a standard way of assessing pathological change and determining treatment in many diseases. In most forms of periodontal disease, however, this approach finds limited application. Here, we review what uses the histopathological approach has in the study and evaluation of the periodontal diseases. Current understanding of the changes in epithelial anatomy during pocket formation, the cellular composition and dynamics of the inflammatory infiltrate and the mechanisms of bone resorption and repair are reviewed from the perspective of the information available from microscopical investigation, including the uses and potential application of modern immunocytochemical methods to these questions. The usefulness of histological study of biopsy material is reassessed in the light of advances made in immunohistochemical techniques and their application to gingival inflammatory infiltrates and epithelia. Such techniques offer immediately valuable research opportunities with potential for diagnostic applications, noteably the recognition of phases of destructive activity and their differentiation from periods of effective host defence. [ABSTRACT FROM AUTHOR]

It is argued that the periodontal diseases can no longer be regarded as universally prevalent conditions to which all members of the world's population are at equal risk if they fail to practise good oral hygiene. Rather, they should be regarded as a range of different diseases for each of which certain individuals, which together comprise certain minority groups, are at relatively high risk, The epidermological evidence for the existence of high-risk groups is reviewed, from which it is concluded that world-wide the prevalence of severe destructive periodontitis is of the order of only 7-15% of the adult dentate population A working classification of the different types of gingivitis and periodontitis is offered, as is a summary of the theoretically possible approaches to the detection of high-risk groups and individuals which are explored in detail in subsequent papers. Successful identification of such individuals will permit scientifically valid, rational and targetted prevention and treatment. [ABSTRACT FROM AUTHOR]

The effects of iron deficiency on the aerobic pathway of energy metabolism were studied using mitochondria isolated from epithelial cells from the hamster cheek pouch. A statistically significant reduction in the concentrations of cytochromes aa3, b and c (P less than 0.05), a reduction (P = 0.064) in cytochrome cl and altered cytochrome ratios were found in the mitochondria of iron deficient compared to normal animals. State 4 respiration was demonstrated in the mitochondria of both normal and iron deficient animals but state 3 respiration could not be demonstrated; this suggests uncoupling of oxidative phosphorylation which may be an artefact associated with the separation of epithelium from its connective tissue. Nevertheless we conclude that the reduction in cytochrome concentration is a real effect of iron deficiency which may explain, at least in part, the reduction of both energy production and cell proliferation seen in oral epithelia under these conditions. [ABSTRACT FROM AUTHOR]

Despite extensive investigation of cell kinetic parameters in a wide range of normal and abnormal tissues and their potential value in understanding the pathogenesis of many disease states, as well as in prognosis and treatment planning, their application to oral epithelia remains limited. In part A the methods most commonly applied to the study of epithelial cell kinetics, i.e., isotope labelling, mitotic arrest and flow cytophotorimetry are reviewed with special emphasis on their technical limitations, sources of variation and inapplicability to humans in vivo. The ability of in vitro methods to reliably reproduce in vivo cell kinetic parameters is also considered. The application of cell kinetic studies to normal and abnormal oral tissues will be discussed in part B. [ABSTRACT FROM AUTHOR]

Hyalin bodies, present in a proportion of 427 jaw cysts, were examined by histological, histochemical and electron microscopical methods. Their overall prevalence in odontogenic cysts was 11 % and all the bodies were confined to the cyst epithelium. The histochemical results were generally in agreement with existing reports of reactions in both hyalin bodies and dental cuticle. An ultrastructural examination of 10 specimens revealed a close relationship of epithelial cells to at least one surface of each body, an attachment being mediated by hemidesmosomes and a basal lamina. The circular bodies surrounded so-called ‘granular material’ which appeared to be composed of degenerating cellular debris and which was sometimes calcified. Curved, elongate bodies bordered cholesterol clefts in the epithelium or showed evidence of having done so at an early stage in their formation. Existing concepts which attribute the origin of hyalin bodies to thrombosed blood vessels or to keratinizing epithelium are refuted, mainly on ultrastructural grounds. It is proposed that hyalin bodies are a secretion from odontogenic epithelium stimulated by cholesterol or cellular debris. [ABSTRACT FROM AUTHOR]

The bone resorbing activity of lipopolysaccharides from oral bacteria has been investigated in vitro. Further, the resorbing activity appeared to be reduced by serum, except in the case of lipopolysaccharide from Bacteroides gingivalis. This micro-organism is commonly associated with periodontal disease in adults. The significance of lipopolysaccharides stimulating bone resorption in vivo has not yet been resolved. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor in the favor of experimental pathology, published in the October 1981 issue of the "Journal of Oral Pathology."

