Lawyers for Fosamax users who believe their jaws were damaged by the osteoporosis drug on Friday asked a federal judge to order Merck & Co. to provide a dental monitoring program for the drug’s users.

The lawyers made the suggestion to U.S. District Judge John F. Keenan, of the Southern District of New York, as they argued for the case to be certified as a class action, in order to pursue claims by users who believe the drug caused osteonecrosis of the jaw, a condition in which portions of the jaw bone die, sometimes leaving the bone exposed.