Procedure-Specific Cranial Base Responses After Surgically Assisted Rapid Palatal Expansion and Le Fort I Osteotomy

The biological effects of maxillary surgery may extend beyond the operative site to involve the posterior cranial base. Although biomechanical studies have suggested force transmission to the spheno-occipital synchondrosis (SOS), procedure-specific cranial base responses have not previously been quantitatively evaluated using cone-beam computed tomography (CBCT)-based radiomics.

To compare postoperative cranial base responses following surgically assisted rapid palatal expansion (SARPE) and Le Fort I osteotomy by quantitatively evaluating the SOS using CBCT-based radiomics.

This retrospective observational study included 25 skeletally mature patients treated with either SARPE (n = 12) or Le Fort I osteotomy (n = 13). Preoperative and three-month postoperative CBCT scans were analyzed. The SOS was manually segmented using a standardized anatomical reference framework, and 107 radiomic features were extracted according to Image Biomarker Standardization Initiative recommendations. Within-group and between-group comparisons were performed using non-parametric tests with Benjamini-Hochberg false discovery rate correction. Selected radiomic features were further analyzed using linear mixed-effects models.

Radiographic SOS separation rates were comparable between the SARPE and Le Fort I groups (p > 0.05). Following false discovery rate correction, 43 radiomic features demonstrated significant postoperative alterations in the SARPE group, whereas four features showed nominally significant changes after Le Fort I osteotomy (p < 0.05), none of which remained significant after FDR correction. Nominal between-group comparisons identified four features with p < 0.05, but none remained significant after FDR correction. Linear mixed-effects analysis identified a significant Group × Time interaction for GLSZM Large Area Low Gray Level Emphasis (FDR-adjusted p = 0.024), supporting a procedure-specific longitudinal response. Heatmap and volcano plot analyses demonstrated a broader distribution of postoperative imaging-derived changes following SARPE than after Le Fort I osteotomy.

SARPE and Le Fort I osteotomy produced distinct postoperative responses within the spheno-occipital synchondrosis, suggesting that cranial base adaptation varies according to the surgical procedure. The broader radiomic response observed following SARPE is consistent with the hypothesis that preservation of the pterygomaxillary connection may permit greater force transmission to the posterior cranial base. CBCT-based radiomics may provide a sensitive quantitative method for characterizing procedure-specific cranial base responses.