Seventy-nine studies were included in the review: 47 single surgical procedures (three RCTs and 44 case series) and 32 studies of multilevel surgical approach (one RCT and 31 case series). Study sample size ranged from three to 239 patients (most had fewer than 50 patients). Study quality ranged from low to very low.
There were statistically significant reductions in apnoea-hypopnoea index of 87% with maxillomandibular advancement surgery (RoM 0.13, 95% CI 0.08 to 0.20, I2=91%; nine case series), 33% with uvulopharyngopalatoplasty (RoM 0.67, 95% CI 0.58 to 0.77, I2=88%; two RCTs and 13 case series), 32% with laser assisted uvulopalatoplasty (RoM 0.68, 95% CI 0.49 to 0.94, I2=83%; two RCTs and six case series), 34% with radiofrequency ablation (RoM 0.66, 95% CI 0.54 to 0.81, I2=38%; one RCT and seven case series) and 26% with implants (RoM 0.74, 95% CI 0.61 to 0.91, I2=41%; one RCT and two case series).
When RCT evidence was considered alone, there were no statistical differences with laser assisted uvulopalatoplasty and radiofrequency ablation. Studies of pharyngeal procedures (three studies) and modified uvulopharyngopalatoplasty (three studies) were generally positive. Multilevel approaches showed generally positive results, but some studies showed no or little benefits (32 studies).
There were few adverse events reported with maxillomandibular advancement. Secondary outcomes were reported in the review.