Introduction: Interprofessional education (IPE) purports to improve team working through improved knowledge of the roles of others, and by engendering mutual respect. This case study aimed to determine the impact of an IPE curriculum on knowledge and attitudes of dentistry and dental technology students undertaking these curricula in the new School of Dentistry and Oral Health at Griffith University. All dental technology students and third- and final- (fifth) year dentistry students were invited to participate. Method: A mixed-method approach was used to compare attitudes, perceptions and experiences of students involved in our IPE curricula. Quantitative data were evaluated with the Statistical Package for the Social Sciences (SPSS), and qualitative findings were explored through an Excel® spreadsheet coding frame tested against LeximancerTM qualitative software for consistency. Results: Forty-six of the 131 eligible students participated. Readiness for Interprofessional Learning Scales (RIPLS) and focus groups consistently showed that IPE positively influenced professional identity and improved communication between and amongst all students and assisted them in developing their roles. A prevailing sense of greater importance and a lack of mutual respect between dentistry and dental technology students were, unfortunately, evident. The process was, however, sufficient to enhance teamwork and collaboration when planned learning revolved around explicit patient care in the provision of dental prostheses. Conclusion: Further development of such curricula is needed to maximise IP learning (IPL) opportunities, to shift traditional attitudes and, potentially, to improve the outcomes of patient care. To enable this, academic and clinical leaders need to embrace the ideals of IPE. [ABSTRACT FROM AUTHOR]

Aberrations of the p53 gene and the overexpression of its protein are described in a variety of neoplasms, including oral and other head and neck cancers. Here we report the association of p53 (over)expression with a downstream cell cycle inhibitor p21/waf 1 in oral squamous cell carcinoma (SCC). The loss of expression of p16 and p27, two other cyclin-dependent kinase (cdk) inhibitors, was also examined. In this panel of tumours, 10/24 carcinomas were p53-immunopositive. Heterogeneous expression of p21 and p27 was seen in 10/24 SCC and 9/16 SCC, respectively, and this was not correlated to p53 status. The expression of p21 and p27 in these SCCs suggests the existence of mechanisms by which some growing tumour cells may tolerate these cell cycle inhibitors; eight SCCs lacked expression of both inhibitors but only two of these cancers overexpressed p53, suggesting that accumulation of p21/p27 can be independent of the functional status of the p53 gene. Data do not support a clear example of a phenotype type that shows an overexpression of p53 with downregulation of p21 or p27 leading to cell cycle alterations. Furthermore, only three SCCs were p16-negative and p53-positive. This suggests that these two tumour suppressors may act in separate pathways. [ABSTRACT FROM AUTHOR]

Oncogene expression in human neoplasia has been examined extensively in the past decade. More recently the advent of the polymerase chain reaction (PCR) has facilitated studies of oncogenes and other DNA structures. Those few studies which have so far searched for oncogene changes in oral cancer have utilized frozen specimens. We report here an adaptation of the PCR technique applicable to DNA extracted from archival specimens. Our data complement recent findings that Ha-ras mutations are infrequent in oral squamous cell carcinomas among white caucasoid populations. [ABSTRACT FROM AUTHOR]

Abstract. The combined effect of ultra-violet radiation and a restricted diet on oral mucosa was investigated using the labial mucosa of pigmented rats. Twenty-four rats were divided so that 12 experimental animals received 50% of the average daily diet of the remaining 12 normal controls. After 1 month, the epithelium of the restricted group had thinned to 2/3 of that of the controls. Nine rats from each group were then subjected to daily ultra-violet irradiation of the labial mucosa, three animals in each group remaining as unirradiated controls. After 1, 4 and 8 weeks irradiation, three experimental and one unirradiated control from each group were sacrificed. Microscopic examination showed that the thickness of the epithelium and the mitotic index increased in both normal and restricted animals at 4 weeks. The increase in thickness was maintained at 8 weeks, but the mitotic index declined in the deficient animals at this time. Evidence of epithelial dysplasia was seen in the normal animals at 4 weeks, and this increased at 8 weeks; such changes were rarely seen in the restricted animals. It thus appears that the extent of ultra-violet induced dysplasia may be related to the mitotic index, a lower mitotic index implying less dysplasia. [ABSTRACT FROM AUTHOR]

Opportunistic fungal infections account for a significant amount of morbidity associated with HIV disease. We report here a case of localised oral histoplasmosis without evidence of disseminated disease in a patient who lacked stigmata of HIV disease at the time of initial presentation. The diagnosis is based on histology with special stains, complement fixing antibodies in serum, and culture of the organism from fresh tissues. Activation of subclinical disease following an infection in Uganda may explain the development of these exophytic oral lesions in this British resident. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the direct and indirect (via oral health-related behaviour) effects of parental rearing practices on children's Oral Health-Related Quality of Life (OHRQoL) within a family-focused, comprehensive predictive model.Methods: Participants were 11- to 14-year-old children and their parents living in Telangana State, India (N = 1130). Children were clinically assessed for dental caries, gingivitis, oral hygiene status, fluorosis, and malocclusion, and completed a self-administered questionnaire on oral health-related behaviour and OHRQoL. Parents answered questions related to their socioeconomic status (SES), family circumstances, parent's perceptions of child's OHRQoL, and child rearing practices. Structural equation modelling was used to evaluate the pathways through which parenting practices were associated with children's OHRQoL.Results: Parents with higher positive (β = -0.106) and lower power assertion rearing practices (β = 0.103) had children with better OHRQoL. Parental rearing practices did not have any effect on children's oral hygiene behaviour. Children who had malocclusion (β = 0.076) and fluorosis (β = 0.38) had lower OHRQoL. Family SES had a significant effect on children's oral hygiene behaviour and oral hygiene status with children of higher SES demonstrating better oral hygiene behaviour and status. Children living in single-parent families reported poorer oral hygiene behaviour (β = -0.048) than those living in other types of families.Conclusions: Parental rearing practices had direct effects on OHRQoL. However, the hypothesised indirect effects of these practices on OHRQoL via poor oral health behaviour were not supported. [ABSTRACT FROM AUTHOR]

