Spheno-Occipital Synchondrosis Stages Evaluation for Patients With Cleft Lip and Palate to Assess Growth and Treatment Timing in East-Asian Population.

Objective: To evaluate spheno-occipital synchondrosis (SOS) fusion stages in patients with cleft lip and palate (CLP) and compare them with cervical vertebral maturation (CVM) stages to determine the timing of treatment.

Materials and methods: The authors examined 230 patients with CLP (131 males and 99 females; mean age 9.3±5.6 y), categorized into unilateral (UCLP) and bilateral (BCLP) subgroups. The SOS and CVM stages were assessed using cone-beam computed tomography (CBCT) and classified into 5 and 6 stages, respectively. Various regression analyses were performed to develop a model that could predict the SOS stage using CVM, chronological age, sex, and type of CLP.

Results: Significant differences were observed in the mean age of CVM and SOS stages by sex, with females being younger than males at all stages and having shorter periods between stages; however, no significant differences were observed between CLP types. CVM and SOS were similarly significantly correlated in females (r=0.86) and males (r=0.85), and were also significantly correlated by CLP type: UCLP (r=0.85) and BCLP (r=0.87). Prediction equations for SOS stage in patients with CLP using CVM stage, sex, and chronological age as predictors were developed; the explanatory power was 0.924 for males and 0.904 for females.

Conclusion: In patients with CLP, CVM, and SOS stages were strongly correlated with age and sex, but not with CLP type. These findings suggest that skeletal maturity indicators should be considered when determining the optimal timing of treatment for patients with CLP, potentially leading to more personalized and effective treatment strategies.