Three-dimensional assessment of upper airway changes following orthognathic surgery and skeletally anchored orthodontics: A systematic review

This systematic review critically evaluates the effects of orthognathic surgery and skeletally anchored orthodontic treatments on upper airway morphology in patients with obstructive sleep apnoea syndrome (OSAS), with particular emphasis on biomechanical mechanisms and methodological limitations. A structured search of PubMed, Scopus, and Web of Science identified 13 human studies published between 2010 and 2025 that met predefined inclusion criteria. Maxillomandibular advancement consistently produced the most stable and clinically relevant airway improvements, primarily through coordinated skeletal repositioning and soft tissue tensioning rather than volumetric enlargement alone. Mandibular setback demonstrated a dose-dependent reduction of lower pharyngeal dimensions, while transverse maxillary expansion mainly affected the nasal cavity with limited impact on the collapsible pharyngeal airway. Considerable heterogeneity in imaging protocols, segmentation methods, and outcome measures limits direct comparison among studies and weakens correlations between anatomical and functional outcomes. Overall, the evidence supports a shift from a purely volumetric interpretation of airway change toward a biomechanical and functional framework emphasizing airway geometry, stability, and neuromuscular adaptation. Standardized three-dimensional imaging integrated with polysomnographic outcomes is required to better define the role of craniofacial interventions in OSAS management.