Department of Ophthalmology, University of São Paulo, Ribeirão Preto, Brazil.
Sleep Breath. 2013 Mar;17(1):395-401. doi: 10.1007/s11325-012-0707-1. Epub 2012 May 6.
Maxillomandibular advancement (MMA) has been reported to be the most effective surgical treatment of obstructive sleep apnea (OSA). Most reports about MMA aim to confirm the efficiency of this treatment modality, but few describe the anatomical changes produced in the pharynx by the surgery. Thus, the objective of the present investigation was to quantify the anatomical changes of the pharynx that occur in patients with OSA after MMA surgery using magnetic resonance (MR).
Twenty patients with a polysomnographic diagnosis of OSA participated in the study. All patients were submitted to image acquisition by MR performed during wakefulness. Polysomnography and MR were performed preoperatively and 6 months after MMA. Volume analysis (in cubic millimeters) was performed as the sum of the areas multiplied by their thickness, with no intervals between sections. The pharyngeal air space of the region between the hard palate and the base of the epiglottis was divided into a retropalatal (RP) region and a retrolingual (RL) region.
Postoperative MR showed a mean volumetric increase of 26.72 % in the RP region and of 27.2 % in the RL region.
MMA increases the air space of the pharynx by expanding the facial skeletal structure to which the soft tissues of the pharynx and tongue are fixed, with a consequent reduction of collapsibility in the presence of negative pressure during inspiration. This reduced possibility of pharyngeal collapse may contribute to the reduction of obstructive events.
上颌骨前移（MMA）已被报道为治疗阻塞性睡眠呼吸暂停（OSA）最有效的手术方法。大多数关于 MMA 的报告旨在证实这种治疗方式的有效性，但很少有报告描述手术对咽解剖结构的改变。因此，本研究的目的是使用磁共振（MR）定量测量 OSA 患者接受 MMA 手术后咽的解剖结构变化。
20 例经多导睡眠图诊断为 OSA 的患者参与了这项研究。所有患者均在清醒状态下接受 MR 图像采集。术前和 MMA 术后 6 个月进行多导睡眠图和 MR 检查。体积分析（以立方毫米为单位）是通过面积乘以厚度的总和进行的，各层之间没有间隔。硬腭和会厌基底之间的咽区的咽腔空气空间分为后咽腔（RP）区和舌后咽腔（RL）区。
术后 MR 显示 RP 区的平均体积增加了 26.72%，RL 区增加了 27.2%。
MMA 通过扩展面部骨骼结构来增加咽腔的空气空间，而咽腔和舌的软组织固定在这个结构上，从而减少了吸气时负压引起的咽腔塌陷的可能性。这种减少的咽腔塌陷的可能性可能有助于减少阻塞性事件的发生。
