The application of optical equipment during examinations enables general dental practitioners to conduct simple and low-invasive screening for oral mucosal diseases. Use of these devices has recently become widespread in North America and South East Asia, with the most common device being the VELscope system. The present study investigated the feasibility of using the VELscope in fluorescent screening for oral mucosal diseases and to determine the extent of resection for oral cancer.
VELscope application has been indicated and approved for aiding in the early detection of oral mucosal diseases and determining the extent of resection for oral cancer; approximately 2,000 units were distributed in North America during 2008. The American Academy of Oral Medicine and other scientific societies and bodies hold training sessions for general dental practitioners on how to use the VELscope for early-stage diagnosis of oral cancer.
The general principle of screening based on oral mucosa observation using fluorescence involves exposing the tissue to shorter-wavelength blue light and observing the reflected longer-wavelength green light to determine whether the mucosa is normal or has atypical epithelium. Healthy tissue emits green fluorescence while atypical epithelium loses this characteristic. With the VELscope, mucosa is exposed to blue light from a metal-halide lamp (wavelength, 400-460 nm; output, 500 mW) and a real image derived from the reflected light, including that emitted from within the tissue, can be visually observed via a half mirror or a filter that blocks wavelengths exceeding that of the irradiating light.
In cases of atypical epithelium and malignant tumor, the observation of decreased fluorescence from the lesion site and the surrounding tissue affected by epithelial dysplasia indicated the effectiveness of the VELscope in screening for lesions. However, care is required when analyzing screening results as decreases in fluorescence cannot be observed in cases of deep-seated tumors. By appropriately adjusting the device settings, the present system can also be used to determine the extent of tumor resection.
