Parasitic colloid cyst: A diagnostic dilemma.

The pathologies of the neck are varied and at times may cause a diagnostic dilemma for the pathologist. In this report, we present a case of a 32-year-old man with a slow-growing nodular swelling in the right neck region, which was diagnosed as a simple colloid cyst arising in a parasitic thyroid nodule. Simple colloid cysts are cysts that develop due to impaired accumulation of thyroglobulin in inactive follicles. Most thyroid-related pathologies occur as midline swellings. However, the present case was unique due to its location with no connection to the thyroid gland. This case report describes the diagnostic process and adds insight into the pathology of a colloid cyst.

Prognostic Nomogram for Lymph-Node Metastasis in Oral Squamous Cell Carcinoma (OSCC) Using Immunohistochemical Marker D2-40.

Introduction: Nomograms are proven in "individualized risk prediction" in sarcomas and breast and prostate cancers. Incorporating immunohistochemical markers and histopathological parameters can enhance accuracy of these graphical representations of statistical predictive models concerning metastasis. D2-40, a monoclonal antibody to podoplanin (regulator of motility expressed in malignant epithelial cells), dually predicts metastatic potential of tumour by estimating the motile tumour phenotype and by detecting lymphatic vessels/density, both essential to metastasis in OSCC. Thus, we propose a model that incorporates D2-40 immunostaining of individual tumour cells (ITC) too with other variables (seen in H+E staining) as a predictive nomogram. Methods: Sixty cases of OSCC were selected with equal number of cases (n=30) of pN0 and pN+ status. Bryne's grading of invasive front of tumour (ITF) was done on H+E-stained slides followed by D2-40 immunostaining for ITCs at ITF and lymphatic vessels. Multivariate regression analysis was used to generate the nomogram of LNM where the predictive contribution of each covariate, namely depth of invasion, D2-40-stained ITCs, gender, histological grade, and worst pattern of invasion (WPOI), was plotted on a scale of 1-100 points. Results: The nomogram showed that the strongest variable in OSCC was the WPOI in H+E-stained section followed by D2-40-positive ITCs and gender. Discussion: Our predictive nomogram for LNM in OSCC surprisingly showed that a tumour with lower score of WPOI (islands vs ITC) showed numerous D2-40-positive ITCs, drastically increasing the probability of metastasis. The concept of "individualized risk prediction" can be used to predict lymph node metastasis using a variety of histopathological criteria that can be visualized in routine and immunohistochemical staining in OSCC with the aid of a nomogram.

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.

Performance of Dental Students in Understanding and Retention of Oral Pathology Concepts: A Comparative Analysis of Traditional versus Live-Field Teaching Methods.

Background: Understanding oral aspects of pathology by traditional techniques has always been a paradigm in the field of dental education. Traditional methods of teaching include interaction using black board, projectors, and alternate methods of teaching such as a student-centered approach where live-field demonstrations, audio visual aids, and student interaction are also gaining importance, ultimately promoting active education. The aim of the study was to compare live-field and static-field teaching methods in understanding and retention of the histopathological features in dental students. Methods: This was a cross-sectional analytical study, wherein a uniform cohort of III-year dental students was obtained by randomizing the study subjects. Practical classes were conducted using traditional black board/static pictures and dynamic live-field teaching comprising of microscope connected to an HD screen and projector demonstrating the preferred microscopic field. Alternately, the level of retention of knowledge was measured using customized topic-based tests. The comparison of average scores was done between live-field and static-field teaching groups using the paired t-test. Results: The test scores using the paired t-test were marginally elevated in the conventional mode of teaching; however, it varied with respect to precise topics taken using both the genres of teaching. Conclusion: A balance of both conventional and virtual teaching needs to be achieved to enhance the comprehension in student learning. Nevertheless, in the impending years, advanced research is entailed to see if the virtual mode of teaching could replace the conventional method for the advancement in the study prospects.

Effect of nano-hydroxyapatite incorporation on fluoride-releasing ability, penetration, and adaptation of a pit and fissure sealant.

