Correlations of spheno-occipital synchondrosis, cervical vertebrae, midpalatal suture, and third molar maturation stages.

Objectives: To estimate the joint correlations among cervical vertebrae maturation (CVM), spheno-occipital synchondrosis (SOS), midpalatal suture maturation (MPS), and third molar mineralization (TMM) and to assess the predictive potential of SOS on CVM and MPS.

Materials and methods: 570 pretreatment cone-beam computed tomogram (CBCT) scans from three private practices were analyzed, and MPS, CVM, SOS, and TMM stages were categorized and recorded by two independent investigators. Intra- and inter-rater reliability tests were evaluated with weighted Cohen's kappa tests. Spearman correlation coefficients for ordinal data were used to estimate the pairwise correlations among SOS, CVM, MPS, and TMM. To evaluate if SOS could predict CVM and MPS, ordinal regression models were estimated and cross-validated.

Results: The analysis demonstrated a robust positive correlation between SOS and CVM (r = 0.845) and between SOS and MPS (r = 0.742). A significant correlation was also observed between CVM and MPS (r = 0.659). Further correlations were identified between TMM and SOS (r = 0.444), TMM and MPS (r = 0.392), and TMM and CVM (r = 0.358). Ordinal regression models indicated the potential of using SOS as a predictive marker for CVM and MPS stages.

Conclusions: With a comprehensive analysis, SOS is strongly correlated with CVM and MPS, and SOS stage can be used to predict CVM and MPS using ordinal regression. Since MPS stages are challenging to categorize due to their anatomy, this finding suggests a diagnostic tool using SOS stages or when more information on skeletal maturity of the patient is desired.