LeAnn Rimes is letting fans know she has nothing to smile about as she recovers from minor oral surgery. 

"K, coming clean ... I had minor surgery this week and I've been in SO much pain it's not even funny. Nothing major just annoying! Pain pain go away!!!!!! When it's mouth pain and jaw pain it makes your whole head pound! YUCK," she tweeted yesterday. 

The 29-year-old country singer complained earlier in the day that her medication wasn't working, but eventually it seemed to kick in.

"The pain is subsiding finally for a moment. My head has been vibrating all day. Maybe the sand under my feet is helping," she tweeted from her Malibu beach house.

However, by Super Bowl time, Rimes seemed to be feeling much better.

"Off and on pain! I'm happy now :)," she tweeted.

Rimes' rep confirmed to "E! News" that the singer underwent oral surgery to correct a jaw disorder known as TMJ. 

Tags: LeAnn Rimes Eddie Cibrian