I'm putting this out in case people are still having this leftover problem after updating to the latest patch, or for anyone still using 1.22.
When a new Sim becomes a vampire, or a newly generated vampire Sim appears in the neighborhood (such as creating a new Bridgeport save), vampires will have all their powers, glowy pale skin and shiny eyes, but their teeth won't appear. This is a real annoyance since... well, what kinda vampire goes about without them fangs?
To fix this, you'll have to enter the console cheat "unlockoutfits on", before going to CAS. This will unlock all "hidden" CAS parts such as career outfits, but also the vampire teeth and birthmark in the accessories section. Just scroll down all the way and you will find near the bottom an accessory showing the lips (same icon as lipsticks). Those are the LN vampire teeth, which you can also give to non-vampire sims if you wish to. There's also
NO NEED to put the teeth on all outfit categories as it autosets it for everything.
This has been fixed since patch 1.24 (latest), but those who encountered this problem before patching will probably still have their fangless vampires, so they will have to manually give their teeth back. Also, even during patch 1.22, if you had vampires BEFORE the patch, they are unaffected and will still have the fangs. It only affected newly generated vampires/newly transformed vampires in patch 1.22.
I hope this has been of help to some of you who didn't find a proper fix.