Evaluation of DNA damage in tobacco associated human buccal cells using comet assay.

AIM AND OBJECTIVE: To assess the DNA damage in tobacco associated human buccal cells using comet assay. METHODS: The study included 75 study subjects, which were divided into 3 groups on the basis of tobacco usage. Group I - 25 individuals with no history of tobacco usage, Group II - 25 individuals with tobacco usage but without oral lesions and Group III - 25 individuals with tobacco associated oral lesions. Cytological smears collected from these individuals were used to assess the tobacco associated DNA damage by measuring the tail length in the comet assay method. RESULTS: The average tail length was found to be 1.46 µm in the normal mucosa, 2.86 µm in tobacco users without oral lesions, 3.86 µm in the lesional sites of tobacco users and 3.67 µm in the non-lesional sites of these individuals. Factors like age, gender, duration and different forms of tobacco habit had their own impact on the oral mucosa. CONCLUSION: Comet assay helps assess the subclinical genetic changes of oral mucosa even before the clinical manifestations of the precancerous lesions appeared due to tobacco usage. Thus, comet assay may bloom out as a novel adjuvant tool for the prevention of oral cancer in the near future.

Cytogenetic analysis of genetic damage in young individuals exposed to chronic mechanical irritation in the lateral border of the tongue due to sharp teeth - a novel study.

BACKGROUND: Chronic inflammation is estimated to contribute to approximately 25% of human cancers. Inflammation can be induced by chronic mechanical irritation which can lead to oral pre-cancer and oral cancer. Though many studies have been conducted to identify the genetic damage in oral cancer or dysplastic stages, no study has been conducted so far on early detection of genetic damage in healthy individuals presenting with sharp teeth in contact with the lateral border of the tongue. OBJECTIVE: The study is aimed at analyzing the genetic damage (micronuclei) in healthy individuals with sharp teeth in contact with the lateral border of the tongue causing chronic mechanical irritation. METHODS: The study group included 75 clinically healthy individuals with sharp teeth in contact with the lateral border of the tongue and 25 clinically healthy individuals with normal teeth in contact with the lateral border of the tongue as a control group. Brush samples of epithelial cells were collected, then spread over clean glass slide and fixed in 100% alcohol, stained with rapid PAP and analyzed under the light microscope. The exfoliated cells were examined to detect micronuclei. RESULTS: Micronuclei frequency was found to be increased in the study group where sharp teeth were in contact with the lateral border of the tongue of healthy individuals without deleterious habits such as usage of tobacco in smoking/smokeless form, areca nut chewing or alcohol consumption. CONCLUSIONS: Cytogenetic analysis is a simple and scantly invasive technique allowing clinicians the early detection of DNA damage in patients with sharp teeth and subsequently preventing carcinogenesis by proper treatment and follow-up.

Immunohistochemical Detection of Nerve Growth Factor (NGF) in Follicular and Plexiform Ameloblastoma - A Novel Study.

BACKGROUND: Ameloblastoma is the second most common odontogenic tumor that holds a unique position among benign tumors due to its locally destructive and invasive nature. The differed tumor biology behind follicular and plexiform ameloblastoma is always an enigma. Nerve growth factor (NGF), a neurotrophin that plays a major role during odontogenesis, could also possibly play a role in the pathogenesis of odontogenic tumors such as ameloblastoma. With this background, the study was aimed to investigate the expression of NGF in follicular and plexiform ameloblastoma. OBJECTIVES: The objectives of this study were to analyze the immunohistochemical expression pattern of NGF in ameloblastoma and to compare the immunohistochemical expression pattern of NGF among the follicular and plexiform histological types of ameloblastoma. MATERIALS AND METHODS: Forty histological sections of ameloblastomas (20 follicular and 20 plexiform) were stained immunohistochemically with anti-human NGF mouse IgG monoclonal antibody and the staining was analyzed statistically. RESULTS: Almost all the 40 ameloblastoma samples (20 follicular and 20 plexiform) showed positive immunoreactivity to NGF. Both peripheral pre-ameloblast-like tall columnar cells and central stellate-reticulum-like cells showed positive reactivity. The pattern of staining was membranous in the immunoreactive cells. The χ2 value for the immunoexpression between follicular and plexiform ameloblastoma was statistically significant with a P value <0.002. A possible mechanism has been proposed after studying the results with the downstream pathways obtained from literature. CONCLUSION: The pattern of expression of NGF is seen in both follicular and plexiform ameloblastoma. But the intensity is more in plexiform than that of follicular ameloblastoma.

Immunohistochemical detection of Tyrosine Kinase receptor (TrK) in follicular and plexiform ameloblastoma - A novel study.

