Periodontal describes the parts of the mouth around the base of the teeth — the gums and the bone that hold the teeth in place. You will meet it most at the dentist: periodontal disease is gum disease, and a periodontist is the specialist who looks after that area. It is a medical word. Ordinary people just say “gums” (“I’ve got gum problems”). Though actually, it does not mean “about the teeth themselves.” The teeth are next to it; periodontal points to the tissue around them, at the root and the gum line.