Dr. R. Ahmed Dental College and Hospital

Oral submucous fibrosis is a potentially malignant disorder of the oral cavity, with a high rate of malignant transformation. It is very common among habitual areca nut chewers. The pathogenesis of oral submucous fibrosis is not well established, but it is believed to be a disease of multifactorial origin, including areca nut chewing, ingestion of chilies, genetic factors, immunologic processes and nutritional deficiencies. Genetically susceptible individuals when exposed to areca nut chewing develop this disease over a variable period of time. Oral submucous fibrosis is considered to be a disease of collagen metabolism. Several genetic factors are reported but there is no consensus about the exact mechanism of disease initiation. Variations in histopathological presentation are noted among oral submucous fibrosis patients with habitual areca nut chewing in different forms and other additive agents, eg betel quid, pan masala and gutkha, together with a variety of tobacco habits. The role of epigenetic modifications, such as miRNA regulation, and DNA methylation is also being reported as part of the pathogenesis of oral submucous fibrosis. A combined approach, including analysis of genetic and epigenetic regulations with different habits, might be helpful to better understand the contributory factors and pathogenesis of this serious disorder.

Infection with specific pathogens and alterations in tissue commensal microbial composition are intricately associated with the development of many human cancers. Likewise, dysbiosis of oral microbiome was also shown to play critical role in the initiation as well as progression of oral cancer. However, there are no reports portraying changes in oral microbial community in the patients of Indian subcontinent, which has the highest incidence of oral cancer per year, globally. To establish the association of bacterial dysbiosis and oral squamous cell carcinoma (OSCC) among the Indian population, malignant lesions and anatomically matched adjacent normal tissues were obtained from fifty well-differentiated OSCC patients and analyzed using 16S rRNA V3-V4 amplicon based sequencing on the MiSeq platform. Interestingly, in contrast to the previous studies, a significantly lower bacterial diversity was observed in the malignant samples as compared to the normal counterpart. Overall our study identified Prevotella, Corynebacterium , Pseudomonas , Deinococcus and Noviherbaspirillum as significantly enriched genera, whereas genera including Actinomyces , Sutterella , Stenotrophomonas , Anoxybacillus , and Serratia were notably decreased in the OSCC lesions. Moreover, we demonstrated HPV-16 but not HPV-18 was significantly associated with the OSCC development. In future, with additional validation, this panel could directly be applied into clinical diagnostic and prognostic workflows for OSCC in Indian scenario.

BACKGROUND: Current trends in clinical dental implant therapy include modification of titanium surfaces for the purpose of improving osseointegration by different additive (bioactive coatings) and subtractive processes (acid etching, grit-blasting). The aim of this study was to evaluate and compare the behaviour of hydroxyapatite and the newly developed bioactive glass coated implants (62 implants) in osseous tissue following implantation in 31 patients. METHODS: Bioactive glass and hydroxyapatite was suitably coated on titanium alloy. Hydroxyapatite coating was applied on the implant surface by air microplasma spray technique and bioactive glass coating was applied by vitreous enamelling technique. The outcome was assessed up to 12 months after prosthetic loading using different clinical and radiological parameters. RESULTS: Hydroxyapatite and bioactive glass coating materials were non-toxic and biocompatible. Overall results showed that bioactive glass coated implants were as equally successful as hydroxyapatite in achieving osseointegration and supporting final restorations. CONCLUSIONS: The newly developed bioactive glass is a good alternative coating material for dental implants.

Autism is an intellectual developmental disorder characterized by insidious disability in communication, social interaction, and using language and abstract concepts. This organic disorder is known to have deformities in brain, i.e., cerebellum and limbic system, showing wide spectrum of systemic and behavioral symptoms. The oral health care of such patients can be complicated as they cannot verbalize complaints about any dental problems they may be experiencing and can display a variety of behaviors and reactions to small changes also.

