Amitha J Lewis

Demirjian's method in the estimation of age: A study on human third molars

Aim: The primary aim of the following study is to estimate the chronological age based on the stages of third molar development following the eight stages (A to H) method of Demirjian et al. (along with two modifications-Orhan) and secondary aim is to compare third molar development with sex and age. Materials and Methods: The sample consisted of 115 orthopantomograms from South Indian subjects with known chronological age and gender. Multiple regression analysis was performed with chronological age as the dependable variable and third molar root development as independent variable. All the statistical analysis was performed using the SPSS 11.0 package (IBM ® Corporation). Results: Statistically no significant differences were found in third molar development between males and females. Depending on the available number of wisdom teeth in an individual, R2 varied for males from 0.21 to 0.48 and for females from 0.16 to 0.38. New equations were derived for estimating the chronological age. Conclusion: The chronological age of a South Indian individual between 14 and 22 years may be estimated based on the regression formulae. However, additional studies with a larger study population must be conducted to meet the need for population-based information on third molar development.

A novel technique to assess chromatin texture using pixel optical densitometry in oral squamous cell carcinoma

Background: The early detection of neoplasia is the prime aim of a diagnostician. Altered chromatin distribution is the earliest microscopic change observed in malignant transformation making it a valuable morphometric parameter. This study was aimed to assess and correlate the progressive changes in chromatin texture from normal to varying grades of premalignancies to malignancy of the oral cavity. Methods: Thirty‐four archival tissue specimens categorized as normal buccal mucosa (5), low‐grade epithelial dysplasia (11), high‐grade epithelial dysplasia (7), and squamous cell carcinoma (11) were stained with Feulgen reaction. Pixel optical densitometry histograms were obtained from analysis of an average of 300 cells/case using ImageJ software. Nine histogram curve characteristics (including area under the curve, area integer percentage, center, centroid) were then analyzed statistically for differences between the four groups. Results: Area integer percentage (P = 0.002), center (P = 0.038), and centroid (P = 0.021) were statistically significant within the four groups The parameters showed a dip in their value from normal to low‐grade dysplasia but showed a steady increase in high‐grade dysplasia and carcinoma. Conclusion: The optical density characteristics had the ability to differentiate the progression of neoplastic changes by extracting information of the chromatin distribution not quantifiable by routine microscopy. The early clumping of chromatin in the periphery in low‐grade dysplasia followed by progressively increasing chromatin aggregates in high‐grade dysplasia and carcinoma correlated well with the shift observed in the histogram center and centroid. The novel pixel optical densitometry technique efficiently predicted malignant transformation. Microsc. Res. Tech. 75:1119–1123, 2012.

Polarizing and Light Microscopic Analysis of Mineralized Components and Stromal Elements in Fibrous Ossifying Lesions

INTRODUCTION Fibro-osseous lesions, along with few reactive lesions of the jaws exhibit an overlapping histo-morphologic spectrum with respect to the nature of calcifications and stromal components. This causes difficulty in assessing the origin, pathogenesis and diagnosis of these lesions. AIM The present study analyses the mineralized components, cellularity, stromal density and stromal composition (nature of collagen, presence of elastic and oxytalan fibres) in cases of ossifying fibroma (OF), fibrous dysplasia (FD) and peripheral ossifying fibroma (POF). MATERIALS AND METHODS The study included a histochemical evaluation of six cases each of FD, OF and POF. Five consecutive sections of each case were stained with hematoxylin and eosin, picrosirius red (to assess maturation of fibres in polarizing light), van Gieson (for area fraction and collagen density) and aldehyde fuchsin (for elastic and oxytalan fibres) respectively. RESULTS Significantly higher amounts of mature bone were seen in FD while cementicles having microlamellar pattern were predominant in OF and POF (p < 0.001). Area fraction, collagen density and immature stromal fibre content was higher in POF followed by FD and OF (p= 0.039). Oxytalan and elastic fibres were absent in FD. CONCLUSION Higher cellularity of the stroma in OF was indicative of its neoplastic behaviour. Higher composition of oxytalan and elastic fibres in OF and POF supports their periodontal ligament origin. FD was distinct with more mature fibres in a lamellated bone and absence of oxytalan fibres.