OBJECTIVES: The objective is to analyze the immunohistochemical expression pattern of tyrosine kinase receptor (TrK) in ameloblastoma and to compare the immunohistochemical expression pattern of TrK among the histological types of ameloblastoma, follicular and plexiform patterns. MATERIALS AND METHODS: Forty ameloblastomas (20 follicular and 20 plexiform) were immunostained with anti-human TrK mouse IgG monoclonal antibody, and the pattern of staining is statistically analyzed. RESULTS: Total 20 (4 follicular and 16 plexiform) out of 40 ameloblastomas showed immunoreactivity to TrK. Only the peripheral preameloblast like tall columnar cells showed reactivity, whereas the stellate reticulum like cells is immunonegative. The staining pattern was membranous in the immunoreactive cells. The Chi-square value for the immunoexpression between follicular and plexiform ameloblastoma was statistically significant with a P < 0.005. The results were studied with the downstream pathways from the literature, and a possible mechanism has been proposed. CONCLUSION: The expression pattern of TrK is found to be more in plexiform ameloblastoma than follicular ameloblastoma.

Immunohistochemical analysis of Nuclear Factor-kappa B (NF-κB) between follicular and plexiform ameloblastomas: A pilot study.

BACKGROUND: Ameloblastoma among benign tumors holds a unique position by its locally destructive and invasive nature. Tumors that originate from the odontogenic apparatus or its remnants in the jaws show diverse clinical presentations, behavior and histologic patterns. The differed biological behavior behind follicular and plexiform ameloblastomas has never attained completeness because of the lack of rhythmic correlation regarding the exact mechanism. Nuclear factor-kappa B (NF-κB) pathways play a crucial role in survival, death and differentiation during physiologic and pathologic conditions. With this background, the study has been aimed to investigate the expression of NF-κB in follicular and plexiform ameloblastomas. OBJECTIVE: The objective of this study was to analyze the immunohistochemical expression pattern of NF-κB in ameloblastoma and to compare the immunohistochemical expression pattern of NF-κB among the histological types of ameloblastoma, follicular and plexiform patterns. METHODOLOGY: Total 20 ameloblastomas (10 follicular, 10 plexiform) were immunostained with antihuman NF-κB p65 mouse IgG monoclonal antibody, and the pattern of staining is statistically analyzed using Chi-square test with the level of significance (P < 0.05). RESULTS: Twelve (3 follicular, 9 plexiform) out of 20 ameloblastomas showed immunoreactivity to NF-κB p65. In ameloblastoma, only the peripheral preameloblast-like tall columnar cells showed reactivity, whereas the stellate reticulum-like cells are immunonegative. The staining pattern was membranous in the immunoreactive cells. The results were studied with the associated and inducing pathways from the literature, and a possible mechanism has been proposed. CONCLUSION: The expression pattern of NF-κB was found to be higher in plexiform ameloblastoma than follicular ameloblastoma.

Morphological Analysis of Elastic Fibers in Various Grades of Oral Squamous Cell Carcinoma and Epithelial Dysplasia Using Verhoeff-Van Gieson Stain.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is the sixth most common malignancy in India. The aggressiveness of OSCC is analyzed not only based on the dysplastic features and tumor infiltration pattern, but also by means of the stromal changes that pave the way for an invasion into the connective tissue. The role of elastic fibers in the progression of OSCC is still unknown because of sparse literature and the masking effect of overlying inflammatory cells and the lower number of elastic fibers in the lamina propria. The present study provides further insight into the qualitative assessment of elastic fibers in various grades of dysplasia and OSCC. OBJECTIVES: To analyze the morphological changes exhibited by the elastic fibers in epithelial dysplasia and OSCC. MATERIALS AND METHODS: Two sections were cut from each of 60 samples of varying grades of OSCC and 60 samples of varying grades of epithelial dysplasia followed by staining with hematoxylin and eosin and Verhoeff-Van Gieson stain. RESULTS: Statistically significant results were obtained for qualitative analysis of elastic fibers. A change in density and orientation to overlying epithelium and tumor islands was seen on progressing from well-differentiated to poorly differentiated OSCC and in progressing grades of dysplasia. CONCLUSION: The uniqueness of this study lies in the exploration of elastic fibers in dysplasia and well-differentiated OSCC, a less explored field. The study of the connective tissue stromal changes can be used as an adjunct to histological grading.

Kerosene as an Alternative to Xylene in Histopathological Tissue Processing and Staining: An Experimental Study.

