Avatar Mesh Issues?

I seem to have quite the problem with my avatar mesh, and there doesn't seem to be anything I can do about it. My chin, on any male shapes I make or use, bulges out in very unnatural ways- and it's not caused by any modifications to my shape. I've looked again and again, played with my shape, and it's there as constantly as every other part of my body. It is not, however, there with any female shapes, and I can't seem to figure out any reason for it being there in the first place.

I didn't have any problem with chins until the client viewer updated to 1.23.4.123908. Normally, I stick with the Emerald Greenlife Viewer (which is also now running on the latest client), but the issue is consistent with every viewer I use, including the official SL viewer.

Does anyone have any idea what the issue is or how to fix it, if possible? I've tried everything short of uninstalling and reinstalling all of my viewers, and can't figure out what it is for the life of me; the only thing that I can think of is some strange bug in SL that messes up the avatar meshes somehow.

Big chin disease is often fixed by wearing a different system hair/bald cap (not prim hair). Give that a try first.

Wow... I'm surprised that a bald base is what causes it. Thanks for the advice; now, time to figure out which base it was so I can get rid of it.