Computed tomography-derived projected morphometry of four zygomatic sutures: distinct geometric profiles and bilateral agreement

Zygomatic sutures are key landmarks in midfacial trauma, yet comparative data on their projected geometry and individual-level bilateral correspondence within a common computed tomography (CT) protocol remain limited. We compared the zygomaticomaxillary, sphenozygomatic, temporozygomatic and frontozygomatic sutures and assessed sex-, side- and age-related variation and bilateral agreement. This retrospective cross-sectional study analysed cranial CT examinations of 762 sides (total 381 adults). Projected length, end-to-end distance, sinuosity and angle to the Frankfort horizontal plane were measured bilaterally on standardised thick-slab maximum intensity projection reformats. Generalised estimating equations and patient-level Spearman correlations were used, with false discovery rate adjustment for multiple comparisons. The sutures had distinct dimensional, sinuosity and orientation profiles. Among the defined projected measurement courses, the zygomaticomaxillary suture showed the greatest mean length and end-to-end distance, and mean angles to the Frankfort horizontal plane ranged from 15.3° (frontozygomatic) to 67.1° (sphenozygomatic). Intersuture correlations were weak to moderate for dimensional and sinuosity parameters (largest ρ = 0.40). Angular correlations were small (largest absolute ρ = 0.12), and none remained significant after false discovery rate adjustment. Length and distance were greater in males for all sutures. Directional side differences were limited to sphenozygomatic straight-line distance, whereas individual bilateral agreement varied across sutures and parameters (bilateral intraclass correlation coefficients, 0.37–0.80). The sutures showed distinct projected profiles, and small group-level side differences coexisted with variable individual bilateral agreement. These single-centre, single-scanner descriptive projected morphometric data require external validation and evaluation in fracture cohorts before use in reduction assessment or surgical planning.