FIGURE 1.
(a) total posterior; (b) partial posterior; (c) anterior 90°; (d) anterior >90°
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.