Craniofacial morphology in patients with obstructive sleep apnea: cephalometric evaluation

Abstract Introduction: Obstructive sleep apnea is characterized by a reduced airflow through the upper airways during sleep. Two forms of obstructive sleep apnea are described: the central form and the obstructive form. The obstructive form is related to many factors, such as the craniofacial morphology. Objective: To evaluate the correlation between the morphology of the cranial base, of the mandible and the maxilla, and obstructive sleep apnea severity. Methods: Eighty-four patients, mean age of 50.4 years old; 73 males and 11 females with obstructive sleep apnea were enrolled in the present study. Patients with high body mass index and comorbidities were excluded. Lateral cephalograms and polysomnography were collected for each patient to evaluate the correlation between craniofacial morphology and obstructive sleep apnea severity. A Spearman’s rho correlation test between cephalometric measurements and obstructive sleep apnea indexes was computed. Statistical significance was set at p < 0.05. Results: Patients with a severe obstructive sleep apnea presented a reduction of sagittal growth of both effective mandibular length and cranio-basal length. The mandibular length was the only variable with a statistical correlation with apnea-hypopnea index. Vertical dimension showed a weak correlation with the severity of obstructive sleep apnea. No correlation with maxillary sagittal dimension was shown. Conclusion: Obstructive sleep apnea severity may be correlated to mandibular and cranial base growth. Facial vertical dimension had no correlation with obstructive sleep apnea severity.

摘要与引言：阻塞性睡眠呼吸暂停（obstructive sleep apnea）以睡眠期间上气道气流减少为特征。目前已明确两种阻塞性睡眠呼吸暂停分型：中枢型与阻塞型。其中阻塞型与多种因素相关，例如颅面形态。
研究目的：评估颅底、下颌骨及上颌骨形态与阻塞性睡眠呼吸暂停严重程度之间的相关性。
研究方法：本研究纳入84例阻塞性睡眠呼吸暂停患者，平均年龄50.4岁，其中男性73例、女性11例。排除存在高体质量指数及合并基础疾病的患者。为每位患者采集头颅侧位片（lateral cephalograms）与多导睡眠监测（polysomnography）数据，以分析颅面形态与阻塞性睡眠呼吸暂停严重程度的相关性。采用斯皮尔曼rho相关性检验（Spearman’s rho correlation test）对头影测量指标与阻塞性睡眠呼吸暂停相关指标进行相关性分析，设定统计学显著性阈值为p<0.05。
研究结果：重度阻塞性睡眠呼吸暂停患者的有效下颌骨矢状向生长长度及颅底长度均存在缩短。下颌骨长度是唯一与呼吸暂停低通气指数（apnea-hypopnea index）存在统计学相关性的变量。垂直向维度与阻塞性睡眠呼吸暂停严重程度仅呈弱相关。而上颌骨矢状向维度未显示出相关性。
研究结论：阻塞性睡眠呼吸暂停的严重程度可能与下颌骨及颅底生长状态相关。面部垂直向维度与阻塞性睡眠呼吸暂停严重程度无相关性。