Optical spectroscopy methods are fast emerging as potential alternatives for early diagnosis of cancer. A Raman spectroscopy method for discrimination of normal and malignant oral tissues has been developed by us earlier. It is necessary to evaluate and establish the validity of the approach before it can be routinely used. In the present study, our Raman spectroscopy investigations are extended further to evaluate the efficacy of the technique to discriminate between normal, inflammatory, premalignant, and malignant conditions in oral tissue. Spectral profiles of normal, malignant, premalignant, and inflammatory conditions show pronounced differences between one another. Spectra of normal tissues can be attributed mainly to lipids whereas pathological tissue spectra are dominated by proteins. Principal components analysis (PCA) of the spectral data sets belonging to the four different categories showed that scores of factors differentiated between

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Oral hairy leukoplakia showed a positive relationship with patients younger than 35 years. Oral candidiasis can act as a marker for immunosuppression. Angular cheilitis was predominant in the symptomatic stage.

The present study was undertaken to evaluate the prevalence of radiographic changes in the condylar morphology and its association with age, clinical signs and symptoms of temporomandibular dysfunction and dentition status and also to evaluate the intra examiner and inter examiner reliability in assessing condylar changes using panoramic radiographs. A total of 75 subjects were recruited for the study. They were divided into 3 age groups. 20–40 yrs (Group A), 41–60 yrs (Group B) and 61 yrs and above (Group C). In each age group 25 subjects were evaluated both clinically and radiographically. The prevalence of radiographic changes in condylar morphology and symptoms of temporomandibular dysfunction was 81.3% and 18.6%, respectively. Radiographic abnormalities in the mandibular condylar morphology increased with age. They were seen more frequently in patients with clinical signs and symptoms of temporomandibular dysfunction and in patients with loss of teeth. Intra examiner and inter examiner reliability was high indicating a good reliability in assessing the condylar changes using panoramic radiograph.

Pulsed laser-induced autofluorescence spectroscopic studies of pathologically certified normal, premalignant, and malignant oral tissues were carried out at 325 nm excitation. The spectral analysis and classification for discrimination among normal, premalignant, and malignant conditions were performed using principal component analysis (PCA) and artificial neural network (ANN) separately on the same set of spectral data. In case of PCA, spectral residuals, Mahalanobis distance, and scores of factors were used for discrimination among normal, premalignant, and malignant cases. In ANN, parameters like mean, spectral residual, standard deviation, and total energy were used to train the network. The ANN used in this study is a classical multiplayer feed-forward type with a back-propagation algorithm for the training of the network. The specificity and sensitivity were determined in both classification schemes. In the case of PCA, they are 100 and 92.9%, respectively, whereas for ANN they are 100 and 96.5% for the data set considered.