研究背景
咽腔是一段受自身张力及周围组织影响的肌性管腔结构，在呼吸和吞咽过程中
承担重要的生理作用。 研究认为， 颅面部结构发育异常如小颌畸形、 下颌骨发育不
良、 面中部凹陷等均可引起咽腔容积和形态的变化[1, 2]。 基于此， 临床医师在进行
颌面外科专科检查时不仅会对患者上呼吸道功能进行评价， 同时也关注颅面形态的
变化对上呼吸道咽腔形态的影响[3]。半侧颜面短小畸形（ Hemifacial microsomia,
HFM）是一种先天下颌骨发育不良颅面畸形，其临床特点为单侧或双侧下颌骨发育
不良， 同时累及其他器官或组织， 如小耳畸形， 面部软组织发育不良， 面神经受损
和眼眶畸形等[4]。 由于半侧颜面短小的下颌骨形态学特点， 大多数学者认为 HFM 患
者比普通人更可能患有睡眠呼吸暂停综合征[5, 6]。
CT 作为三维重建的影像学基础， 可比二维影像学技术提供更直观、 更有效的立
体空间解剖信息，是广泛应用于颅面外科的辅助检查手段。 利用 CT 影像学资料进
行三维重建， 可清晰地显示 HFM 患者咽腔结构及周围软、 硬组织之间的关系， 同时
利用术前术后 CT 资料的对比， 可有效显示 HFM 患者 MDO 治疗前后咽腔结构、形态
的变化。 睡眠呼吸监测（ Polysomnography， PSG） 是睡眠医学的基础检查技术， 也
是对睡眠-呼吸功能评价的金标准，可有效反应被检查者的上呼吸道功能[7]。结合
呼吸、 心电技术的睡眠功能监测又叫多导睡眠呼吸监测， 可准确描述在有效睡眠范
围内被检查者呼吸与不同睡眠分期的关系。 尽管有研究针对半侧颜面短小患者咽腔
结构进行了形态学描述[8]， 但是对不同分型下 HFM 咽腔结构特点国内外尚无报道。
同 时 ， 目 前 研 究 对 接 受 了 下 颌 骨 牵 张 成 骨 (Mandibular osteogenesis
distraction, MDO)治疗的HFM咽腔结构形态及睡眠呼吸监测结果的变化报道较少[9,10]
。 Pourtaheri N 等[10]对 5 例接受 MDO 治疗的 HFM 患者咽腔形态结构进行了分析，
研究结果表明 MDO 增大了 HFM 患者咽腔容积及表面积，但该研究中病例数目较少，
缺乏统计学证据。 Baugh AD 等[9]曾对 9 例 HFM 患者进行呼吸睡眠监测检查结果进行
分析， 研究结果显示 HFM 合并 OSA 具有高二氧化碳分压和低血氧饱和的特点。 但是，
研究未对咽腔结构及治疗后的 HFM 患者进行功能学分析。 因此， 目前国内外缺乏对
HFM 咽腔形态及 MDO 术后咽腔形态结构变化的系统性研究。基于此，通过系统性研
究分析不同分型 HFM 患者的咽腔形态特点及手术治疗对咽腔形态及功能的影响， 在
临床制定治疗计划时对咽腔进行详细评估， HFM 患者将获得更好的治疗效果[11]。
研究目的
对 3-15 岁儿童[12, 13]HFM 病例影像学资料进行研究， 测量、 分析不同 Pruzansky
分型下 HFM 患者咽腔结构特点。同时通过对 MDO 术前术后影像学资料的对比研究，
分析总结 MDO 治疗对 HFM 患者咽腔结构及舌骨位置的影响。 通过对完善了呼吸睡眠
监测检查的 HFM 患者进行功能学参数分析， 研究 MDO 治疗对 HFM 上呼吸道功能的影
响。
研究方法
选取自 2009 年至 2020 年间就诊于中国医学科学院整形外科医院颌面整形一中
心的单侧发病的 HFM 患者， 其中第一部分收集病例 66 例， 第二部分病例 32 例， 第
三部分病例 8 例。
第一部分研究选取 66 例单侧发病 HFM 患者头颅螺旋 CT 数据， 导入 Mimics
17.0 软件中建立咽腔模型， 对不同分型下 HFM 患者咽腔的鼻咽、 口咽、 喉咽的容积、
长径、 表面积、 最窄横截面积、 平均横截面积、 特定横截面的前后径及左右径进行
测量分析。
第二部分回顾性研究 32 例 MDO 治疗 HFM 患者的术前头颅螺旋 CT 资料及术后头
颅螺旋 CT 资料，测量咽腔相关形态、舌骨空间位置和下颌骨形态参数， 分析 MDO
对 HFM 咽腔结构、 舌骨位置和下颌骨形态的影响。 同时通过对入组患者头颅侧位平
片行头影测量， 对 MDO 术后舌骨-眶耳平面距离进行评价。
第三部分分析 8 例接受睡眠呼吸监测（ Polysomnography， PSG） HFM 患者术前
术后 PSG 资料， 对 MDO 治疗前后呼吸暂停低通气指数（ AHI）， 氧减指数（ ODI）， 最
低血氧饱和度（ LSO2），平均血氧饱和度（ MSO2），最长呼吸暂停事件时间（ LAT），
平均呼吸暂停事件时间（ MAT）进行统计分析。
上述研究数据使用皮尔逊相关系数、费舍尔精确检验、 配对样本 t 检验，威尔
科克森符号秩和检验等统计学方法进行分析。
结果
鼻咽部测量数据显示， I、 II 和 III 型鼻咽形态学和横截面形态测量数据无组
间差异（ P>0.05）； 口咽部测量数据显示， I 与 III 型进行组间比较时， I 型患者平均横截面积（ P=0.037） 和最窄横截面积（ P=0.017） 较 III 型更大， II 型与 III 型
患者各口咽形态学数据无组间差异（ P>0.05）。口咽部横截面形态测量显示前后径
在 I、 II、 III 型逐渐减小（ P=0.05）； 喉咽部测量结果显示， I、 II、 III 型形态学
