Study of Hypoxia-inducible factor-2α expression in the malignant transformation of Oral submucous fibrosis.

CONTEXT: Hypoxia-inducible factor (HIF)-2α is overexpressed in primary and metastatic human cancers, whose expression is correlated with tumor angiogenesis and patient mortality. HIF plays a role in the progression of fibrosis in oral submucous fibrosis (OSF). AIM AND OBJECTIVE: The aim is to study and compare the expression of HIF-2α in OSF (a), oral squamous cell carcinoma (OSCC) with areca nut usage (b), OSCC without areca nut usage (c) and normal mucosa (d) by immunohistochemistry. SUBJECTS AND METHODS: Immunohistochemical detection of HIF-2α was done on 51 samples, which included 11 cases (a), 15 cases (b), 15 cases (c) and the expression was compared with that of (d). STATISTICAL ANALYSIS: Data were analyzed using the SPSS™ software (ver. 21.0). Chi-square test and kappa analysis were performed to compare the intensity of staining between the groups and for inter-observer agreement, respectively. Value of P ≤ 0.05 was considered statistically significant. The mean labeling index between the groups was studied by the Kruskal-Wallis test. RESULTS: All the cases of (d), (a), (b) and (c) showed HIF-2α expression (P = 0.329). About 13% cases of (c) showed intense expression (P = 0.406) and 27% of (a) cases showed expression only in the connective tissue (P = 0.023). The number of positively stained nuclei in both (b and c) cases reduced as the tumor progression was from well to poorly differentiated. CONCLUSION: Areca nut initiates fibrosis and subsequent hypoxia in OSF which triggers HIF-2α expression in the epithelium. HIF-2α could be a surrogate marker for cancer initiation and progression.

"Burden of the Triumph:" Burden of peri-implantitis in Indian population - A mathematical model.

CONTEXT: India suffers from a heavy burden of oral diseases. Dental implants (DIs) are prescribed widely by the dental practitioners to replace lost natural teeth. There is no estimate, however, to determine the number of DIs or the number of people with peri-implantitis or the failure of implants after placement. In this modeling study, we attempted to estimate the prevalence of adult Indians who would choose DI in the near future and to calculate the peri-implantitis and failure of DI. MATERIALS AND METHODS: Using the Global Burden of Disease database (2016), the number of dental caries in permanent dentition, periodontal diseases, and edentulism was obtained. Empirical assumptions of patients with anodontia in urban and rural areas who opted for DI, percentage of implants placed, the affordability factors, and mathematical models for DI were formed and executed. Peri-implantitis and survival data from literary evidence were collated. RESULTS: Based on assumptions, 909,643 Indians, (830,231-858,703) would choose DI. Estimated number of peri-implantitis would be 145,543-254,700 and estimated number of failures should be 50,940-79,412 in the near future. CONCLUSIONS: In spite of the high economic challenge and the risks or complications of peri-implantitis, DIs are gaining prominence. It is the dentists' burden to face the renewed challenges due to emerge and provide remedial measures.

Chemical and physical basics of routine formaldehyde fixation.

Formaldehyde is the widely employed fixative that has been studied for decades. The chemistry of fixation has been studied widely since the early 20(th) century. However, very few studies have been focused on the actual physics/chemistry aspect of process of this fixation. This article attempts to explain the chemistry of formaldehyde fixation and also to study the physical aspects involved in the fixation. The factors involved in the fixation process are discussed using well documented mathematical and physical formulae. The deeper understanding of these factors will enable pathologist to optimize the factors and use them in their favor.

Oral submucous fibrosis: a clinico-histopathological study in Chennai.

BACKGROUND: Oral submucous fibrosis (OSF) is a precancerous condition associated with the use of areca nut in various forms. There are very few reports to correlate the clinical stage to histopathological grading in OSF. MATERIALS AND METHODS: A hospital-based study was conducted on 75 OSF cases who visited our hospital in Chennai from 2000-2003. A detailed history of each patient was recorded along with a clinical examination. Biopsy was performed for histopathological correlation. Clinical stage of the disease in terms of the ability to open one's mouth was correlated with histopathological grading. RESULTS: The male to female ratio of OSF cases was 6:1. All forms of areca nut products were associated with OSF. Chewing of paanmasala was associated with early presentation of OSF as compared to chewing of the betel nut. Out of 57 cases, which were in clinical stage II, 91.2% had histological grading of I and II in equal proportions and 8.8% had histological grade III. Out of 13 cases that showed a clinical stage of III, 52% showed a histological grade of II, 40% grade III and 8% grade I. CONCLUSION: In the present study, there was no direct correlation between clinical stages and histopathological grading. The possibility of difference in the severity and extent of fibrosis in different regions of the oral mucosa and involved muscles were considered as contributory factors for this variation.