李继华医生的科普号

患者：大夫您好， 我想请问一下 可能是我颞骨宽度比较大 使得颧弓和下颌骨都比较大 使得脸型又大有宽 ，完全是大方脸，我想请教大夫 现在整形医学技术能不能改变颞骨的宽度，颧骨颧弓内推的极限是什么? 下颌升支颞颌关节能否缩小? 我是属于颞骨突出, 使得鬓角那部分的骨头突出可是我不知道那是颧弓根还是还是下颌升支，或关节。华西口腔正颌外科李继华：颧弓上方的宽度即两侧太阳穴之间的宽度由颞骨表面附着的颞肌厚度决定，下颌角截除或颧弓内推后可造成部分颞肌萎缩，但常发生在术后3月到2年。颧弓内推的极限决定于颧弓和下颌骨喙突之间的距离，颧弓内推只要不妨碍下颌骨喙突的运动，可以达到极限值。临床上诊断外伤性颧骨骨折是否需要手术复位的最基本原则就是颧骨骨折片是否已压迫下颌骨喙突，影响下颌骨喙突的运动。颞颌关节位置的宽度可稍稍削去骨表面的少许骨皮质，但宽度改善有限。过多的削除骨质，会造成颞颌关节功能不稳定，颞颌关节囊的结构性破坏。不建议过多改变这一区域的结构。

在东亚地区，部分人群由于下颌角肥大导致面下1/3过宽，面部轮廓呈方形即所谓方颌，传统审美观普遍认为这种面型缺乏东方女性的柔美感而青睐“瓜子脸” 或“鹅蛋脸”。目前，受影视等时尚因素影响，面型不佳而求美者日渐增多，因此下颌角成形术已成为现代面部轮廓美容整形外科的一项重要内容。我科通过颜面美学研究的基础上提出了方颌的外科矫正原则：新形成的下颌角应具有自然、协调而流畅的轮廓，不但面部在正、侧面观都符合大众美容标准，还要兼顾求治者的个人审美要求。为此，我们将下颌骨作为整体进行美学评价、精确分类并综合矫治，灵活运用下颌角弧形截骨术、下颌外板劈开切除术，并发展了“V-line”截骨术、颏部滑行缩窄术等术式对面部进行全方位轮廓整形与重塑，使患者的下颌轮廓外形达到理想美容效果。在此领域，本科室已在国际整形美容外科核心期刊如PRS，JPRAS，APS，JCMFS,OOOOE,中华整形外科杂志等发表了系列论文。 下颌角“V-line”截骨术 下颌角成形术前后对比图 下颌角成形术前后对比图

【摘要】目的 在东亚人群中，长方形和方形的脸型给人以粗犷和男性化特征而往往不受人喜欢，因此很多东方人通过接受各整形手术以获得柔美而和谐的面部轮廓。然而，很少有文献研究报道长方形或者不对称脸型（无论有无方颌）患者的面部轮廓整形。因此，本文探讨全部或部分下颌下缘截骨术在该类患者下颌轮廓整形中的适应证和效果。方法 从2005年到2011年，共有34名患者接受了全部或者部分下颌下缘截骨术以矫正不协调或不对称的面部轮廓。结果 所有34名患者术后面形长度和宽度有效减小，下颌轮廓改良达到预期效果，不对称明显得到明显纠正，医患双方都对外形美观评价满意。结论 通过运用全部或者部分下颌下缘截骨术可以改善长方形或不对称的面部轮廓外形并且获得符合东方人审美的协调，流畅的面部轮廓。【关键词】：下颌轮廓整形；下颌下缘截骨术；适应症Total or partial inferior border ostectomy for mandibular contouring: indications and outcomes【Abstract】 Objective Among the East Asian population, A long or square face produces a characteristic coarse and masculine appearance and is therefore considered undesirable and unattractive. So, many Orientals pursue harmonious contour of face by undergoing various cosmetic surgeries. However, the mandibular contouring for a long or asymmetrical face with/without square jaw is rarely reported in the literature. Thus, the objective of this study was to investigate the feasibility and effectiveness of total or partial inferior border ostectomy for mandibular contouring and to discuss its indications. Methods From July 2005 to November 2009, there were 34 patients in this study who received mandibular contouring by total or partial inferior border ostectomy procedure to correct a disharmonious facial contour. Result Postoperative appearance of all 34 cases showed that the length of lower 3rd of the face and the width of the mandible were decreased effectively, and the mandibular contour was improved expectedly. The final aesthetic outcomes were quite satisfactory for both the surgeons and the patients. Conclusions The results suggests thatthe facial contour could be improved by using total or partial inferior border ostectomy of the mandible thus achieving a harmonious facial outline based on the East Asians aesthetics.【Key words】 mandibular contouring; inferior border ostectomy; indications在东方文化中，人们特别是女性更加喜欢一个卵圆形的面部轮廓，该脸型显得柔和而有亲和力。而长方形和方形脸显得粗犷并且有男性化倾向，因而常常不受人喜欢。所以，许多东方人通过接受各种整形手术去追求柔美而和谐的面部轮廓外形。在1880年Legg的首次报道咬肌肥大切除术后许多学者试图通过各种技术矫治方颌面型[1-8]。但是现有文献很少有报道长方形或者不对称脸型（无论有无方颌）的面部轮廓整形手术方法。在此所谓的“长方形脸型”是指面下1/3过长而宽大，但不伴咬合关系异常，该面形在东方人中较常见。传统的面部轮廓整形更侧重于下颌宽度的减少[4]而较少关注面部垂直比例的协调，这在长方形脸型轮廓矫治中可能宽度缩窄了，而长度没有得到有效改善。因此，我们应用全下颌下缘截骨术矫正长的或者呈方形的面部轮廓。该术式可以有效地缩减下颌轮廓的宽度和长度，增大下颌平面角和下颌角开张度，使下面部比例匀称，协调。由于下颌角和下颌下缘发育程度不一导致的面部轮廓不对称也常常在东方人群中出现。这种面部不对称与其他面部不对称往往不同，其咬合关系往往是正常的而不是倾斜的，而且没有牙中线不齐的情况。因此，不必要采取正颌外科的治疗程序来矫正面形偏斜。我们运用局部的下颌下缘截除术配合外板劈除术来矫正此类面廓不对称，达到较为理想的治疗效果。1．临床资料从2005年1月到2011年12月，共有34名患者接受了全部或部分下颌下缘截骨术以矫正长方形或者不对称的脸型。年龄从20到31岁，在这些患者中14人下颌下缘不对称，另20人属于长方形的面型”。术前应仔细检查测量面廓特征，由于目前下颌轮廓的审美标准还没有完全一致的观点。因此，在设计手术方案时，患者自身的审美要求也要仔细地考虑。而且，当制定下颌轮廓矫治方案时，整个下颌外形都要从三维方向和各个视角都需要加以充分评估和考量。术前需要与患者充分沟通了解其美容诉求并取得一致意见。手术方案和截骨线在头影测量正、侧位片和全景片上进行初步确定。基于三维CT数据的快速成型的树脂颅面骨骼实体模型被用来设计和确定截骨线的位置和方向。该截骨线设计时应避免损伤下牙槽神经血管(图.1)。2．手术方法我们先以全下颌下缘截骨术为例。所有患者采用经鼻腔气管内插管全麻，在口内切开完成所有手术操作。在局部浸润注射1:200000肾上腺素生理盐水溶液后，切口设计是从咬合平面的下颌升支外侧面沿着下颌外斜线颊侧直达下颌中切牙的唇侧粘骨膜，切透并剥离粘骨膜完全暴露下颌骨外侧骨皮质及颏部。当剥离双侧颏孔区时应小心保护颏神经以免损伤。同样方法暴露另一侧下颌骨以完全暴露术区。用Shea式拉钩牵开软组织充分显露下颌升支后缘、下颌角和整个下颌下缘。运用往复锯从下颌升支后缘至中切牙根尖下按照预定截骨线完整下颌下缘(图. 3a)，切开时须用手指深入口底舌侧粘膜以感知往复锯深度，当切开舌侧骨皮质时应立即停止。用薄骨凿轻轻劈开截除的下颌骨下缘，剥离附着在下颌骨下缘内侧的翼内肌和下颌舌骨肌，完整取出全半侧下颌下缘骨块，对侧实施同样手术(图. 3b)。对于下颌轮廓不对称患者，切口的范围取决于个体特点，根据需要可以部分或全部切开。为了准确标记解除范围和截除量做到精确截骨确保术后外形对称，可以运用基于三维CT数据的快速成型树脂颅面骨骼实体模型上进行模拟截骨来辅助操作。截骨线的位置和走向由模型模拟标记完成后，操作与全下颌下缘截除术相同。最后用往复骨锉或者大号磨头修整锋利的下颌边缘，以得到自然流畅的下颌下缘外形线。对于咬肌肥大的患者施以内侧部分咬肌切除术，对于一些颊部过于丰满的患者施以颊脂垫部分切除术。