The ability to function as an effective member of a dental care team is a highly desirable - frequently mandated - attribute of dental technology (DT) graduates. Currently, there is little rigorous examination of how the learning of team-working skills might best be structured in a DT curriculum. This research compares DT curricula, and students' attitudes and perceptions regarding collaboration in practice, from four countries. Students (n = 376) were invited to complete an education profile questionnaire, and the standardised measure - the shared learning scale. There were 196 (52%) responses. Students given opportunities to engage with others had better perceptions of inter-professional learning (IPL). Most believed that team-work and collaborative skills were best acquired by learning together with other dental care professionals, preferably sharing cases for real patients. Curricula should maximise opportunities for dental technology students to experience authentic IPL. Collaboration and team-work needs to be embedded through the whole undergraduate programme. [ABSTRACT FROM AUTHOR]

It is commonly believed that fine particles have low flotation recoveries. Indeed, size-recovery graphs often are 'hill shaped' with high recovery in the mid sizes and low recovery at the fine and coarse ends. Yet rather than being due to 'overgrinding', fines recovery may be low because the grind is not fine enough! The different flotation needs of fine and coarse particles have long been recognised, for example, in the old design for separate 'sand and slimes' circuits. Yet the principles may be overlooked in the desire for simpler circuits and larger equipment. Most plants now treat all particles together in one wide size distribution. Reagent conditions are set for the dominant coarser particles, so fines are starved of collector. Worse still, if there are significant mid sized composites, they often have to be rejected in cleaning to achieve target concentrate grade. Yet the conditions which reject mid size composites (collector starvation and high depressants) also reject fine liberated particles. In contrast to this common result, fines flotation can be excellent when flotation chemistry is tailored to them. After first recovering fast floating liberated particles, it is essential to adequately grind remaining composites to enable fines recovery. First, this allows lower depressant and higher collector additions since composites do not have to be rejected from concentrate. Second, finer grinding in appropriate equipment may be managed to narrow the size distribution to flotation, allowing reagent conditions to be set to suit the majority of particles. Third, grinding in an inert attritioning environment like an IsaMill increases fine flotation rates by producing clean mineral surfaces. An excellent case study is the installation of IsaMills in the Mount Isa lead zinc concentrator to grind lead and zinc rougher concentrate to P80 of 12 μm and zinc cleaner tailings to 7 μm. Most plant losses had previously been in the sub 10 μm fraction, yet the finer grinding increased plant recovery by 5% lead and 10% zinc and also increased concentrate grades. Circulating loads dropped, reagent additions dropped in spite of the much higher particle surface area, and the plant became much more operable and responsive. [ABSTRACT FROM AUTHOR]

Decades of research and advocacy to control tobacco use and related public-health harm have not counterbalanced the tobacco industry's successful stronghold, which is ever-increasing in countries with weaker anti-tobacco leadership. Current rates of tobacco use and harm in Hungary and other Central European countries mark them as some of the industry's greater successes. Following the Behavioural Ecological Model, a framework for behavioural and cultural change, this paper reviews important ways that dentists, physicians and other healthcare providers can counter the tobacco industry's influence on patients, communities, and the nation. The analysis includes policies and practices shown to be effective in controlling and undermining the tobacco industry, and outlines new policies and practices that show promise based on the behavioural change framework. The components of an all-encompassing tobacco-control programme are described through explicit recommendations for research, practice and policy that are necessary to establish a professional and societal culture that extinguishes the influence and harm of the tobacco industry in Hungary, Central Europe and developing countries worldwide. [ABSTRACT FROM AUTHOR]

Background: Human Immunodeficiency Virus (HIV) infection is associated with oral manifestations of diagnostic and prognostic importance. With the advent of Highly Active Anti-retroviral Therapy (HAART) there is anecdotal evidence to suggest that the prevalence of oral lesions has declined. The number of prevalence studies, carried out in the era of HAART is, however, meagre. Our aim was to study the prevalence of the oral manifestations of HIV in a population, predominantly on HAART, attending a Genito-Urinary Medicine Centre in South London.Methods: This cross sectional study included 203 adult volunteers, comprising 76% males and 24% females. One third of the subjects were from the predominantly African or Afro- Caribbean ethnic minority groups resident in London. The relationship between the prevalence of oral lesions and demographic variables, therapeutic regimes, viral load and CD4 counts were evaluated.Results: One hundred (49%) of the patients had no detectable oral lesions. Oral lesions detected most frequently included oral hairy leukoplakia (9.9%), HIV associated periodontal diseases (9.9%) and oral candidiasis (4.9%). Three subjects had multiple papillomatous growths. Most cases (n = 17/20) of oral hairy leukoplakia were in individuals with a detectable (> 400 copies/ml) plasma RNA viral load. The majority (n = 8/10) of our patients with oral candidiasis had a plasma RNA viral load > 10,000 copies/ml and half (n = 5/10) had a CD4 count < 200 cells/mm3. Logistic regression analysis suggested that the presence of an oral lesion was not associated with any demographic features except for periodontal diseases which were associated with tobacco smoking (P = 0.023).Conclusions: The prevalence of so called 'strongly associated' oral lesions of HIV is low in this South London HIV-infected population on HAART, and the relative frequency is different from that cited in the literature from the pre-HAART era. The oral lesions detected were found mostly in people with low CD4 counts and high HIV-1 RNA viral loads, suggesting they were very immunocompromised, not on, or declining therapy, or that their therapy was failing. [ABSTRACT FROM AUTHOR]

