Three-dimensional analysis of changes in airway space after bimaxillary orthognathic surgery with maxillomandibular setback and their association with obstructive sleep apnea

Abstract

BackgroundBimaxillary orthognathic surgery with maxillomandibular setback is often accompanied by changes in airway space. We analyzed the changes in airway space before and after surgery and assessed their association with obstructive sleep apnea.MethodsThis study is based on the cohort of 13 adult patients (9 males, 4 females, average age 23.85 years) who underwent bimaxillary orthognathic surgery with maxillomandibular setback.We performed computed tomography and portable polysomnography before and after the surgery to assess changes in airway space and Apnea-Hypopnea Index (AHI) values (total, supine, non-supine).ResultsThe oropharyngeal airway volume decreased by 29% after the surgery, which was statistically significant (p < .05). The upper airway volume and hypopharyngeal airway volume were decreased, but not significantly (4 and 19%, respectively). The changes in airway surface area were statistically significant at all levels examined (p < .05). Changes in the maximum anteroposterior width of the airway were also significant at all levels (p < .05). However, the changes in maximum lateral width were only statistically significant at C2 level (p < .05). AHI values were increased after the surgery but not significantly at any position.ConclusionsAlthough bimaxillary surgery with maxillomandibular setback significantly reduces the airway space, it does not affect AHI values or induce obstructive sleep apnea.

Gender-specific cephalometric features related to obesity in sleep apnea patients: trilogy of soft palate-mandible-hyoid bone

“…Obstructive sleep apnea (OSA) refers to sleep-disordered breathing showing repetitive episodes of upper airway collapse during sleep [1]. The risk factors for OSA have been reported as old age, male, smoker, alcohol use, obesity, and craniofacial abnormality [2–6]. Therefore, the pathogenesis of OSA may be related to altered anatomy (small box) and physiology (increased collapsibility) of the upper airway.…”

Why most patients do not exhibit obstructive sleep apnea after mandibular setback surgery?

“…When mandibular setback was performed with maxillary advancement or posterior impaction, the pharyngeal airway volume significantly decreased. However, it did not significantly affect AHI values or induce OSA [6].…”

“…The TPV was decreased to 82.0~96.8% in the short term after surgery and recovered to 84.5~98.0% around 6 months after surgery (Table 2). However, the degree of airway reduction was smaller than that in mandibular setback surgery alone [6,14,16,25,26]. Immediately after surgery, airway narrowing was more severe because of soft tissue edema.…”

“…According to World Health Organization definitions, BMI ≥ 30 kg/m 2 can be defined as obesity, and BMI 25-29.9 kg/m 2 can be defined as overweight [31]. Since the most of the studies on airway changes after mandibular setback surgery frequently included non-obese or non-overweight (BMI < 25) and non-OSA patients before surgery, it can be hypothesized that there may be a lower risk of OSA development among these patients [3,6,16,20,21,23,26,28,29,32] (Table 3).…”

Comparing Outcomes of Airway Changes and Risk of Sleep Apnea after Bimaxillary Orthognathic Surgery and Mandibular Setback Surgery in Patients with Skeletal Class III Malocclusion: A Systematic Review and Meta-Analysis

“…A three-dimensional (3D) PAS volume showed a significant decrease in the oropharyngeal airway, and no significant change has been observed in the sleep symptoms [8]. Reports indicated that bimaxillary orthognathic surgery to reduce PAS played a role, but it does not increase AHI, one of the important determinants of sleep apnea [18,19,21,23]. As a result of a significant decrease in the airway space, it did not influence the AHI-values or cause OSA.…”