We heard this small tidbid in anatomy class, and it sounds simultaneously plausible and very incorrect.
The parotid gland lies anterior to the ear, superficial, posterior and deep to the ramus. The duct of this glands has a relatively superficial course, and it pierces the cheek and opens into the mouth (the vestibule specifically) on either side opposite the 2nd upper molar teeth.
Our anatomy lecturer said that an inflammation and a tumor of this gland can be differentiated as such: look at the site where the duct opens into the mouth, if there's redness there and it looks inflamed it's likely an inflammation. If not, some other diagnosis must be reached.
I couldn't find any source describing such a thing, and I was wondering if it's actually true.