E-cadherin Expression in Premalignant Lesions, Premalignant Conditions, Oral Squamous Cell Carcinoma, and Normal Mucosa: An Immunohistochemical Study.

Background Oral squamous cell carcinoma (OSCC) is a multi-step process. Epithelial-mesenchymal transition (EMT) is an important step in the progression of OSCC. One of the components that influence EMT is E-cadherin. The aim of this study was to determine the expression of E-cadherin in oral submucous fibrosis (OSMF), various grades of epithelial dysplasia, OSCC, and to compare it with the expression in the normal mucosa. Material and methods E-cadherin immunohistochemical detection was done using a monoclonal antibody of clone EP-6TM and the PolyExcel HRP/DAB chromogen detection system. A total of 100 samples, were divided into four groups, which included epithelial dysplasia (group 2) (30 cases), oral submucous fibrosis (group 3) (OSMF-30 cases), and oral squamous cell carcinoma (group 4) (OSCC-30 cases), which was compared with normal mucosa (group 1) (10 cases). The positive control used for E-cadherin was ductal breast carcinoma. Results All the cases of normal mucosa, epithelial dysplasia, and OSMF showed positivity for E-cadherin expression. In OSCC, 97% of cases expressed E-cadherin except one case. Out of 30 cases of epithelial dysplasia, 53% of mild epithelial dysplasia had a moderate intensity of expression and 75% had a mild intensity of E-cadherin expression. In moderately differentiated OSCC, 82% of cases showed mild intensity. Tissue localization of the E-cadherin stain in the basal layer decreased from normal mucosa to grades of epithelial dysplasia and OSCC. The pattern of E-cadherin staining in all the cases of group I, group II, and group III was membranous. In 97% of OSCC cases, both membranous and cytoplasmic staining were seen. Conclusion E-cadherin expression was reduced in increasing grades of epithelial dysplasia, OSCC, and OSMF compared to that of normal mucosa. E-cadherin expression is reduced as the lesions progress to malignancy. Hence, E-cadherin can be considered a surrogate marker of malignancy.

Decoding the link associated with areca nut chewing and cardiovascular disease using hsCRP as a biomarker.

Background: Chewing of areca nut is associated with various oral and systemic ill effects. The deleterious oral effects of areca nut have been widely documented to range from reactive lesions, periodontal health compromise to oral pre-cancer and cancerous states and have been described widely in the literature. The reported systemic effects of areca nut chewing are relatively less documented but reported in literature. Areca nut chewing may predispose to cardiovascular disease due to a systemic inflammatory response from the elevated levels of circulating inflammatory mediators. High-sensitivity C-reactive protein (hsCRP) is a systemic inflammatory biomarker to assess the risk of cardiovascular disease. Materials and Methods: This cross-sectional, observational study was conducted among areca nut chewers (n = 50) and non-chewers (n = 50). Areca nut chewers were considered as chewers/cases. Blood samples were collected from the participants and hsCRP levels were studied. The data were analysed using SPSS software, version 21 for statistical significance. Chi-square test was used to compare categorical variables. Mann-Whitney U test was done to analyse continuous variables. The level of statistical significance was set at P value < 0.05. Results: hsCRP mean was higher among the chewers (2.3 ± 3.7) compared to non-chewers (0.9 ± 1.3). The difference in hsCRP levels between the study group was statistically significant (P = 0.002). Conclusion: This study demonstrates the link between areca nut and cardiovascular disease using hsCRP as biomarker.

Evaluation of stress among dental undergraduates and postgraduates using salivary cortisol as a biomarker.

