Impact of surgical maxillomandibular advancement upon pharyngeal airway volume and the apnoea–hypopnoea index in the treatment of obstructive sleep apnoea: systematic review and meta-analysis

BACKGROUND: A systematic review was carried out on the effect of surgical maxillomandibular advancement (MMA) on pharyngeal airway (PA) dimensions and the apnoea–hypopnoea index (AHI) in the treatment of obstructive sleep apnoea (OSA), with the aim of determining whether increased PA in the context of MMA is the main factor conditioning the subsequent decrease in AHI. METHODS: A search was made of the PubMed, Embase, Google Scholar and Cochrane databases. A total of 496 studies were identified. The inclusion criteria were a diagnosis of moderate to severe OSA, MMA success evaluated by polysomnography, reporting of the magnitude of MMA achieved, PA increase and a minimum follow-up of 6 months. RESULTS: Following application of the eligibility criteria, eight articles were included. Metaregression analysis showed MMA to significantly increase both pharyngeal airway volume (PAV) (mean 7.35 cm(3) (range 5.35–9.34)) and pharyngeal airway space (mean 4.75 mm (range 3.15–6.35)) and ensure a final AHI score below the threshold of 20 (mean 12.9 events/hour). CONCLUSIONS: Although subgroup analysis showed MMA to be effective in treating OSA, more randomised trials are needed to individualise the required magnitude and direction of surgical movements in each patient, and to standardise the measurements of linear and nonlinear PAV parameters.