严密缝合手术切口，持续负压吸引48小时，术后用抗生素3到4天，面部弹力绷带加压5-7天。3.结果所有患者的手术均成功实施。没有面瘫、严重出血发生，也没有下颌髁突颈、升支意外骨折发生。术后恢复正常，没有感染发生，6到12月随访，所有患者没有面瘫或者张口受限发生。有7个患者颏神经分布区的下唇麻木，但是所有患者在6个月内感觉都恢复正常。术后进行回访评估手术效果。长方形面廓患者，均有效地减低了面下1/3高度，恢复面部三庭比例协调的协调性，下颌宽度也得到明显缩窄。面廓不对称患者，其不对称得以明显矫正，下颌下缘的轮廓也得到有效地改善。所有患者和医生都对术后的美学效果表示满意。4.病例报告4.1 典型病例125岁的女性，主诉为：长而且方的面形，要求面部轮廓整形。面部特征为：正面观面下1/3过长并且颏部长而突出。下颌角开张度约125度，下颌平面角约25度，面下1/3比面中1/3长5mm。下颌升支过长，耳垂到下颌角为3.3cm(图.2 a,c)。2008年5月，在全麻下施以全部下颌下缘截骨术以矫正长方形的面部轮廓(图.3 a,b)。在术后11月随访外形改善如预期。面下1/3比与面中1/3等长。耳垂到下颌角调整为2.0mm。下颌下缘轮廓从下颌角到颏部平滑而流畅，面部比例平衡并协调(图.2 b,d)。4.2 典型病例221岁女性因为自觉方且不对称的面下部轮廓寻求外科矫治。面部特征为：正面观面下部方而且不对称，右侧下颌角区更明显突出。右侧下颌平面角只有15度，面下1/3与面中1/3相比不协调。右侧下颌支长，耳垂到下颌角距离为3.0cm(图.4 a,c)。在2008年对其不对称的部分施以下颌下缘截骨术(图.5a,b)，术后12个月随访，外形改善明显，不对称得以矫正，耳垂到下颌角减少为2.0mm，下颌下缘轮廓线从下颌角到颏部变陡峭而流畅，面部比例协调(图.4 b,d)。5. 讨论在西方长而有棱角的面部外形被认为是理想的面型，同时着女性年轻貌美的象征，但是，在东方卵圆形或者瓜子形的脸更受偏爱[3-8] 。长方的面型会产生粗狂和男性化的外貌特征，因此在东亚人群认为是种不讨人喜欢的容貌缺陷。以时尚为主导的年代，越来越多的东方女性通过接受各种美容手术来获得协调的面部轮廓外形。早在1949年，Adams通过手术切除咬肌肥大来改变方形面容[1]。随后Converse通过口内外联合切口实施下颌角截除术来矫治方颌畸形[2]。Yang、Gui和 Hsu克服了一些缺点提出了较为精确的手术方法来矫治突出的下颌角[3,6,7]。“长方面型”在此的含义是指面下1/3过长，而面中和上1/3以及颧骨和牙齿咬合关系均正常。 “长方面型”通常伴有方颌，这种面部外形轮廓在东亚人群中较为常见。但是现有文献很少有报道此面形的特征和矫正方法。传统的手术方法主要集中在下颌骨的后分，而忽视了面部垂直比例的协调性，这在长方面型患者中是关键，如果只减少下颌骨的宽度则面部比例会显得更加不协调而且面部看起来比术前更长。临床上，部分患者由于下颌角和下颌下缘发育程度不一导致的面部轮廓不对称，而这种面部不对称一般不伴有咬合关系错乱。因此，也不必要采取正畸-正颌外科联合治疗程序来矫正面形偏斜和矫正咬合错乱。为了解决上述问题，我们基于三维考量基础上上提出了全部或部分下颌下缘截骨术。命名为全部或部分下颌下缘截骨术是因为该术式全部或者部分地去除了下颌骨下缘以矫治伸长的和（或）不对称的面部轮廓外形。该截骨术不但可以矫正长方形的面部轮廓，或者不对称的下颌下缘，同时这该手术针对后份操作也可以解除下颌角和下颌缘来矫治方颌畸形。为了精确截骨，手术过程可以先在三维CT基础上的快速成型树脂颅面骨骼模型上模拟，截骨线可以实现精确定位。截除后新形成的下颌角由下颌支后缘和下颌下缘截骨线相交构成，下颌角到耳垂的距离在美貌人群通常是2cm。为了避免损伤颏神经，下颌下缘截骨线通常设计在颏孔下方3mm以下的安全区域。全部或部分下颌下缘截骨术的适应症是长方形面型或者下颌轮廓不对称面型”。该手术方法可以有效地减少下颌骨的长度和宽度，改变下颌骨轮廓和使得面下1/3匀称协调，获得了令人满意的美容效果。但是，仔细筛选适应证是有必要的，下颌过长的患者多半是由于下颌前突导致的，同样在不对称的患者中，不对称可能是由于错牙合、咬合倾斜和面中部发育不对称引起的。因此，伴有咬合错乱的在病例，需要进行正畸-正颌联合治疗。此外，中年患者或者脖子短的患者本身颌颈交界不清晰，可能会在术后下下颌部位皮肤显得松垂多余，而越加显老。因此，给这些患者实施该手术也要相当慎重。参考文献【1】 Adams WA. Bilateral hypertrophy of masseter muscle: an operation for correction (case report). Br J Plast Surg 2:78-81,1949【2】 Converse JM. Deformities of the jaws. Reconstructive plastic surgery. Philadelphia: Saunders;1977. p. 1406-1411.【3】 Yang DB, Park CG. Mandibular contouring surgery for purely aesthetic reasons. Aesth Plast Surg，1991,15:53-60【4】 Deguchi M, Iio Y, Kobayashi K, Shirakabe T.Angle-splitting ostectomy for reducing the width of the lower face. Plast Reconstr Surg，1997， 99:1831-1839【5】Satoh K. Mandibular contouring surgery by angular contouring combined with genioplasty in Orientals. Plast Reconstr Surg. 1998，101:461–472【6】Lai Gui,Dong Yu. Intraoral One-stage curved osteotomy for the prominent mandibular angle: a clinical study of 407 cases. Aesth Plast Surg, 2005, 29:552-557.【7】 Hsu YC, Li J, Hu J, Luo E, Hsu MS, Zhu S. Correction of square jaw with low angles using mandibular“V-line” ostectomy combined with outer cortex ostectomy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod，2000，109:197-202【8】张智勇，归来，藤利，等.双侧下颌角突出合并小颏畸形的治疗. 中华整形外科杂志, 2002,18（4）:214-216. 图示图.1 在快速成型的树脂实体颅面骨骼模型上,标记截骨线延长至整个下颌骨下缘。Fig.1 The line of total inferior border ostectomy was drew on the resin model obtained from 3D-CT.Note the ostectomy line extending the full length of the lower border of the mandible. 图.2 术前长方形的面部轮廓(a,c)。全下颌下缘截骨术后面部比例协调柔和(b,d)。Fig.2 Preoperative views. Note the elongated lower 3rd of the face(a,c). Postoperative views after total inferior border ostectomy. Note the well balanced facial profile (b,d)图.3 口内观全下颌下缘截骨术显示截骨线延长至整个下颌骨下缘(a)。切除的马蹄形下颌骨下缘(b)。Fig.3 Intraoperative view of total inferior border ostectomy. Note the ostectomy line extending the whole length of the mandibular border(a). The resected horseshoe shaped mandibular inferior border(b).图.4 术前面形显方方且不对称，右侧面部下颌角及下颌缘突出(a,c)。部分下颌下缘截骨术后面部对称性明显改善，下颌下缘轮廓从下颌角到颏部协调而流畅(b,d)。Fig.4 Preoperative views. Note the square and asymmetrical face with prominent right lower side of face (a,c). Postoperative views after partial inferior border ostectomy. Note the facial symmetry with steep and smooth contour of lower mandible from mental region to mandibular angle region (b, d)图.5 不对称的部分下颌下缘截骨术(a)；截除的不对称的下颌骨下缘(b)。Fig.5 Intraoperative view of asymmetrical partial inferior border ostectomy was carried out（a）. The resected asymmetrical mandibular inferior border(b).

