Use of 3-dimensional computed tomography scan to evaluate upper airway patency for patients undergoing sleep-disordered breathing surgery

Abstract

Modification of palatal surgery to increase the lateral dimension of the RP may be a breakthrough in increasing its success rate.

A comparative CT evaluation of pharyngeal airway changes in class III patients receiving bimaxillary surgery or mandibular setback surgery

“…Schwab 34 proposed that the retropalatal region in patients with OSA was narrowed in the lateral aspect and the contrary, the retropalatal region in nonapneic people was narrowed in the AP dimension 34 . Li et al 20 reported that lateral narrowing of retropalatal region was closely associated with the degree of sleep apnea in their study 20 . In our study, average rate of lateral pharyngeal narrowing was 12% and 7% at the level of SP-PPW and BoT-PPW, respectively in mandibular setback surgery group while it was 5% and 2% at the level of SP-PPW and BoT-PPW, respectively, in bimaxillary surgery group.…”

“…Skeletal maxillary and mandibular changes may be described by the change in the sagittal dimension only, whereas the soft tissue pharyngeal changes must be considered in a 3D way 7 . CT scan is a noninvasive technique that permits a detailed 3D assessment of the entire upper airway and has been validated for quantitative measurements of the pharyngeal CSA 20 . Kawamata et al 8 …”

“…Mehra et al 18 A number of studies have also shown that diminished CSA of the pharynx may predispose a person to pharyngeal collapse 20,22,24,25 In our study, however, postoperative PAS CSA decreased at both levels evaluated in all patients, regardless of type of surgery performed, either mandibular setback surgery or bimaxillary surgery, the decreases were less in cases treated with bimaxillary surgery than mandibular setback surgery (p<.05) and any of the patients complained about any symptoms of pharyngeal collapse. The reason of absence of complains about any symptoms of pharyngeal collapse might be the larger AP dimensions and theoratically larger CSA dimensions related to AP dimension-.…”

“…Some studies suggested that ethnicity also was an important factor in OSA [20][21][22] . Li et al 35 reported that many Far East Asian subjects had greater severity of OSA syndrome 35 Although many of the cephalometric measurements are less abnormal in the Far East Asian subjects, the cranial base dimensions were significantly decreased, thus, potentially contributing to narrowing of the airway between uvula and PPW [35][36] However, in our study, we did not observe any significant narrowing at the level of SP-PPW preoperatively, CSA at the level of SP-PPW was the most narrowing part of the entire airway in both groups postoperatively.…”

“…Several studies have used CT to evaluate the airway in patients with OSA [20][21][22][23] . However, the information within the CT image data includes both hard and soft tissue structures, it allows visualization of the pharyngeal airway without any obstruction of bony tissue structures 8 The purpose of this study was to evaluate and compare the 3D morphologic changes in pharyngeal airway in Japanese patients with class III deformities who underwent bimaxillary surgery or mandibular setback surgery with CT imaging.…”