Sinus problems

Hey there,
Had a cat scan done of my sinus's a few days ago. May have to have surgery to correct chronic problems. My sister just had surgery. It turned out that she only had one sinus in her forehead instead of two. My cat scan looked like I didn't have any in the forehead, or if there is they are almost nonexitant. Strange. We must have been born that way. Anyone ever hear of that?
They don't add them in, they just open up what is there. I have an appt with the Doc next thursday to see what happens next.
Anybody else have no sinus's in their forehead?
bye bye.........