Role of S100 A7 as a diagnostic biomarker in oral potentially malignant disorders and oral cancer.

Background: S100 proteins have been implicated in the tumorigenesis of different human cancers and in oral dysplasia, as they are keratinocytes. Materials and Methods: In the present study, we have attempted to compare the expression of S100-A7 within young-onset (age ≤45 years, Group 1) oral squamous cell carcinoma (OSCC), OSCC in older age groups (age >45 years Group 2), oral potentially malignant disorders (OPMDs, Group 3) and inflammatory lesions (Group 4). The tissue sections were scored based on the percentage of immunostained cells and staining intensity. Nuclear, cytoplasmic and membrane immunoreactivity were also scored. Results: The present study comprised 153 histopathologically diagnosed case subjects of OSCC >45 years (n = 41), OSCC <45 years (n = 36), OPMD (n = 40) and inflammatory lesions (n = 36). The present study revealed a statistically significant difference of distribution with regard to S100A7 staining (cytoplasmic and nuclear) between OPMDs and OSCC (P < 0.05). The nuclear, cytoplasmic and membrane staining as well as the staining intensity had significantly different scoring patterns among the OSCC group, OPMD group and the inflammatory lesions with the OSCC group having the highest scoring of the S100A7 staining (irrespective of the age). Conclusions: The present study concludes that S100A7 can be used as a diagnostic biomarker to differentiate between OPMDs and OSCC lesions. However, the marker is unable to distinguish between OSCCs in younger and older patients as the molecular pathogenesis of tumors in either of these age groups is probably similar.

NOVEL USE OF FLUORESCEIN DYE IN DETECTION OF ORAL DYSPLASIA AND ORAL CANCER.

BACKGROUND: India is now regarded as the country with one of the highest incidence of oral cancer in the world. Considering poor survival in cases with late diagnosis, early detection can reduce morbidity and mortality of cancer patients and may impede malignant transformation in cases of oral potentially malignant disorders (OPMD). Most of the diagnostic aids are expensive and not available for mass screenings in developing countries. There is a need to develop a sensitive and affordable technique for screening of oral cancer, which can be accurate even in hands of health care workers with limited experience. Fluorescein dye has been used for tumour detection in colon, stomach, breast and brain. However, its utility in the diagnosis of oral cancer and OPMD has not yet been explored. METHODS: This is the first study to report the role of fluorescein in the detection of oral cancer and OPMD. The present cross sectional study was conducted at a tertiary care dental centre. It included 100 individuals presenting with 42 OPMDs, 40 oral squamous cell carcinoma (OSCC) and 18 controls. RESULTS: The sensitivity and specificity for the fluorescein detection method for OPMDs and OSCC was found to be 96.6% and 52.4% respectively. The positive predictive value was 73.7% and the negative predictive value was 91.7% for the fluorescein method. The likelihood ratios stood at 2.03 for a positive test and 0.066 for a negative test. CONCLUSION: We conclude that fluorescein staining along with blue light is likely to improve detection of early oral cancers and dysplasia and can play a vital role in mass screening programmes of oral cancer.

Correlation of mitosis obtained by using 1% crystal violet stain with Ki67LI in histological grades of oral squamous cell carcinoma.

AIM: The purpose of this study was to use a simple, cost-effective technique for studying mitosis in various grades of oral squamous cell carcinoma (OSCC) using 1% Crystal-violet stain and to correlate mitotic frequency index (MFI) obtained by it with Ki67 labeling index (Ki67LI) so as to validate its usefulness as a selective stain for evaluating proliferation. MATERIALS AND METHODS: The invasive front grading score (IFG Score) was recorded in 40 patients of OSCC. Mitotic figures were assessed in hematoxylin and eosin (H and E) stained section as well as in 1% crystal-violet stained section using MFI (MFI = Mitosis/total number of cell counted X100). Comparison between MFI obtained by 1% crystal violet stain and H and E stain was done. Ki67LI was assessed using Ki67 immunohistochemical (IHC) marker. Correlation between Ki67LI and MFI obtained by using 1% crystal-violet stain was performed. RESULTS: There was statistically significant increase in MFI obtained by using 1% crystal-violet stain compared to routine H and E stain. Statistically significant positive correlation was observed between Ki67LI and mitosis in well and moderately differentiated OSCC. Positive correlation was also observed in poorly differentiated OSCC, but it was not statistically significant. Both mean MFI and mean Ki67LI significantly increased from grade I to grade II to grade III OSCC. CONCLUSION: 1% crystal violet stain provides a definite advantage over the H and E stained sections. Thus crystal violet stain is easy and cost effective to evaluate proliferation when compared with expensive proliferative IHC marker.

Mandibular canine: A tool for sex identification in forensic odontology.

AIM: The aim of this study was to investigate the accuracy of mandibular canine index (MCI) and mandibular mesiodistal odontometrics in sex identification in the age group of 17-25 years in central Indian population. MATERIALS AND METHODS: The study sample comprised total 300 individuals (150 males and 150 females) of an age group ranging from 17 to 25 years of central Indian population. The maximum mesiodistal diameter of mandibular canines, the linear distance between the tips of mandibular canines, was measured using digital vernier caliper on the study models. RESULTS: Overall sex could be predicted accurately in 79.66% (81.33% males and 78% females) of the population by MCI. Whereas, considering the mandibular canine width for sex identification, the overall accuracy was 75% for the right mandibular canine and 73% for the left mandibular canine observed. CONCLUSION: Sexual dimorphism of canine is population specific, and among the Indian population, MCI and mesiodistal dimension of mandibular canine can aid in sex determination.

Detection of Porphyromonas gingivalis and Treponema denticola in chronic and aggressive periodontitis patients: A comparative polymerase chain reaction study.

BACKGROUND: The detection frequency of Porphyromonas gingivalis and Treponema denticola in chronic periodontitis (CP) and aggressive periodontitis (AgP) is not explored well in Indian population. AIM: The study was undertaken to detect P. gingivalis and T. denticola in CP as well as in AgP patients using polymerase chain reaction (PCR), and to determine the relationship between the frequency of these two microorganisms and the severity of clinical periodontal parameters. MATERIALS AND METHODS: Subgingival plaque samples were collected from ninety participants (thirty CP patients, thirty AgP patients, and thirty healthy participants) and the aforementioned two microorganisms were detected using PCR. RESULTS: However, when CP and AgP were compared for the detection frequency of two microorganisms, no statistically significant difference was noted. A statistically significant increase in the number of bacteria-positive sites increased as the score of plaque index (PI), gingival index (GI), and clinical attachment level of CP and AgP patients increased. Coexistence of P. gingivalis and T. denticola was frequently observed in deep periodontal pockets. CONCLUSIONS: Study findings suggest that P. gingivalis and T. denticola are significantly associated with the severity of periodontal tissue destruction. Statistically significant association exists between clinical periodontal parameters such as PI, GI, periodontal pocket depth (PPD), and clinical attachment loss and presence of both the microorganisms.