RESUMEN
Community water fluoridation is widely used worldwide and its role in preventive dental health care is well established. However, there is sufficient evidence of the ill effects of excessive fluoride content in water, causing skeletal and dental fluorosis. Alongside, there was also extraskeletal and dental manifestations of excessive fluorides reported. They include the effect on thyroid function, but the literature regarding this is sparse. Aim: The present systematic review aims to analyze the data from controlled studies about the effect of fluoride on thyroid function. Materials and Methods: A systematic literature search was performed using PUBMED, MEDLINE, EMBASE, COCHRANE Library, EBSCO search, and the internet search, with language restriction to English. The search included published studies which dealt with the association of fluorine with hypothyroidism, from January 1981 to November 2015. Literature search was done using keywords: fluoride and hypothyroidism, dental fluorosis and thyroid disorders, systemic fluorosis and thyroid disease, excessive water fluoridation and hypothyroidism, thyroid and fluoride, fluorosis and its adverse effects. Results: Out of 166 publications, related to search strategy, 37 full articles which were related with the association of fluoride and hypothyroidism were acquired for further inspection. Out of the 37 articles, 10 articles met the inclusion criteria. The data were extracted and placed in an excel sheet and were analyzed. The analysis suggested a positive correlation of excess fluoride and hypothyroidism. Conclusion: The present systematic review suggests a positive correlation between excess fluoride and hypothyroidism. This calls the need for further well-controlled studies in this otherwise emerging alarming issue. It also calls for considerable community network through health informatics for problem sensitization.
RESUMEN
Objectives Intra oral radiographic imaging is the most widely used method for obtaining information about root canal anatomy and working length determination. Measuring exact working length is the most essential step for the success of root canal treatment. Bisecting angle technique (BAT) is the most widely used technique for this purpose. However, zygomatic superimposition over the apices of maxillary molars makes it difficult for the dentist to estimate exact working length. The present study made certain modifications in BAT to overcome these undiagnostic shadows. The aim of the study is to compare three techniques, namely paralleling cone technique (PCT), BAT and modified bisecting angle technique (MBAT) to prevent such superimposition over molar apices. Materials and Methods A total of 53 patients requiring endodontic treatment for maxillary molars were included in the study. Three radiographs one with each PCT, BAT, MBAT were made. Each radiographic image was recorded acceptable or unacceptable based on the zygomatic superimposition. The data thus collected was subjected to statistical analysis using chi-square test. Results The percentage of acceptability in MBAT was 56.6% (n = 30) when compared with BAT which was only 28.3% (n = 15) and PCT was 58.3% (n = 31) indicating statistically significant difference between BAT and MBAT. But no statistically significant difference was found between MBAT and PCT. Conclusion In the present study, MBAT was found to be more accurate than BAT, and it was relatively as accurate as PCT in eliminating zygomatic superimposition over the apices of maxillary molars.