Background: Stress is a non-specific response of the body to any demand. Professional education has a certain level of stress inherent in it. Dental students have been reported in the literature to experience more stress than medical students. Objective: To evaluate the stress levels of dental students: first-year undergraduates, house surgeons, and final-year postgraduates, using salivary cortisol as a stress biomarker. Materials and Methods: Dental students above 18 years of age and without any systemic illness were included in the study. Those students with a drug history of corticosteroids, anti-depressants, and oral contraceptives were excluded from the study. Female participants experiencing pre-menstrual symptoms, pregnancy, and familial stressor issues were excluded from the study. First-year undergraduates, house surgeons, and final-year postgraduates were enrolled in the study. Unstimulated whole saliva was collected in the morning and evening between 9:00 and 10:00 am and between 3:00 and 4:00 pm. Salivary cortisol levels were assessed by chemiluminescence immuno-assay (CLIA). Results: Paired sample t-test was used to compare the diurnal variation among morning and afternoon samples within the groups. The salivary cortisol levels were found to be significant within the groups. One-way ANOVA was used to compare the salivary cortisol levels between the groups. The salivary cortisol levels within the groups were not statistically significant. Conclusion: Salivary cortisol is a non-invasive biomarker of stress. Postgraduates had higher salivary cortisol levels than other study groups.

Study of expression of endoglin (CD105) in oral squamous cell carcinoma.

Context: Oral cancer is the 8th most common cancer in the world. An important feature of carcinogenesis is angiogenesis. Endoglin is a powerful marker of neovascularization in solid malignancies. This study was done to ascertain its role as an indicator of metastasis and prognosis. Aim: This study aimed to evaluate and compare the expression of endoglin (CD105) in metastatic primary tumor, lymph node of the metastasized tumor, nonmetastatic primary tumor and in normal buccal mucosa immunohistochemically. Settings and Design: The total sample size comprised 45 formalin-fixed paraffin-embedded tissue blocks, n = 10 metastasized primary tumor, n = 10 lymph nodes of metastasized primary tumor, n = 20 nonmetastasized oral squamous cell carcinoma and n = 5 normal buccal mucosa were studied. Subjects and Methods: Immunohistochemistry for endoglin was performed and microvessel density (MVD) was determined by hot spot method. Microvessel density was compared between the groups. Statistical Analysis: Statistical analysis was used using one-way ANOVA. P < 0.05 was statistically significant. Results: Endoglin expression in metastatic cases (0.68 + 0.10) was higher than nonmetastatic cases (0.45 + 0.20) and the difference was statistically significant (P = 0.002). Conclusion: This study shows that presence of endoglin determines the metastatic potential of the tumor and its prognosis, thus, could be considered as a potential target of therapy.

Areca nut use disorder: A dynamic model map.

PROBLEM: Areca nut (AN) chewing is common among Southeast Asian population. Use of AN products (with or without tobacco) have a multifaceted effect on physical health, especially on cardiovascular, nervous, gastrointestinal, metabolic, respiratory, and reproductive systems. AN is a known group 1 carcinogen and carries addictive potential. Varying degrees of AN-related substance use disorder (SUD) have been reported among AN chewers. There is a lacuna in awareness of the health risk of AN use, prevention, and cessation programs among AN users, particularly in those who have developed SUD. EXISTING LACUNAE: The dynamic interaction of factors that promote AN use and later the risk of developing SUD at individual and community level has not been studied in depth. Understanding of the bio-psycho-socio-economic-cultural factors is necessary to identify the factors that prelude, promote, and reinforce AN usage. For managing AN-related conditions, including the several systemic disorders, there is a knowledge lacunae, among health care providers with respect to the pathophysiology of AN-related health issues, SUD, and nonavailability of structured, evidence-based cessation protocols. SOLUTIONS/RECOMMENDATIONS: This manuscript presents a model-map to study the dynamics of AN use and the impact of AN on health and health care system at individual as well as community level. The model proposed can help the health policymakers to create evidence-based awareness and cessation protocols for AN.

Evaluating and comparing the morphological and histopathological changes induced by erbium:yttrium-aluminum-garnet laser and diamond bur on enamel, dentin and pulp tissue.

