Correlations Between Mandible Condylar Structures and External Ear Deformities in Hemifacial Microsomia With Three-Dimensional Analysis

This study aimed to explore correlations between mandible and ear deformities and quantitative volumetric relations between condylar structures and external ear in hemifacial microsomia. The authors reconstructed three-dimensional craniofacial models from 212 patients with unilateral hemifacial microsomia (the unaffected side as the controls). Patients were evaluated by Pruzansky-Kaban and Marx classification, and divided into 3 age groups (0-6, 7-12, and >12 years of age). The mandible condylar structures, including condyle and the condylar skeletal unit, were selected (except the classification of the mandibular or ear deformities (M3)). Along with the external ear (except the classification of the mandibular or ear deformities (E4)), their volumes were measured and analyzed. Spearman correlation coefficient analysis was applied. There was a positive correlation between the mandible and ear deformities (r = 0.301, P < 0.001). Either between the condyle and external ear ( P = 0.071-0.493) or between the condylar unit and external ear ( P = 0.080 - 0.488), there were no volumetric relations on the affected side, whereas on the unaffected side were (r = 0.492-0.929 for condyle, r = 0.443-0.929 for the condylar unit, P < 0.05). In most cases, the condylar structures of the classification of the mandibular or ear deformities (M2b) were significantly smaller than the classification of the mandibular or ear deformities (M2a). Results suggested deformities of mandibular condylar structures and ear did not correlate, although deformities of mandible and ear did. The condylar deformity might develop independently from microtia and be more severe within relatively more abnormal temporomandibular joints.