目的

1、探讨数字化技术在半侧颜面短小畸形手术治疗和术后临床效果评价中的应用。

2、探讨通过将数字化技术应用于牵引成骨术中矫治半侧颜面短小畸形，术后患者对称性的改变及术后患者对称性与正常人对称性的比较分析。

3、探讨在数字化技术辅助下，应用口内入路的改良内置式牵引成骨和口外入路的内置式牵引成骨矫治半侧颜面短小畸形的临床效果对比分析。

方法

选取2011年1月至2017年5月就诊于我院颌面整形外科中心的半侧颜面短小畸形患者共18例。其中9例（C组）应用口内入路的改良内置式牵引成骨矫治半侧颜面短小畸形，9例（D组）应用口外入路的内置式牵引成骨矫治半侧颜面短小畸形，用于这两种牵引成骨方法矫正半侧颜面短小畸形的临床效果比较。再根据入组标准选取上诉18例中的14例（A组）和正常人对照组21例(B组)，用于比较经牵引成骨术后患者对称性的改善及与正常人对称性的比较分析。

1、将研究对象的CT数据导入数字化软件平台ProPlan中进行建模，标记骨组织标记点，建立三维坐标系，通过该软件对研究对象的面部硬组织进行精确测量和定量化分析来对比术前术后以及和正常人的比较，评估其对此性改善情况。

 2、术前通过数字化软件ProPlan重建患者的头颅模型，通过该软件可标出术中容易损伤的下牙槽神经和血管束的走行，将下颌骨模型通过3D打印机打印出来，模拟术中截骨方案。其中的9例应用口内入路的下颌升支矢装劈开截骨的方式进行截骨，并安置内置式牵引器（德国，Medicon）；另外9例应用口外入路的下颌升支全层截骨术进行截骨并安置内置式牵引器(中国，宁波慈北)。术后通过牵引器牵引患侧的下颌骨，改善患者面部的不对称畸形。

3、确定对称性的测量评价指标，将半侧颜面短小畸形患者自身术前术后对比、不同手术方式术后对比以及行牵引成骨术患者和正常人对照组的三维CT数据进行对比分析，计算各测量指标的变化情况，定量化分析半侧颜面短小畸形患者应用牵引成骨术后对称性的改善情况及比较口内入路的改良内置式牵引成骨术和口外入路的内置式牵引成骨术对半侧颜面短小畸形的临床效果。

结果

1、数字化技术的应用在半侧颜面短小畸形患者的治疗中有助于提升牵引成骨术的临床效果，方便进行临床效果的评价。

2、半侧颜面短小畸形患者行下颌升支牵引成骨术后面部硬组织对称性指标比较结果：半侧颜面短小畸形组内术前术后比较下颌骨的对称性，颏部对称性，上颌骨的对称性均获得明显改善（P<0.05），面中部与面中下部的比例术前术后也有显著改变（P<0.05）；但半侧颜面短小畸形组术后与正常人对照组比较，在下颌骨的对称性，颏部对称性，上颌骨的对称性和面中与面中下比例上仍有显著性差异（P<0.05）。

3、两种手术方法均使得患者面部骨性对称性获得明显改善；临床指标比较结果：组内术前术后比较患侧下颌骨长度两组均获得明显的改善（P<0.05），但两种手术方式之间的比较，D组在延长上优于C组（P<0.05）；患侧下颌骨厚度C组和D组均获得明显改善（P<0.05），组间比较并没有统计学意义（P>0.05）；患侧下颌骨的宽度方面C组没有明显改善（P>0.05），D组下颌骨宽度反而明显缩窄（P<0.05），可见口内入路的改良内置式牵引成骨术在下颌骨宽度保持上有优势；颏偏距两组均获得明显改善（P<0.05）

结论

1、将数字化技术应用在半侧颜面短小畸形患者的治疗和评价中，能够提高手术精准性，使术后疗效评价定量化，利于提高半侧颜面短小畸形患者的临床治疗效果。

2、半侧颜面短小畸形的患者行下颌升支牵引成骨术后患者的面部对称性获得了明显改善，但术后距离正常人的面部对称性仍有较大差距。

3、应用两种牵引成骨术治疗半侧颜面短小均能明显改善患者面部骨性对称和患侧下颌骨升支的厚度，口内入路的改良内置式牵引成骨在患侧下颌升支宽度的保持上较外置式有优势，而口外入路的内置式牵引成骨在下颌升支长度改善方面占优势。因此临床上需要根据患者半侧颜面短小下颌升支严重程度选择合适的牵引成骨方法，力求最佳效果。

Objective:

  1. To discuss the application of digital technology in the clinical effect of distraction osteogenesis to treat hemifacial microsomia.