AIM: Lasers are used for different types of dental treatments. Using the erbium:yttrium-aluminum-garnet (Er:YAG) laser to remove dental hard tissue is simple, advantageous and influences the type of cavity preparation, whether conventional or conservative in nature. The aim of the present study was to evaluate and compare the morphological and histopathological changes in the enamel, dentin and pulp tissue of the teeth treated by Er:YAG laser and conventional burs. METHODS: A conventional class I cavity was prepared in orthodontic patients by laser and bur. The teeth were extracted and analyzed for morphological changes using a scanning electron microscope, ground sections and histopathological changes under a light microscope. RESULTS: The time with laser was longer than the conventional methods. The lased cavity showed irregular appearance with absence of smear layer which is suitable for the resin restoration. The ground section and the histopathological study showed no differences between the groups. CONCLUSION: The Er:YAG laser is effective in the removal of dental hard tissue without damaging the pulp when coupled with ideal energy output. It is widely used in different dental fields. It needs time to be accepted by dentist and patients and further studies are required to explore its advantages.

Loricrin expression and its implication in oral submucous fibrosis, hyperkeratosis and normal mucosa with association to habits - An immunohistochemical study.

OBJECTIVE: The coarse fibres of areca nut and the continuous friction from occluding teeth are major causes of mechanical stress to the oral mucosa in conditions like oral submucous fibrosis and frictional keratosis. The continuous micro trauma provided in areca nut chewers, creates an environment where the keratinocytes exhibit alteration. Loricrin, is expressed abundantly in keratinizing epithelium in response to mechanical stress. Their expression or absence could play a role in malignant transformation. This study attempts to assess the potential of Loricrin as an early diagnostic marker in patients with chewing habit. METHODS: 73 archival samples of formalin fixed, paraffin embedded tissue specimens histopathologically confirmed, were segregated as normal mucosa 11, hyperkeratotic 32 and oral submucous fibrosis 30 and stained with antibodies to Loricrin and graded as negative, mild, moderate and intense based on the staining intensity. Pearson's chi square test was done for statistical analysis. RESULTS: Loricrin expression was observed in all groups with staining in the stratum granulosum showing a significant association to habits (P = 0.000). CONCLUSION: This prominent staining indicates a compensatory cytoskeletal rearrangement of surface epithelium during cell division in early oral submucous fibrosis showing potential as an early marker of the condition.

Identification of Helicobacter pylori in Saliva of Patients with and without Gastritis by Polymerase Chain Reaction.

AIMS AND OBJECTIVE: The aim of this study was to identify the presence of Helicobacter pylori in saliva of patients with and without gastritis by polymerase chain reaction (PCR) method. MATERIALS AND METHODS: The study comprised 20 patients in Group I presenting with various symptoms of gastritis and 10 asymptomatic subjects in Group II. The intestinal endoscopy antral biopsies were collected from 20 symptomatic patients with gastroduodenal disorders. The saliva specimens were taken from all patients before endoscopy. PCR was performed using genomic DNA, isolated from the saliva and the biopsies of the patients as the template to detect the presence of the 16S ribosomal RNA gene in H. pylori. RESULTS: In Group I, 10 (50%) cases of clinical gastritis were positive for H. pylori by endoscopy biopsy and 10 (50%) were negative. Of the 10 endoscopy biopsy positive cases for H. pylori, eight were PCR positive in saliva and two were negative. Of the 10 endoscopy biopsy negative cases, three were PCR positive for H. pylori in saliva and seven were negative. In Groups II, four were symptomatic for gastritis and six were negative. Of the six gastritis negative cases, three were PCR positive, four were gastritis positive, and three were PCR positive. Sensitivity and specificity of PCR were found to be 80% and 70%, respectively. The positive predictive and negative predictive values of PCR in saliva were 72.7% and 77.7%, respectively. CONCLUSION: PCR analysis of saliva may be handy in identification of H. pylori and serves as a noninvasive technique to diagnose and monitor the prognosis.

