Maxillary Expansion With C-Expander Using Digital Planning and CBCT-Based Surgical Guidance: A Case Report

This clinical case report describes the clinical management of a patient with a transverse maxillary deficiency treated with a C-expander. The objective is to present the diagnosis, tomographic planning, implantation, and postexpansion evolution. The patient presented with typical characteristics of a transverse maxillary deficiency, with a maxillomandibular discrepancy of 6.8 mm; the insertion of miniscrews was planned using cone-beam computed tomography (CBCT) and intraoral scanning with BlueSky Plan 4 software. A surgical guide was fabricated, and the C-expander was installed; activation was performed progressively under weekly clinical monitoring. Another CBCT scan was performed after the expansion. Follow-up CT showed transverse improvement with a nearly parallel opening pattern of the median palatine suture of approximately 6.5 mm on the axial view. Dentoalveolarly, the upper intermolar distance increased by 7.1 mm and the lower by 1 mm. Intermolar angulation increased by 2° in the upper arch and 5° in the lower arch; overjet increased by 1 mm and overbite decreased by 15%. Furthermore, the 3D frontal facial reconstruction revealed an increase in the intercanthal distance of 0.3 mm, an increase in the nasal interalar distance of 3.5 mm, and an increase in the nasal base width of 4.4 mm. In conclusion, maxillary expansion using a digitally guided C-expander successfully achieved separation of the midpalatal suture in this patient, with limited dental and facial effects during the immediate postexpansion.