Figure 3a. Squamous cell carcinoma of the anterior floor of the mouth. (a) Axial CT scan shows a tumor of the right side of the anterior floor of the mouth and the mandibular gingiva (*). It is unclear whether there is involvement of the lower lip (arrowheads). (b) Sagittal reformatted image shows the lower extent of the tumor at the floor of the mouth above the geniohyoid and mylohyoid muscles (arrow), but the tongue is not clearly distinguished from the gingiva. The lower lip and the gingiva are still apposed (arrowheads). (c) Axial CT scan obtained with the puffed cheek technique shows that the anterior floor of the mouth is inflated. The medial limit of the tumor is clearly seen in the midline (arrow). It is still unclear whether there is involvement of the lower lip (arrowheads). (d) Sagittal reformatted image obtained with the puffed cheek technique shows that the tumor involves the gingiva (arrow) but does not involve the tongue. The lower lip is separated from the gingiva and appears preserved (arrowheads). * = inflated buccal vestibule.