RESUMEN
OBJECTIVE: The transverse maxillary deficiency frequently observed in patients with cleft lip and palate (CLP) is usually treated by rapid maxillary expansion (RME). Considering that RME causes a significant increase of the internal nasal dimensions in children with unilateral CLP (UCLP), this study aimed to characterize the internal nasal geometry of children with bilateral CLP (BCLP) and transverse maxillary deficiency using acoustic rhinometry. The study also aimed to analyze changes caused by RME. DESIGN: Cross-sectional prospective study. SETTING: Laboratory of Physiology, Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo, Bauru, SP, Brazil. PARTICIPANTS: Fifteen children with repaired BCLP of both genders, aged 8 to 15 years, referred for RME, were prospectively analyzed. INTERVENTIONS: Subjects underwent acoustic rhinometry before the expander installation and after the active phase of expansion. Cross-sectional areas (CSA) and volumes (V) of the nasal valve regions (CSA1 and V1) and turbinates (CSA2, CSA3, and V2), were measured after nasal decongestion. MAIN OUTCOME MEASURES: In the majority of the subjects, an increase of internal nasal dimensions was observed. RESULTS: Percent changes of CSA1, CSA2, CSA3, V1, and V2 were: +25%, +11%, +9%, 20%, and +12%, respectively. Differences were significant for all variables studied, except CSA3 (P < .05). CONCLUSIONS: RME promotes an increase in the internal nasal dimensions of children with BCLP, suggesting that RME is capable of substantially improving nasal patency in this population.