A Study on Drug-Induced Tardive Dyskinesia: Orofacial Musculature Involvement and Patient's Awareness.

OBJECTIVE: Schizophrenia is a psychiatric disorder that requires long-term treatment. Long-term antipsychotic treatment is often associated with the emergence of tardive dyskinesia (TD), the severity of which is measured by Abnormal Involuntary Movement Scale (AIMS). This study examined the relationship among TD, orofacial musculature activity, and patient's awareness of AIM. The knowledge would help dentists to deliver oral care for schizophrenics with TD. MATERIALS AND METHODS: We identified 317 patients from a standard, data sharing initiative, of whom 38.3% exhibited AIM score of 2 to 15. The patient demographics, drug history, details of AIMS were subjected to descriptive and inferential statistical analysis using SPSS with P≤0.05 as significance. RESULTS: The mean of only orofacial features (n = 56) was 3.43 ± 2.68. Muscles of facial expression was involved in nine (7.9% of all TD), lip/perioral area in 27 (23.68%), jaw in 52 (45.61%), and tongue in 77 (67.54%). The patient's perception of AIM precipitated stress when involving jaw, tongue, limbs, and trunk was statistically significant (P≤0.05). The multiple regression model statistically significantly predicted TD for factors considered. CONCLUSION: Around 1% of global population is being diagnosed with schizophrenia, carry an inherent risk of developing TD. They might have orodental care requirements, including prosthodontic and restorative services. Primary physicians and dentists need to be aware of TD and its mechanism for appropriate patient management.

High-risk human papilloma virus in archival tissues of oral pathosis and normal oral mucosa.

OBJECTIVES: Oral cancer ranks third among all cancers in the Indian population. Human papilloma virus (HPV) plays a significant role in oral carcinogenesis. Population-based subtype variations are present in the HPV prevalence. This study gives an emphasis on the parameters to be considered in formalin fixed paraffin embedded tissues for polymerase chain reaction (PCR)-based research work. MATERIALS AND METHODS: Cross-sectional study on archival paraffin-embedded tissue samples of oral squamous cell carcinoma (OSCC), epithelial dysplasia, and normal oral mucosa surrounding impacted tooth was amplified by PCR for the E6 gene of HPV type 16 and E1 gene of HPV type 18. RESULTS: HPV 18 was positive in three OSCC cases. There was no statistically significant association of the positivity of HPV with the age, gender or habit. The HPV positive patients had a tobacco habit and were of a younger age group. CONCLUSION: The presence of HPV in carcinomatous tissue highlights the possible role of HPV in carcinogenesis and archival paraffin embedded tissue specimen can be used for this analysis. Recent studies on genomic analyses have highlighted that the HPV positive tumors are a separate subgroup based on genomic sequencing. The results of a larger retrospective study will help further in our understanding of the role of HPV in carcinogenesis, this study could form the baseline for such follow-up studies.

Awareness of Forensic Odontology among Legal Professionals, Chennai, India.

BACKGROUND: The forensic discipline of law is a multidisciplinary team comprising of specialists in forensic medicine, forensic odontology, security and law. AIM: The study was to find the awareness level of scope and utility of forensic odontology among lawyers in Chennai, South India. MATERIALS AND METHODS: A cross-sectional study using a self administered structured questionnaire was conducted in 200 lawyers between August and September of 2013. The data was analyzed depending on age, gender, type and years of practice. RESULTS: Lawyers above 40 years of experience were more aware of palatal rugae analysis (P = 0.02), and those with more than 20 years were aware of lip print (P = 0.001) and bite mark analysis (P = 0.001). Males were more aware of forensic odontology with respect to criminal identification (P = 0.001). The knowledge of bite mark analysis was higher among male lawyers (P = 0.001), civil and criminal practicing lawyers (P = 0.004). All participants were aware that loss or fracture of tooth constitutes a grievous injury under Indian Penal Code (IPC) 320 clause 7(5). CONCLUSION: This study highlighted the knowledge of forensic odontology among legal professionals and also identified the areas in which they need further appraisal.