Abstract Aim: The aims of this study were to monitor the prevalence and progression of lifetime cumulative attachment loss (LCAL) in a group of young British male military recruits over a 3-year period, and to determine the relationship between signs of LCAL and selected periodontal variables. Methods: 100 subjects, aged 16–20 years (mean 17 years) at baseline, were examined at 0 (baseline), 12 and 30 months. LCAL, probing depth, plaque, bleeding on probing, gingival colour and supra- and subgingival calculus were assessed on the mesio-buccal, disto-buccal, mesio-lingual and disto-lingual surfaces of all teeth present, excluding third molars. Data were analysed cross-sectionally at each examination. Results: Over the period of the study, the prevalence of LCAL >=1 and 2 mm ranged from 95–100%, whereas LCAL >=3 mm ranged from 40–47%. The extent of LCAL >=1 mm ranged from 76–86%. However, the extent of LCAL >=2 mm was dramatically lower (10.5–12.7%), and LCAL >=3 mm was uncommon (0.5–0.9%). Examining the number of subjects according to the number of sites affected above a threshold, showed that a small number of subjects have a large number of sites above threshold. Using Pearson’s rank correlation coefficient a significant correlation (p<0.05) was found between LCAL and the periodontal variables of gingival bleeding and supra- and subgingival calculus. Conclusions: These data suggest that the onset and progression of chronic periodontitis can be seen in young adults, and in this group gingival bleeding and supra- and subgingival calculus are the variables most strongly associated with early periodontitis. [ABSTRACT FROM AUTHOR]

Copper is implicated in the pathogenesis of several fibrotic disorders. Areca nut has been shown to have a high copper content and areca chewing is associated with oral submucous fibrosis (OSF). The effects of copper on human oral fibroblasts were investigated in vitro. Human oral fibroblasts were incubated with copper chloride (CuCl2) at concentrations ranging from 0.01 microM to 500 microM for 24 h, and in vitro cell proliferation was assayed by incorporation of tritiated-thymidine; soluble and non-soluble collagen synthesis was assayed using tritiated-proline. Addition of copper chloride at concentrations ranging from 0.1 microM to 50 microM increased the collagen synthesis by the oral fibroblasts compared with growth without copper (P<0.05). The addition of copper chloride neither increased the synthesis of non-collagenous proteins by the fibroblasts nor influenced their proliferation rate. We conclude that copper upregulates collagen production in oral fibroblasts. This appears to be concentration dependent, with peak collagen synthesis at 50 microM CuCl2. These in vitro results taken together with the recent findings of copper in oral biopsies from OSF subjects support the hypothesis that copper in areca nut acts as a mediator of OSF. [ABSTRACT FROM AUTHOR]

Copper is implicated in the pathogenesis of several fibrotic disorders. Areca nut has been shown to have a high copper content and areca chewing is associated with oral submucous fibrosis (OSF). The effects of copper on human oral fibroblasts were investigated in vitro. Human oral fibroblasts were incubated with copper chloride (CuCl2) at concentrations ranging from 0.01 μM to 500 μM for 24 h, and in vitro cell proliferation was assayed by incorporation of tritiated-thymidine; soluble and non-soluble collagen synthesis was assayed using tritiated-proline. Addition of copper chloride at concentrations ranging from 0.1 μM to 50 pM increased the collagen synthesis by the oral fibroblasts compared with growth without copper (P<0.05). The addition of copper chloride neither increased the synthesis of non-collagenous proteins by the fibroblasts nor influenced their proliferation rate. We conclude that copper upregulates collagen production in oral fibroblasts. This appears to be concentration dependent, with peak collagen synthesis at 50 μM CuCI2. These in vitro results taken together with the recent findings of copper in oral biopsies from OSF subjects support the hypothesis that copper in areca nut acts as a mediator of OSF. [ABSTRACT FROM AUTHOR]

In 1998, the UK government published a White Paper outlining a comprehensive range of measures to reduce smoking rates across the population. In the same year a detailed overview of the evidence base for smoking cessation activities within the NHS was published. Both these documents provide useful information for health professionals interested in developing their roles in smoking cessation and prevention. An increased risk for the development of oral malignancies and a susceptibility for the breakdown of periodontal tissues are the most significant effects of smoking on the mouth. This paper aims to highlight how dentists and their team members can become actively involved in efforts to reduce smoking. Opportunities at both a clinical and public health level are considered. [ABSTRACT FROM AUTHOR]

Oral submucous fibrosis (OSF) is a well-recognised-potentially malignant condition of the oral cavity associated with areca nut chewing. Areca nut has been shown to have a high copper content compared to other commonly eaten nuts, and chewing areca nut for 5-30 min significantly increases soluble copper in whole mouth fluids. Our aims were to determine if tissue and serum concentrations of copper were raised in patients with OSF as a result of chewing areca nut. A panel of buccal mucosal biopsies from patients with OSF from Nagpur, India, was used to measure the tissue concentrations of copper by mass absorption spectrometry (MAS). By MAS, the mean tissue copper level was 5.5+/-2.9 microg/g in the OSF specimens (n=11) compared with 4+/-1.9 microg/g in the non-areca chewing controls (n=7) (P=0.2). Energy dispersive x-ray microanalysis (EDX) was used to identify the presence and distribution of the metal element. EDX showed distinct peaks corresponding to copper (Kalpha 8.04 keV; Kbeta, 8.91 keV) in the epithelium (21/23) and in the connective tissue (17/23) of the OSF specimens compared to spectra obtained from control oral biopsies from non-areca chewing subjects (n=7). These findings were confirmed by secondary ion mass spectrometry (SIMS) analysis in a small number of samples. Serum copper (17.23+/-1.80 pmol/l), caeruloplasmin (0.32+/-0.04 g/l) levels and urinary copper (0.52+/-0.26 micromol/l) in OSF patients (n=14) were within the laboratory reference ranges. The finding of copper in OSF tissue supports the hypothesis of copper as an initiating factor in OSF, playing a role in stimulating fibrogenesis by the upregulation of lysyl oxidase activity. [ABSTRACT FROM AUTHOR]

