The structural changes of upper airway and newly developed sleep breathing disorders after surgical treatment in class III malocclusion subjects

Abstract

Bimaxillary surgery is the traditional treatment of choice for correcting class III malocclusion which is reported to cause an alteration of oropharyngeal structures and upper airway narrowing that might be a predisposing factor for obstructive sleep apnea (OSA). This study aimed to analyze sleep parameters in class III malocclusion subjects and ascertain the prevalence of snoring or OSA following bimaxillary surgery.A total of 22 patients with Le Fort I osteotomy and mandibular setback for class III malocclusion were prospectively enrolled. All patients received endoscopic examination, cephalometry, 3-dimensional computed tomography (3D-CT), and sleep study twice at 1 month before and 3 months after surgery.The patient population consisted of 5 males and 17 females with a mean body mass index of 22.5 kg/m2 and mean age of 22.1 years. No patients complained of sleep-related symptoms, and the results of sleep study showed normal values before surgery. Three patients (13%) were newly diagnosed with mild or moderate OSA and 6 patients (27%) showed increased loudness of snoring (over 40 dB) after bimaxillary surgery. According to cephalometric analysis and 3D-CT results, the retropalatal and retroglossal areas were significantly narrowed in class III malocclusion patients, showing snoring and sleep apnea after surgery. In addition, the total volume of the upper airway was considerably reduced following surgery in the same patients.Postoperative narrowing of the upper airway and a reduction of total upper airway volume can be induced, and causes snoring and OSA in class III malocclusion subjects following bimaxillary surgery.

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

“…In contrast, the study by Lee et al [ 14 ] showed a decrease in airway space and increase in AHI after bimaxillary orthognathic surgery, with the average maxillary setback and mandibular setback of 1.01 ± 1.54 mm and 8.23 ± 3.59 mm, respectively. The difference between these studies is thought to come from the difference in maxillary movement (5 ± 2.2 mm and − 1.01 mm) despite a similar mandibular setback amount.…”

Change of the upper airway after mandibular setback surgery in patients with mandibular prognathism and anterior open bite

“…Some of the earlier studies did not report any significant changes being present in the airway space after MS [9, 23, 24]. Several other studies performed using CT, however, suggested that PAS was significantly decreased after MS [2, 3, 10–13, 25–27]. For example, Lee et al achieved a decrease of 14.07% in the total volume following a mean MS of 9.20 mm [11], while Kim et al reported a decrease of 15.80% in total PAS and decreases of 22.08%, 8.10%, and 12.43% in the oropharynx, nasopharynx, and hypopharynx, respectively, after a mean MS of 8.25 mm [28].…”

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.…”