buccal cavity vs orifice

buccal cavity

noun
  • 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. 

  • 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. 

orifice

noun
  • A mouth or aperture, such as of a tube, pipe, etc.; an opening. 

How often have the words buccal cavity and orifice occurred in a corpus of books? (source: Google Ngram Viewer )