AbstractObjective: To compare the progression of periodontal destruction in people with and without HIV. Method: Relative attachment loss on 6 index teeth was compared between 19 people with HIV and 17 people without HIV infection over 12 and 18 month follow ups. Results: The proportions of sites with 1, 2 or 3 mm of relative attachment loss were similar in the study and control groups. Mean maximum relative attachment loss was similar in both groups after 12 months but greater in the study group after 18 months. Conclusions: The data are not compelling evidence of greater periodontal destruction associated with HIV infection. Large scale cohort studies or meta-analyses would be more conclusive. [ABSTRACT FROM AUTHOR]

Objective: To determine public awareness and knowledge of oral cancer in Great Britain.Design: The respondents were selected according to a systematic probability sample designed to be representative of all adults in Great Britain (GB). The overall design was similar to previous omnibus surveys carried out by National Opinion Poll (NOP). The survey was carried out in ten regions of GB in September 1995 and was commissioned by the Health Education Authority (HEA).Subjects and Methods: A random sample of 1,894 members of the public over the age of 16 years were asked in face-to-face interviews their knowledge relating to cancer, with particular reference to oral cancer, its causes and those at high risk and general attitudes to cancer.Results: Oral cancer was one of the least heard of cancers by the public with only 56% of the participants being aware, whereas 96% had heard of skin cancer, 97% lung cancer and 86% cervical cancer. There was a 76% awareness of the link between smoking and oral cancer but only 19% were aware of its association with alcohol misuse. Whereas 94% agreed that early detection can improve the treatment outcome, a disheartening 43% believed that whether a person developed a cancer or not was a matter of chance and therefore was unavoidable.Conclusions: This survey highlights a general lack of awareness among the public about mouth cancer and a lack of knowledge about its causation especially the excess risk associated with alcohol.Recommendations: There is a clear need to inform and educate the public in matters relating to the known risk factors associated with oral cancer. A media campaign informing the public about oral cancer is clearly required. The need for the reduction in the incidence of oral cancer should be included in 'Our healthier nation' targets. An overall health promotion strategy to reduce cancers should include oral cancer as a priority. In addition the European Code against Cancer which aims to improve prevention, the early detection of oral cancer and the necessity for fast track referral should be made more widely known. Recognition of oral cancer in local strategies for oral health should be encouraged. [ABSTRACT FROM AUTHOR]

One of the most important components of G1 checkpoint is the retinoblastoma protein (pRB[SUP110]). The activity of pRB is regulated by its phosphorylation, which is mediated by genes such ascyclin D1 andp16/MTS1. All three genes have been shown to be commonly altered in human malignancies. We have screened a panel of 26 oral squamous cell carcinomas (OSCC), nine premalignant and three normal oral tissue samples as well as eight established OSCC cell lines for mutations in thep16/MTS1 gene. The expression ofp16/MTS1,cyclin D1 and pRB[SUP110] was also studied in the same panel. We have foundp16/MTS1 gene alterations in 5/26 (19%) primary tumours and 6/8 (75%) cell lines. Two primary tumours and five OSCC cell lines had p16/MTS1 point mutations and another three primary and one OSCC cell line contained partial gene deletions. Six of seven p16/MTS1 point mutations resulted in termination codons and the remaining mutation caused a frameshift. Western blot analysis showed absence of p16/MTS1 expression in 18/26 (69%) OSCC, 7/9 (78%) premalignant lesions and 8/8 cell lines. One cell line, H314, contained a frameshift mutation possibly resulting in a truncated p16/MTS1 protein. pRB was detected in 14/25 (56%) of OSCC but only 11/14 (78%) of these contained all or some hypophosphorylated (active) pRB. In premalignant samples, 6/8 (75%) displayed pRB, and all three normal samples and eight cell lines analysed contained RB protein. p16/MTS1 protein was undetectable in 10/11 (91%) OSCCs with positive pRB. Overexpression of cyclin D1 was observed in 9/22 (41%) OSCC, 3/9 (33%) premalignant and 8/8 (100%) of OSCC cell lines. Our data suggest p16/MTS1 mutations and loss of expression to be very common in oral cancer cell lines and less frequent in primary OSCC tumours. A different pattern of p16/MTS1 mutations was observed in OSCC compared to other cancers with all the detected p16/MTS1 mutations resulting in premature termination codons or a frameshift. The RB protein was... [ABSTRACT FROM AUTHOR]