Odontogenic Cyst with Verrucous Proliferation Exhibiting Melanin Pigmentation

Verrucous proliferation arising from odontogenic cysts is a rare entity. We report an unusual case of an infected odontogenic cyst with verrucous proliferation and melanin pigmentation in a 13-year-old male patient who presented with an intraoral swelling in relation to impacted teeth 26 and 27. The enucleated lesion was diagnosed as an odontogenic keratocyst and the patient died within two years of presentation due to multiple recurrences. The clinical, radiological, and microscopic features of the lesion are presented with an attempt to discuss the etiopathogenesis. The case hereby reported is uncommon with only eight cases reported in the literature.

Nuclear Fractal Dimensions as a Tool for Prognostication of Oral Squamous Cell Carcinoma.

BACKGROUND Carcinogenesis follows complex molecular alterations, which are triggered by subtle chromatin architectural changes that are imperceptible to the human eye. As the treatment decisions in Oral Squamous Cell Carcinoma (OSCC) are hindered by the imprecise clinical stage determination and inter-observer variability in histological grading, focus in recent years has shifted to discovering identifiers related to neoplastic cell morphology studied through computer-aided image analysis. One such approach is the assessment of fractal geometry, a technique first described by Mandelbrot, which aids in precise assessment of architecture of natural objects. Assessment and quantification of degree of complexity of these fractal objects (self-similarities in structural complexity at different magnifying scales) is described as fractal dimension (FD). AIM To evaluate the nuclear fractal dimension (NFD) in OSCC using computer-aided image analysis. MATERIALS AND METHODS Histological sections of 14 selected cases of Oral Squamous Cell Carcinoma (OSCC) and 6 samples of normal buccal mucosa (as control) were stained with Haematoxylin-Eosin and Feulgen stain for histopathological examination and evaluation of nuclear complexity respectively. Fifteen HPF at Invasive Tumour Front (ITF) and Tumour Proper (TP) of Feulgen-stained sections were selected and photographed in test and control samples. At ITF, TP and normal buccal mucosa 200 nuclei each were selected and analyzed using Image J software to quantify FD. The test and control groups were compared statistically using Independent sample t-test and One-way ANOVA. RESULTS Nuclear FD increased progressively towards worst tumour staging as compared to normal buccal mucosa. CONCLUSION Nuclear FD can be considered for quantification of nuclear architectural changes as a prognostic indicator in OSCC.

Oral epithelium in diabetics: A cytomorphometriccorrelation

Objectives: The study aims to establish an etiological association between diabetes and precancerous lesions of the oral cavity by cytomorphometric analysis of the oral epithelium. Study Design: Smears were obtained from three distinct oral sites – buccal mucosa, dorsum of the tongue and the floor of the mouth in ten controls and ten patients previously diagnosed with type II diabetes. The oral smears were stained with Papanicolaou SA-36 solution. An eye – piece graticule was used to obtain the cytoplasm and nuclear dimension; where larger dimension was denoted as “D” and the smaller dimension was denoted as “d”. The nuclear area (NA), nuclear diameter (ND), cytoplasmic area (CA) and the cytoplasmic / nuclear ratio (C/N) were evaluated from 50 cells predominant in each oral site. Statistical Analysis: The cytomorphometric data obtained was compared between the group of diabetic patients and the control groups using the student’s t- test (SPSS version 11.0). Results: Results showed that the nuclear area and the nuclear diameter of oral epithelial cells were increased in diabetic patients, as compared to non- diabetics, while the non- diabetic patients demonstrated an increase in nuclear ratio. Conclusions: The results from this study suggest that diabetes mellitus can cause alterations in oral epithelial cells that are detectable with exfoliative cytology. Key words: Cytomorphometry, diabetes mellitus, oral exfoliative cytology