«A genuine and sincere smile is a sign of confidence»

Eerie/sharp teeth smiles inspired by unsettling/manga/comic illustrations

I suggest you to mix/experiment it with other LORAs to match a preferred style, like:
Richard Anderson - painting
Horror Eyeshine - FLUX - glowing eyes
Naoki Urasawa manga style - manga

note: increasing CFG scale and adding "sharp, shark-like teeth" to a prompt should help you to get sharp teeth smile

Enjoy!