Lysyl oxidase (LO) takes part in the initial steps of converting soluble monomers of collagen and elastin into insoluble fibres in the extracellular matrix. We have studied the immunolocalization of LO as a marker of fibrogenesis in oral submucous fibrosis (OSF). Oral biopsies from 13 subjects with OSF, 6 with histologically confirmed squamous cell carcinoma (SCC) arising in OSF and 10 SCC nonrelated to OSF, were examined. Strong positive staining was observed in 7/13 OSF samples in the cytoplasmic processes of fibroblasts and extracellularly in the upper third of the lamina propria. Furthermore, LO was found to co-localize in the areas stained strongly for collagen and elastin by histochemical stains. Examination of SCC tissues showed localization of LO adjacent to invading epithelial islands as evidence of a stromal reaction both in carcinomas arising from OSF and in SCC from non-OSF cases. These findings suggest that upregulation of LO may be an important factor in the pathogenesis of OSF and in the early stromal reaction of oral cancer. [ABSTRACT FROM AUTHOR]

This study describes the results of a survey undertaken to assess the management of potentially malignant oral mucosal lesions by oral medicine practitioners and compares their approach with that of oral & maxillofacial surgeons that we have previously described. Significant differences were noted between the two groups in the use of photography to document the lesions and in the use of certain special investigations, which included measurement of serum iron, serum ferritin, serum Vit B12, red cell folate and candidal isolation. The groups also varied in the perceived importance of the age of the patient and anatomical site of the lesion when deciding on the need for further biopsy. There was also significant variation in the use of certain treatment modalities, including excising non-dysplastic and severely dysplastic/carcinoma in-situ lesions and eliminating trauma when treating mild/moderately dysplastic and severely dysplastic/carcinoma in-situ lesions. Significant differences in the frequency and duration of follow-up were noted for non-dysplastic lesions. Finally, the two groups differed significantly when asked to rank the perceived importance of certain factors (the histopathology of the most recent biopsy and the anatomical site of the lesion) when deciding the need to follow-up. Possible reasons for the variation are discussed. [ABSTRACT FROM AUTHOR]

Gingival crevicular fluid (GCF) sampling was performed on 2 occasions separated by 1 year, at 2 sites in the mouths of 102 male adolescents, mean age 17.85 years. Samples were collected onto 5 filter paper strips which were sequentially applied to the mouth of the crevice over a 9-min collection period. Volume and flow rates of GCF were determined for each site and were compared with clinical measurements of plaque, gingival colour, bleeding, gingival index (GI) and pocket depth, using a general linear models (GLM) procedure. While the initial volume of GCF showed no association with any clinical measurement, there was an association between flow rate of GCF and gingival colour. The volume of GCF collected in the final, 5th sample was associated with the GI. The sample site strongly influenced all measures of GCF volume. It is proposed that the flow rate of GCF may be a better indicator of gingival inflammation than the more imprecise clinical assessments of inflammation, since GCF flow rates more precisely reflect changes in tissue permeability. The association between the final sample, collected after 9 min, and clinical measurements, was probably a reflection of the association between clinically-detectable inflammation and the susceptibility of the site to mild irritation. [ABSTRACT FROM AUTHOR]

We have estimated the levels of Interleukin-1 beta (IL-1β) by ELISA in gingival crevicular fluid (GCF) at 58 sites from 37 patients with adult periodontitis. GCF was collected for 5 s on filter papers and a 2nd sample was collected for 30 s 1 min later. 68/116 strips yielded detectable levels of IL-1β. IL-1β was present in both the 1st and 2nd samples at 28 sites, in the 1st only at 4 sites and in the 2nd only at 8 sites; 18 sites were below the level of detection for the assay. When the concentrations of IL-1β were calculated in the original volume of GCF on each strip, the mean value for positive strips was 34.16±29.45 (SD) pg/μl with a range from 1.75 to 97.13 pg/μl. There were no statistically significant correlations with the plaque index, bleeding index or probeable crevice depth (pocket depth). The results indicate that IL-1 is present in the GCF from a proportion of sites with evidence of previous periodontal destruction. [ABSTRACT FROM AUTHOR]

Many factors have been hypothesised either to characterise groups and individuals at risk for periodontal disease or to be markers of periodontal breaks down, in order to identify these as associated either with disease status or progression, a statistical association between the factor and a measure of disease will have to be demonstrated. The statistical modelling of data arising from periodontal research presents special problems. These include the large number of measurements made in each subject, the large magnitude of measurement error compared to the changes in attachment level, the analysis of longitudinal studies, the lack of a measure of instantaneous rate of attachment loss and controversies over the nature of the progression of the disease. We consider statistical methods currently available in the light of these difficulties and identify areas in which further research is necessary. [ABSTRACT FROM AUTHOR]

Periodontal microbiology is reviewed with regard to the potential of certain characteristics to serve as markers of high risk groups or individuals for periodontal diseases. The generally accepted associations between particular organisms and the various periodontal diseases are discussed. The usefulness of various clinical study designs is reviewed. The ecology of the subgingival plaque microflora is discussed and a number of suggestions for future research are made. We have concluded that there is no monospecific aetiology to any of the various periodontal conditions. Nevertheless, we give particular attention to the role of the black-pigmented bacteroides based upon our belief that they, and Bacteroides gingivalis in particular, are fundamental to our understanding of the biology of periodontal diseases in humans and other animals. Consequently, the contribution of its various virulence factors and their potential as markers of disease susceptibility and activity is addressed. [ABSTRACT FROM AUTHOR]

