The effects of incremental maxillomandibular advancement surgery on airway morphology: a cadaveric study.

Evidence demonstrates efficacy of maxillomandibular advancement (MMA) treatment of obstructive sleep apnea (OSA) and airway expansion. Patient studies are limited to pre/post-surgery comparisons. This cadaveric study evaluated intra-individual relationships between magnitudes of MMA advancement and airway changes. MMA with distraction osteogenesis devices and incremental advancement of the maxillomandibular complex, was performed on cadavers (n = 5). Computed tomography at each 2-mm advancement was used to measure volume and dimension of the oropharyngeal airway. Three-dimensional shape analysis visualized magnitudes and locations of changes. Incremental advancements caused volume, anteroposterior, and lateral dimensions to increase progressively, while length decreased. Changes were significant at lower advancements. Comparisons of MMA indicate alterations in airway volume from 4 to 6 mm and 6 to 8 mm were relatively greater than the changes from 8 to 10 mm (P = 0.044, P = 0.028, respectively), 10 to 12 mm (P = 0.024, P = 0.023), and 12 to 14 mm (P = 0.021, P = 0.019). These results may expand MMA application suggesting 6-8 mm advancements provide substantial increases in airway volume. MMA may be an OSA treatment option when large advancements are not possible. Lower magnitudes of advancement decrease risks of unfavorable facial esthetics from excess protrusion.