Here's another old wives' tale, not about teeth though. A child who doesn't crawl (who just gets up and walks - I guess there are such children) will never learn to read. The longer they crawl before they walk, the better reader they will be.
I love that one too

DS6 never crawled. He started reading chapter books at the age of 3

DS4 did crawl and started reading earlier than DS6 though.
Crawling is supposed to increase development of the parts of brain used for reading.
I am afraid our family just doesn't fit the norms

Not even with teeth and crawling. At least the kids like pasta and cookies. That sounds pretty normal, doesn't it?