作者单位:610041 口腔疾病研究国家重点实验室、四川大学华西口腔医学院正颌外科中心通信作者:李继华,610041 ,口腔疾病研究国家重点实验室、四川大学华西口腔医学院正颌外科中心,Email:leejimwa6698@sohu.com【摘要】 目的 探讨应用下颌骨外板劈除术及颏前下滑行内缩并配合嵌入式植骨术矫治短面型方颌的可行性及效果评价。方法 2005年7月至2009 年10月，对57例短面型方颌伴颏部过方、过短及后缩的患者,应用下颌骨外板劈除术及颏前下滑行内缩并配合嵌入式植骨术进行矫治，以缩小下颌宽度、增大下颌平面角、延长并缩窄颏部，从而获得协调流畅的面部轮廓。术前和术后拍摄定位标准面像、X线头影测量片、全景片等，以评价矫正效果。术后进行6～24个月的随访,调查患者满意度。结果 术后57例患者伤口均一期愈合,下颌平面角增大至25 o～30o,下颌角开张度增大至120o，两下颌角间距明显减小,下颌整体宽度缩窄，颏部尖翘，下颌轮廓协调,效果评价均满意。结论 联合应用下颌骨外板劈除术及颏前下滑行内缩术，可有效地矫治短面型方颌，使下颌骨轮廓达到较为理想的美学标准。[关键词] 面型,方颌；下颌骨外板劈除术；颏缩小成形术Narrowing and sliding genioplasty procedure combined with mandibular outer cortex ostectomy technique to correct square jaw on short faceXU Yu-chun,LI Ji-hua, HU Jing, ZHU Song-song,LUO En,FENG Ge,WANG Da-zhang. The State Key Laboratory of Oral Diseases and Orthognathic Surgery, Sichuan University West China College of Stomatology, Chengdu 610041,ChinaCorresponding author: LI Ji-hua, Email:Leejimwa6698@sohu.com【Abstract】 Objective To evaluate the the feasiblility and effectiveness of narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy technique to reshape a wide, weak chin, square jaw on short face. Methods From July 2005 to October 2009, there were a total of 57 patients in this study who received narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy procedure to correct square jaw on short face. All the patients had standard frontal and lateral cephalometric radiographs, panoramic radiographs, and were photographed preoperatively and postoperatively to assess their face contour. The alteration of mandibular angle, mental contour and width of lower face was observed for 6 to 24 months postoperatively. Questionnaires were used to assess the patents ' level of satisfaction. Results Postoperative appearance of all 57 cases showed that the lower face had narrowed and had become softer, slender and oval, with a slick mental region. The final aesthetic outcomes were quite satisfactory in all cases for both the surgeons and the patients.Conclusion Narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy procedure could efficiently adjust the shape and position of chin to obtain a good proportion of the lower face, and change square and short face to slender oval one by single operation in accordance with the fashionable aesthetics in Orientals.[Key words] facial contouring, square jaw; mandibular outer cortex ostectomy; sliding and narrowing genioplasty对方颌人群的容貌特征观察和分析后发现：其中部分为下颌升支较短的短面型方颌，该类患者多伴有颏部后缩、过短或过方。若单纯行下颌角成形术，会导致下颌后份轮廓丧失，短而宽的颏部则显得尤为突出，使得下颌骨重心前移、轮廓笨重、面下1/3 比例失调。为此，2005年7月至2009年10月,我们应用下颌骨外板劈除术及颏前下滑行内缩并配合嵌入式植骨术对此类患者进行矫治，获得较好的效果。1.临床资料本组共57例,其中女性54例，男性3例，年龄20～35岁,均为方颌面型。面部容貌特征为：正面观面下份宽、方颏，且比例过短；侧面观颏后缩,未达到Ricketts's E-line标准，下颌升支较短, 从耳垂到下颌角距离不大于2 cm, 部分患者下颌角开张度小于120o, 下颌平面角小于30o, 部分病例伴有明显的咬肌肥大，软组织丰满（颊脂垫肥大）。术前常规拍摄头颅正﹑侧位X线头影测量片与颌骨全景片, 排除局部骨质病变与肿瘤, 并了解左右下颌角对称性及外展情况﹑下颌角开张度与下颌支下颌体形态及下颌神经管的位置与走行,对颏部的形态和前后位置也同时进行分析,根据患者的脸型及个人需求与其进行充分的沟通，以拟定最适合的手术方案并确定是否切除部分咬肌及取颊脂垫等。2.手术方法（图1,2） 所有手术均采用经鼻腔气管内插管全身麻醉。2.1切开与显露: 局部浸润注射含1/100 000肾上腺素的1%利多卡因溶液，从下颌升支前缘平上颌牙合平面，沿外斜线向前下至中切牙龈前庭沟靠唇侧6 mm处切开黏膜、黏膜下层及骨膜,在骨膜下剥离完整显露下颌升支、下颌角、下颌体及颏部，颏神经作适当游离并妥善保护。对侧行同样操作。2.2颏水平切开术：按常规颏成形的手术方式，在颏孔下3 mm处行水平骨切开术，骨切开线的后缘尽可能向下颌角方向延伸，全层切开从颏正中至角前切迹的内外层骨皮质，但暂时不将颏部及下颌下缘骨块折断降下。2.3 下颌外层骨板劈除：在下颌支中上份距乙状切迹1.5 cm处，用往复锯或长裂钻从升支前缘至后缘作一水平骨切开线, 深度以切透颊侧骨皮质为度，再于颏孔后1 cm处作一垂直骨切开线, 深度也以切透颊侧骨皮质为度。用裂钻沿下颌支外斜线从升支水平骨切开线向前下钻一排骨孔至垂直骨切开线，并深达髓腔, 将水平骨切口与垂直骨切口相连, 消除所有骨切开线之骨皮质桥后,以薄刃骨刀插入骨切口内, 轻轻敲击骨刀逐渐劈开下颌骨外板，劈开完成后以kocher钳夹持外板并摘除。2.4前下滑行内缩颏部：折断并降下颏部及下颌下缘之骨段，于颏部骨块中央截除顶边在唇侧、底边在舌侧的梯形骨块，顶边长度即颏部需要缩窄的量，一般为4～8 mm,底边长度则等于颏部需要缩窄的量（顶边）与劈除的双侧骨外板的厚度之和，一般为8～14 mm，骨块截除后应将附着在舌侧软组织（主要是颏舌肌、颏舌骨肌）用粗线结扎并钻孔固定在两侧颏部骨块上。截除颏部正中骨块后，将两侧颏部及下颌下缘骨块及其上附着的软组织向中线移位并对接。根据术前设计，可同时前徙或下移颏部骨块来调整颏点前后向或垂直向位置。若需要行颏部下移以增加面下1/3高，增大下颌平面角，则应在下移颏部骨块留下的间隙内植入劈除后经修整的单层或双层骨外板，最后在唇侧骨面以预成形的小型钛板及镙钉行坚固内固定。术中注意保护颏神经并预防意外骨折。2.4 修整塑形：在劈除下颌外侧骨板及颏成形后，可能在骨块衔接处(尤其下颌下缘)留下台阶或骨刺，需要用电动骨锉或大号圆钻磨平并修整，确保轮廓线自然、流畅、平顺。咬肌特别肥大的患者可同期切除部分内1/3层咬肌，颊部丰满者适当去除部分颊脂垫。如果骨创面有明显的骨髓腔出血点，可用骨蜡涂布止血。2.5冲洗缝合: 生理盐水冲洗创面，妥善止血后缝合口内黏膜切口，放置负压引流。下颌角区置放敷料于颌周加压包扎，术后4～5 d应用抗生素预防感染，单侧负压引流物每天少于5 ml时可拔除引流管。3.结果57例患者伤口均一期愈合，无感染，术后1周出院。术后随访6～24个月，均无张口受限及面瘫等严重并发症发生，其中25例患者术后自觉口角区下唇麻木，但均在6个月内恢复。所有患者面下部正、侧面轮廓均得到明显改善，面型协调、对称，面下部轮廓流畅、柔和，两侧下颌角间距均明显缩小，但下颌角区轮廓得以保留，术后下颌角角度平均增大至120°，下颌平面角平均增大至25°。所有病例医患双方均对术后效果感到满意。 4. 典型病例患者女，22 岁，自觉面下部过宽，要求外科矫治。专科检查: 正面观面下份宽, 左右尚对称, 方颏, 面下份比例略短，面下1/3比面中1/3短5 mm；侧面观：下颌角开张度约110.o，下颌平面角约20°,下颌下缘轮廓线从颏点至下颌角平坦无提升，下颌升支较短，从耳垂到下颌角间距离为1.5 cm, 颏部后缩，颏前点距审美平面（Ricketts's E-line）7 mm。软组织丰满，颊脂垫肥大。于2008 年6月行“下颌骨外板劈除术联合颏前下滑行内缩及植骨术+颊脂垫去除术”。其术中内缩颏部截除的梯形骨块顶边长4 mm，底边长10 mm，颏前移8 mm,下移5 mm。术后9个月复诊, 正面观面下份明显缩窄，左右对称，颏部尖俏，与面中上分比例协调，等高；侧面观下颌角开张度约120o，下颌平面角约30°，颏部达到审美平面，下颌角轮廓保留，从耳垂到下颌角间距离为1.5 cm,下颌下缘轮廓线流畅自然，下缘曲线从颏点至下颌角提升较陡峭。医患双方均对效果评价满意（图3,4）。5.讨论经口内入路的多种术式均能有效矫治方颌面型，然而却没有一种术式适合于所有的求美者【1-4】，术者应根据每个求美者的容貌特征制定最优化的手术方案，以满足其审美诉求并达到通行的审美标准，同时降低并发症的发生率。