BACKGROUND: Dental caries is one of the most common multifactorial oral diseases and can be prevented using pit and fissure sealants. AIM: To evaluate the effect of nano-hydroxyapatite (nanoHAP) incorporation on fluoride-releasing ability, penetration, and adaptation of a pit and fissure sealant. DESIGN: This was an in vitro study with two groups: conventional sealant and nanoHAP-incorporated sealant. Sealant penetration and adaptation were assessed using stereomicroscope and scanning electron microscope (SEM) (15 and 10 samples per group, respectively). Fluoride release was analyzed using ion-selective electrode (15 samples per group). The chi-square test was used to compare penetration and adaptation between the 2 groups, and an independent Student t test was used to compare fluoride release. RESULTS: The nanoHAP group showed significantly more samples with no bubbles (P = .001) and no debris (P < .001). SEM analysis showed a significantly greater percentage of adequate fissures in the test group (P = .007). The fluoride release was significantly higher in test samples with p values of .001 and .016 on day 1 and day 60, respectively. CONCLUSION: The incorporation of nanoHAP into the conventional pit and fissure sealant improved its penetration and adaptation properties along with fluoride release.

Estimation of Age by Evaluating the Occlusal Tooth Wear in Molars: A Study on Dakshina Kannada Population.

PURPOSE: Assessment of teeth to estimate age in the living as well as the dead is well documented in the literature. Though applied in conjunction with other parameters in Gustafson's technique, attrition of teeth solely is an underexplored indicator for age estimation mainly in India. Most of the studies using attrition of teeth have been conducted in bioarchaeology, and in populations where studies are being conducted in forensic contexts, the results are debatable. Thus, the present study aimed to evaluate the accuracy of age estimation using the Average Stage of Attrition (ASA) method by Li and Ji in adults of the Dakshina Kannada region. MATERIALS AND METHODS: This cross-sectional study assessed the degree of attrition in both maxillary and mandibular first and second molars of 136 adults of Dakshina Kannada origin (age range: 20-70 years) according to the 10 stages given by Li and Ji to derive population-specific linear regression equations. RESULTS: Univariate analysis of prediction of age with attrition showed a significant association of attrition score with age, stratified by sex, arch as well as in total (p-value <0.001) with a standard error of estimate of 9.231 years. The estimated age was within ±5 years of the actual age in 44.2% of the females and 50.0% of the males. A comparative review of 23 studies done to estimate age from attrition score clinically is documented in the manuscript. CONCLUSION: The findings of this study suggest that evaluation of tooth wear by the Average Stage of Attrition (ASA) method can be used as a non-invasive means to aid in the determination of age in adults of Dakshina Kannada origin. Although the error increases with age, this method provides a measurable means of seriation into older and younger categories.

Recognition of lysyl oxidase as a potential predictive biomarker for oral squamous cell carcinoma: an immunohistochemical study.

BACKGROUND: Lysyl oxidase (LOX) is a copper amine oxidase which belongs to the LOX multigene family and is normally involved in cross-linking of stromal collagen fibers. LOX expression has been found to be associated with increased episodes of recurrence, metastasis and overall poor prognosis in renal cell carcinomas and melanomas. This study aimed to assess the effects of LOX on the prognosis of oral squamous cell carcinoma (OSCC), which is one of the most common cancers in India. METHODS: The immunohistochemical expression of lysyl oxidase using LOX2 primary antibody was assessed at the tumor proper, invasive tumor front and peritumoral stroma in tissue sections from 40 cases of histologically proven OSCC. RESULTS: LOX expression was elevated in OSCC patients who had lymph node metastasis and in those who died of disease. No significant variation was seen with histological grade. CONCLUSIONS: LOX has a 'pro-neoplastic' effect as it modulates the host stroma to favor increasing tumor mass and worsening prognosis. Increased expression of LOX causes increased collagen fiber cross-linkage that stiffens the stromal matrix. This increases compressive stresses contributing to tissue hypoxia that elevates Rho GTPase-dependent cytoskeletal tension leading to erratic tumor cell morphogenesis that in turn confers motility to these cells resulting in metastasis. Inhibitors of LOX can potentially down-regulate LOX levels in the tumor micro-environment by controlling tissue hypoxia and curtailing the production of hypoxic LOX molecules.