The use of saliva as a source of components that may identify subjects at risk of developing destructive periodontitis, or provide markers of disease potential or activity, has been reviewed. It was concluded that bacteria, their constituents or products are unlikely to be rewarding and that host-derived salivary factors such as enzymes cannot identify risk, as deficiency states for these do not exist. Secretory IgA, plasma IgA and lgG isotype levels and specific antibodies may be associated with risk, but probably only if levels fall below those which are protective or a specific antibody response is absent. More work is needed to distinguish between monomeric and dimeric IgA antibodies and to identify IgG antibodies in longitudinal clinical studies. In general, although saliva may prove to be useful as a source of indicators of current disease activity or as a means of assessing responses to treatment, it is unlikely to provide evidence for the existence of risk factors. [ABSTRACT FROM AUTHOR]

Gingival crevicular fluid is regarded as a promising medium for the detection of markers of periodontal diseases activity. The collection protocols are straight forward and non-invasive and can be performed at specific sites of interest in the periodontium. Because the fluid accumulates at the gingival margin, it will contain potential markers derived not only from the host tissues and serum but also the subgingival microbial plaque, and thus an extremely broad range of candidate molecules may be investigated. However, the ability to successfully describe indicators of current disease activity and predictors of future disease is dependent not only upon the choice of the biochemical marker but also on the accurate description of the health status of the sample sites using currently available clinical and radiographic methods. Areas of study which currently show the most promise involve the analysis of host enzyme activities directed against components of the extracellular matrix, the nature of the glycosaminoglycans released into the sulcus and the concentration in gingival crevicular fluid of certain mediators of the inflammatory process, most notably prostaglandin E2. [ABSTRACT FROM AUTHOR]

The total protein concentration of gingival crevicular fluid (GCF), sampled repeatedly over a 10-min period with the minimum of physical irritation to the sulcus, was evaluated in a group of 32 healthy adolescents. The mean concentration of the 1st sample was comparable to that of normal tissue fluids and lymph, irrespective of the state of inflammation of the sample site. However, during repeated sampling, the values rose to resemble serum protein levels, except at those sites with no clinically detectable inflammation. Gel electrophoretic analysis confirmed the increasing proportion of serum-derived molecules in the more proteinaceous GCF samples. The results demonstrate the extreme sensitivity of the gingival vasculature to GCF sampling and consequently the need for accurate standardisation of GCF collection protocols. This will apply particularly when compositional data is to be normalised with respect to the total protein content or when the levels of a serum constituent are being examined. [ABSTRACT FROM AUTHOR]

The fundamental concepts of measuring periodontal diseases and the interpretation of such information as an historical record of disease, rather than disease activity, emphasises the need for improved diagnostic and prognostic tests. Criteria for an indicator of disease activity were suggested and an index fulfilling these should allow sites to be categorised as "active", quiescent or healing, and enable one to predict the risk of future disease activity. The ability of current measurements and indices, routinely used during clinical assessments of periodontal diseases, to fulfill the suggested criteria was considered and rejected in all cases. It is concluded that clinical parameters are only capable of identifying disease retrospectively, indicating the need for longitudinal, rather than cross-sectional studies in the search for clinical and laboratory markers of disease activity and susceptibility. [ABSTRACT FROM AUTHOR]

The evidence for systemic predisposition to periodontal diseases is reviewed in relation to cellular and humoral immunity, drug therapy, diet and nutrition and stress. It is concluded that, apart from defects of polymorphonuclear leukocytes (PMN) and Ehlers-Danlos Syndrome, little firm evidence exists for other diseases, though insulin-dependent diabetes and acquired immune deficiency syndrome (AIDS) may accelerate and/or potentiate the damage of existing disease. The precise rôle of drugs, diet and nutrition and stress remain to be elucidated, but recent advances in these areas offer the prospect of assessing risk using carefully controlled studies. [ABSTRACT FROM AUTHOR]

p53 is a nuclear phosphoprotein recognised as important in the regulation of normal cell growth and proliferation, the wild-type protein suppressing cell division. Expression of presumptive mutant protein, detected by immunohistochemistry, is used increasingly as a diagnostic and prognostic marker in human neoplasms. A question arises as to whether or not p53 (over)expression in a lesion is any more or less informative than other markers of cell proliferation. Twenty well-differentiated oral squamous cell carcinomas which had earlier been examined for immunoreactivity against a panel of p53 antibodies were examined for the status of cell proliferation--both in islands of invading neoplastic cells and in the non-malignant epithelial margins. The status of epithelial cell proliferation was found to be significantly higher in p53-positive tumours when enumerated by Ki-67 antibody, both within the tumour as well as its margins. This may confer a growth advantage to these neoplasms and reflect a status of inactivated p53 protein, although the actual cause of the rapid proliferation may lie in activation/inactivation of other genes. The PCNA labelling indices, on the other hand, were closely similar in both p53-positive and -negative groups, suggesting that stabilisation of p53 protein does not influence the proliferative advantage in these carcinomas via a deregulation step of PCNA-related gene products. [ABSTRACT FROM AUTHOR]

The presence and distribution of Epstein-Barr Virus receptors (EBVR's) on a range of normal (n = 18), dysplastic (n = 10) and malignant (n = 20) oral mucosa were studied by immunocytochemical methods using the monoclonal antibodies (MAb s) l-1B5 and B2. EBVR s were demonstrated as membrane staining of the spinous layers of normal non- and parakeratinized epithelium. indicating that EBVR's are differentiation-linked. This distribution was retained in dysplastic epithelium. Tissue from oral squamous cell carcinomas (SCC's) showed variable reactivity of only a few cells scattered randomly within the samples. Furthermore, a sensitive in situ hybridization (ISH) technique was used to determine if Epstein- Barr virus (EBV) was present in normal (n= 15) and oral squamous cell carcinoma tissues (n=20). No EBV DNA was demonstrated within either normal or malignant epithelium, suggesting that the virus does not persist in normal oral stratified squamous epithelium nor is there any evidence for a role in oral carcinogenesis. [ABSTRACT FROM AUTHOR]

