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Airway cephalometric change following mandibular setback surgery: a review article

Background and Aim: mandibular setback surgery is one of the common treatments in patients with mandibular prognathism. In this surgery, the mandible is placed backward from its original position, and as a result, the soft tissue, tongue, and hyoid bone are slightly displaced, all of which can affect the dimensions of the airway. Given that these changes in the dimensions of the airway can lead to obstructive sleep apnea, it is important to examine these changes and their stability. In this regard, cephalometric radiography can be used, which haslowcost and dose in comparison to 3D radiographs, to examine changes in airway dimensions. The aim of this study was to evaluate the short-term and long-term changes in airway dimensions following mandibular steback surgery with the help of cephalometric radiography. 
Methods: The study was conducted by review method. Using the keywords 'orthognathic surgery,' 'mandibular setback,' 'Malocclusion angle class III,' 'prognathism,' 'airway,' 'posterior airway space,' 'PAS,' 'pharyngeal space, 'hypopharynx, a review of articles in PubMed and Embase databases, Google Scholar, and Cochranedatabases was performed. The range of article searches was from 2000 to 2020. 
Conclusion: The results of studies showed that in the first 6 months after surgery, the dimensions of the airway decrease, but over time, due to the adaptation of the surrounding tissues and relapse after surgery, there is an improvement in the dimensions of the airway; Also, the study of index-related breathing disorders during sleep disorders during sleep showed that this surgery does not necessarily lead to obstructive sleep apnea.