The term 'tooth-related' can be summarized by the crossword solution 'dental, ' which is a six-letter word. Dental refers to anything related to teeth, such as dentistry, which is the branch of medicine that deals with the diagnosis, prevention, and treatment of diseases and conditions of the oral cavity. Dentists are medical professionals who specialize in the care of teeth and gums. Dental hygiene is also an important part of tooth-related care, which involves regular brushing and flossing to prevent cavities and other dental problems.