Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Schematic diagrams for the rat tooth movement model and root resorption. (A) The nickel-titanium coil spring between the first molar and incisors was activated to create a 50-g force. (B) Root resorption area ratio was calculated by dividing the total root surface area (gray) by the resorption area (black).
