Do pacifiers have an effect on tooth development? My 2-month-old can't sleep without his paci and I'm worried that he's getting too attached to it.

To some extent yes. http://www.babycenter.com/0_pacifiers-and-your-toddler_12254.bc When he is sleeping just make sure to remove the pacifier, Some babes will spit out. If you worry about the teeth development, try to use orthodontic pacifier instead. http://www.bundoo.com/articles/what-is-an-orthodontic-pacifier/