A meatus is an opening; therefor, it's a depression, not a projection.
projection
projection
projection
projection
projection
....opening?
is a depression
"A crest is a projection or ridge, especially of bone; cresta"source: chacha.com
Calyces
projection. The bumps of bone around your knees and elbows are almost all called condyles.
root canal problem sinus condition over lapping condition embedded tooth