Understanding the Anatomy  The mandible is the lower jawbone. It is made up of fused right and left halves. The parts of the mouth (or oral cavity) from which tumours most commonly invade into the mandible include:
  • Floor of mouth:This is the part in the front or side of the mouth that you can see if you lift your tongue up to the roof of the mouth. It goes from the gingiva (gums) on the inside of the mandible (lower jawbone) just to the under surface of the tongue. The lingual frenulum separates the floor of the mouth into a left and right side.
  • Lower alveolar ridge:These are the gums, or the pink mucosa that is attached to the mandible.
  • Retromolar trigone: This is the lining on each side of the mouth that is attached to bone in the back corner of the mouth behind the very last lower tooth. It is a thin piece of “mucosa” that sits over the part of the lower jawbone (known as the ramus of the mandible).