Autofluorescence in the Oral Cavity: Difference between revisions
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The data from these studies is shown in Figure 1. The results of all of these studies suggest to us that we can expect to see significant autofluorescence in healthy oral tissue, due either to autofluorescence of oral mucosa or to the presence of porphyrins. This project seeks to collect further data about fluorescence and its ties to oral health. Fluorescence on volunteers’ tongues was measured under 400 nm light, chosen because it will excite relevant fluorescent species and is visible, preventing damage from unseen light. This data was analyzed using singular-value decomposition and least squares estimation in an effort to elucidate connections between fluorescence data and oral health. | The data from these studies is shown in Figure 1. The results of all of these studies suggest to us that we can expect to see significant autofluorescence in healthy oral tissue, due either to autofluorescence of oral mucosa or to the presence of porphyrins. This project seeks to collect further data about fluorescence and its ties to oral health. Fluorescence on volunteers’ tongues was measured under 400 nm light, chosen because it will excite relevant fluorescent species and is visible, preventing damage from unseen light. This data was analyzed using singular-value decomposition and least squares estimation in an effort to elucidate connections between fluorescence data and oral health. | ||
[[File: | [[File:VeldEtAl_Bjurshammar_Wu_Qu.png|800px|Figure 1. Previously obtained fluorescent data is plotted. Veld et.al. measured a fluorescent curve with two primary peaks. Wu and Qu found a broad peak suspected to be due to overlapping NADH, FAD, and keratin fluorescent spectra, while Bjurshammar published the fluorescence spectra for protoporphyrin IX.]] | ||
Revision as of 05:13, 14 December 2018
Introduction
In recent years, dentists have begun using the VELscope Vx, a handheld scope that enables fluorescence imaging to visualize oral mucosal abnormalities, in oral exams. This technology enables imaging of abnormalities that may not be visible to the naked eye and has enhanced diagnosis of oral cancer and dysplasia. This device offers clear proof that there is interesting health data contained in oral fluorescence, and this project seeks to pursue that information. Specifically, this project aims to determine what data exists in the fluorescent spectrum, how we can reliably obtain this data, and how this can be used in diagnosis of oral disease.
Background
In 2003, Veld et.al. conducted a comprehensive study aimed at characterizing the autofluorescence of healthy oral mucosa in different parts of the mouth. This group recognized the power of autofluorescence spectroscopy in oral cancer detection and hoped to construct a reference database of fluorescent spectra from healthy oral mucosa. In this study, spectra were recorded from 97 volunteers under a selection of excitation wavelengths between 350 and 450 nm at different anatomical sites. Of particular interest to this project, the fluorescence measured on the dorsal side of the tongue exhibited a broad peak between 500 and 550 nm and a sharp peak above 600 nm.
In 2006, Wu and Qu studied autofluorescence of human epithelial tissue and obtained a similar broad fluorescent spectrum around 500 nm in oral tissue excited at 405 nm. They hypothesized that this peak may be due to overlapping of NADH, FAD, and keratin fluorescent spectra. They also observed a sharp peak in esophageal fluorescence around 680 nm and hypothesized that this peak may be attributed to porphyrin derivatives.
In 2017, Bjurshammar published a thesis exploring “Porphyrins and Phototherapy of Oral Bacteria.” This study discussed the spectral properties of porphyrins, a group of macromolecules found in most bacteria typically in the oral cavity. Notably, protoporphyrin IX has a sharp fluorescence emission peak around 635 nm and is efficiently excited at 405 nm. The data from these studies is shown in Figure 1. The results of all of these studies suggest to us that we can expect to see significant autofluorescence in healthy oral tissue, due either to autofluorescence of oral mucosa or to the presence of porphyrins. This project seeks to collect further data about fluorescence and its ties to oral health. Fluorescence on volunteers’ tongues was measured under 400 nm light, chosen because it will excite relevant fluorescent species and is visible, preventing damage from unseen light. This data was analyzed using singular-value decomposition and least squares estimation in an effort to elucidate connections between fluorescence data and oral health.