Immunohistochemical study of p53 and proliferating cell nuclear antigen expression in odontogenic keratocyst and periapical cyst.

INTRODUCTION: p53 protein is a product of p53 gene, which is now classified as a tumor suppressor gene. The gene is a frequent target for mutation, being seen as a common step in the pathogenesis of many human cancers. Proliferating cell nuclear antigen (PCNA) is an auxiliary protein of DNA polymerase delta and plays a critical role in initiation of cell proliferation. AIM: The aim of this study is to assess and compare the expression of p53 and PCNA in lining epithelium of odontogenic keratocyst (OKC) and periapical cyst (PA). MATERIALS AND METHODS: A total of 20 cases comprising 10 OKC and 10 PA were included in retrospective study. Three paraffin section of 4 µm were cut, one was used for routine hematoxylin and eosin stain, while the other two were used for immunohistochemistry. Statistical analysis was performed using Chi-square test. RESULTS: The level of staining and intensity were assessed in all these cases. OKC showed PCNA expression in all cases (100%), whereas in perapical cyst only 60% of cases exhibited PCNA staining. (1) OKC showed p53 expression in 6 cases (60%) whereas in PA only 10% of the cases exhibited p53 staining. Chi-square test showed PCNA staining intensity was more significant than p53 in OKC. (2) The staining intensity of PA using p53, PCNA revealed that PCNA stating intensity was more significant than p53. CONCLUSION: OKC shows significant proliferative activity than PA using PCNA and p53. PCNA staining was more intense when compared with p53 in both OKC and PA.

On factors influencing the absorption capacity of surgical sponges.

BACKGROUND: Cotton balls and surgical gauzes (CSG) have been routinely used for mopping fluids and blood in surgeries. Polyurethane sheets (PUS) are increasingly used instead of CSG. The factors influencing the absorption of fluids by CSG and PUS have not been studied in detail. There are a variety of factors that could be modified by the manufacturer while a limited number of them could be manipulated by the operator. MATERIALS AND METHODS: Mathematical models and equations have been employed in this study. The impact of absorbency was performed by modulating various factors. RESULTS AND DISCUSSION: A variety of factors such as thickness, density of the web, radius of fiber, temperature, surface tension and viscosity of fluid, all influenced the absorption rate and capacity to varying degrees. The optimal variation by which the PUS can be effectively used is discussed. The suggested mathematical model will help the operator to choose the appropriate type of PUS based on the individual's needs. CONCLUSION: In an area of rapidly developing technology and change in biomaterials, where the choice of such materials are overwhelming, hopefully this basic knowledge will help the clinician to make a more educated and rational decision.

Immunohistochemical detection of p53 and p63 in oral squamous cell carcinoma, oral leukoplakia, and oral submucous fibrosis.

AIM: Oral squamous cell carcinoma (OSCC) may be preceded by potentially malignant disorders such as leukoplakia and oral submucous fibrosis (OSF). p63 in concert with p53 regulates cell proliferation and differentiation and may have a role in potentially malignant and malignant lesions of the oral cavity. The aim of the study was to evaluate and compare the expression of p53 and p63 proteins in OSCC, leukoplakia, and OSF by immunohistochemistry (IHC). METHODS: Tissue sections of OSCC (n = 20), leukoplakia (n = 20), OSF (n = 20) and normal oral mucosa (n = 10) were stained with p53 and p63 antibodies by IHC. Mean labeling index (LI) among the study groups were compared using the Kruskal-Wallis test. RESULTS: The mean LI of p53 for OSCC, leukoplakia, OSF, and normal mucosa were 56.9 ± 21.3, 37.6 ± 12.6, 34.6 ± 8.7 and 15.1 ± 9, while mean LI of p63 were 56.8 ± 19.6, 42.3 ± 10.5, 32.8 ± 12.1, and 26.4 ± 9.4. The mean LI of p53 and p63 were significantly higher in OSCC, leukoplakia and OSF compared to normal mucosa (P < 0.01; P < 0.01). CONCLUSION: The significant increase in expression of p53 and p63 proteins in OSCC, leukoplakia, and OSF suggests their role as surrogate markers of malignant transformation.

