Best Pediatric Dentist in 200 Feet Radial road What causes misalignment of children's teeth? Mouth breathing Children today are less likely to chew their food properly, which can prevent the jaws from developing properly and lead to problems with tooth alignment. Genetic factors and habits such as thumb sucking and resting your chin on your hand can cause problems with the development of normal teeth alignment, but malocclusion caused by mouth breathing is also thought to be a contributing factor.