buccal cavity

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun of an animal The oral cavity, bound by the cheeks of the face, the palate, and the flesh of the mandible, opening onto the mouth and the fauces, and containing the teeth, tongue, gums, and other structures.
• noun of an insect The first part of the stomodaeum, lying just within the mouth; its dilator muscles arising on the clypeus, and inserted before the frontal ganglion and its connectives.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the cavity between the jaws and the cheeks