Immunohistochemical study of polycystin-1 in dentigerous cysts.

BACKGROUND: The alterations involved in step-wise transformation of a dental follicle to dentigerous cyst (DC) is not clearly known. Primary cilium and its protein have been hypothesized to be associated with DC. Mutation of a ciliary protein, polycystin-1 (PC1) is associated with autosomal dominant polycystic kidney disease. This study was performed to assess the immunohistochemical expression of PC1 between DC and postfunctional follicular tissue (PFFT). MATERIALS AND METHODS: Thirty-one consecutive PFFT and 15 DC formed the study group. The PFFT and DC tissues were stained with antibody against PC1. Statistical Package for Social Service was used to analyze data. Descriptive statistics and Student's Chi-square test were appropriately used. P≤0.05 was taken as significant. RESULTS: Fifteen DC (100%) and 7 (22.58%) PFFT were positive for PC1. The difference was statistically significant (P=0.000). PC1 expression was observed in the cytoplasm with varying intensity. DISCUSSION AND CONCLUSION: All PC1 positive epithelial cells' cytoplasm stained diffusely. Abnormal cytoplasmic expression of PC1 in all positive epithelial lining indicates that the PC1 probably is associated with cystic transformation.

A study of sister chromatid exchange in patients with dental amalgam restorations.

STUDY BACKGROUND: Dental amalgam is still widely used as a restorative material in developing countries due to its low cost and ease of manipulation. The health risks associated with the components of this restorative material has always been a matter of concern. Our study was designed to address this question regarding dental amalgam. OBJECTIVE: To study sister chromatid exchange (SCE) as an indicator of systemic genotoxicity, due to the exposure from the components of amalgam restorations during its placement and chronic use. MATERIALS AND METHODS: Systemic genotoxicity in subjects exposed to amalgam during its placement (Group II; n=5) and subjects with chronic exposure to amalgam (Group III; n=5) were compared with controls (Group I; n=5) by SCE assay in cultured peripheral blood lymphocytes. RESULT: Subjects exposed to amalgam during its placement and subjects having chronic exposure to amalgam showed an increase in the frequency of SCE, but the change was not statistically significant (P=0.84, P=0.123 respectively). CONCLUSION: Systemic genotoxicity was not observed due to the components of amalgam restorations released during its placement and chronic use. The findings of this study can be considered as preliminary information on the systemic toxicity due to the components of amalgam restorations.

Survey of responsible handling of local anesthetic in Indian dental operatory.

BACKGROUND: Dental operatory requires handling of numerous toxic fluids such as denture acrylic monomer, alcohol and formalin for effective oral care delivery. The efficacy and responsible handling of such fluids has not been analyzed among Indian dentists and this study aims to address this lacunae. MATERIALS AND METHODS: Closed ended questionnaire was distributed through email to Indian dentists in July 2012. After inclusion/exclusion criteria, 1484 practitioners constituted the study group with a response rate of 52%. STATISTICS: SPSS(®) Version 17.0 (SPSS-IBM Inc., IL, USA) was used to carry out statistical analysis. Descriptive statistics were presented. Chi square test was used to identify the association between the parameters; P ≤ 0.05 was considered as statistically significant. RESULTS: Males (80.8%), undergraduates (78%), exclusive practitioners (81.2%), urban practitioners (68.5%) were the predominant respondents. Predominant of the respondents (97%) used local anesthetic (LA) from bottles. Eight percent have encountered instances of injecting formalin instead of LA in their settings. Safe disposal rules and regulations (P ≤ 0.05), opinion on injecting the other fluids instead of LA as a severe negligent act (P ≤ 0.05) were statistically significant between age groups. Educational status did not appear to influence the outcome. Only a third of the respondents were aware of the rules and regulations for safe disposal of empty LA bottles while 49.1% were not aware of them and willing to learn. DISCUSSION: The lacunae in responsible handling of toxic fluids need to be addressed to prevent inadvertent and negligence suits against dentists, highlighting the need through continuing dental education programmes.