Twenty-eight young, healthy adults completed an experimental gingivitis study in which blood and clinical recordings were obtained at baseline; after a 4-week period of thorough oral hygiene; after a subsequent 3-week period of plaque accumulation; and after another 2 weeks of thorough oral hygiene, Serum immunoglobin G antibodies against whole cells of Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucmeatum and Streptococcus sanguis were determined using enzyme-linked immunosorbent assay. Mean serum immunoglobin G antibody levels to P. intermedia, F. nucleatum and S. sanguis remained essentially constant during the experiment, whereas the immunoglobin G antibodies to P. gingivalis declined during the initial period of oral hygiene and the subsequent period of plaque accumulation to an average of 84.5% of the baseline value. This reduction could be attributed to the people who developed marked gingival inflammation during the period of plaque accumulation, indicating that the systemic host response may be associated with local characterized by higher initial serum immunoglobin G responses to P. gingivalis than people who developed less pronounced gingival inflammation during the experiment. The variability and individuality noted in the host response to potential pathogens have implications for attempts to use such measures for establishing a diagnosis or prognosis for the individual patient. [ABSTRACT FROM AUTHOR]

The identity of the major surface antigens of Porphyromonas gingivalis was investigated. Outer membranes of P. gingivalis strains W83, W50, 381 and NCTC 11843 were prepared following inactivation of the trypsin-like enzyme activity. Three proteins, molecular weight 115, 55 and 40 kDa, were major components of the outer membranes of strains W83 and W50 and were also present in strains 381 and NCTC 11834. Two proteins, 55 and 47 kDa, were released from the cells during the sonication step of the outer membrane preparation procedure. Immunoblots using preparations of P. gingivalis W83 and serum from a case-control study of adult periodontitis demonstrated higher mean antibody reactivity in the case population to all the major proteins except for the 115 kDa outer membrane protein, which was recognized equally well by both populations. We conclude that the 55, 47 and 40 kDa proteins are important surface antigens of P. gingivalis. Characterization of the structure and function of these components should lead to an improved understanding of the host-parasite interactions in adult periodontitis. [ABSTRACT FROM AUTHOR]

The potential of p53 protein expression as a marker for determining which oral precancerous lesions may transform to malignancy with time was assessed. We compared the p53 expression in archival formalin-fixed, paraffin-embedded tissues from 22 baseline biopsies of precancerous lesions that transformed to cancer in 4-25 years against that in 68 similar lesions that did not transform over the same time period. Twenty-nine percent of precancers that transformed were p53-positive at baseline, compared to 31% of the biopsies that did not transform to malignancy. When examined by immunohistochemical methods p53 expression failed to detect potential malignant status of oral precancer. Non-specificity of the assay may account for this result but overexpression of p53 due to DNA damage by tobacco/betel-quid in non-progressive lesions needs further study. Nine precancerous lesions became p53-immunoreactive from precancer to cancer. This may suggest p53 overexpression peaks close to the time of transition from precancer to cancer rather than early in the natural history of oral precancer. [ABSTRACT FROM AUTHOR]

Histological and ultrastructural features of 25 oral snuff dipper's lesions with distinctive subepithelial hyaline deposits were investigated. Periodic acid-Schiff reaction with and without diastase digestion demonstrated the presence of glycogen and other carbohydrates, but histochemical stains for normal collagen, elastin and fibrin showed a weak variable reactivity of the deposit. Although in 7/25 cases the deposit was in close proximity to labial salivary glands and on occasions ducts were found within the deposit, the presence of mucin was not a consistent feature. Congo red staining and immunohistochemical investigation with an anti-amyloid antibody did not support the previous contention that such deposits were amyloid in nature. Immunohistochemically, collagen antibodies also provided negative results, but ultrastructural features of three biopsies studied suggest that the bulk of this deposit is made up of collagen, as typical cross-striated fibrils were found. The pathogenesis of this deposit could therefore be interpreted as over-production and/or reduced turnover of collagen by resident fibroblasts, which is further altered by the ingredients of toombak. The deposit does not appear to be a secretory product. [ABSTRACT FROM AUTHOR]

An archival series of oral biopsies from Karachi, Pakistan, consisting of 21 cases of oral submucous fibrosis (OSF) and 27 cases of squamous cell carcinoma (SCC), of which 6 had arisen from OSF, were used to examine the aberrations in the structure and expression of the p53 tumour suppressor gene. The PCR-SSCP method was used for mutation analysis of exons 2-9, and (over)expression of p53 protein was detected by immunocytochemistry using monoclonal antibody DO 7. Positive immunostaining was observed in 15/20 (75%) of OSF specimens, 3/6 (50%) of SCC arising from OSF and 14/21 (67%) of SCC not arising from OSF. Mobility shifts in SSCP indicative of a mutation in p53 or loss of heterozygosity (deletion of a band) were seen in 13/21 cases of OSF and 15/27 cases of SCC. There was concordance between immunocytochemistry and SSCP results in a majority (33/48) of samples. Though the number of analysed SCC cases arising from OSF was limited, the results suggest that p53 mutation/protein stabilisation may play a part in the pathogenesis of OSF and its progression to SCC. [ABSTRACT FROM AUTHOR]