Spontaneous correction and new development of posterior crossbite from the deciduous to the mixed dentition.

In the present sample, 1 in 10 children have a posterior crossbite in the deciduous dentition, which is however autocorrected in about three-quarters of cases. On the other hand, 4% of children developed a new crossbite in the mixed dentition. It may thus be reasonable in cases with posterior crossbite in the deciduous dentition to wait for the first permanent molars to erupt before initiating treatment.