Polymorphism in glutathione S-transferase (GST) genes, causing variations in enzyme activities, may influence susceptibility to oral cancer and leukoplakia in smokers and/or smokeless tobacco users. In this case-control study consisting of 109 leukoplakia and 256 oral cancer patients and 259 controls, genotype frequencies at GSTM1, GSTT1, GSTM3 and GSTP1 loci were determined by polymerase chain reaction-restriction fragment length polymorphism methods and analyzed by multiple logistic regression to determine the risks of the diseases. There were no significant differences in the distributions of GSTM1, GSTM3 and GSTT1 genotypes in patients and controls when all individuals were compared. In contrast, frequencies of ile/ile genotype at codon 105 and variant val-ala haplotype of GSTP1 was significantly higher (OR = 1.5; 95% CI = 1.0-2.0) and lower (OR = 1.4; 95% CI = 1.0-1.9) in oral cancer patients compare to controls, respectively. The impacts of all genotypes on risks of oral cancer and leukoplakia were also analyzed in patients with different tobacco habits and doses. Increased risks of cancer and leukoplakia were observed in tobacco smokers with GSTM3 (A/A) genotype (OR = 2.0, 95% CI = 1.0-4.0; OR = 2.0, 95% CI = 1.0-4.4, respectively). So, GSTM3 (A/A) genotype could become one of the markers to know which of the leukoplakia would be transformed into cancer. Heavy tobacco chewing (> 124 chewing-year) increased the risk of cancer in individuals with GSTT1 homozygous null genotype (OR = 3.0; 95% CI = 1.0-9.8). Furthermore, increased lifetime exposure to tobacco smoking (> 11.5 pack-year) increased the risk of leukoplakia in individuals with GSTM1 homozygous null genotype (OR = 2.4; 95% CI = 1.0-5.7). It may be suggested that polymorphisms in GSTP1, GSTM1, GSTM3 and GSTT1 genes regulate risk of cancer and leukoplakia differentially among different tobacco habituals.

An individual's susceptibility to oral precancer and cancer depends not only on tobacco exposure but also on the genotypes/haplotypes at susceptible loci. In this hospital-based case-control study, 310 cancer patients, 197 leukoplakia patients, and 348 controls were studied to determine risk of the disease due to polymorphisms at three sites on XRCC1 and one site on XRCC3. Independently, variant genotypes on these loci did not modulate risk of leukoplakia and cancer except for the XRCC1 (codon 280) risk genotype in exclusive smokeless tobacco users with leukoplakia [odds ratios (OR), 2.4; 95% confidence intervals (CI), 1.0-5.7]. But variant haplotypes, containing one variant allele, on XRCC1 increased the risk of leukoplakia (OR, 1.3; 95% CI, 1.0-1.7). Among stratified samples, mixed tobacco users, carrying variant haplotypes, also had increased risk of both leukoplakia (OR, 2.2; 95% CI, 1.3-3.9) and cancer (OR, 1.9; 95% CI, 1.2-3.1). In a previous study on this population, it was shown that the GSTM3 (A/A) genotype increased the risk of oral leukoplakia and cancer among smokers, which has also been substantiated in this study with expanded sample sizes. The simultaneous presence of two risk genotypes in smokers, one on each of two loci, GSTM3 and XRCC1 (codon 280), increased the risk of cancer (OR, 2.4; 95% CI, 1.0-5.8). Again, smokers carrying two risk genotypes, one on each of two loci, GSTM3 and XRCC1 (codon 399), were also overrepresented in both leukoplakia and cancer populations (P(trend) = 0.02 and 0.04, respectively) but enhancement of risks were not observed; probably due to small sample sizes. Therefore, the presence of variant haplotypes on XRCC1 and two risk genotypes, one on each of two loci, GSTM3 and XRCC1, could be useful to determine the leukoplakias that might progress to cancer in a group of patients.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is one of the common malignancies in Southeast Asia. Epigenetic changes, mainly the altered DNA methylation, have been implicated in many cancers. Considering the varied environmental and genotoxic exposures among the Indian population, we conducted a genome-wide DNA methylation study on paired tumor and adjacent normal tissues of ten well-differentiated OSCC patients and validated in an additional 53 well-differentiated OSCC and adjacent normal samples. RESULTS: Genome-wide DNA methylation analysis identified several novel differentially methylated regions associated with OSCC. Hypermethylation is primarily enriched in the CpG-rich regions, while hypomethylation is mainly in the open sea. Distinct epigenetic drifts for hypo- and hypermethylation across CpG islands suggested independent mechanisms of hypo- and hypermethylation in OSCC development. Aberrant DNA methylation in the promoter regions are concomitant with gene expression. Hypomethylation of immune genes reflect the lymphocyte infiltration into the tumor microenvironment. Comparison of methylome data with 312 TCGA HNSCC samples identified a unique set of hypomethylated promoters among the OSCC patients in India. Pathway analysis of unique hypomethylated promoters indicated that the OSCC patients in India induce an anti-tumor T cell response, with mobilization of T lymphocytes in the neoplastic environment. Survival analysis of these epigenetically regulated immune genes suggested their prominent role in OSCC progression. CONCLUSIONS: Our study identified a unique set of hypomethylated regions, enriched in the promoters of immune response genes, and indicated the presence of a strong immune component in the tumor microenvironment. These methylation changes may serve as potential molecular markers to define risk and to monitor the prognosis of OSCC patients in India.

