Three-dimensional cephalometric analysis of morphological characteristics in children with bilateral craniofacial microsomia

Abstract

Purpose

Craniofacial microsomia (CFM), the second most common congenital craniofacial anomaly, is poorly characterized in bilateral cases because conventional cephalometry cannot accurately assess facial asymmetry. This study aims to characterize craniofacial morphology in children with bilateral CFM using three-dimensional (3D) cephalometric analysis.

Materials and methods

A retrospective 3D cephalometric analysis was conducted on 8 bilateral CFM patients and 10 age-/sex-matched normal patients as controls. A coordinate system was established with three reference planes: the Frankfurt Horizontal Plane (FHP), the Midsagittal Plane (MSP) and the Nasion Perpendicular Plane (CP). Fifteen linear and angular measurements assessed maxillary, mandibular, chin, and occlusal parameters. Subgroups were stratified by bilateral mandibular deficiency severity according to Pruzansky-Kaban classification (Group A: similar; Group B: different). Statistical comparisons utilized independent t-tests (CFM vs. controls) and Mann-Whitney U tests (subgroups), with Pearson's correlation analysis exploring variable relationships.

Results

Bilateral CFM patients exhibited significant reductions in ramal height (Co-Go: p < 0.001) and mandibular body length (Go-Me: p < 0.001), a posteriorly inclined occlusal plane (OP-FHP: 27.63° ± 5.50° vs. 8.13° ± 3.33°, p < 0.001), and pronounced chin retrusion (Me-NP: 46.08 ± 6.66 mm vs. 8.28 ± 7.71 mm, p < 0.001) and lateral deviation (Me-MSP: 5.84 ± 4.64 mm vs. 1.73 ± 0.93 mm, p < 0.05). Me-NP and Me-MSP differed significantly in subgroup analyses. Pearson correlation analysis revealed strong associations between Me-NP and Me-MSP and OP-MSP, posterior maxillary height (U6-FHP) and Co-Go.

Conclusion

Bilateral CFM is mainly characterized by posteriorly inclined occlusal plane and pronounced mandibular retrognathia. The occlusal plane and chin will consistently deviate toward the more severely affected side. When bilateral mandibular involvement is similar in extent, chin deviation tends to be mild, resulting in less severe facial asymmetry.