I hear it all the time — “It’s just a picture of a tooth, not a full face, so what’s the big deal?”
There’s a few things wrong here.
First, a picture is Protected Health Information (PHI), as it does identify a patient — maybe not easily to the general public, but the field of forensic dentistry exists for the purpose of identifying remains by dental work.
Second, you didn’t get permission fromt he patient to take that photo, put it on your personal device or use it for education.
Third is that you have it on a persoanl device. Is it secured? Encrypted? iCloud turned off since Apple won’t sign a BAA?
In the world of HIPAA, there are many factors to consider before doing what is ‘easy’.