Efficiency of Mobile Video Sharing Application (WhatsApp®) in Live Field Image Transmission for Telepathology.

Telepathology is in its nascent stages in India. Video calling applications in mobile phones can be efficiently used to transmit static and live field microscopic images hastening low cost telepathology. To evaluate the efficiency of WhatsApp® Video Calling for dynamic microscopy in distant diagnosis. Thirty haematoxylin and eosin stained slides of common pathologies were retrieved from the archives of Department of Oral Pathology and Microbiology, coded with relevant history and given to three untrained investigators. The investigators then connected a mobile phone with VOIP facility to a microscope using a custom adaptor. Dynamic fields were transferred to three independent pathologists via WhatsApp® video call. The pathologists attempted to diagnose the lesion based on the live field video over their display screen (phone). Audio quality was found to be better than that of video. In 70% of the cases, pathologists could render a diagnosis (13% gave a confirmed diagnosis, 57.7% gave a probable diagnosis). The average time taken for connecting the adaptor, connecting the call to the pathologist and then receiving the diagnosis was 9:30 min. In addition, proper history taking and staining of the tissue slides were critical to arrive at the diagnosis. WhatsApp® free VOIP facility helped untrained investigators to send the live-field pathologic fields to a specialist rendering histopathological diagnosis. The factors affecting the diagnosis included network stability, clarity of images transmitted, staining quality and contrast of nuclear details of the stain. The history, clinico-pathologic correlation, transmission of static images, training of the person transmitting the images plays a vital role in rendering accurate diagnosis. Telepathology over WhatsApp® video calling could be used as an efficient screening tool to identify suspicious lesions and follow-up critical cases.

A time based objective evaluation of the erosive effects of various beverages on enamel and cementum of deciduous and permanent teeth.

BACKGROUND: Erosion of the teeth is a chronic irreversible process leading to loss of surface enamel and even the dentin, in turn causing sensitivity and pain. Increased consumption of carbonated beverages remains a major cause for dental erosion. However, many of the so called safe beverages that are consumed may also have sufficiently low pH to cause dental erosion. One of the parameters to measure the dental erosion is estimation of hardness and surface roughness. Thus, this study aims to evaluate the difference in hardness and surface roughness of enamel and cementum using three beverages namely (carbonated drink, lime soda, lime juice) in deciduous and permanent teeth. MATERIAL AND METHODS: Ten permanent and three deciduous teeth samples each were kept in lime juice, lime soda, carbonated beverage and tap water. The VHN using Vickers hardness tester and Ra value using surface profilometer were assessed at baseline, 1 day and 10 days. RESULTS: At the end of 10 days the decrease in hardness of enamel of permanent teeth was maximum for teeth immersed in carbonated beverage followed by lime soda and lime juice. However, in the deciduous teeth it was observed that the VHN drop was maximum at 1 day in relation to teeth immersed in carbonated beverage followed by lime juice and lime soda. The hardness of cementum decreased significantly at the end of ten days both in deciduous as well as permanent teeth. CONCLUSIONS: The present study shows that many of the most commonly used beverages like lime juice and lime soda have a sufficiently low pH to cause erosion of the enamel surface as well as that of cementum of both deciduous and permanent teeth. Though protective mechanisms do exist in the oral cavity to neutralize the acids present in these beverages, continuous usage of these beverages leads to irreversible damage to the tooth structure. Key words:Dental erosion, hardness, surface roughness, permanent teeth, deciduous teeth.

Pattern-Corrected Mitotic Activity Index (PMAI): A Novel Prognosticator of Oral Squamous Cell Carcinoma.

