Mandibular Ramus Vertical Augmentation in Hemifacial Microsomia: Technical Evolution from Osteogenic Distraction to Sagittal Osteotomy

Introduction: Hemifacial hypoplasia is the second most common congenital craniofacial anomaly after cleft lip and palate. Mandibular ramus deficiency represents a key component of this condition, and vertical augmentation is traditionally managed with distraction osteogenesis. However, technical challenges related to device positioning and vector control continue to limit its reproducibility. This study aims to describe and compare three surgical techniques for mandibular ramus augmentation in hemifacial microsomia and to develop a surgical treatment algorithm based on individual anatomical characteristics and clinical complexity. Materials and Methods: From 2010 to 2022, eighteen patients with Pruzansky–Kaban grade I–IIb hypoplasia underwent staged orthodontic–surgical treatment at our institutions. The standard protocol included initial ramus vertical augmentation followed by bimaxillary osteotomy for asymmetry correction. The patients were equally divided into three groups of six patients each, based on the surgical technique employed. Three representative cases were selected to illustrate the evolution of our approach: (1) bidirectional distraction following a full-thickness osteotomy above the lingula; (2) unidirectional distraction applied to a sagittal ramus osteotomy according to Obwegeser; and (3) direct vertical augmentation with rigid fixation after sagittal osteotomy, supported by virtual surgical planning. Results: Vertical ramus augmentation of 15–25 mm was achieved in all cases. The first technique proved effective but technically demanding. The second approach improved vector control and device stability. The third, involving direct vertical augmentation with rigid fixation, simplified the procedure, reduced costs, and maintained bony contact for stable healing. Conclusions: Sagittal ramus osteotomy with direct stabilization represents a promising alternative to traditional distraction in selected patients, combining historical surgical principles with computer-assisted planning to achieve reproducible outcomes.