RME: effects on the nasal septum. A CBCT evaluation

Three-dimensional images have been evaluated to study the changes that occur on the maxillary complex and the nasal septum, following rapid maxillary expansion (RME) in growing children.

The records of 39 consecutively treated patients (20 male, 19 female), aged between 6.2 and 12.3 years (mean 8.6 years, S.D. 1.5), presenting a septal deviation of more than 1 mm, were analysed. Each patient was scanned at two distinct periods. The first image (T0) was obtained before treatment and hence represented the patient's baseline condition prior to expansion. The second time point (T1) was set after removal of the expander. The skeletal modifications induced by RME have been evaluated via cephalometric tracings obtained at T0 and at T1. The time lapse between T0 and T1 was 12 months.

The nasal septum has been modified in its length more significantly in its lower rather than its upper tract. The width of the piriform aperture increased of 1.58 mm with an increase in the lateral walls and a downward movement of the nasal floor (consequent to an increase in septal length). There was also a reduction of septal deviation. The control group measurements did not vary during the considered period.

Evidences of this study suggest that RME procedures can result in: a potentially positive effect on the nasal septum asymmetry during childhood; an increase of the nasal cavity volume due to a downward and forward movement; a lateral inclination of the nasal cavity reducing air resistance and improving breathing pattern; an increase of the length of the septum in its lower third improving its possible deviations and growth disturbances; favourable effects on the growth of the entire maxillary complex.