Possible Clues:

• Word in a dentist's request
• Less confined
• American's teeth so much cleaner, they say, given dentist's request?
• What aging rockers get, perhaps
• Dentist's order after "open"
• Three-lane, vis-Г -vis two-lane
• Like the Atlantic Ocean, slightly, from year to year
• With individual, German the more open
• More vast
• Not so narrow