OBJECTIVE: The main aim was to assess the efficiency of the Mitotic Activity Index (MAI) and a novel index devised by us, the Pattern-Corrected Mitotic Activity Index (PMAI) in prognostication of Oral Squamous Cell Carcinoma in terms of lymph node involvement, margin, recurrence and survival status. MATERIAL AND METHOD: The study group consisted of 60 cases of histologically-proven Oral Squamous Cell Carcinoma with known status of prognostic indicators. Hematoxylin and eosin stained sections of the tumor proper were utilized for assessment of mitotic activity and pattern of invasion. The Mitotic Activity Index and Pattern-Corrected Mitotic Activity Index were then calculated and correlated with the prognosticators. RESULTS: Mitotic Activity Index was higher in patients who had better survival and low recurrence rates. Pattern-Corrected Mitotic Activity Index showed the greatest percentage increase in relation to lymph node involvement as compared to the other indices. Kaplan Meier survival analysis showed that a higher Pattern-Corrected Mitotic Activity Index ( > 1.45) was associated with poorer survival (37.19 months). CONCLUSION: Lack of significant association of the Mitotic Activity Index in relation to prognosticators could be attributed to a tumor having a migratory phenotype rather than a proliferative phenotype as seen in late-stage tumors. Late-stage tumors have more of a poorer pattern of invasion which is reflected best by Pattern-Corrected Mitotic Activity Index by correlating with poorer survival and lymph node involvement.

Expression of α-smooth muscle actin in benign and malignant salivary gland tumors: An immunohistochemical study.

BACKGROUND AND OBJECTIVES: Myoepithelial cells (ME) are known to contribute in the patterning of salivary gland neoplasms (SGN) and possess cytoplasmic smooth muscle actin (SMA) revealed by alpha SMA (α-SMA). The present study aimed to assess the expression of α-SMA in selected benign and malignant SGN (pleomorphic adenoma [PA], mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (ACC), and polymorphous low-grade adenocarcinoma (PLGA). MATERIALS AND METHODS: The intensity and pattern of expression of α-SMA were studied in 25 cases of SGN's ACC (n = 7), MEC (n = 8), PA (n = 8), and PLGA (n = 2), and correlated with the histological patterns. RESULTS: Maximum expression of α-SMA in the epithelial compartment was seen in ACC, followed by PA, whereas MEC and PLGA showed completely negative staining. The connective tissue expression was mild in ACC and MEC. The myxoid stroma of PA with "melting" pattern was weakly positive for α-SMA. The stroma in PLGA showed complete negativity. In ACC, α-SMA-positive cells were lining the cribriform spaces, small islands, and dispersed within large islands. Small nests showed complete positivity for α-SMA. INTERPRETATION AND CONCLUSION: In ACC, α-SMA expression supports the involvement of ME in epithelial organization explaining the histological patterns seen. In PA, the expression correlates with the predominantly secretory nature of ME. The absence of epithelial positivity in MEC and PLGA suggest that ME has less role to play in their histogenesis. The weak stromal positivity observed in MEC and ACC may be attributed to the positive immunoreactivity of myofibroblasts playing a role in modulating the course of SGN's.

A correlation of immunohistochemical expression of TP53 and CDKN1A in oral epithelial dysplasia and oral squamous cell carcinoma.

PURPOSE: Oral epithelial dysplasia (OED) occurs on exposure of epithelial cells to carcinogens and genetic alteration. Once the reversible cell damage is surpassed, cells either undergo apoptosis or transform into malignancy, chiefly oral squamous cell carcinoma (OSCC). Progressive accumulation of genetic errors (including mutations in TP53 and CDKN1A) is associated with the initiation and progression of potentially malignant oral lesions toward frank malignancy. The present study attempted to correlate the immunohistochemical expression of CDKN1A and TP53 with increasing severity of OED along with increased aggressiveness of OSCC as reflected in the clinicopathologic variables. MATERIALS AND METHODS: Tissue sections from forty biopsy-proven cases of OED and OSCC were stained with anti-TP53 and anti-CDKN1A mouse monoclonal antibodies. One hundred cells in each case were counted under high power magnification. RESULTS: Poorly differentiated OSCC showed the highest TP53 expression (mean = 70.285), with least expression seen in mild dysplasia (mean = 22.125) (P < 0.001). Higher TP53 count was seen in cases with margin involvement, without recurrence and lymph node involvement and in cases which died of disease. CDKN1A expression was seen only in five cases and that too focally in the cytoplasm, thereby warranting removal of analysis of CDKN1A positivity from the study. CONCLUSION: The expression of TP53 in OED highlights its role in initial carcinogenesis. Although the role of CDKN1A in the cell cycle has been documented, its relationship to various clinical and pathological variables of OSCC and its different treatment modalities could not be adequately assessed.

