Without further information, it's difficult to provide a specific answer. Here are a few possibilities:

Character or Persona: "OC" often stands for "Original Character" in various creative communities, such as fanfiction or art. "Graceful Smiles" could be the name of an original character who is known for their elegant and pleasant demeanor.

Business or Brand: "OC Graceful Smiles" might be the name of a business, perhaps related to dental care, beauty, or wellness. It could refer to a clinic, spa, or other establishment that specializes in services that promote graceful and beautiful smiles.

Online Username or Handle: People often use creative usernames or handles for their online profiles. "OC Graceful Smiles" could be the chosen name of a person's social media, gaming, or forum account.

Artwork or Creation: It could also be the title of an artwork, story, or other creative work that focuses on the theme of elegance and smiles.

Event or Gathering: "OC Graceful Smiles" might refer to an event, workshop, or gathering that emphasizes cultivating a positive and graceful outlook on life, potentially with a focus on improving one's smile.

If you can provide more context or details about where you encountered the term "OC Graceful Smiles," I'd be happy to give a more precise explanation.