BACKGROUND: Conventional tissue processing is as old as 100 years and still remains the gold standard. Tissue processing involves many steps, of which one of the important steps is clearing. Xylene is one of the common clearing agents used in laboratory, but it is carcinogenic and teratogenic. AIM: The aim of this study was to substitute conventionally used xylene with kerosene in tissue processing and staining. MATERIALS AND METHODS: Thirty bits of chicken tissue samples were collected; each was randomly separated into two groups: tissue processing and staining. Instead of conventional xylene, we used kerosene. The tissue blocks were subjected to sectioning and staining, and finally, they were observed under light microscope. RESULTS: Tissue samples that were processed and cleared with kerosene showed equal clearing and staining without any alterations of the tissue morphology and cellular details with that of xylene. CONCLUSION: Kerosene can be used as a substitute to xylene without posing any health risk or compromising the cellular integrity.

Recurrent keratocystic odontogenic tumor of right maxillary sinus involving the right infraorbital rim.

Keratocystic odontogenic tumor (KCOT) is a benign odontogenic tumor with an aggressive behavior and high recurrence rate. The most common site of predilection is the posterior mandible. In contrast, KCOTs occurring in the maxillary region are relatively rare. However, the maxillary involvement poses a greater and increased threat, due to proximity to vital structures such as maxillary sinus, orbital floor, and infratemporal fossa. This report presents such a case of KCOT involving the maxillary sinus eroding the floor of the orbit and provides an account of the factors that need to be considered during management.

Denture bar-coding: An innovative technique in forensic dentistry.

Denture markers play an important role in forensic odontology and also in identifying a person. A number of methods are there for identifying dentures from a less expensive technique to a more expensive technique. Out of different denture markers, the bar-coding system is a way of collecting data from the mobile. Even a huge amount of data can be stored in that. It can be easily incorporated during acrylization of the denture and thus could be helpful in identification. This article reviews the strengths of bar-coding and how easily it can be used in the routine procedure.

Liaison between micro-organisms and oral cancer.

Oral cancer which is a subtype of head and neck, cancer is any neoplastic tissue growth in the oral cavity. It comprises an abnormal mass of cells that foists genetic mutation and impedes the normal cell cycle, resulting in its unrestrained growth. Various studies on the plausible link between oral microbial flora and cancer notwithstanding, our understanding of their link remains obscure and inadequate. The multitude of mechanisms by which the microflora initiate or spur Carcinogenesis are still under study and scrutiny. As is widely known, the oral cavity is an abode to a wide assortment of microbes, each present in contrasting amounts. It is observed that increased growth of the microflora is concomitant with known clinical risk factors for oral cancer. Manifold bacterial species have been found to interfere directly with eukaryotic cellular signaling, adopting a style typical of tumor promoters. Bacteria are also known to impede apoptosis thereby potentially promoting carcinogenesis. The viral role in carcinogenesis (by annulling of p53 tumor suppressor gene and other cellular proteins with subsequent alteration in host genome function) is well documented. Furthermore, the changes occurring in the commensal microflora in accompaniment with cancer development could possibly be used as a diagnostic indicator for early cancer detection. The intention of this review is to obtain a better understanding of the "role" that micro-organisms play in oral cancer etiology.

Eagle's syndrome - Masquerading as ear pain: Review of literature.

The name styloid process (SP) was derived from the Greek word "stylos" meaning a pillar. It is a bony, cylindrical, needle-shaped projection, which originates from the posterior-inferior side of the petrous bone, immediately in front of the stylomastoid foramen, and goes obliquely down and forward. When elongated leads to pain and discomfort called Eagle's syndrome. Elongated SP accounts approximately to 4-7% of the population, 4% only are symptomatic.

Stem cells: An insight into the therapeutic aspects from medical and dental perspectives.

The recent advancements in the field of stem cell (SC) biology have increased the hope of achieving the definitive treatments for the diseases which are now considered incurable such as diabetes, Parkinson's disease and other chronic long standing conditions. To achieve this possibility, it is necessary to understand the basic concepts of SC biology to utilize in various advanced techniques of regenerative medicine including tissue engineering and gene therapy. This article highlights the types of SCs available and their therapeutic capacity in regenerative medical and dental fields.

A clinical study on oral lichen planus with special emphasis on hyperpigmentation.

BACKGROUND: Oral lichen planus (OLP) is a unique disorder affecting generally the older age group. Numerous studies have been done on various aspects of OLP such as pathogenesis, rate of malignant transformation, etc. However, very few studies are available with respect to clinical features especially association of hyperpigmentation and OLP. This study aims at studying the clinical aspects of OLP and study the association between hyperpigmentation and OLP in a south Indian population. MATERIALS AND METHODS: A total of 58 patients with OLP who attended the outpatient department of our institution were included in the study and a complete history, followed by thorough intraoral examination was done. All the data were recorded and assessed for statistical analysis using SPSS software. RESULTS: We found that the male to female ratio affected with OLP was 1:1 and the most common form of OLP that was seen was the reticular subtype. Also, buccal mucosa was the most common affected site and more than 60% patients had hyperpigmentation associated with the site affected by OLP. We found a statistically significant relation between the reticular type of OLP and the older age group (51-70 years) with hyperpigmentation. CONCLUSION: Although further studies are required to say anything conclusively, post-inflammatory changes occurring the mucosa due to OLP could be a cause for hyperpigmentation in the sites affected.

