Variability in the Epithelial Expression of Ki67 and Polarization Characteristics of Collagen in Odontogenic Cysts and Tumours

ABSTRACT Objective: To assess the proliferation of epithelium (using the Ki67 index) and the polarization pattern of collagen in selected odontogenic cysts and tumours. In addition, an exploratory analysis of the effect of inflammation on the proliferation rate was done. Material and Methods: Following immunohistochemical staining, the labelling/proliferation index of Ki67 was calculated. The thickness and corresponding polarization colour of 100 juxta-epithelial picrosirius red-stained collagen fibers were assessed using linear micrometry with an eyepiece reticule under × 1000 magnification. Inflammation was graded subjectively as mild, moderate, and severe. Results: Overall Ki-67 expression was higher in the radicular cyst, Odontogenic Keratocyst, Ameloblastoma, while suprabasal Ki-67 positivity was maximum in Odontogenic Keratocyst. The stromal collagen fibers in Ameloblastoma showed predominantly green birefringence, whereas Odontogenic Keratocyst had orange birefringence. There was no significant association of inflammation with Ki-67 expression or birefringence patterns. Conclusion: The highest Ki67 expression in the radicular cyst, followed by Odontogenic Keratocyst and Ameloblastoma. Differences in the collagen maturation pattern were noted innately in five lesions studied and were further influenced by inflammatory changes. Epithelial proliferation and concomitant expression of thickness and maturity of the stromal collagen are innate features of the lesion further influenced by inflammation in various odontogenic cysts and tumours and may, in turn, guide the clinical behavior.

Third Molar Maturity Index as an Efficient Tool for Prediction of Age in a Sample Indian Population - A Retrospective Study

Introduction: The age of 18 years is an important milestone for legal matters, and developmental parameters of teeth are often used for estimation of this age. The aim of this study is to assess the efficiency of third molar maturity index (I3M) in establishing age of 18 years in Dakshina Kannada population. Methods: A total of 700 orthopantomograms were retrieved from the archives of the radiology department of Manipal College of Dental Sciences, Mangalore. The length and the width of the open apex of the mandibular left third molar was assessed using Image J software and the Third molar maturity Index (I3M) was calculated and correlated with the age of the individual. Results: Receiver operating characteristic (ROC) curve analysis showed the Area under curve of 0.94 and 0.96 in females and males, respectively, for prediction of age of 18 years. The cut?off of 0.08 predicted the 18?year cut?off with 97% specificity and 90.2% negative predictive value. The percentage of the accuracy was 80.23% if the I3M was <0.08. Conclusion: The efficiency of the cut?off of 0.08 of I3M has been tested in various population including Kosovar, Peruvian, South Indian, Libyan, Montenegro, Croatian, African (Botswana), Albanian, and Serbian. Our study also shows the efficiency of the same in South Indian Dakshina Kannada population.

Effectiveness of Laser Fluorescence–Based Device in Detecting the Extent of Re-Mineralisation in Primary Teeth Compared to the Conventional Method: An In vitro Study

Background: Laser fluorescence (LF)–based clinical device DIAGNOdent™ is at present being used to detect caries. Can the same be used to detect therapeutic remineralisation of early white spot lesions? Aims: To explore the feasibility of using LF?based device in monitoring the changes following remineralisation of demineralised primary teeth. Materials and Method: The sample number for the present experimental in vitro study was 10. The LF based device readings were correlated with surface microhardness (SMH) test values to evaluate its efficiency. SMH analysis was performed using a microhardness tester (Tescol?HT1000AD). All the samples were demineralised, followed by remineralisation using fluoride varnish and pH cycling. The data was analysed using the Statistical Package for the Social Sciences (SPSS) version 17.0 (IBM SPSS®) software. Paired t?test was performed to compare laser fluorescence readings and SMH test result values at baseline, after demineralisation, and after remineralisation. Pearson’s correlation was used to compare the relation between the laser fluorescence and SMH test. Results: A good negative correlation was seen between the two methods at the baseline readings even though it was not statistically significant (P = 0.069). A positive correlation between the methods existed following demineralisation which was not significant (P = 0.074). The correlation between the parameters following remineralisation showed a moderate negative correlation but was not significant (P = 0.55). Conclusion: DIAGNOdent™ values at baseline, after demineralisation, and after remineralisation was consistent with SMH values. Thus, DIAGNOdent™ can be explored to provide chairside assistance in identifying remineralisation of white spot lesions.

Comparison of the efficacy of parental brushing using powered versus manual tooth brush A randomized, four-period, two-treatment, single-blinded crossover study

Background: Children <5 years of age need parental assistance with tooth brushing. Purpose: The aim is to compare the efficacy of manual and powered toothbrushes for plaque removal when used by parents to brush their children's teeth. Methods: This randomized, four-period, two-treatment, examiner-blinded, crossover clinical trial comprised children aged 3–5 years. Tooth brushing was performed by the parent using a manual or powered toothbrush. Pre- and post-brushing plaque assessments were performed using the Turesky Modified Quigley-Hein Plaque Index. Differences in plaque scores were calculated using the paired t-test. Results: A significant difference (P < 0.001) in the reduction of the plaque score was observed between the manual and powered tooth brushing groups. Conclusion: Powered toothbrushes performed significantly better than manual toothbrushes in terms of plaque removal when used by parents to brush their child's teeth.

A correlation of immunohistochemical expression of TP53 and severity of inflammation with varying grades of oral squamous cell carcinoma

Purpose: Epithelial cells exposed to carcinogens and genetic damage, once surpass reversible cell damage, either undergo apoptosis or transform into malignancy, chiefly oral squamous cell carcinoma (OSCC). Progressive accumulation of genetic errors in TP53 results in tumorigenesis. Inflammation is also a modulator in this process. The present study attempted to correlate the immunohistochemical expression of TP53 with increased aggressiveness of OSCC, to determine how these immune cells regulate the path of carcinogenesis and to define the role of inflammation in TP53 immunoexpression. Materials and Methods: Tissue sections from 24 biopsy-proven cases of OSCC were stained with anti-TP53 antibody. Five hundred neoplastic epithelial cells and inflammatory cells, each, were counted at invasive tumor front. Two hundred peritumoral neutrophils were counted based on nuclear lobes present. Results: The least TP53 expression was seen in well-differentiated OSCC (P < 0.001), whereas neutrophil count and plasma cell count were found to be least in well-differentiated OSCC (P < 0.001), whereas the number of lymphocytes and macrophages decreased with increased grading of OSCC (P < 0.001). Four- and five-lobed neutrophils were found to be highest in poorly differentiated OSCC (P < 0.001), whereas two-lobed neutrophil count was seen to be maximum in well-differentiated OSCC (P < 0.001). Conclusion: TP53 plays a significant role in the initiation and progression of OSCC. Inflammation plays a role of friend and a foe simultaneously, and little modification in the present treatment modalities for OSCC can bring a favorable change in the life of cancer survivors