RESUMEN
Aim and Objectives: The aim and objective of the study were to evaluate the immunohistochemical expression of proliferative markers, Ki67, and MCM2 in oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC), to compare the relationship of their staining patterns, and to look for correlation between them, if any. Materials and Methods: Thirty archival paraffin-embedded tissue blocks of previously diagnosed cases of OED, OSCC each, and 10 normal oral mucosa were used in the study. Immunohistochemical staining for MCM2 and Ki67 markers was done and the slides were individually evaluated for MCM2 and Ki67 expression, with immunopositivity determined on the basis of dark brown staining of the nucleus. The number of positively stained nuclei was counted in 10 representative areas and the data were charted and statistically analyzed. Results: The overall mean expression of both the proteins increased progressively from normal mucosa to OED to OSCC. In normal mucosa, all positively stained nuclei were seen in the basal compartment of the epithelium, while in dysplastic cases, expression was seen toward the surface of squamous epithelium. In OSCC, the frequency of expression of MCM2 and Ki-67 proteins showed an inverse correlation with the degree of tumor differentiation. In well-differentiated cases, the positivity of either marker was restricted to the outermost layer of the tumor cells. In moderately differentiated cases, an expression of Ki-67 was more diffuse in inner layers, whereas the MCM2 antigen was found to be more intense and diffuse in both the inner and outer layers. Whereas in poorly differentiated SCC, positive expression was seen in most of the tumor cells, the mean expression of MCM2 was found to be higher than that of Ki67 in all cases. Conclusion: MCM2, as a proliferation marker, is superior to Ki67 as it indicates the capacity of proliferation and the ability of DNA replication of a cell.
Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/patología , Humanos , Hiperplasia , Antígeno Ki-67/metabolismo , Componente 2 del Complejo de Mantenimiento de Minicromosoma , Neoplasias de la Boca/patología , Carcinoma de Células Escamosas de Cabeza y CuelloRESUMEN
AIM: The aim of the article was to evaluate the feasibility of pulp/tooth area ratio in three mandibular teeth, namely left canine, left first premolar, and left second premolar (33, 34, and 35), as an indicator of age using digital panoramic radiograph and Kvaal's parameters. The study also aimed at computing an area-specific formula for age estimation in Odisha population. MATERIALS AND METHODS: Observation and analysis of 50 digital orthopantomographs (OPGs) and clinical data of patients were made. These images were saved as high-resolution JPEG files. Using the Adobe Photoshop CS3 (extended) image editing software program (Adobe Systems Inc, San Jose, California, United States), the pulp/tooth area ratio of 33, 34, and 35 was analyzed. These ratios were substituted in Odisha population-specific formula, derived using principal component regression analysis. RESULTS: The mean chronological age was 33.24 years. Principal component regression analysis was used to derive multiple regression formulae for individual teeth as well as a combined formula. R2 (coefficient of determination) for combined three mandibular teeth was highest (0.7769) with a standard error of 4.5969 years and thus was a better predictor of age in the population of Odisha. In terms of an individual tooth, comparison between chronological and predicted age revealed that left second mandibular premolar (35) had highest correlation to actual age. Karl Pearson's correlation coefficient showed correlation between age and the mean of ratios from combined three mandibular teeth was stronger than that of single tooth. CONCLUSION: In the present study, second left mandibular premolar showed highest correlation to actual age when used alone. The use of three teeth in combination increased the correlation. This Odisha-specific formula showed promising results and can be used for forensic applications in this population. CLINICAL SIGNIFICANCE: Using three different teeth for age estimation proved to be a better predictor of age in the Odisha population. Moreover, the obtained formula can act as a standard and be used for anthropological or forensic investigations in the said population.