Bone augmentation for large maxillomandibular advancements in orthognathic surgery

The Situation

A 57 year-old male patient was referred to my clinic for treatment of a severe Obstructive Sleep Apnea (OSA, apnea-hypopnea index 66). Prior treatment with Continuous Positive Airway Pressure Therapy was unsuccessful because of non-acceptance. Treatment was indicated because of the severity of the patient’s apnea and debilitating symptoms of daytime sleepiness. Patient opted for a definite and surgical treatment of his OSA. Therefore Maxillomandibular Advancement (MMA) surgery was performed with large advancement of the maxillomandibular complex.

The Approach

The main goal of MMA surgery for OSA is to create a profound enlargement of the upper airway. A Le Fort І osteotomy is combined with a Bilateral Sagittal Split Osteotomy (BSSO). Because of the large advancement of the maxillomandibular complex, grafting of the osteotomy sites is recommended. Thus minimizing the risk of postoperative complications (e.g. non-union). Grafting of the osteotomy sites was accomplished by means of autologous bone chips harvested during the osteotomy and deproteinized bovine bone mineral mixed with 10% collagen (Geistlich Bio-Oss® Collagen).

The Outcome

Postoperative recovery of the patient was without complications (e.g. wound dehiscence, osteosynthesis failure or infection). Follow-up and a postoperative sleep study showed a resolution of symptoms and nocturnal airway obstructions. In addition, the maxillary and mandibular osteotomy sites showed signs of complete bony ingrowth. Grafting large bony defects during MMA surgery with a combination of autologous bone and Geistlich Bio-Oss® Collagen appears to be a predictable means of reconstruction.

Keys to Success

• Aim at the maximum possible maxillomandibular advancement while respecting the patients profile and the surgical limitations in such large advancements.
• Graft the osteotomy sites in case of large advancements of the mandible or maxilla with autologous bone and Geistlich Bio-Oss® Collagen blocks.
• Use additional means of osteosynthesis for stabilizing the mandible (e.g. double plating) in case of large mandibularadvancements (i.e. ≥ 10 mm).
• Use double layer closure (i.e. both the muscular and mucosal layer) in order to shield maxillary and mandibular grafting sites from the oral environment.