Satoh提出要把下颌轮廓作为一个整体来考量，选择适当的下颌角成形和颏成形术式【5,6】。而张智勇和归来采用下颌角弧形截骨术联合颏水平切开前徙术来矫正双侧下颌角突出合并小颏畸形也取得满意的临床治疗效果【7】。我们观察发现：有部分方颌患者属于短面型,下颌升支较短，且常伴有颏部垂直向发育不足或颏部过方过短等缺陷。采用下颌角截骨术后将导致下颌角上提过高，下颌后份轮廓完全丧失；单纯的下颌外板劈除术虽可以缩窄后份下颌宽度，却无法有效增大其下颌角开张度及下颌平面角；下颌下缘截骨术也因切除下缘及下颌角致使后份轮廓丧失且容易伤及下齿槽神经血管骨而不适用于短面方颌【8】。另一方面，由于颏部的缺陷得不到有效处理，致使术后下颌重心前移，颏部尤显方、短【9】。 因此，根据审美标准和容貌特征分析及各种术式的适应证，我们应用下颌骨外板劈除术及颏前下滑行内缩并配合嵌入式植骨术矫治短面方颌畸形,可有效增大下颌平面角，延长并缩窄颏部及面下部整体宽度,以达到通行审美标准，获得面部轮廓整体的协调，满足求美者的诉求。该术式的主要并发症包括下唇麻木、颏下部赘肉形成及轮廓不流畅。术中要暴露充分以获得良好的术野，妥善保护颏神经，从而可以有效地预防或减轻下唇麻木【9,10】；做好颏部骨块截除后颏舌肌的结扎处理，以形成新的附着，避免发生舌后坠而引起窒息；骨块移动后形成台阶，应仔细打磨以消除，并充分检查以获得流畅平顺的轮廓。掌握好适应证，对于年龄偏大、颏部及下颌区域软组织堆积者尽量不要行下颌骨外板劈除术及颏内缩术，以免造成颏下赘肉，而颏部前下滑行移位有利于消除赘肉，术者应当仔细考量，准确把握。目前，方颌矫治术的轮廓外科理念, 应以全下颌作为整体来设计, 手术范围从下颌升支到下颌角、下颌体、下颌下缘到颏部，进行全下颌轮廓雕塑。应重视整体的协调性、线条的流畅性和比例的均衡性。同时要准确掌握各种术式的适应证，并要考虑到术后可能带来的新的缺陷。参考文献[1] Baek SM, Baek RM, Shin MS. Refinement in aesthetic contouring of the prominent mandibular angle. Aesth. Plast. Surg，1994，18;283-289[2] Deguchi M, Iio Y. Angle-splitting ostectomy for reducing the width of the lower face. Plast. Reconstr. Surg. 1997;99;1831-1839[3] Han, K., and Kim, J. Reduction mandibuloplasty: Ostectomy of the lateral cortex around the mandibular angle. J. Craniofac.Surg. 2001;12; 314-25[4] Converse JM. Deformities of the jaw. In: Converse JM(ed): Reconstructive plastic surgery. Philadephia: WB Saunders, 1977, p.1406.[5] Satoh, K. Mandibular contouring surgery by angular contouring combined with genioplasty in orientals. Plast. Reconstr. Surg. 2004;113; 425-30 [6] Satoh K. Mandibular contouring surgery by angular contouring combined with genioplasty in orientals. Plast. Reconstr. Surg. 2004;113:425-30.[7] 张智勇，归来，藤利，等.双侧下颌角突出合并小颏畸形的治疗. 中华整形外科杂志, 2002,18（4）:214-216.[8] Yu-chun Hsu, Jihua Li, Jing Hu,et al. Correction of square jaw with low angles using mandibular“V-line” ostectomy combined with outer cortex ostectomy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod.2010;109:197-202[9] Park,S.H, Noh,J.H. Importance of the Chin in Lower Facial Contour: Narrowing Genioplasty to Achieve a Feminine and Slim Lower Face. Plast. Reconstr. Surg.2008;122:261-264[10] Guyuron, B., and Kadi, J. S. Problems following genioplasty: Diagnosis and treatment. Clin. Plast. Surg.1997; 24: 507-511.图片（Pictures）图1. 下颌骨外板劈除术与颏前徙内缩术示意图Fig.1. Frontal illustration of narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy procedure. 图2 下颌骨外板劈除术与颏前徙内缩术。颏水平骨切开降下后颏部正中行2条垂直截骨线(a)。下颌骨外板劈除术（b）及所劈除的外板(c)。正中楔形截除后，两侧颏部骨块向中线内移对接并向前下滑行，并将骨外板修整后做嵌入式植入颏前下滑行后所产生的间隙内，最后用钛板钛钉固定（d）。Fig. 2. Photograph of narrowing and sliding genioplasty combined with mandibular outer cortex ostectomy procedure. Horizontal osteotomy and two vertical osteotomies were performed and the central segment was resected（a）The mandibular outer cortex ostectomy (b,c). After removal of the central segment, two lateral segments were approximated medially, and bone grafts were placed in the space produced by downward and forward sliding mental segments, using the trimmed mandibular outer cortex segment and fixed with miniplate and screws (d). 图3 术前正、侧位(a,c)，术后9个月正、侧位（(b,d)Fig.3. Preoperative frontal and lateral views (a,ct). Postoperative frontal and lateral views (b,d).图4.术前(a)和术后9个月(b)颌骨全景片；术前(c)和术后9个月(d)侧位X线片Fig.4.Panoramic radiographs: preoperative(a) and postoperative(b); lateral cephalometric radiographs: preoperative(c) and postoperative(d)

【摘要】 目的 由于传统术式对于低角型方颌畸形不能有效增加下颌平面角而往往难以达到理想的矫治效果，本研究探讨应用下颌骨“V-line”截骨术与外板劈除术联合矫治低角型方颌畸形的可行性并评价其治疗效果。方法 选择本科室2005年7 月～2007 年11 月间治疗的31例低角型方颌畸形患者，在全麻下应用下颌骨“V-line”截骨术与下颌骨外板劈除术进行联合矫治。术后6月至24月进行随访, 调查患者满意度，并用术前后定位标准面像、X线头影测量等方法评价其矫正效果。结果 所有31 例患者术后伤口Ⅰ期愈合, 下颌平面角增大至30o, 下颌角开张度增大至120o，两下颌角间宽度明显减小, 达到了下颌轮廓的美学标准，均获得较理想的美容效果。结论 下颌“V-line”截骨术与外板劈除术联合应用, 可有效地矫治低角型方颌畸形，使患者下颌骨轮廓达到较理想的美学标准。关键词 方颌；低角； V- line截骨术；下颌骨外板劈除术目前，经口内入路的方颌矫治术已经是整形外科的常规手术，多种术式均可用于矫治方颌畸形。然而，相当多的方颌患者均属于低角畸形，“低角型方颌畸形”即下颌角开张度小于110o或近似呈直角，下颌平面角小于20o甚至达0o，下颌下缘曲线过于平缓,或下颌下缘轮廓下坠（图1）。应用传统术式因不能有效增加下颌平面角而往往难以获得理想的矫治效果。近来，由于受影视明星等时尚因素的影响，东亚地区愈加崇尚“瓜子脸”，欲达此目的，改善下颌平面角过小，使下颌下缘向后提升较为陡峭，以获得更灵巧、尖俏的面下部轮廓成为必要手段。因此，针对方颌畸形及求美者不同的容貌特征和审美要求，我们经口内入路运用下颌下缘截骨术(V-line)联合下颌骨外板劈除术 ，矫治低角型方颌畸形，达到改变下颌下缘轮廓，增大下颌角开张度及下颌平面角，使原本过于平缓的下颌下缘变陡峭,达到的“瓜子脸”的效果整形美容效果。1. 临床资料本组共31例, 年龄20岁～ 31 岁, 均为方颌畸形，双侧对称或不对称。其中面部容貌特征为： 正面观面下份宽, 侧面观下颌角开张度小于120o近似呈直角或下颌角向后下方突出，下颌平面角过小，下颌下缘曲线过于平缓，下颌体下缘轮廓下坠，左右下颌下缘不对称，方颏，部分病例伴有明显的咬肌肥大，软组织丰满（颊脂垫肥大）。治疗目的均为改变面下部轮廓达到审美要求。术前依照患者的脸型及个人要求与其进行充分的沟通，常规拍摄头颅正﹑侧位X线头影测量片与颌骨全景片, 排除局部骨质病变﹑肿瘤, 并了解左右下颌角对称性及外展情况﹑下颌角开张度与下颌支下颌体形态及下颌管的位置与走行, 对颏部的形态也同时分析,设计所需调整下颌平面角的幅度决定截骨线的倾斜程度，并确定是否切除部分咬肌及颊脂垫等。2手术方法（图2、3）所有手术均采用经鼻腔气管内插管全身麻醉。2.1切开与显露: 局部浸润注射含1/100000肾上腺素的1%利多卡因溶液，从下颌升支前缘平上颌牙合平面沿外斜线向前下至中切牙龈前庭沟靠唇侧6mm处切开黏膜直达骨膜, 用骨膜剥离器在骨膜下剥离完整显露下颌升支、下颌角、下颌体及颏部，颏神经适当游离并妥善保护。对侧行同样操作后完整显露术区。