Facial asymmetry outcome of orthognathic surgery in mild craniofacial microsomia compared to non-syndromic class II asymmetry

TL;DR

This study compares facial asymmetry outcomes after orthognathic surgery in mild craniofacial microsomia and non-syndromic class II asymmetry patients.

Contribution

It identifies that vertical contour asymmetry is significantly worse in mild CFM compared to non-CFM class II after surgery.

Findings

Mild CFM and Class II groups showed similar hemi-facial and hemi-jaw area asymmetry post-surgery.

Vertical contour asymmetry was significantly larger in CFM compared to Class II group.

Correcting vertical asymmetry in CFM remains challenging despite similar outcomes in other asymmetry measures.

Abstract

To compare the facial asymmetry after bimaxillary surgery between mild craniofacial microsomia (CFM) and non-syndromic class II asymmetry.

Cone-beam computed tomography scans of adults with Pruzansky-Kaban types I and IIA CFM (CFM groups, n = 20), non-syndromic skeletal class II asymmetry (Class II group, n = 20), and normal controls (control group, n = 20) were compared. The area asymmetry of lower face and jaw bones was quantified. Landmark-based method was used to evaluate the lower facial asymmetry regarding midline, cants, and contour.

There were no significant postoperative differences in the hemi-facial and hemi-jaw area asymmetry between CFM and Class II groups, both of which were significantly larger than the control group. No significant difference was found in the midline deviation and lip and occlusal cants between CFM and Class II groups. The vertical contour asymmetry in CFM group became significantly larger than Class II group. Compared to the control group, the deviation of pronasale, subnasale, and soft-tissue menton, lip and occlusal cants, and sagittal and vertical contour asymmetry in CFM group were significantly larger, as were the deviation of subnasale and soft-tissue menton and vertical contour asymmetry in Class II group.

The vertical contour asymmetry of mild CFM was significantly larger than non-CFM class II after surgery, while the area asymmetry, midline deviation, cants, and sagittal contour asymmetry of lower face showed no significant difference.

Be aware that correcting vertical asymmetry of contour, lip, and dentition in CFM is still challenging.

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