Figure 12a. Squamous cell carcinoma of the right wall of the oropharynx. (a) Axial CT scan shows that the right part of the oropharynx (*) is poorly seen due to dental amalgam artifact, which results in blind areas and poor contrast. Arrow = adenopathy. (b) Tomogram obtained with the open mouth technique shows the levels for performing additional CT with the mouth open. (c) Axial CT scan obtained through the open mouth shows that the previously shadowed areas are visible and the contrast is improved. A tumor is evident (arrow).