Tumors of jaw bones are among the most uncommon of all types of neoplasms. Osteosarcoma of jaw bones represents a distinct group of lesions from the conventional type commonly occurring in long bones. Nonetheless, our present knowledge of the tumor allows us to affirm that its clinical behavior and pathologic features differ markedly from those of its homolog in the long bones. The maxillary tumors show predilection for posterior portion of the alveolar process and the antrum, whereas the body is most commonly involved in the mandible followed, by angle, symphysis, and ascending ramus. We have reviewed around 300 cases of osteosarcoma of varied racial origin from PubMed indexed journals spanning from 1967 to 2010 and present their etiology, pathogenesis, features and treatment modalities.

UNLABELLED: The relationship between diabetes mellitus and periodontal disease is not clear, even though studied intensively. From the available data, it seemed reasonable to believe that diabetics were more susceptible to periodontal disease than non.diabetics. AIM: The present study was to clinically evaluate the relationship of diabetes mellitus with periodontal disease along with various parameters. MATERIALS AND METHODS: Fifteen hundred patients with diabetes mellitus were examined. A thorough oral examination was carried out and relevant history was recorded for all the patients. RESULTS: Results indicated that the prevalence of periodontal disease in diabetic patients was 86.8%. CONCLUSION: It can be concluded that poorer the glycemic control, and longer the duration of diabetes, the greater will be the prevalence and severity of periodontal disease.

OBJECTIVE: The present study was undertaken to access the level of knowledge and attitude of patients toward implant treatment as an option for replacement of missing teeth. MATERIALS AND METHODS: An epidemiological study was conducted among 440 subjects who attended the OPD of two Departments (Prosthodontics and Oral and Maxillofacial Surgery). A self-administered structured closed ended questionnaire pretested through a pilot survey was used in the study. The data were analyzed using the SPSS version 15.0. The Student's t-test and ANOVA test were used as test of significance. RESULTS: Out of 440 subjects asked about the knowledge and attitude about implants, only 33.3% had heard of implants as a treatment modality and dentists were the main source of information. Very few people had undergone implant surgery. The level of awareness increased with education. The main factor for not having implants was due to its high treatment charges. However, they were interested to know more about the implant treatment modality. CONCLUSION: The survey was conducted in a dental institute and majority of the participants were unaware about dental implants. It also showed that need for providing more information to the patients about this treatment modality.

OBJECTIVES: The aim of this study was to evaluate clinically and radiographically zinc oxide eugenol (ZOE) and Metapex as root canal filling material in primary teeth. MATERIALS AND METHODS: Forty-two necrotic primary teeth in two groups of children in the age group of 4-7 years were obturated with ZOE and Metapex and were followed up clinically and radiographically for a period of 6 months postoperatively. RESULTS: The overall success rates of ZOE and Metapex were 85.71% and 90.48%, respectively. CONCLUSION: Both ZOE and Metapex gave encouraging results; however, Metapex can be used more safely whenever there is a doubt about the patient's return for follow-up.

INTRODUCTION: The main aim of root canal treatment is cleaning, shaping and then obturating three dimensionally to prevent reinfection. This includes chemicomechanical cleansing by instrumentation and the use of irrigating solutions. Therefore, the purpose of this study was to compare the smear layer removal from root canal dentine subjected to two root canal irrigants, 17% EDTA and 0.2% Chitosan, a new irrigant using Scanning Electron Microscope. METHODOLOGY: 40 single rooted premolars were decoronated followed by instrumentation with I Race files and intermediate irrigation with 3% sodium hypochlorite and activation with ultrasonics. Then the samples were longitudinally sectioned and place in the respective test solutions and their controls for 5 minutes. Scanning Electron Microscopic evaluation was further carried out. RESULTS: The results of the present study indicates that the Chitosan which was proved effective in removing smear layer. CONCLUSION: A moderate concentration of 0.2% chitosan removes the smear layer with greater efficiency.