2.2 下颌下缘截除术：骨切开线的设计要避免损伤下牙槽神经血管束，术前仔细研读X线片上的下颌管影像，一般于双侧颏孔下3mm设计骨切开线，根据术前设计所需调整下颌平面角的幅度决定截骨线的倾斜程度，术中需特别注意保护颏神经。用Shea's 光导拉钩钩住并显露好下颌角及下颌下缘，用往复锯在下颌神经管走行之下依照设计之骨切开线从颏部至下颌角行截骨定位线，定位后沿已经切开的骨沟向深部切割，直至舌侧骨板完全切开，操作时将手指置于下颌舌侧黏膜处以感受切割深度，一旦切透舌侧骨板应停止截骨，以薄刃弯骨刀插入骨切开间隙，轻轻撬动或凿开骨切开处少许骨连接，离断此区域的全层下颌下缘。切断内侧的翼内肌附着及下颌舌骨肌附着，将下颌下缘充分游离并完整取出。2.3 下颌外侧骨板劈除：在下颌支中上1/3处以往复锯或长裂钻从升支前缘到后缘做一水平骨切口标志线, 深度以切透颊侧皮质骨板, 不可切割过深以免伤及下颌管，根据患者具体情况, 于颏孔后作一垂直骨切开线达下颌下缘, 深度以切透颊侧皮质骨板。用裂钻沿下颌支外斜线水平骨切口向前钻一排骨孔至垂直骨切口，深达髓腔, 将水平骨切口与垂直骨切口相连, 消除所有切骨线之骨皮质连接后, 以薄刃骨刀插入骨切口内, 轻敲击骨刀逐渐劈开下颌骨外板， kocher钳夹持外板并摘除。2.4 修整塑形：在劈除下颌角外侧骨板后，用电动骨锉或大号圆钻磨平垂直截骨处的台阶，确保轮廓线自然流畅。咬肌特别肥大的患者可同期切除部分内层咬肌，颊部丰满者适当祛除部分颊脂垫。如果骨创面有明显的骨髓腔出血点，可用骨蜡止血。2.5冲洗缝合: 生理盐水冲洗伤口，妥善止血后缝合口内伤口，放置负压引流。下颌角区置放敷料颌周加压包扎。术后应用抗生素预防感染。单侧负压引流物少于8ml/d拔除引流管。3 . 结果所有31例患者创口均为Ⅰ期愈合，无感染，术后一周出院。术后随访6~24个月，均无张口受限及面瘫等严重并发症，其中13例患者术后自觉口角区下唇麻木，但均在4月内恢复。所有患者面下部正侧面轮廓均得到改善，术后下颌角角度增大至110°～120°，下颌平面角增大到25°～30°，下颌角间宽度均明显减小。所有病例医患双方均对手术后效果感到满意，结果表明下颌下缘“V-line”截骨术联合下颌骨外板劈除术矫治低角型方颌畸形可获得满意的美容效果。4. 典型病例患者张XX，女，26 岁，自觉面下部过宽，要求手术矫治; 专科查体: 正面观面下份宽, 左右尚对称, 侧面观下颌角开张度约90.o，方颏但不后缩，颊脂垫肥大。 于2007 年3月行下颌下缘“V-line”截骨术+下颌骨外板劈除术+颊脂垫去除术”。术后1年复诊, 正面观面下分不宽，左右对称，颏部变尖俏，与面中上分比例协调；侧面观下颌角开张度124o，下颌下缘轮廓线流畅，从颏点至下颌角逐渐提升，下颌平面角达到28 o。医患双方均对效果感到满意（图4、5）。5.讨论从东方传统审美观角度看方形脸的女性容貌呈现粗旷感, 缺乏女性面部柔和、流畅的美感。而美貌人群面部轮廓分析表明：正常面形下颌角开张度约为110o~130o ，下颌平面角约为25o~30o。部分方颌畸形属于低角型，下颌角开张度小于110o，严重的近似直角，同时下颌平面角过小，下颌下缘曲线从颏点至下颌角过于平缓，或下颌体下缘轮廓下坠，使正面观面下部宽大，侧面观曲线生硬不流畅。目前，由于受影视等时尚因素的影响，东亚地区愈加崇尚“瓜子脸”。不仅面型不佳表现为方颌畸形而求美者日渐增多，而且相当多正常面型的女性为追求侧面观下颌下缘向后提升的陡峭曲线，拥有更灵巧、尖俏的面下部轮廓而要求行下颌成形术。近年来下颌成形术无论是理念和实际操作都有了很大的进步，Converse(1951)[1] 提出“下颌角一次性直线截骨术”，其缺点为容易出现第二下颌角，下颌曲线不流畅；Baek(1989)[2]报道了“二次弧形截骨术”和Yang(1991)[3]提出“三次或四次弧形截骨术”，这两种方法手术效果较好但手术过程显得比较复杂。归来[4]1999 年提出“一次性下颌角弧形截骨术”，避免形成第二下颌角现象，但对操作技术及手术器械的要求较高，且容易造成两侧不对称。目前常用的下颌角切除术，过分侧重下颌后分的整形，而忽视下颌前分及颏部的整形，使得下颌骨重心前移，术后患者常常诉面形不佳，下巴方短，钝重。单纯行下颌骨外板劈除术，虽然正面观可以缩窄下颌角间的距离, 但无法改变下颌角开张度过小，难以矫正过于平缓的下颌下缘曲线，也不能使原来下坠的下颌角足够上提，因而术后侧面形态常常不够理想。对于低角型方颌畸形，下颌 “V-line” 截骨术可以大幅度增加下颌角开张度及下颌平面角，改善下颌下缘轮廓，使原本过于平缓的下颌下缘变陡峭, 且可达到下颌骨整体缩小的美容效果，正面观面下部较宽者 配合“下颌骨外板劈除术”可以大幅度缩窄，达到的“瓜子脸”的美容效果。下颌成形的手术设计应根据方颌及求美者不同的容貌特征，下颌神经管的位置与走行，颏部的形态，预计所需调整下颌平面角的幅度决定截骨线的倾斜程度。新形成的下颌角是下颌升支后缘与截骨线间所形成的角度，截骨线的高低,决定了术后耳垂至新下颌角的高度，一般形成的下颌角位置体表投影距耳垂2cm为宜，截骨线向前下通过颏孔下3mm，继续向前延伸到达颏部下颌尖牙根尖下的位置，此处正好是颏部两侧的转折点，截骨线到此可以避免第二下颌角的发生，形成协调流畅的面部侧貌轮廓线。参考文献1. Converse JM. Deformities of the jaws. Reconstructive plastic surgery. Saunders: Philadelphia, 1977:1406-14112. Baek SM, Baek RM, Shin MS. Refinement in aesthetic contouring of the prominent mandibular angle. Aesth. Plast. Surg. 1994; 18;283-93. Yang DB, Park CG. Mandibular contouring surgery for purely aesthetic reasons. Aesth. Plast. Surg 1991; 15;53-60, 4.Lai Gui,Dong Yu. Intraoral One-Stage Curved Osteotomy for the Prominent Mandibular Angle: A Clinical Study of 407 Cases. Aesth. Plast. Surg. 2005; 29;552-7Pictures图1.a:头影测量侧位片；b:头影测量正位片1：下颌角开张度（Ar-Go-Me）2：下颌平面角（MP-FH）3：下颌骨宽度（Go-Go）Fig.1.a: Lateral cephalometric radiographs b:the frontal cephalometric radiographs1.The gonial angle (Ar-Go-Me) 2. The mandibular plane angle (MP-FH) 3. the mandibular width (Go-Go)图2 下颌“V-Line”截骨术(a,b)及下颌骨外板劈除术(c,d,e)Fig. 2. “V-Line” ostectomy (a,b) and mandibular outer cortex ostectomy(c,d,e)图3.切除的下颌下缘及下颌骨外板Fig.3. The excised mandibular inferior margin and mandibular outer cortex 图4.应用下颌“V-line”截骨术与下颌骨外板劈除术进行联合矫治的病例术前(a,c)，术后（(b,d)面像Fig.4. Preoperative views of one case(a,c). Postoperative views after mandibular “V-Line” ostectomy combined with mandibular outer cortex ostectomy and buccal fat pad resection(b,d)图5.应用下颌骨“V-line”截骨术与下颌骨外板劈除术进行联合矫治的病例全景术前(a)，术后(b)；侧位术前(c)，术后(d)X线片。Fig.5. Case 1. panoramic radiographs: preoperative(a) and postoperative(b); lateral cephalometric radiographs: preoperative(c) and postoperative(d)

正畸-正颌联合矫治颌骨发育畸形及获得性畸形是国际通行采用的基本方式，一般程序是先正畸，然后手术，再正畸的三阶段治疗，患者就诊可挂正畸科或者颌面外科，做完检查及资料齐全后，正畸-正颌外科医师会组织联合会诊，确定正畸方案和手术基本方式，确定方案后进入正畸治疗过程。一般讲术前正畸的时间较长，平均约1年时间（根据难易程度时间略有不同），手术住院只需10-14天左右，术后一月再次进入术后正畸阶段，约半年时间，这是基本的诊疗方式。 有治疗需求的患者不要把你的牙颌面畸形与整形外科的单纯整形混为一谈，正畸-正颌的治疗要严谨的多，一般强调形态与功能并重，程序和过程都与整形不一样。 但目前也有经过正畸-正颌医生商讨后采用先手术后正畸的方式(surgery first)，这是目前新的治疗模式，主要目的是缩短疗程，这种方法在台北和韩国率先开展，但美日等同行比较反对。目前来看，不是所有患者都适合于这种方式治疗，有适应证限制，必须谨慎推行。比如：对于双颌前突患者（龅牙），如果咬合关系良好，牙齿排列良好，也可以直接手术而省去术前正畸阶段，但是否能直接手术，要经过医生的仔细检查并决定。但比如说上颌前突，没有术前正畸，直接手术，是很难获得理想的咬合与面形的。还有更为复杂的不对称畸形，更不能舍弃术前正畸。 向我咨询的患者，请准备好你的x线片（全口曲面断层片，头影测量正、侧位片），石膏咬合模型等，还有你面部的正、侧面照片，以便我能够为你做出准确的判断和建议。不要将正颌外科等同于整形外科，正颌外科的治疗方案是严谨的，没有检查资料做出的诊断和建议都是不准确的。正畸是整个治疗过程的重要过程，不可替代，要想取得好的治疗效果，必须经过有经验的正畸医生治疗，包括牙齿去代偿，把拥挤的牙列排齐，调整好牙合曲线，这些做好了就会取得好效果。

龅牙是怎么回事呢？这就涉及到牙齿的排列问题，我们的牙齿在嘴巴里面排列成弓形，这叫做牙弓。一般情况下，上颌的牙弓要大于下颌的牙弓，表现在前牙区，就是上颌前牙要盖过下颌前牙，这个盖过要有一定的范围的，如果距离过大，就叫深覆盖。所谓的“龅牙”就是指闭嘴时上颌前牙盖过下颌前牙的距离过大而使上颌前牙露出在嘴唇之外，这在医学上也叫做前牙深覆盖。 那么，“龅牙”是怎么形成的呢？我们知道，牙齿是长在上下颌骨里的。上下牙齿和上下颌骨的相对位置的异常都可能引起“龅牙”。如果颌骨的位置正常，仅有上颌牙拥挤和前突，治疗起来相对简单，通过一般的牙齿正畸就可解决。 但更多的情况是上下颌骨的位置异常引起的。如果颌骨的位置变化了，牙齿的位置也就发生了改变，我们就可以把“龅牙”看做是上颌骨位置的相对靠前。相对于谁呢？当然是下颌骨，就象我们初中物理学过的，运动一定要有参照物一样，在这里上下颌骨的位置构成了一种相对的参照关系。于是形成了三种情况：第一种情况最好想像：下颌骨位置正常，上颌骨前突；第二种是上颌骨位置正常，下颌骨后缩，这就是上颌位置的相对靠前；第三种是上颌骨前突，下颌骨后缩，这样上颌的位置就更靠前了。 对于颌骨位置异常引起的“龅牙”，靠单纯的牙齿正畸通常不能达到最好的美容效果。需要配合颌骨手术，将移位的上或下颌骨移至相对正常位置，再结合牙齿正畸，这样既能整齐牙列，又能改善面容。

