Introduction: The presence of maxilla deformity together with respiratory problems, mostly nasal obstruction, have been attention of investigators for the possibility that these events keep a correlation to each other. Study design: Clinical prospective randomized. Material and method: It's took place otorrinolaryngologic evaluation and by nasofibroscopy of 30 adults patients with posterior crossbite and with indication of orthodontic-surgical treatment (surgically assisted rapid maxillary expansion). Results: It was demonstrated that 56,7% of the patients presented nasal obstruction, against 43,3% without the symptom. Studying the nasal septum by nasofibroscopy, it was found 100% of septal deformity. According Cottle, it was found septal deformity in area I (13,4%), area II (83,3%); area III (90%), area IV (83,3%) and area V (3,3%). Conclusions: Nasal obstruction isn't present in all cases of posterior crossbite. It's important nasofibroscopy in the evaluation of these patients and it's also important the Maxilo-Facial surgeon working together with the Otorrinolaryngologist, since the cases with indication of surgically assisted rapid maxillary expansion and the patient having nasal obstruction with septal deformity, both procedures (maxillary osteotomy and septoplasty) can be done in the same operation.
posterior crossbite; septal deformity; transversal maxillary deficiency; nasofibroscopy; septoplasty; orthognatic surgery