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.

Computer-based method of bite mark analysis: A benchmark in forensic dentistry?

AIM: The study aimed to determine the technique with maximum accuracy in production of bite mark overlay. MATERIALS AND METHODS: Thirty subjects (10 males and 20 females; all aged 20-30 years) with complete set of natural upper and lower anterior teeth were selected for this study after obtaining approval from the Institutional Ethical Committee. The upper and lower alginate impressions were taken and die stone models were obtained from each impression; overlays were produced from the biting surfaces of six upper and six lower anterior teeth by hand tracing from study casts, hand tracing from wax impressions of the bite surface, radiopaque wax impression method, and xerographic method. These were compared with the original overlay produced digitally. RESULTS: Xerographic method was the most accurate of the four techniques, with the highest reproducibility for bite mark analysis. The methods of wax impression were better for producing overlay of tooth away from the occlusal plane. CONCLUSIONS: Various techniques are used in bite mark analysis and the choice of technique depends largely on personal preference. No single technique has been shown to be better than the others and very little research has been carried out to compare different methods. This study evaluated the accuracy of direct comparisons between suspect's models and bite marks with indirect comparisons in the form of conventional traced overlays of suspects and found the xerographic technique to be the best.

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.

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, R (2) 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.

Bond strength of a sealant to enamel after a cariogenic challenge using three bonding protocols: an in vitro study.

PURPOSE: The purpose of this study was to evaluate in vitro the tensile bond strength of a resin-based pit and fissure sealant to enamel after a cariogenic challenge using three bonding protocols. METHODS: The demineralized tooth specimens were assigned to three groups of equal size: Group 1 (37 percent phosphoric acid gel), Group 2 (total-etch adhesive system), and Group 3 (one-step self-etch adhesive system). After the surface treatment, a resin-based sealant was applied and cured. The specimens were thermocycled and tensile bond strength was measured using a universal testing machine by an investigator who was blinded to the group distribution. RESULTS: The mean tensile bond strength was highest with the total-etch adhesive system, which was statistically significant (P<.001). A post hoc test revealed a significant difference between Groups 1 and 2 (P<.001) and Groups 2 and 3 (P<.001), but none between Groups 1 and 3 (P=.44). CONCLUSION: The total-etch bonding system resulted in significantly higher tensile bond strength with incipient enamel caries.

Oral Cytology for HIV: A New Diagnostic Tool?

AIM: To asses morphological and morphometrical alterations of oral squamous epithelial cells in HIV infected individuals, and determine its diagnostic significance for HIV infection. MATERIALS AND METHODS: Informed Consent was obtained from all study subjects. 40 adult HIV infected patients (experimental group) and 40 adult non-infected volunteers (control group) participated. Age, occupation, and relevant medical history were recorded. The following laboratory tests reports were recorded: complete blood cell counts, blood glucose levels, serum iron and erythrocyte sedimentation rate. Oral smears were collected from normal appearing tongue and buccal mucosa of the individuals by exfoliative cytology. The cells were morphologically analysed and the nuclear area (NA), the cytoplasmic area (CA) and the nucleus-to-cytoplasm area ratio (NA/CA) were calculated. Cell yield, cell cohesion, presence/absence of inflammatory cells and candida were observed. RESULTS: The cytological smears of HIV patients showed abundant cell yield and the epithelial cells were found to be in close cohesive clusters and both findings were found to be statistically significant. Nuclear cytoplasmic ratio was seen to be increased in 93.8% of HIV positive patientsand Mild to moderate pleomorphism was observed in 17.9% of HIV positive patients. HIV positive patients had a diminished inflammatory response and this was found to be statistically significant. CONCLUSION: Statistically significant deviations from normal oral epithelium were found in the study conducted. With further research, oral exfoliative cytology may form a new, painless, inexpensive diagnostic method for HIV infections.

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.

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.