Interactive associations of sagittal and vertical craniofacial skeletal patterns with upper cervical spine morphology and posture in growing patients.

Abstract

Objectives: To investigate the independent and interactive associations of sagittal and vertical craniofacial skeletal dimensions with upper cervical spine posture and morphology in growing patients.

Materials and methods: Pretreatment lateral cephalograms of 726 children aged 7-14 years were retrospectively analyzed. Sagittal (ANB) and vertical (SN-MP) skeletal dimensions were treated as continuous variables. General linear models were constructed to evaluate their associations with cervical spine parameters while adjusting for sex and skeletal maturation. Significant ANB × SN-MP interaction effects were further explored using simple slope analyses.

Results: The vertical skeletal dimension demonstrated the strongest and most consistent associations with cervical posture and upper cervical orientation parameters. In contrast, sagittal skeletal discrepancy showed more selective associations, primarily involving cervical inclination and selected intrinsic vertebral morphology variables. Significant ANB × SN-MP interaction effects were identified for CVT/NL, AIA, PDA, and ADA. Simple slope analyses demonstrated that the associations between ANB and selected cervical variables differed according to the underlying vertical skeletal pattern, although interaction effect sizes were generally modest (η² = 0.005-0.013).

Conclusions: Distinct cervical domains demonstrated different patterns of association with sagittal and vertical craniofacial skeletal dimensions. While vertical skeletal characteristics were associated with broader cervical variations, sagittal skeletal discrepancy showed more region-specific relationships. In addition, significant interaction effects indicate that sagittal and vertical skeletal dimensions do not operate independently when examining craniofacial-cervical relationships.

Clinical relevance: Assessment of cervical characteristics in growing orthodontic patients may benefit from simultaneous consideration of sagittal and vertical skeletal dimensions rather than evaluation of either dimension alone. These findings support a more integrated diagnostic perspective regarding craniofacial-cervical relationships during growth, rather than implying direct therapeutic consequences.