Unilateral Mandible Hyperplasia: Individualized Protocols Integrating Digital Technology and Modified Techniques

Unilateral mandibular hyperplasia (UMH) frequently results in facial asymmetry and occlusal disturbances, with no unified diagnostic or therapeutic guidelines currently available.

A retrospective analysis was conducted on 8 adult UMH patients, with digital technology as the core component. Preoperative virtual surgical planning (VSP) precisely determined the extent of osteotomy and condylectomy, while 3D-printed cutting guides and splints ensured accurate intraoperative execution. Single-photon emission computed tomography (SPECT) was used to assess growth activity but demonstrated limitations; therefore, a comprehensive evaluation integrating clinical history, patient age, and CT follow-up was emphasized to avoid false-positive results. All cases adhered to the one-stage surgery principle (simultaneous condylar management, orthognathic surgery, and contouring in a single procedure). Two modified surgical techniques were introduced: modified intraoral IVRO on the affected side, enabling synchronous condylectomy and joint reconstruction without facial scarring; modified SSRO on the affected side with the osteotomy line extended anterior to the mental foramen, allowing single-stage dissection and protection of the inferior alveolar nerve and facilitating contouring. Based on individual characteristics, 3 personalized protocols were proposed: condylectomy combined with orthodontics only; condylectomy combined with orthognathic surgery and contouring (for active condyles); and orthognathic surgery combined with contouring only (for inactive condyles).

Postoperative follow-up of all 8 patients demonstrated stable occlusion, restored facial symmetry, and no evidence of recurrence.

This study establishes a digital technology-supported personalized surgical system for UMH, enabling precise, safe, and effective restoration of facial aesthetics and function.