Cell Proliferation in Human Oral Mucosa

Studies of cell proliferation and migration - cell kinetics - have been described extensively on animal tissues and to a more limited extent in human tissues. These reported studies are reviewed and the deficiencies in available knowledge are highlighted. One of the main difficulties in studying the kinetics of human tissues is that the most widely used technique in animal work, namely parenteral injection of radioactive isotopes to label specific cells, is not generally applicable in man. The initial work in the present study was concerned with investigation of techniques for quantitating cell kinetics and the development of an in vitro radioactive labelling technique suitable for use with human tissues. The reliability of this technique was evaluated in the animal study where the in vitro labelling was shown to give comparable results to the classical in vivo labelling techniques. The in vitro radioactive labelling technique was then used on biopsies from normal cheek mucosa obtained at six times of the day. This allowed diurnal variations in cell kinetic parameters to be quantitated. In conjunction with this investigation a stereologic study of the epithelium was undertaken. The cell kinetic and stereologic techniques were next used to study eight cases of leukoplakia of cheek, a clinical disorder characterised by keratosis. The findings in the leukoplakia lesions were contrasted with those in biopsies from clinically normal mucosa in the same individuals. Epithelial cell production was found to be increased although the viable cellular layers of the epithelium were atrophic in the leukoplakias. The control biopsies, although obtained from clinically normal mucosa, were shown to exhibit several abnormalities. The degree of increased cell producation in leukoplakia in these control specimens was shown to have a positive correlation with the severity of epithelial atypia. The further applications of kinetic studies and epithelial morphometry are outlined and the difficulties encountered in the use of in vitro radioactive labelling techniques and other morphometric methods in the study of cell proliferation are discussed

Oral Lichenoid Contact Lesions to Mercury and Dental Amalgam—A Review

Human oral mucosa is subjected to many noxious stimuli. One of these substances, in those who have restorations, is dental amalgam which contains mercury. This paper focuses on the local toxic effects of amalgam and mercury from dental restorations. Components of amalgam may, in rare instances, cause local side effects or allergic reactions referred to as oral lichenoid lesions (OLLs). OLLs to amalgams are recognised as hypersensitivity reactions to low-level mercury exposure. The use of patch testing to identify those susceptible from OLL is explored, and recommendations for removing amalgam fillings, when indicated are outlined. We conclude that evidence does not show that exposure to mercury from amalgam restorations poses a serious health risk in humans, except for an exceedingly small number of hypersensitivity reactions that are discussed

A Scoping Review on Gaps in the Diagnostic Criteria for Proliferative Verrucous Leukoplakia: A Conceptual Proposal and Diagnostic Evidence-Based Criteria

We would like to thank the research group CTS-392 (Plan Andaluz de Investigacion, Junta de Andalucia, Spain).Proliferative verrucous leukoplakia (PVL) is considered as an oral potentially malignant disorder (OPMD) that presents with a high tendency to recurrence after treatment and has the highest malignant transformation ratio among all OPMD (50%). Evidence-based publications have indicated that the malignant evolution reported is significantly related to the inconsistent diagnostic criteria used in primary-level studies; so, it has been hypothesized that the risk of oral cancer for this disease could even be underestimated. This is important because PVL requires specific management protocols, evidence-based, aimed at the early diagnosis of cancer developing in these lesions. We present a scoping review—a novel approach to mapping the available literature on a given topic to provide an overview of the available research evidence and to highlight possible gaps in the evidence—especially related in our study to the diagnostic aspects of PVL, and to issue a conceptual proposal and diagnostic criteria for PVL.We conclude that PVL is a white, multifocal and progressive lesion with a high malignant transformation rate which is diagnosed mainly around the age of 60 years without any specific histological characterization. We also advise a personal reflection on the level of certainty with which the clinician makes the diagnosis of a particular case of PVL.Junta de Andalucia CTS-39

Prognosis Parameters of Oral Carcinomas Developed in Proliferative Verrucous Leukoplakia: A Systematic Review and Meta-Analysis

Research group CTS-392 (Plan Andaluz de Investigacion, Junta de Andalucia, Spain).Proliferative verrucous leukoplakia (PVL) is contemplated by the World Health Organization (WHO) as an oral potentially malignant disorder (OPMD) with a high the highest malignant transformation ratio among all OPMD (approximately 50%). Our aim was to evaluate the current evidence in relation to the prognosis of oral carcinoma developed in patients with proliferative verrucous leukoplakia (PVL-OC). We searched PubMed, Embase, Web of Science and Scopus for published studies (upper date limit = June 2021). We evaluated the quality of studies (QUIPS tool). We carried out meta-analyses, examined inter-study heterogeneity through subgroup and metaregression analyses, and performed sensitivity and small-study effects analyses to test the stability and reliability of results. 23 studies met inclusion criteria (505 patients with PVL, of which 288 developed a total of 504 carcinomas). The meta-analyzed overall mortality rate was 21.29% (pooled proportions [PP] = 95% confidence intervals [CI] = 8.77–36.36) for PVL-OC, clearly lower than the 34.7–50% mortality rate for conventional oral cancer reported in previous studies. In comparison with a single study reporting on conventional oral cancers, mortality was significantly lower for PVL-OC (hazard ratio = 0.29 [95%CI = 0.10–0.89], p = 0.03). Univariable meta-regression verified that case series that presented higher proportions of verrucous carcinomas showed a better survival of PVL-OC (p = 0.05), but not with higher proportion of oral squamous cell carcinomas (p = 0.74). Significant differences were not found for other relevant variables such as follow up period (p = 0.44) or multiple tumor development (p = 0.74). In conclusion, PVL-OC show favorable prognostic parameters, especially with regard to the mortality rate.Junta de Andalucia CTS-39