  2. To discuss the effect of distraction osteogenesis to treat hemifacial microsomia and to compare its facial symmetry with that of normal people with aid of digital technology．

  3. To measure and analyze changes of bone tissues before and after the two methods distraction osteogenesis treatment for hemifacial microsomia,and to compare the result of operation quantitatively of the two treatment methods with aid of digital technology．

Methods:

Selecte cases of 18 pationts with hemifacial microsomia treated at the Department of Maxillofacial Plastic Surgery,Plastic Surgery Hospital Chinese Academy of Medical Sciences from January 2013 to May 2017 for this study.Among which 9 pationts(Group C) were treated with the intraoral internal distraction osteogenesis with gittal split ramus osteonomy,the other 9 pationts (Group D)were treated with the extraoral internal distraction osteogenesis. According to enter criterions, we selected 14 case(Group A) from above 18 case and other 21 case（Group B）of people were normal. To compare the facial symmetry of hemifacial microsomia with that of normal people with aid of digital technology.

1.After the the CT data and three-dimensional facial scanning data of hemifacial microsomia patients were input into ProPlan to establish the three-dimensional coordinate system for measuring bone tissues，the anatomical landmarks would be marked to conduct accurate quantitative analysis of both side of face.Further,the morphological characteristics of facial asymmetry deformity would be discussed and the method for preoperative evaluation would be assured．

  2. Before the surgery,three-dimensional CT data were used to reconstruct bone tissues models．We marked the location of inferior alveolar neurovascular bundle and dental germs，on the basis of which an accurate operation design for osteotomy would be worked out．The distances and directions of distraction according to the asymmetry of the affected and unaffected sides will also be planned．9 pationts were treated with the intraoral internal distraction osteogenesis with gittal split ramus osteonomy,the other 9 pationts were treated with extraoral internal distraction osteogenesis. After surgery,the traction would be applied to lengthen the mandible and improve facial asymmetry．

  3. We used the three-dimensional measurement method to conduct pre-postoperative and nomal people’s comparative analysis of hemifacial microsomia patients,and calculated the changes of facial symmetrical indexes.Besides,We quantitatively analyzed the improvement of asymmetry of bone tissues in hemifacial microsomia patients who have undergone the two different distraction osteogenesis．

Results:

1.The application of digital technology in the treatment for hemiafacial microsomia can improve the patients’ clinical effect and evaluate it more conviniently.

   2. The facial asymmetry of mandibula, maxilla and chin was significantly improved compared with pre-operation in group of hemifacial microsomia (p<0.05), while the same indexes after operation in group of hemifacial microsomia still had significantly difference compared with that in group of normal people(p<0.05).

  3.The facial asymmetry was significantly improved in both groups compared with pre-operation.The length of mandibular ramus in group C and group D were both significantly improved compared pre-operation(p<0.05),while the group D was better than group C (p<0.05). The thickness of mandibular ramus were both significantly improved compared pre-operation(p<0.05),but there was no statistical significance between two groups (p>0.05). The width of mandibular ramus in group C was no significantly improved(p>0.05),while in Group D ,the width of mandibular ramus become smaller compared pre-operation(p<0.05). The distance from chin point to facial midline were significantly improved both in the two group(p<0.05).

.Conclusions：

1.The application of digital technology in the treatment and evaluation of hemifacial microsomia can improve the accuracy of surgery and analyze the the facial symmetry quantitatively．

2. The facial asymmetry of HFM was significantly improved after the operation of distraction osteogenesis,while the facial symmetry of HFM still have difference compared with normal people.

3. The facial asymmetry of hemifacial microsomia was significantly improved through the two methods of distraction osteogenesis,while the method of intraoral internal modified distraction osteogenesis has advantage in maintaining the width of mandibular ramus and the method of intraoral internal distraction osteogenesis has adwantages in extenning the length of mandibular ramus. Therefore,to acquire the best clinical effect,surgeons shoud select the suitable method according the acuity of patients with hemifacial microsomia.