Sagittal split ramus osteotomy-enhanced mandibular distraction osteogenesis: A biomechanically superior approach for three-dimensional reconstruction in severe micrognathia.

BACKGROUND

Mandibular distraction osteogenesis (MDO) remains essential for severe micrognathia correction. The clinical adoption of conventional osteotomy techniques has been constrained by complications including non-union, inferior alveolar nerve injury, and dental germ damage, compounded by suboptimal occlusal relationships and compromised facial aesthetics. Critical considerations in MDO execution encompass neural structure preservation, osteotomy gap integrity, and achieving three-dimensional skeletal augmentation to enhance both functional stability and craniofacial proportions.

METHODS

Between January 2020 and September 2024, ten patients with severe micrognathia underwent MDO via sagittal split ramus osteotomy (SSRO) or vertical transversal osteotomy (VTO). A subset of patients subsequently underwent staged orthognathic procedures to optimize facial balance.

RESULTS

SSRO-based MDO (SSRO-DO) demonstrated superior clinical outcomes relative to VTO-DO, evidenced by 3-fold greater osteotomy surface area (p < 0.01) and thus 33 % superior central ossification area ratio (COAR) (p = 0.02). Postoperative enhance was confirmed with SSRO, achieving significant transverse expansion of mandibular body (p = 0.02). SSRO-DO group demonstrated significant improvement in sagittal advancement of mandibular body as well as facial contour against VTO-DO group.

CONCLUSIONS

SSRO-DO demonstrates potential advantages over current VTO-DO. This technique facilitates primary deformity correction and preserves anatomical foundations for subsequent orthognathic refinement. Further studies and long-term follow-up are needed.