If you agree to take part in this study, a clinician may first use the MDM, PS2, or IMSsystem. If one of these systems are used, the clinician will examine the inside of your mouth with a gloved finger while using standard white light or one or more of the imaging systems for viewing. The instrument will then take pictures of abnormal-appearing and normal-appearing areas in the mouth. The edge between these areas will then be marked with a surgical pen to outline the border between the abnormal-appearing tissue and normal-appearing tissue to be seen on a digital photo. Imaging with each device will take about 2 minutes or less. Between each use of the instrument, it will be sterilized according to standard practices.