An evaluation of the efficacy of a topical gel with Triester Glycerol Oxide (TGO) in the treatment of minor recurrent aphthous stomatitis in a Turkish cohort : a randomized, double-blind, placebo-controlled clinical trial

Triester glycerol oxide gel (Protefix® Queisser Pharma, Germany) is a new topical agent that has the property of adherence to the oral mucosa by forming a lipid film which protects against mechanical trauma and may help to reduce oral tissue moisture loss and inflammation. The aim of this clinical trial was to determine the efficacy of a topical TGO gel and to also compare it with triamcinolone acetonide pomade in the treatment of minor recurrent aphthous stomatitis. This study was a randomized, double-blind, placebo-controlled clinical trial and 180 patients with the complaint of minor aphthous ulcers were enrolled in this study. The sociodemographic data and clinical characteristics of the ulcer were collected by questionnaire. Ulcer size and pain level measurements were performed and the efficacy indices for ulcer pain and size were calculated at day 0,2,4,6 by the same investigator. Significant differences were not detected among the demographics and ulcer histories including age, gender, onset of ulcer, mean healing time, family RAS history and ulcer localization between three groups. The pain score in TGO group was found statistically lower at day 2,4, and 6. Efficacy index and improvement rate of TGO group, regarding pain score, was higher than the other two groups at day 2 and 4. The reduction in ulcer size was statistically higher in TGO group than the other two groups at day 4 and 6. Topical application of TGO gel could decrease pain intensity, accelerate ulcer healing without any side effects, utilizing an easy appliable and accessible procedure. Therefore TGO gel could be a well-tolerated, safe, topical therapeutic agent in the clinical practice of RAS treatment

Tooth Decay in Alcohol Abusers Compared to Alcohol and Drug Abusers

Alcohol and drug abuse are detrimental to general and oral health. Though we know the effects of these harmful habits on oral mucosa, their independent and combined effect on the dental caries experience is unknown and worthy of investigation. We compared 363 “alcohol only” abusers to 300 “alcohol and drug” abusers to test the hypothesis that various components of their dental caries experience are significantly different due to plausible sociobiological explanations. After controlling for the potential confounders, we observe that the “alcohol and drug” group had a 38% higher risk of having decayed teeth compared to the “alcohol only” group (P < .05). As expected, those who belonged to a higher social class (OR = 1.98; 95%  CI = 1.43–2.75) and drank wine (OR = 1.85; 95%  CI = 1.16–2.96) had a higher risk of having more filled teeth. We conclude that the risk of tooth decay among “alcohol only” abusers is significantly lower compared to “alcohol and drug” abusers

Malignant transformation of oral potentially malignant disorders in males: a retrospective cohort study

<p>Abstract</p> <p>Background</p> <p>Oral squamous cell carcinoma could be preceded by clinically evident oral potentially malignant disorders (OPMDs). Transformation of OPMDs to cancer has been studied in several population groups. It is difficult to undertake comparisons across populations due to variations in the methods of computation of malignancy rates among different studies. The aim of our study was to estimate the rate of malignant transformation of OPMDs taking into account the duration of follow-up and to identify the significant factors indicative of malignant potential.</p> <p>Methods</p> <p>A total of 148 male patients with OPMDs were included. They were selected among all consecutive subjects registered at the maxillofacial clinic at a medical hospital in Kaohsiung, Taiwan. The mean follow up period was 37.8 months.</p> <p>Results</p> <p>The malignant transformation rate was highest in subjects diagnosed with oral epithelial dysplasia. In this group the transformation rate was 7.62 per 100 persons-year. The rate in the group with verrucous hyperplasia (VH) was 5.21 per 100 persons-year, and in those with hyperkeratosis or epithelial hyperplasia was 3.26 per 100 persons-year. The anatomical site of OPMDs was the only statistically significant variable associated with malignancy. The hazard rate ratio (HRR) was 2.41 times for tongue lesions when compared with buccal lesions.</p> <p>Conclusion</p> <p>The reported discrepancies of malignant transformation of OPMDs involve the follow-up time to cancer development and hence it is preferable to use a time-to-event estimation for comparisons. We found that malignant transformation of OPMDs involving the tongue was significantly higher than in other anatomical subsites after adjusting for the clinicopathological type or lifestyle factors at diagnosis.</p

Available web-based teaching resources for health care professionals on screening for oral cancer

Objectives: To identify websites with adequate information on oral cancer screening for healthcare professionals (HCPs) and to assess both their quality and contents. Study Design: Websites were identified using Google and HON medical professional search engines using the terms “screening for oral cancer”. The first 100 sites retrieved by each engine were analysed using the DISCERN questionnaire (reliability), the V instrument (contents on oral cancer) and further by the Flesch-Kinkaid Reading Grade Level and the Flesch Reading Ease (readability). Results: The overall rating showed minimal shortcomings in the quality of the information in the websites. The coverage and correctness of information on “visual examination” was rated as fair/good, whereas updating of contents resulted very variable (eg: 81% for visual examination and 18.2% for molecular biomarkers). These results permitted to rank the websites housing relevant information for oral cancer. Top ranking websites were affiliated to the Oral Cancer Foundation (USA), WHO Collaborating Centre for oral cancer (UK) whose webpage is entitled “Oral Cancer Education and Research”, and the Clinical Guidelines maintained by the British Columbia Cancer Agency (Canada) and the British Dental Association (UK) respectively. Conclusions: There are web-based, HCP-addressed, resources on screening for oral cancer housing heterogeneous information both in quality and contents. The use of specific evaluation tools permits the selection of reliable websites on this topic with a potential to improve the existing educational gaps among HCPs