In the beginning of Dragon Ball (not DBZ), Goku was shown quite often either partially or completely naked. Some may make the argument that this was necessary to showcase his tail in the beginning of the series. However, according to Toriyama, Dragon Ball started as a gag reel, and then was a show for children. If this is the case, they why did they allow Goku to be vividly naked without censorship? Was this interpretted differently in Japan, because I feel this would have been odd to American viewers at the time.
First, in Japan, it was a non issue. Different culture. Check out all the different animes and mangas that pull off similar or even worse moves.
Once it went to the western world where it is an issue... Networks did not realize (sold as kids show -> didn't bother checking the tapes).
Back here there was an issue where, at a kids show on national tv, the host presented the newest show!, ranma 1/2's first episode. Turn out it was the uncensored version, after the episode was over and the camera returned to the host, she was evidently quite upset and embarrased. Myself and my brothers were watching along with our parents, all of us were quite embarrased as well (and most likely everyone that watched that show). It was only then that more attention was put on these shows :)