Staged treatment of temporomandibular joint ankylosis with micrognathia using mandibular osteodistraction and advancement genioplastyJihua Li, DDS, * Songsong Zhu DDS, Tao Wang DDS, , En Luo, PhD, § Lin Xiao, DDS,‖ and Jing Hu, DDS, PhD, * Associate professor, State Key Laboratory of Oral Diseases and Department of Oral and Maxillofacial Surgery, Sichuan University, Chengdu, China.Assistant professor, Department of Oral and Maxillofacial Surgery, West China Stomatology Sichuan University, Chengdu, China. Professor, Department of Oral and Maxillofacial Surgery, Chongqing Medical University, Chongqing, China.§ Associate professor, State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, China.‖Associate professor, Fulin Hospital of Stomatology, Chongqing, China Professor and Chair, Center of Orthognathic and TMJ Surgery, West China Stomatology, Sichuan University, Chengdu, China.Supported by a grant from National Science Funds for Distinguished Young Scholar of China (No. 30825040).Address correspondence and reprint request to Dr Hu: Center of Orthognathic and TMJ Surgery, West China College of Stomatology Sichuan University, Chengdu 610041, China; email: drhu@vip.sohu.comCorrection of micrognathia following TMJ ankylosis using mandibular osteodistraction combined with genioplastyJ.-H Li1, S.-S Zhu1, E. Luo1, T. Wang2, G. Feng1, L. Xiao1, J. Hu11State Key Laboratory of Oral Diseases and Department of Oral and Maxillofacial Surgery, Sichuan University, West China College of Stomatology, Chengdu, P.R. China2 Department of Oral and Maxillofacial Surgery, Chongqing Medical University, School of Stomatology, Chongqing, P.R. China☆This study was supported by a grant from National Science Funds for Distinguished Young Scholars (No. 30825040).Abstract: Treatment of the patients with micrognathia following temporomandibular joint (TMJ) ankylosis is a challenging problem. In recent years, distraction osteogeneis (DO) has been used to deal with TMJ ankylosis patients. However, there has been still some controversy over proper sequencing of correction for the ankylosed patients with secondary deformities. Based on a series of cases that had bilateral TMJ ankylosis with micrognathia, we have applied a 2-stage treatment protocol, composed of interpositional arthoplasty as the initial surgery, followed by orthodontic treatment, and mandibular osteodistraction combined with genioplasty as the second surgical procedures for the management of the patients with this condition. Micrognathia was corrected using mandibular elongation and advancement genioplasty, satisfactory occlusion was achieved by the orthodontic treatment, and the obstructive sleep apnea and hypopnea syndrome (OSAHS) was cured remarkably. Our clinical data suggested that mandibular DO combined with genioplasty can be sound method to correct severe micrognathia and OSAHS following TMJ ankylosis, and orthodontic treatment is very important for achieving a stable treatment outcomes and good occlusion. Keywords: TMJ ankylosis; micrognathia; OSAHS; distraction osteogenesis; genioplastyTemporomandibular joint (TMJ) ankylosis, which is the bony or fibrous adhesion of the anatomic joint components, is a common cause of acquired mandibular deformity and is primarily caused by trauma, infections, autoimmune disease, or failed surgery 4. When this event takes place during the developmental age, it results in an alteration of the normal potential growth and reduction of the normal functional spurs necessary for the development of the whole maxillofacial complex 5. The ensuing features include hypomobility of the mandible, retrogenia, micrognathia, dental malocclusion. The retruded mandible and micrognathia in these patients give rise to narrowing of the oro-pharyngeal space with resultant mechanical obstruction during respiration which may lead to the obstructive sleep apnoea and hypopnea syndrome (OSAHS) 12.For patients with TMJ ankylosis with micrognathia, the treatment is often performed in one or two phases consisting of the initial release of ankylosis with/without TMJ reconstruction followed by correction of micrognathia by osteotomies, bone grafts or distraction osteogenesis (DO) 9, 11, 15. However, there has still been controversial over proper sequencing of the treatment for the joint ankylosed patients with secondary dentofacial deformities. Some surgeons recommend a staged approach for the treatment of the patient with concomitant TMJ ankylosis and secondary deformities, whereas others prefer to release the ankylosis and correction of secondary deformities simultaneously 2, 7, 10. Here, we report our experiences and results in 11 cases of TMJ ankylosis with micrognathia, who were treated by mandibular osteodistraction and genioplasty with the help of preoperative and postoperative orthodontic treatment following interpositional arthroplasty. Patients and methods From March 2004 to July 2010, 11 patients (5 male and 6 female), whose ages ranged from 17–27 years (mean 22.5 years), presenting with bilateral TMJ ankylosis and micrognathia were treated. All patients initially underwent arthroplasty by free grafting of autogenous coronoid process or costochondral for condylar reconstruction18. Postoperatively, patients were encouraged to exercise extensively by opening and closing their mandible using metallic mouth gag or jack screw. The reankylosis didn’t occur before the initiation of DO, and the range of mouth opening was normal.The preoperative orthodontic scheme comprising of tooth extraction, dentition alignment, dental arch levelling and decompensation was performed. The average respiratory disturbance index (RDI) was 42.6, and the average lowest arterial oxygen saturation was 65% for all patients during the polysomnography examination. According to the polysomnography results, 8 patients were diagnosed with severe OSAHS and 3 with intermediate OSAHS. Radiological examinations included cephalometric radiographs (antero-posterior and lateral) and panoramic radiograph.The average sella-nasion-supramental (SNB) angle was 67.4° by cephalometric analysis. If necessary, CT scan was taken, and the data were imported into the Simplant Pro 11.02 software system (Materialise Corporation, Belgium) for three-dimensional morphometry, diagnosis, and planning and simulation of the surgical procedures (Fig.1). Fig.1. Surgical simulation of arthroplasty, mandible and chin advancement First phase consisted of placement of intraoral distractors. Under general anaesthesia, the mandibular body was carefully osteotomised, followed by insetting of an intraoral distractor (Medicon Corporation, Germany). Complete osteotomy was insured by intraoperative distraction (Fig.2). Distraction was activated on the 7th postoperative day at a distraction rate of 0.5mm twice daily. Mandibular distraction was maintained until the occlusion achieved the requirement of orthodontists. The second phase treatment was carried out, which consisted of an either single step or double step genioplasty either at the same time during insetting distractor or removing distractor at 12 weeks after end of distraction (Fig.3). The distractor was finally removed after osteogenesis was confirmed in the distraction gap by radiographs (Fig.4). Fig.2. Placement of the intraoral distractors Fig.3. Single or double step genioplasty was performed simultaneouslyFig.4. (A) The distraction gap (arrows) was seen clearly during osteodistraction; (B) The newly formed bone was seen in the distraction gap at 3 months after osteodistraction. ResultsThe detailed data of the patients are shown in Tables 1. The mean follow-up period was 29.9 (17-48) monthes. The mean (range) mouth opening was 36.7 (31–42) mm, and mean length (range) of the mandibular body increased by DO was 12.7 (9–17) mm. Micrognathia was successfully corrected in all cases. The OSAHS was cured, as evaluated by polysomnography, and the RDI and lower arterial oxygen saturation were markedly improved. The average RDI was 3.4, and the average lower arterial oxygen saturation was 93.1%. The average SNB angle on cephalometry was 76.2° postoperatively, significantly increased compared with that preoperatively, and the width of upper air way was increased greatly after operation (Fig.5). No patient had infection or excessive pain at the distraction site. New bone with sufficient volume and density for satisfactory chewing had formed after a consolidation of 3 months’ period. Mild open bite was found in 5 patients after mandibular osteodistraction, but it was corrected by postoperative orthodontic treatment. There was no permanent damage to the inferior alveolar nerve and no complaints of numbness or discomfort in the lower lip. The improvement of the facial appearances, occlusion and oral function were satisfactory in all the patients (Fig. 6-9). Table 1. Summary of patient dataCase No.Age(yrs)/SexDO length(mm)SNBRDILowest SaO2 Pre-OPPost-OPPre-OPPost-OPPre-OPPost-OP117/Female968o74o39.62.6 65% 96%223/Male1269o75o39.73.2 71% 92%321/Female1070o78o37.62.7 63% 95%420/Female1167o76o46.24.3 61% 93%524/Male1563o72o47.15.162%93%622/Male1367o76o42.53.859% 94%727/Male1466o76o48.24.868%91%825/Female1270o78o40.42.0 