Enlargement of the Pharynx Resulting From Surgically Assisted Rapid Maxillary Expansion

Given that transverse maxillary deficiency is an etiologic factor of obstructive sleep apnea and is intimately connected to pharyngeal size, the objective of this study was to determine whether surgically assisted rapid maxillary expansion (SARME) would promote pharyngeal enlargement in adults.

This prospective study was conducted in patients with uni- or bilateral posterior crossbite who underwent SARME. Participants were recruited from the Integrated Center for the Study of Face Defects, School of Medicine of Ribeirão Preto, University of São Paulo (São Paulo, Brazil). All patients underwent computed tomography of the pharynx before and after surgery (171.5 days on average), and the sagittal and transverse planes and the total area across 3 levels of the pharynx, including the upper (posterior nasal spine), middle (first cervical vertebra), and lower (second cervical vertebra) levels, were measured on the images. A paired-samples t test was used to evaluate changes in the pharynx before and after surgery.

The studied sample consisted of 18 adult patients (10 women and 8 men) with an average age of 37.11 years (standard deviation, 11.73 yr); all patients resided in the region of Ribeirão Preto, São Paulo, Brazil. No statistical changes were observed in the upper level. An enlargement of 17.82% (P = .0107) was observed in the sagittal plane of the middle level. The cross-sectional and area values of this same portion were enlarged (16.96 and 37.38%, respectively), with a trend toward statistical significance (P = .067 and .051, respectively). The airway enlargements in the lower level were 26.41, 24.87, and 53.87% in the sagittal and transverse planes and total area, respectively; these differences were statistically significant (P = .0003, .0033, and .0016, respectively) for all 3 measurements.

SARME promotes pharyngeal enlargement, especially in the lower levels of the pharynx.