I had a retainer just like that before i got my fixed braces, but just with springs to move back two teeth. The ortho was also trying to correct a massive overbite. Which he did!
It took me around 2 weeks to get completely used to it - the speech slurring was my greatest problem, but after two weeks of continual wear, i spoke almost normally. The face that the back teeth didn't meet was so strange, but i did get used to it in the end. Apparently it's to encourage the molars to extend up a little bit so that by the end, your bite will meet a little earlier (or at least, that was in my case). I didn't notice any change while the retainer was in, but after two months i could feel the difference when i took it out to brush. Do you keep it in while eating?
Heh, after 9 months of wearing it, I'd almost ground through that extra acrylic with my bottom teeth. I found keeping well hydrated was important (just like for braces) but more so because of that darned bite plate thing, otherwise I'd sound like Shelley from South Park. You'll soon get used to it!
Oh, and fantastic teeth btw!!