长度、 容积、 表面积存在组间差异， I、 II、 III 型喉咽部测量结果显示长度、 容积
和表面积逐渐减小。喉咽部横截面形态学参数未发现统计学差异。
MDO 术后， HFM 患者鼻咽、 口咽和喉咽在容积（ V） 表面积（ SA）、 平均横截面积
（ Mean-CSA） 和最窄横截面积（ Min-CSA） 均较术前明显增加。 MDO 术后测量结果显
示，舌骨至第三颈椎的距离（ H-C3）较术前显著增加（ P<0.01）；同时， 舌骨到
Frankfort 平面距离在治疗后明显增加（ P=0.004）。以下颌骨及颈椎作为参考标志，
测量结果显示 MDO 术后舌骨呈向前下方移动。 在 MDO 治疗后， 下颌弓宽度较术前增
加（ P<0.01）； 同时，健侧下颌骨体部长度较术前增加（ P<0.01），而患侧下颌骨体
部长度在术前术后未发现治疗前后差异（ P=0.352）。
MDO 术后， HFM 患者最低血氧饱和度较术前明显改善（ P=0.038）， AHI 较术前降
低， 在统计学分析中表现为弱相关性（ P=0.053）。 氧减指数、 平均呼吸暂停事件时
长、最长呼吸暂停事件时长和平均血氧饱和度未发现存在统计学差异。
结论
不同分型 HFM 患者咽部形态结构特点： 1.不同分型间鼻咽部上呼吸道形态参数
未见差异； 2.随着下颌骨发育不良严重程度的增加，口咽和喉咽部容积、表面积、
平均横截面积逐渐缩小。 MDO 术后咽腔不良形态得以改善，舌骨位置向前下方移动，
同时下颌弓宽度增加， HFM 患者最低血氧饱和度和 AHI 明显改善。 MDO 对改善 HFM
患儿咽腔形态与通气功能有积极的临床意义。
 

Background
The pharynx is one muscular duct structure affected by its own tension and surrounding
tissues, which plays an important physiological role in the process of respiration and
swallowing. It is widely accepted that the craniofacial abnormalities such as micrognathia,
mandibular dysplasia or mid-facial dysplasia could change the volume and morphology of
pharynx. Thus, clinicians not only assess the upper respiratory airway function of patients
in maxillofacial examination but also pay attention to the influence of craniofacial
morphology on the pharyngeal structures. Hemifacial microsomia (HFM) is a kind of
craniofacial malformation with hypoplasia of the mandible. The clinical features are
unilateral or bilateral hypoplasia of the mandible and the undeveloped soft tissue in the
suffering side. According to the morphology of undeveloped mandible, there are four types
of HFM based on the Pruzansky-Kaban classification including I， IIa， IIb and III type.
Also, it is believed that the HFM patients are more likely to suffering from the apnea
syndrome comparing with normal individuals.
As the basis of three-dimension reconstruction, computed tomography (CT) can provide
more effective anatomical information than two-dimensional imaging technologies. After
reconstruction with CT scan, the relationship between pharyngeal cavity structure and
surrounding tissues can be clearly displayed in the software. At the same time, the
comparison of preoperative and postoperative CT scans can effectively show the changes
of pharyngeal morphology after mandibular distraction osteogenesis (MDO).
