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.

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.

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.

Digitized Morphometric Analysis using Maxillary Canine and Mandibular First Molar for Age Estimation in South Indian Population.

BACKGROUND: In recent years, the estimation of age in living individuals have become important to solve judicial or civil problems. Secondary dentin deposition occurs as the age advances and can be measured by calculating the reduction in pulp chamber through Noninvasive radiograph techniques. AIM: The aim is to derive precise population specific formulae for age estimation. MATERIALS AND METHODS: Digitalized Orthopantomography of 150 subjects, was retrieved. The subjects were divided into study and test group. Pulp tooth area ratio was recorded from the maxillary canine and pulp chamber crown root trunk height ratio was recorded from a mandibular first molar. STATISTICAL ANALYSIS: Regression equation was derived from study group subjects and this equation was used to estimate the age of subjects in the test group. RESULTS: No significant differences were seen between mean chronological age and mean estimated age (p-value- 0.157). Mean Absolute Error (MAE) was estimated to be 2.76 years. The percentage of estimated ages in test sample < ± MAE was 72%. The difference was higher in the group I and II (p-value- 0.001 and 0.002). CONCLUSION: The equation derived from the anterior and posterior teeth together gave more accurate results in the present study. The prediction accuracy can further be enhanced by using multiple teeth or by utilizing other linear measurements in the same teeth.

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.

Acinic cell carcinoma of minor salivary gland showing features of high-grade transformation.

INTRODUCTION: Acinic cell carcinoma (AciCC) of salivary gland is a relatively infrequent tumor. Though known for its low-grade behavior, its unpredictable element of recurrence and malignancy should never be ignored. CASE REPORT: A male patient with complaints of pain and swelling in the left jaw region since a year was operated based on the computed tomography (CT) and incisional biopsy report. Histopathology (routine staining, special staining, immunostaining and electron microscopy) of the excised specimen revealed it to be a variant of AciCC from minor salivary gland. DISCUSSION: To the best of our knowledge, this is the first case of AciCC showing propensity for high-grade transformation (HGT), arising from minor salivary gland, being reported. The rarity of such variants and the importance of various investigative techniques in the diagnosis of such cases are discussed.

Intraosseous myofibroma of mandible: A rarity of jaws: With clinical, radiological, histopathological and immunohistochemical features.

Myofibroma is an uncommon benign mesenchymal neoplasm composed of myofibroblasts, but it can be confused with more aggressive spindle cell tumors. Solitary myofibroma is common in soft tissues of head and neck, but rare in the jaw bones with only 38 cases of central myofibroma of mandible reported in English medical literature. When encountered in the jaws, lesions exhibit clinical and radiographic features suggestive of odontogenic cysts/tumors or other neoplastic conditions. We hereby present the 39(th) case of intraosseous myofibroma of the mandible which had been reported to our institution. A 16-year-old male reported with a chief complaint of swelling in the right side of face. Intraorally there was a firm, nontender swelling in the right buccal aspect of the mandible. Radiologically the lesion was osteolytic, destroying the buccal cortical plate. Histologically, characteristic biphasic pattern of myofibroma was noticed. Immunoreactivity was positive for vimentin and αSMA but negative for desmin, thus confirming our diagnosis. The patient was treated by local-wide surgical excision of the lesion. A 3-year follow-up revealed no signs of recurrence. Occurrence of myofibroma involving the jaw bones is common in the younger age groups and represents a unique diagnostic and therapeutic challenge. Differentiating this lesion from other benign and malignant neoplasms is crucial in deciding between a radical and a conservative treatment approach.

Determining dental sex dimorphism in South Indians using discriminant function analysis.

Dental forensics forms a vital branch of forensic science which deals with proper handling, examination and evaluation of dental evidences for identification of victims of crime, accidents or calamities. Therefore skull and teeth often provide the identification material. The aim of the study was to investigate the accuracy of odontometric methods in sex determination of permanent teeth and to compute new formula to differentiate male and female teeth using discriminant function analysis for South Indian population. A total of 100 subjects were selected for the study from a parent population of 4800 students by simple random sampling method. Alginate impressions of the upper dental arch were made and casts were poured immediately. A digital vernier calliper was used for the measurement of all upper anteriors. Twelve different tooth measurements were recorded and from those two indexes have been computed. Statistical analysis was performed using the SPSS version 17.0 software. All the predictor variables were subjected to stepwise discriminant function analysis which optimally separates the genders and a best discriminant function was generated. In all the observed mean dimensions, male values exceed the female values. Student's 't' test for the different predictor variables of all teeth selected between male and females were found significant (p < 0.05). Very high significance was found in mean MD of 11, 12 and 13 and |c| of 23. The variables exhibiting best discriminant powers were mesiodistal width of both upper central incisors, DB-ML of 13 and canine crown module of 13. Sexual dimorphism in the size of permanent teeth differs from one population to the other and hence the standards set for one population could not be applied for another population. Hence this technique would be a simple, quick, cost effective, reliable and accurate for sex determination.