A little over 3 months ago, I had a lefort 1 to correct my underbite. Everything's gone pretty smoothly, and I highly recommend the procedure if your insurance covers it. However...
Hair loss does seem to be a problem associated with this surgery; or, at least, it has been for me. The generally brutal nature of the first couple weeks of recovery, combined with drastic weight loss, resulted in some hair loss for me. About a week after surgery, I remember taking a bath and seeing hair everywhere. However, this can be expected just by using common sense. Recovering from a major surgery, accompanied by usually drastic weight loss, results in the body de-prioritizing the hair on your head. However, my hair loss was definitely not bad enough to be significantly noticeable, and everything returned to normal once I got back on a solid diet (I think).
If that was all I'd had to deal with, I'd be content. However, I've been dealing with a secondary hair loss as of late, called Telogen Effluvium. Intensive surgery can actually 'shock' the hair follicles into entering their resting state. Hair follicles stay in this phase for 3 months until they fall out, and then they regrow. Due to all of the follicles' 'internal clocks' being lined up, more hair tends to diffuse at once than usual. Sometimes it's not visible, sometimes temporary bald spots develop. My point is; watch out for the 3 month mark. Here's a pic that's pretty similar to what I'm going through:
http://www.dermnet.com/images/telogen-effluvium/picture/21662I got hit pretty hard:
Relaxed:
http://i.imgur.com/D9gcWqu.jpgPulled back:
http://i.imgur.com/gWn60LY.jpgThe first pic gives a decent indicator of where my hairline usually is. While the second exaggerates the issue a bit, even in the first picture you can see thinning in the same general area as the guy with TE. TE can actually cause diffusion and thinning all over the place in major cases, so there's that to take into account.