Theory #2: The Hot Boys started Grillz.

This one is just plain false.  Although Turk, BG, Juvenile, and Lil Wayne did give grillz a lot of exposure, they were not the originators.  There is much speculation as to who was the first rapper to rock a grill.  
The grillz trend actually began taking shape much earlier- during the early 1980s.  Most people credit New York’s Eddie Plein (owner of Eddie’s Gold Teeth) for kicking things off.  Plein reportedly outfitted Flava Flav with a set of gold caps, who was eventually followed by a slew of other top New York rappers, including Big Daddy Kane and Kool G Rap. Plein then moved to Atlanta and began designing more elaborate (and more expensive) grillz for artists including OutKast, Goodie Mob, Ludacris and Lil Jon.

When the south exploded into the forefront of hip hop in the early 2000s, so did the grillz phenomenon. From there the grillz lineage can be clearly traced from Atlanta (see above) to Memphis (8-Ball & MJG) to New Orleans (No Limit, Cash Money), to Houston (Bun B, Paul Wall), to St. Louis (Nelly).  And of course, Bay area natives stake a rightful claim to the grillz tradition as well (Too Short, others).

Theory #3: Having a grill means you’re tough.

C’Mon.  Bow Wow has a grill.

Grillz have been a part of hip hop since the early days, and all indications are that they are not going anywhere anytime soon.  Like everything else hip hop, grillz are big business.  Companies are springing up all across the country that cater to the grillz market, with names like GotGrillz, GoldTeeth.com, and Mr. Bling.  With unlimited advertising supplied by the legions of artists rocking grillz (I saw one on Regis and Kelly the other day) the grillz movement may not even be at its peak.

Of course, there are haters.  School districts in Alabama and Georgia have banned students from wearing grillz in the classroom, and similar measures are being planned in Texas. Apparently some educators aren’t cool with students wanting to Rob the jewelry store and tell them make me a grill.  And let’s not forget those pesky dental health advocates who point out the health risks associated with having foreign metal objects in your mouth for long periods of time, such as cavities, gum disease and even bone loss.
Grillz may be here to stay, but this is one bandwagon you won’t see me jumping on.