Introduction: Nasopharyngeal obstruction is an important etiologic factor in the development of an extreme vertical growth facial pattern, and insufficient transversal growth of the maxilla. The treatment outcomes associated with rapid maxillary expansion in the literature are mainly discussed in terms of changes in dentofacial morphology, without special reference to changes in the pharyngeal airway, the position of the mandible, hyoid bone and the tongue.

Introduction: Nasopharyngeal obstruction is an important etiologic factor in the development of an extreme vertical growth facial pattern, and insufficient transversal growth of the maxilla. The treatment outcomes associated with rapid maxillary expansion in the literature are mainly discussed in terms of changes in dentofacial morphology, without special reference to changes in the pharyngeal airway, the position of the mandible, hyoid bone and the tongue.