Push 99 w/10xbb at full table?

[EasilyFound]

This hand arose at a home tourney. First time playing with these guys. Have very little read on the players. 18 players have been reduced to one table of ten. The blinds are 100/200. UTG raises to 400. The next player folds. I have 99 and $2100 in chips. There are mixed stacks behind me. I don't put the raiser on a big pocket pair, but on two over cards. I've gone all-in three times before and not been called. Do you push here or do something else?

I've started playing two-table tourneys. I don't seem to be as successful at these as I have been at a single-table tourney. I often find myself in this kind of spot. Tight play early puts me at a full or near full table w/10xbb or less of chips. At a single-table tourney, the table is short-handed when the blinds reach that level, and I feel more confident about how to play. But with a full table, I am less confident about how to play when I get this kind of medium pair. Do you fold and wait for better spot, or do you make your move here, hoping your opponent folds or that you're in a coinflip situation if he doesn't?