Subclass 1/253: Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes (examination of body cavities or body tracts using ultrasonic, sonic or infrasonic waves A61B 8/12; endoscopic instruments for taking cell samples or for biopsy A61B 10/04; for surgical purposes A61B 17/00; surgical instruments using a laser beam being directed along or through a flexible conduit A61B 18/22); Illuminating arrangements therefor (for the eyes A61B 3/00) for the mouth, i.e. stomatoscopes, e.g. with tongue depressors (tongue depressors per seA61B 13/00); Instruments for opening or keeping open the mouth (combined with saliva removers A61C 17/1) with means for viewing areas outside the direct line of sight, e.g. dentists' mirrors with means for preventing fogging