Avaliação tridimensional das vias aéreas orofaríngeas em pacientes com e sem fissura lábio-palatal submetidos à expansão maxilar

Abstract

INTRODUCTION : Rapid maxillary expansion (RME) has an extensive history in the orthodontic literature, and the correction of transverse maxillary discrepancy in growing patients is its main objective. Patients with transverse maxillary deficiency may also have functional problems such as the narrowing of the nasopharyngeal and oropharyngeal airways. The RME can promote a breathing improvement, since the external walls of the nasal cavity are included in the maxilla, and the expansion increases the nasal capacity. OBJECTIVES : To review the literature associating aspects about RME and changes resulting from this kind of procedure on the upper airways, as well as to assess and compare the oropharyngeal airway dimensions in cleft and noncleft lip and palate growing patients with maxillary constriction, after and before RME. MATERIAL AND METHODS : Among different methods for airway assessment, as described in the literature, linear, area and volumetric measurements of oropharyngeal airway were taken from cone-beam computed tomography (CBCT) scans, in a sample composed of 63 patients (30 cleft and 33 non-cleft). Shapiro-Wilk normality test and Generalized Estimating Equations (GEE) with Bonferroni adjustment were used. The intrarater repeatability was calculated with intraclass correlation coefficient (ICC). RESULTS : The oropharyngeal airway dimensions were not significantly different when cleft and non-cleft patients were compared before the treatment. After RME, the total airway volume and the upper cross-sectional area were significantly increased in cleft patients. Non-cleft patients presented significant increases in the area and transverse measurements at the upper crosssectional plane of oropharynx. CONCLUSIONS : There were no dimensional differences in the oropharynx between cleft and non-cleft patients before the treatment. RME increased the airway volume, and it was significant in cleft patients. Non-cleft subjects presented increases in the transverse widths at upper limit and minimal crosssectional planes of oropharynx after RME.