Virtual Surgical Planning-Guided Correction of Hemifacial Microsomia With Inverted-L Osteotomy

Hemifacial microsomia (HFM) produces facial asymmetry involving the skeleton and overlying soft tissues, and skeletal correction may leave residual soft-tissue deficiency. We report a 23-year-old woman with left HFM (Pruzansky-Kaban type IIb; OMENS-Plus O0M2E1N0S2), maxillary occlusal cant, and leftward chin deviation. Three-dimensional virtual surgical planning (VSP) was performed using patient-specific osteotomy guides and wafers. One-stage treatment comprised Le Fort I osteotomy, left mandibular inverted-L osteotomy with autogenous iliac interpositional grafting, right sagittal split ramus osteotomy with angle reduction, advancement genioplasty, and porous polyethylene augmentation of the left malar region and mandibular angle. The planned movements were accurately reproduced, achieving Class I occlusion and stable bony healing. Residual left cheek deficiency was corrected by autologous fat grafting 6 months later, producing a symmetric facial contour. VSP with patient-specific guides enabled accurate, stable correction of complex 3-dimensional skeletal asymmetry, while staged fat grafting addressed the residual soft-tissue deficiency.