CONTEXT: With an increase in the abuse of various oral habitual products in India over the past few decades; the incidence of oral potentially malignant conditions as leukoplakia, oral submucous fibrosis and squamous cell carcinoma (SCC) rates have also increased. No recent study has been conducted reporting the scenario of oral cancer and potentially malignant conditions in Eastern India (specifically Kolkata). AIMS: The present study was conducted at Dr. R. Ahmed Dental College, Kolkata during 2010-2011 to find a possible correlation between the effects of the different oral habits, age, sex and the different types of oral mucosal lesions among patients reported to the hospital. This study also enabled us to see the predilection of the various histopathological stages of the lesions for different sites of the oral cavity. SUBJECTS AND METHODS: The study group consisted of 698 patients having either oral potentially malignant or malignant lesion. The control group consisted of 948 patients who had reported to the hospital for different oral/dental problems and had the habit of tobacco, areca nut and/or alcohol usage for at least 1 year. STATISTICAL ANALYSIS: The unadjusted odds ratio, the 95% confidence interval, and the P value were calculated to correlate patients with/without different kinds of habit and having/not having various kinds of oral lesions. RESULTS: Our study shows that for males having the habit of taking smokeless tobacco or mixed habit poses the highest risk for developing SCC. For females, significant risk of developing SCC was found in patients habituated to processed areca nut chewing. CONCLUSION: This study presents probably for the first time in recent years the occurrence of oral potentially malignant and malignant conditions amongst patients having deleterious habits in a hospital based population of Kolkata.

AIM: The aim of this study was to determine the diagnostic accuracy of routine Papanicolaou stain (PAP) and Silver stained Nucleolar Organizer Regions (AgNOR) staining in brush biopsies taken from suspected oral lesions for early detection of oral cancer. MATERIALS AND METHODS: Brush biopsies were collected from macroscopically suspicious lesions of the oral cavity of 34 patients and 10 normal-aged and sex-matched controls. The numbers of AgNORs were counted in 100 squamous epithelial cell nuclei per slide after silver staining of the smears (Ploton's one-step method). RESULTS: Sensitivity and specificity of PAP analysis in the oral smears for detection of oral cancer and normal cells was 91.176% and 100%. The positive and negative prediction values were 100% and 76.92%, respectively. Sensitivity and specificity of AgNOR analysis in the oral smears for detection of oral cancer and normal cells was 100%. The positive and negative prediction values were 100% each. CONCLUSION: Based on the above facts, we conclude that brush biopsy in conjunction with AgNOR staining is an easily practicable, non-invasive, safe and accurate screening method for the detection of macroscopically suspicious oral cancerous lesions. Because of its simple technique and high reliability for cellular proliferation, AgNOR staining in brush smears can be used as an adjunct to other routine cytological diagnoses for the early detection of oral cancer. However, further investigations with more number of study samples will be needed to establish this correlation beyond doubt.

AIM: To describe a novel neural network based oral precancer (oral submucous fibrosis; OSF) stage detection method. METHOD: The wavelet coefficients of transmission electron microscopy images of collagen fibres from normal oral submucosa and OSF tissues were used to choose the feature vector which, in turn, was used to train the artificial neural network. RESULTS: The trained network was able to classify normal and oral precancer stages (less advanced and advanced) after obtaining the image as an input. CONCLUSIONS: The results obtained from this proposed technique were promising and suggest that with further optimisation this method could be used to detect and stage OSF, and could be adapted for other conditions.

A total of 1042, 3-14-year-old children with different types of handicapping conditions when recorded for dental caries using WHO 1987 caries recording index revealed that dental caries experience was higher in handicapped children than normal children. The prevalence of dental caries was highest in mentally retarded children followed by cerebral palsied, blind, epileptic, physically handicapped, children with Down's syndrome and deaf and dumb. Higher deft+DMFT was recorded in mandibular teeth compared to maxillary teeth.

Clear cell odontogenic carcinoma is a rare odontogenic tumor occurring predominantly in posterior mandible during 5(th)-7(th) decades with a female predilection. It is a potentially aggressive tumor, capable of frequent recurrences and loco-regional and distant metastases. Till date, only 73 cases have been reported in the literature. Current case is of a 55-year-old woman with tumor mass extending from canine to molar region on the left maxillary arch. Being locally aggressive tumor with the capacity to metastasize, it demands to be distinguished from other primary and metastatic clear cell tumors of the oral and maxillofacial region. A brief compilation of the reported cases is being attempted in the current article to better understand the behavior of the tumor.

