Both of my vets said that the majority of bunny teeth problems can be put down to diet but I'm not sure I totally agree. I got Charlie and Fern from the same pet shop 6 months apart. Charlie was from a 'breeder' and was apparently the healthiest of the litter but unwanted cos he's male. Touch wood, fingers crossed etc etc he's never had any teeth problems and he is a real round head flat faced lop. I don't know how Fern ended up at the pet shop but I got her cos she had poorly eyes and I saw her in the pet shop 3 weekends in a row and just couldn't leave her there any longer. They've always been fed on supa rabbit, lots of hay, v few bits of veg cos of Charlies sensitive tum/bottom. At the age of 2 Fern started having teeth problems - her front teeth were out of line, the back ones went wobbly in their sockets, molars growing through the bottom of her jaw etc etc. The specialist vet told me it was my fault for giving her the wrong diet (not enough calcium) and not letting her go out in the sun - whatever vitamin it is we get from the sun helps bone development and without it bones are spongy which is why her teeth went wobbly. How true this is I don't know, but her and Charlie led the exact same lives - they shared a cage, shared the lounge, shared the same food bowl and were rarely apart. My conclusion is that she was born like it, it has to be genetic, otherwise Charlie would have it to.
Sorry, I waffled a fair bit there, I suppose this is something close to my heart. Fern was PTS in my arms 6 months ago cos there was nothing else we could do for her, I still wonder if it is anything to do with being an indoor bunny. I'd be interested to know the difference in the prevalence of any teeth probs in indoor buns vs outdoor buns.