Irradiation Induced Biochemical Changes in Human Mandibular Bone: A Raman Spectroscopic Study.

Understanding the biochemical changes in irradiated human mandible after radiotherapy of cancer patients is critical for oral rehabilitation. The underlying mechanism for radiation-associated changes in the bone at the molecular level could lead to implant failure and osteoradionecrosis. The study aimed to assess the chemical composition and bone quality in irradiated human mandibular bone using Raman spectroscopy. A total of 33 bone biopsies from 16 control and 17 irradiated patients were included to quantify different biochemical parameters from the Raman spectra. The differences in bone mineral and matrix band intensities between control and irradiated groups were analyzed using unpaired Student's t-test with statistical significance at p < 0.05. Findings suggest that the intensity of the phosphate band is significantly decreased and the carbonate band is significantly increased in the irradiated group. Further, the mineral crystallinity and carbonate to phosphate ratio are increased. The mineral to matrix ratio is decreased in the irradiated group. Principal component analysis (PCA) based on the local radiation dose and biopsy time interval of irradiated samples did not show any specific classification between irradiation sub-groups. Irradiation disrupted the interaction and bonding between the organic matrix and hydroxyapatite minerals affecting the bone biochemical properties. However, the normal clinical appearance of irradiated bone would have been accompanied by underlying biochemical and microscopical changes which might result in radiation-induced delayed complications.

Use of microwave in diagnostic pathology.

Conventional tissue fixation and processing is as old as 100 years and still remains the gold standard against which all new technologies and methods need to be assessed. Tissue processing is one of the important steps for obtaining good thin sections without artifacts. Though conventional tissue-processing methods are most commonly followed, they are well-known as very laborious and tedious procedures. Microwaves a form of electromagnetic wave-induced heat, when applied in histotechnology, reproducibly yields histolologic material of similar or superior quality to that provided by conventional processing methods, making it more popular in the recent years. A laboratory microwave offers features like maximum output of 2000-3000 watts, an in-built source of adjustable temperature probe, facility for ventilation of hazardous fumes, but is expensive. Considering the usefulness of microwave in histotechnology, i.e., reducing the time required for the diagnosis, replacing the conventional equipments of laboratories by microwave-guided ones is a remarkable and an acceptable change.

Micronuclei assay of exfoliated oral buccal cells: means to assess the nuclear abnormalities in different diseases.

The micronuclei assay (MA) in exfoliated buccal cells is an innovative genotoxicity technique, which holds promise for the study of epithelial carcinogens. Micronuclei are suitable internal dosimeters for revealing tissue-specific genotoxic damage in individuals exposed to carcinogenic mixtures. This article reviews the MN assay with respect to oral buccal mucosa, which has been used since the 1980s to demonstrate cytogenetic effects of environmental and occupational exposures, lifestyle factors, dietary deficiencies, and different diseases along with the characteristics of micronuclei and other nuclear abnormalities.