Impact of highly active antiretroviral therapy on salivary flow in patients with human-immuno deficiency virus disease in Southern India.

AIMS: To ascertain and compare between highly active antiretroviral therapy (HAART) and non-HAART patients, the stimulated salivary flow rates and unstimulated salivary flow rates (USFR and SSFR) and to correlate the salivary flow rates with immune suppression. MATERIALS AND METHODS: One hundred human-immuno deficiency virus seropositive patients attending RAGAS-YRG CARE were examined and divided into two groups, a HAART group (patients on combination antiretroviral therapy) comprising 50 patients and a non-HAART group comprising 50 patients. The HAART group was followed every 3 months after the baseline visit (0) for a period of 9 months, during which a clinical oral examination and collection of unstimulated and stimulated saliva was done. Their salivary gland function was assessed using a xerostomia inventory during each visit. The study on non-HAART group was cross-sectional. STATISTICAL ANALYSIS: Statistical analysis were performed with the aid of the Statistical Package for the Social Sciences (SPSS version 10.05) software. RESULTS: There was no significant difference in mean SSFR and USFR between the two groups at baseline. In the HAART group, the mean stimulated salivary flow rate increased from baseline to 3 months (P = 0.02), with the increase being maintained at 6 months and 9 months. When salivary flow rates were correlated with Cluster of Differentiation, CD4 counts, patients in the HAART group with a CD4 ≤ 200 at 6 months visit had a higher mean stimulated salivary flow rate when compared with patients with CD4 ≥ 200 (P = 0.02). The xerostomia inventory did not reveal any significant difference between the two groups and HAART was not significantly associated with xerostomia. CONCLUSION: In our study HAART was neither associated with xerostomia nor a reduction in salivary flow rate and immune suppression was not a significant factor for decreasing the salivary flow rate.

Immunohistochemical Expression of PCNA in Epithelial Linings of Selected Odontogenic Lesions.

AIM: Though odontogenic lesions have in common origin from the primitive odontogenic epithelium , there is a diversity in their initiation behavior and growth. The aggressive nature of odontogenic keratocyst similar to ameloblastoma in comparision with the other common odontogenic (dentigerous and radicular) cyst could be due to possible differences in their epithelial linings. PCNA (Proliferating cell nuclear antigen) is a cell cycle related antigen, used in the study of cell kinetics of these epithelial linings, to corelate the biological behaviour among these common odontogenic lesions. OBJECTIVES: This paper has intended to study the cell kinetics of 4 selected odontogenic lesions (dentigerous cyst, radicular cyst,odontogenic keratocyst and ameloblastoma) to demonstrate differences in their epithelial linings. MATERIAL AND METHODS: Sixty samples of paraffin embedded tissue specimens (archival tissues) were included (15 radicularcysts, 15 odontogenic keratocysts; 15 dentigerous cysts and15 Ameloblastoma. RESULTS: Among cyst OKC had higher values than DC and RC. When staining results of all the cyst were compared individually with ameloblastoma ,the staining results of OKC was similar to ameloblastoma ,and ameloblastoma presented higher values than OKC (p=0.000). CONCLUSION: The results of this study show 1) Though OKC and DC are developmental in origin and radicular cyst is inflammatory, OKC has intrinsic growth potential among these cyst 2). Ameloblastoma has similar proliferative potential as OKC and hence it has been reinforced as KCOT(Keratocystic odontogenic tumour) in the recent classification.