Early detection and quantification of DNA damage in oral premalignancy or malignancy may help in management of the disease and improve survival rates. The comet assay has been successfully utilised to detect DNA damage in oral premalignant or malignancy. However, due to the invasive nature of collecting blood, it may be painful for many unwilling patients. This study compares the micronucleus (MN) assay in oral buccal mucosa cells with the comet assay in peripheral blood cells in a subset of oral habit-induced precancer and cancer patients. For this, MN assay of exfoliated epithelial cells was compared with comet assay of peripheral blood leucocytes among 260 participants, including those with oral lichen planus (OLP; n = 52), leukoplakia (LPK; n = 51), oral submucous fibrosis (OSF; n = 51), oral squamous cell carcinoma (OSCC; n = 54) and normal volunteers (n = 52). Among the precancer groups, LPK patients showed significantly higher levels of DNA damage as reflected by both comet tail length (P < 0.0001) and micronuclei (MNi) frequency (P = 0.0009). The DNA damage pattern in precancer and cancer patients was OLP < OSF < LPK < OSCC, and with respective oral habits, it was multiple habits > cigarette + khaini > cigarette smokers > areca + khaini > areca. There was no significant difference in the comet length and MNi frequency between males and females who had oral chewing habits. An overall significant correlation was observed between MNi frequency and comet tail length with r = 0.844 and P < 0.0001. Thus, the extent of DNA damage evaluation by the comet assay in peripheral blood cells is perfectly reflected by the MN assay on oral exfoliated epithelial cells, and MNi frequency can be used with the same effectiveness and greater efficiency in early detection of oral premalignant conditions.

BACKGROUND: Patients undergoing mandibular advancement device (MAD) therapy for obstructive sleep apnea (OSA) may experience changes in jaw position and altered occlusion. This could potentially contribute to the development or exacerbation of TMD symptoms. The literature on the long-term impact of MAD treated for OSA on TMD is scarce. Hence, this review was undertaken to ascertain the occurrence of TMD in MAD users. METHODS: A comprehensive search protocol was implemented across several online databases using MeSH keywords and Boolean operators. A standardised data extraction form was developed specifically for this review. Two reviewers independently extracted the data. RoB-2 was used to evaluate the methodological quality of the included studies. RESULTS: A total of 13 clinical studies were selected for this review. Some studies reported a significant reduction in the severity and frequency of TMD symptoms following MAD treatment. However, other studies did not observe significant changes in TMD symptoms or TMJ-related parameters from baseline to follow-up intervals. Temporary increases in TMJ-related pain or symptoms at the beginning of the follow-up period, which later subsided, were reported in some studies. Overall, MAD was not discontinued in any OSA patient due to TMDs. CONCLUSION: The findings reveal that different outcomes associated with TMD are affected differently by MAD treatment for OSAS. According to a few studies, MAD therapy significantly reduced the severity and frequency of TMD symptoms. Other research, however, found no appreciable modifications in TMD symptoms or TMJ-related indicators. Although the overall results point to no significant effect of MAD treatment on TMD symptoms, the disparity in results between studies highlights the need for additional studies using standardised approaches.

Oral submucous fibrosis (OSF) is prevalent mostly in Southeast Asia, particularly in the Indian subcontinent. Chewing betel nuts and betel leaves, with or without tobacco, has been associated with OSF. Betel quid contents including guvacine, arecoline, guvacoline, arecaidine, and chavibetol are considered to play an important part in the occurrence of OSF. Transformation of OSF to squamous cell carcinoma (SCC) is variable, but up to 13% conversion of OSF to SCC has been reported. Various genetic and molecular mechanisms impact the malignant transformation of OSF, causing changes in the cell cycle, DNA, keratinocytes, and keratin; tumor-cell proliferation and survival; angiogenesis; fibrosis through epithelial-mesenchymal transitions (EMTs), and tissue hypoxia. All are reviewed here, including potential biomarkers for malignant transformation of OSF. These interactions are not fully understood, but a critical mass of knowledge is building up to ultimately allow the understanding of all mechanisms involved.