Maybe someone out there can help me with the concept of “submucosa” in the oral cavity. Although I was trained, as most oral pathologists were, to use that term, I have moved away from it altogether. Where does the mucosa end and the submucosa begin? In the small and large intestines, the submucosa is separated from the mucosa by the muscularis mucosa, a clearly discernible band of smooth muscle. There is no such band of muscle in the mouth and the lamina propria looks different depending on where in the mouth you are.

So, the palatal mucosa and gingiva consists mostly of just mucosa (epithelium and dense lamina propria) that abuts the periosteum; the normal dense fibrous tissue for these two sites is often mislabeled as “scarring and fibrosis”.

The nonkeratinized sites of the buccal mucosa and vestibule, lip mucosa, ventral tongue, floor of mouth and soft palate contain delicately collagenized lamina propria which is loose with more ground substance. Depending on the exact site, they merge with the underlying skeletal muscle whether this is the buccinator of the buccal mucosa or the hyoglossus of the tongue. So where does the submucosa begin?

Maybe it is time to stop using that term, and just say “deep” or “superficial” mucosa. Although this too is somewhat arbitrary, at least it does not give a sense that the oral submucosa is a defined location in the mucosa, which it isn't.