Dermatoglyphic patterns and salivary pH in subjects with and without dental caries: A cross-sectional study.

BACKGROUND: Dermatoglyphic patterns, which are regularly used in judicial and legal investigations, can be valuable in the diagnosis of many diseases associated with genetic disorders. Dental caries although of infectious origin, may have a genetic predisposition. Hence, we evaluated the correlation between dental caries and dermatoglyphic patterns among subjects with and without dental caries and evaluated its association with environmental factors such as salivary pH. MATERIALS AND METHODS: Totally, 76 female students within the age group of 18-23 years were clinically examined, and their decayed, missing, filled teeth (DMFT) score and oral hygiene index-simplified were recorded. Based on their DMFT score, they were divided into following three groups; group I (n = 16, DMFT score = 0), group II (n = 30, DMFT score <5), and group III (n = 30, DMFT score ≥5). Their fingerprint patterns and salivary pH were recorded and analyzed using descriptive statistics. RESULTS: Dermatoglyphic pattern distribution in caries-free group showed more ulnar loops than high caries group (group III) while high caries group showed more whorl patterns. Presence of whorl with double loop, whorl within a loop was associated with high DMFT score. The total finger ridge count was lower in caries group. The mean salivary pH was higher in caries-free group than high caries group. Thus, we conclude that dermatoglyphic patterns may be potential diagnostic tool for detecting patients prone to develop dental caries.

Taurodontism.

Taurodontism can be defined as a change in tooth shape caused by the failure of Hertwig's epithelial sheath diaphragm to invaginate at the proper horizontal level. An enlarged pulp chamber, apical displacement of the pulpal floor, and no constriction at the level of the cemento-enamel junction are the characteristic features. Although permanent molar teeth are most commonly affected, this change can also be seen in both the permanent and deciduous dentition, unilaterally or bilaterally, and in any combination of teeth or quadrants. Whilst it appears most frequently as an isolated anomaly, its association with several syndromes and abnormalities has also been reported. Despite the clinical challenges, taurodontism has received little attention from clinicians. Due to the prevalence of taurodontism in modern dentitions and the critical need for its true diagnosis and management, this review addresses the etiology, clinical and radiographic features of taurodontism, its association with various syndromes and anomalies, as well as important considerations in various areas of expertise dental treatments of such teeth.

Immunology of oral candidiasis.

A successful pathogen is one that is able to effectively survive and evade detection by the host immune defense. Oral candidiasis has adopted strategies, which evade host defense and eventually cause disease in at-risk patients. Host defense against infections with Candida spp. depends on rapid activation of an acute inflammatory response by innate immunity, followed by an incremental stimulation of specific immune responses mediated by T-cells (cellular immunity) or B-cells (humoral immunity). Understanding these complex pathways of immune evasion can potentially contribute to the development of novel therapeutic strategies against oral candidiasis.

Pathogenesis and therapeutic intervention of oral submucous fibrosis.

Oral submucous fibrosis (OSF) is a chronic, progressive, potentially malignant condition affecting the oral cavity and frequently involving the upper part of the aerodigestive tract including the oropharynx and the upper part of the esophagus. It is characterized by juxtaepithelial inflammatory reaction and progressive fibrosis of lamina propria, leading to stiffening of the oral mucosa eventually causing trismus. This condition is associated with significant morbidity and high risk of malignancy. Over the years, several drugs and combinations have been tried for the treatment of submucous fibrosis, but with limited success, because of its unclear molecular pathogenesis. Till date, there are no known effective treatments for OSF. The aim of this article is to emphasize on the molecular changes taking place in OSF and possible therapeutic interventions.

Lip prints: Role in forensic odontology.

Identification plays a major role in any crime investigation. The pattern of wrinkles on the lips has individual characteristics like fingerprints. Cheiloscopy is a forensic investigation technique that deals with identification of humans based on lips traces. In the past decades, lip-print studies attracted the attention of many scientists as a new tool for human identification in both civil and criminal issues. The lip crease pattern is on the vermilion border of the lip, which is quite mobile and lip prints may vary in appearance according to the pressure, direction and method used in making the print. It concludes by enlightening the readers with the fact that the possibilities to use the red part of lips to identify a human being are wider than it is commonly thought.