Evaluation of the effect of rapid maxillary expansion on intracranial pressure

The aim of this study was to evaluate the effect of rapid maxillary expansion on intracranial pressure in patients with maxillary transverse deficiency by measuring optic nerve sheath diameter with ultrasonography. A total of 25 patients with bilateral posterior crossbite, aged 11-15 years, were included in the study. Acrylic cap splint hyrax appliance was applied to all patients for rapid maxillary expansion (RME). Just before the first screw activation (T0); the patient was monitored, vital signs were recorded and optic nerve sheath diameter (ONSD) was measured with ultrasonography (US). The same measurements were repeated 1 minute (T1), 10 minutes (T2), and 60 minutes (T3) after the screw was turned a quarter turn by the researcher. Patient's perception of pain during screw activation (T1,T5) was also noted by a four-category verbal rating scale (VRS-4). In the last session of RME therapy, the same measurement procedure was performed as in the first activation session (T4,T5,T6,T7). In the results; A statistically significant increase was found in optic nerve sheath diameter values measured immediately after screw activation (T1, T5) compared to optic nerve sheath diameter values measured before screw activation (T0, T4) (p<0.01). When the measurements recorded before the first screw activation and 60 minutes after the last screw activation (T0-T7) were evaluated, the relationship between them was not significant (p>0.01). As a result, an increase in ultrasonographically measured ONSD value not exceed the critical value, was detected in patients who underwent rapid maxillary expansion theraphy immediately after screw activation.