Posterior crossbite - Treatment and stability

Posterior crossbite is defined as an inadequate transversal relationship of maxillary and mandibular teeth. even when eliminating the etiologic factors,this malocclusion does not have a spontaneous correction,and should be treated with maxillary expansion as early as possible. this treatment aims at providing a better tooth/skeletal relationship,thereby improving masticatory function,and establishing a symmetrical condyle/fossa relationship. should posterior crossbite not be treated early,it may result in skeletal changes,demanding a more complex approach. additionally,an overcorrection expansion protocol should be applied in order to improve the treatment stability. although the literature has reported a high rate of relapse after maxillary expansion,the goal of this study was to demonstrate excellent stability of the posterior crossbite correction 21 years post treatment.