Bone density-based maturation of the midpalatal suture in children aged 8-15 years

Morphological maturation of the midpalatal suture (MPS) has been widely used to guide maxillary expansion. However, whether densitometric maturation follows the same posterior-to-anterior developmental sequence or represents a distinct biological process remains unclear. This study aimed to evaluate bone density-based maturation of the MPS in children aged 8-15 years and its relationship to morphological maturation.

This retrospective cross-sectional study included 100 multislice computed tomography (MSCT) scans of patients aged 8-15 years. MPS maturation was classified according to Angelieri stages (A-E). Bone density was quantified in Hounsfield units (HU) at standardized anterior, middle, and posterior regions. Statistical analyses included repeated-measures ANOVA, nonparametric tests, Spearman correlation, and multivariable linear regression.

Bone density showed significant regional variation, with consistently higher values in the middle palatal region compared with the anterior and posterior regions (p < 0.001). Bone density increased with age and differed significantly by sex (p < 0.001). In multivariable regression, age was independently and positively associated with bone density (B = 32.47 HU/year, p < 0.001), with a significant age-by-sex interaction indicating that this increase was approximately 18 HU/year slower in males (p = 0.020). In contrast, the MPS morphological stage did not retain statistical significance after adjustment (p = 0.190).

MPS bone density exhibits a region-specific and age-dependent pattern that does not parallel morphological maturation, suggesting a biological process potentially influenced by functional loading. These findings further suggest that densitometric and morphological maturation may represent partially overlapping yet distinct aspects of MPS development.