What I understand is that it's not really a toupee as such. But that the Shat's hair was always thin (and I don't mean balding... just that each strand of hair was thin) and that it looked balder on camera than it did in person, so he did have a hair piece just to fill out his natural hair.
However, I'm not sure if this counts as Trek Tech. I bet a moderator will magically whisk it away to General Discussion or the TOS forum.
--Alex