Why is it that everyone’s baby teeth seem to be so straight and perfect? I never did understand that.
I’ll wait till this gets over to GQ before posting my WAG.
Let’s let them chew on this over at General Questions, shall we?
You’d think that, after 4000 posts, he’d know where to post a GQ ferchisakes!
Yeah. Way to mark a milestone, ya dork.
Happy 4K to Mr.C and Demo, my two favorite posters! 
Ah, that’s better. 
Now for my WAG: baby teeth come in straight as a rule because they are smaller (not just absolutely, but also relative to the amount of space available). Smaller teeth equals less crowding and since usually it is crowding that causes teeth to come in crooked, less crowding results in straighter teeth.
Sounds good, doesn’t it?
The other mystery with baby teeth is: Why aren’t children allowed to gorge themselves on as much candy as they want while they still have teeth they won’t need for the rest of their lives?
Heart attacks for everyone!
My only addition to this is to wonder about the point of switching out teeth. Is it just to give our ancient ancestors extra time with teeth? (ie: replace the ones that inevitably fall out). If so, why only 2 sets? Simply because that was about all people ever needed since they didn’t live very long? Are we born with an extra set of teeth (albeit is small) way up in the gums that slowly build up and eventually push the others out of the way?
Ah…so many questions, so little space.
I thought this too, so I let them eat whatever they wanted. One son had to have 3 root canals 2 caps and 3 crowns (not to mention countless fillings) by the time he was 3 1/2. The next wound up with a root canal at age 4 and a few fillings.
My pediatrician says this had less to do with their dietary habits than their genes. He could be right since my oldest had the same “eat all the crap you want” upbringing and never got a cavity until he was 17.
As to why we need two sets of teeth, I believe it’s because our head grows so much and we’need bigger teeth than we can fit in children.
And, finally, as to the OP, I agree it has to do with relative size. However, you can certainly predict which kids are going to need braces. Baby teeth that have a few millimeters between each tooth belong to kids that will never meet an orthodontist. Children whose baby teeth are perfect and straight but are touching each other like adult teeth have parents who need to start saving up for big bills.
My son has a crown on a baby tooth. The crown is metal since no one cares what it looks like and the tooth will fall out anyway.
You should take your kids to a pediatric dentist if you can - they are a lot better in working with kids than most dentists. They also have equipment that is smaller for kids. He doesn’t ever use the word “drill” to not scare kids. Pediatric dentistry is sort of a new speciality so there are not a lot of them around yet but you should be able to find one if you live in a city over 100k population.