I personally write and publish NYCdentist.com, which offers over 2,500 pages of free content in academic dentistry. The content shows dental procedures including surgery in detail based upon visitor choices. There is NO sexual content in all 2,500 pages
I didn't know this, but it does make sense, Google may block "particularly graphic or violent" images. And if you look at some of the images on that site, I think some of you may get a bit queazy in the stomach. But what is interesting to me, is that the dentists don't see it that way. I have a dentist right next to me in my office building. He borrowed my camera once to take before and after pictures. I had to email those pictures to him afterwards and let me tell you, they were extremely graphic!
In any event, Googler, Susan Moskwa said:
I'll pass this along, but FYI SafeSearch filters non just sexually-related content, but also stuff that's particularly graphic or violent. Some of your surgery photos may be graphic enough that they fall under our filtering criteria. I'll try to get some more feedback on this from the Image Search team. Thanks for reporting this here.
So technically, I am not sure where this would fall - but personally, I would not like to see these images come up for a search on [teeth].
Forum discussion at Google Webmaster Help.