Polysomnography (PSG) is one of basic examination technology of sleep medicine and
was seen as the gold standard of sleep respiratory function evaluation. With the sleep
monitoring and ECG technology, the PSG can describe the relationship between
respiration and different sleep stages within the effective sleep ranges. Although previous
studies have described the pharyngeal characters of patients with hemifacial microsomia,
there were few reports on the pharyngeal characters between different types of HFM. Also,
there were few reports about the influence of mandibular distraction osteogenesis on
pharyngeal morphology and the functional examinations. Pourtaheri N et al analyzed the
morphology and structure of pharynx with 5 HFM cases treated with MDO. The results
showed that MDO increased the volume and surface area of the pharynx in HFM patients,
but the number of cases in this study was small and there was no statistical analysis in the
report. Baugh AD et al has analyzed the results of PSG in 9 HFM cases. The results showed
that HFM combined with OSA has the characteristics of high carbon dioxide partial
pressure and low oxygen saturation. However, the study did not analyze the structure of
pharynx and the changes after MDO. Therefore, if the study makes a detailed analysis of
the pharyngeal morphology and functional evaluation between different types, it may be
obtained better clinical outcomes after treatment.
Objective
Through the study of imaging data and PSG of HFM patients aged from 3 to15, the
pharyngeal morphology of HFM patients with different types were calculated and analyzed.
In addition, with the comparative research of preoperative and postoperative imaging data,
we analyzed the influence of MDO on pharyngeal morphology and hyoid bone position of
HFM patients. Finally, by analyzing the functional parameters of HFM patients who
accepted the PSG, the effect of MDO on the upper airway function of HFM was evaluated.
The purpose of this study is to evaluate the influence of MDO on HFM pharynx and help
plastic surgeons to make reasonable treatment plan to HFM patients.
Method
This study selected HFM patients with unilateral subgroup who seek the consulation to the
department of maxillofacial plastic surgery, plastic surgery hospital of Chinese Academy
of Medical Sciences from 2009 to 2020. The first part of the study involved 66 cases, the
second part involved 32 cases, and the third part involved 8 cases.
The first section: Selected 66 CT scans of unilateral HFM patients who have not received
treatment were imported the software. Pharyngeal model of HFM patients was established
in Mimics 19.0 software. The volume(V), length(L), surface area (SA), minimum crosssectional area (Min-CSA), mean cross-sectional area (Mean-CSA), anterior posterior
width (AP) and lateral width (LAT) of the pharynx of HFM patients with different types
were measured and analyzed in Mimics 19.0.
The second section: Retrospective study was undertaken by analyzing 32 cases of HFM
patients accepted MDO treatment. The morphological parameters of the pharynx were
measured and the effect of MDO on the pharyngeal structure of HFM was analyzed. The
height of hyoid bone in the vertical direction was measured.
The third section: 8 patients with HFM who received PSG were analyzed retrospectively.
According to the PSG reports, the apnea hypopnea index (AHI), oxygen desaturation index
(ODI), lowest oxygen saturation (LSO2), mean oxygen saturation (MSO2), longest apnea
event time (LAT) and mean apnea event time (MAT) were statistically analyzed before
and after MDO treatment.
Pearson correlation coefficient, Fisher exact test, paired sample t test, Wilcoxon signed
rank sum test and other statistical methods were used to analyze the above data.
Results
1. In the nasopharynx, there was no significant difference in the morphological parameters
between type I, II and III (P > 0.05). The oropharyngeal measurement data showed that the
average cross-sectional area (P = 0.037) and narrowest cross-sectional area (P = 0.017) in
type I patients were larger than those parameters in type III patients, and there was no
statistical significance in oropharyngeal morphological data between II and III groups (P >
0.05). In the measurement of cross-sectional morphology, the AP and LAT results showed
the decreased trend from I to III groups. In the laryngopharyngeal section, the length,
volume and surface area were decreased from I to III groups according to the data. And no
statistical difference was found in laryngopharyngeal cross-sectional morphological
parameters.
2. After MDO, the nasopharyngeal, oropharyngeal and laryngopharyngeal parameters of
HFM patients were measured. There were significant differences in area (SA), mean crosssectional area (mean-CSA) and minimum cross-sectional area (min-CSA) compared with
preoperative parameters showing the increase trend after MDO.The distance from hyoid
bone to the third cervical vertebra (H-C3) had found significant increased after MDO
treatment(P<0.01).At the same time, there was a significant difference in the distance
between hyoid bone and Frankfort plane before and after treatment showing the longer
distance after MDO (P = 0.004).With the mandible and cervical vertebra were used as
reference system, the hyoid bone position was found moving forward and lower after MDO.
3. The lowest oxygen saturation of HFM patients was found significantly improved after
treatment (P = 0.038), while AHI was found weakly correlated in the study (P = 0.053).
There was no significant difference in oxygen desaturation index, mean apnea duration,
longest apnea duration and mean oxygen saturation.
Conclusion
In the measurement of parameters in pharynx of HFM patients, there was no difference
between groups in nasopharyngeal section. With the measurement in different types of
HFM patient pharyngeal section, the outcomes of V, SA and mean-CSA of oropharyngeal
and laryngopharynx showed the decreasing trend from I to III groups. MDO can affect the
morphology of pharyngeal and mandibular morphology in HFM patients, which was
related to the spatial position of hyoid bone. MDO can improve the lowest oxygen
saturation and reduce the sleep apnea index in HFM patients during sleep showing the
positive effect of MDO.