The aim of this study was to investigate the influence of pterygomaxillary disconnection on the transversal expansion of the maxilla.Fifteen cadaver heads were used for surgically assisted rapid palatal expansion (SARPE), which was carried out twice on the same heads—with and without pterygoid disconnection. The maxillae were expanded by 10 mm by using a rapid palatal expander. Study models before and after both SARPE techniques were made and scanned by an oral scanner for virtual analysis by software.Performing pterygomaxillary disconnection during SARPE led to a decrease in the deviation between the incisor regions from 5.42 ± 1.13 mm to 4.05 ± 1.12 mm (P = .002) and an increase in the distance between second premolar regions from 2.63 ± 1.64 mm to 4.07 ± 2.01 mm (P = .040).SARPE without pterygomaxillary disconnection led to a V-shaped transverse expansion of the maxilla, whereas osteotomy of the pterygoid plates led to a parallel transverse expansion.