The main, or central, idea of the passage is To facilitate regrowth of a green sea turtle's broken shell, rescuers used orthodontic braces. How does the detail in bold develop the main idea?
An injured green sea turtle, its shell slashed by a boat's propeller, was found on a Florida beach in 2010. In addition to its broken shell, the 170-pound turtle was suffering from a damaged lung, and its internal organs had been exposed to infection. Rescuers transported the turtle, soon named Andre, to the Loggerhead Marinelife Center, where veterinarians treated Andre's devastating injuries. When it came to the gaping hole in Andre's shell, they faced a challenge that tested the limits of their expertise. While turtles' shells can regenerate naturally after injury, Andre's wound was too severe to regrow on its own. An orthodontist came to Andre's rescue by fitting his shell with braces similar to those used on people, using expanders to gradually stretch sections of the shell to fill the gaps. In the ensuing months, center staff regularly adjusted the braces, and over time, Andre's shell almost completely regenerated.