74%95%919/Female1167o77o42.72.9 75%94%1026/Female1669o78o40.31.856%89%1123/Male1765o74o44.13.961%92%Mean12.767.4o75.8o42.63.465%93.1%Fig.5. The width of upper airway(arrows) was increased after mandibular distraction and genioplasty.Fig.6. The photo showing a great change in maximal mouth opening of a patient after operation.Fig.7. Pre-operative(A) and post-operative(B) frontal view of the same patient Fig.8. Pre-operative(A) and post-operative(B) lateral view of the same patient Fig.9. Malocclusion in TMJ ankylosed patient can be corrected well by surgical-orthodontic treatment. DiscussionTMJ ankylosis is a serious and disabling condition that may cause problems in mastication, digestion, speech, appearance, and hygiene. When ankylosis occurs in children, it can cause secondary dentofacial deformities; a common finding associated with TMJ ankylosis is the hypoplastic mandible. This presentation besides imparting an aesthetic and functional problem can create a narrowing of the upper airway space with obstruction during respiration 14. Since first use of distraction osteogenesis (DO) for mandibular lengthening by McCarthy et al. in 1992, the technique has since been accepted as a good modality in management of hypoplastic mandible, avoiding the necessity for bone grafts or complex osteotomies 13, 17. Moreover, it is seen that DO in addition to correction of facial deformity also results in relief of OSAHS by advancing the mandible and associated soft tissue 12.There have been three methods regarding application of DO in treatment TMJ ankylosis: (1) simultaneous osteodistraction with ankylosis release. (2) release of ankylosis followed by osteodistraction at a later stage. (3) osteodistraction followed by release of ankylosis at a later stage 1, 2, 6, 11. The simultaneous use of mandibular distraction with ankylosis results in simultaneous correction of ankylosis and the associated deformities obviating the need for a second operation. However, it may result in an improper outcome of distraction due to unpredictable vector management and the active post-operation physiotherapy may cause physical interference to the distraction process 11. Likewise DO is best performed after a detailed preoperative surgeon-orthodontist evaluation and development of a comprehensive treatment plan, and dental hygiene must be optimal, which is not the case if distraction is performed initially. In our cases here, we first released the ankylotic joint using interpositional arthroplasty, and then performed dental decomposition by orthodontics, and finally corrected the mandibular deficiency with osteodistraction. We are of the view that initial release of ankylosis enables the patient to regain mandibular function allowing adequate food intake, increases the feasibility of performing pre-surgical orthodontics and also prepares the patient for a later more complex and prolonged procedures. Likewise during this period the surgeons will also be able to observe any cases of recurrence that might adjust the later treatment plan. One of the main advantages of DO is that as a result of controlled distraction of the bone, there is not only elongation of the mandibular bony tissue but also proportional and harmonic modification of the surrounding soft tissues 2. Mandibular distraction can improve the facial profile and relief of airway obstruction in the TMJ ankylosis patients with retruded mandible. However, we found that DO failed to completely address the deficient chin that almost exists in those ankylosis cases, which affects the improvement on the facial appearances and obstructive sleep apnoea. In order to achieve the best cosmetic and functional outcomes, advancement geoiplasty was used routinely to correct the small chin in our hospitals. Since the first description of genioplasty by Hofer, genioplasty has been a commonly performed procedure to alter the chin’s size and position 3-dimensionally 3, 8. TMJ ankylosis patients often have a bird face deformity with an almost absent chin projection from lateral view. Genioplasty can move chin point forward, improve the chin profile with a proper projection and good-looking neck chin angle. Moreover, advancement genioplasty results in pull of genioglossus, geniohyoid and digastric muscles, with subsequent repositioning of hyoid bone as well, with overall increase in the posterior airspace 16. Therefore, advancement genioplasty can results in an additive improvement of the facial appearances and OASHS in the TMJ ankynosis patients.For the TMJ ankylosis patients with secondary deformities, orthodontics must be included in the treatment plan. Orthodontic treatment can begin after the release of TMJ ankylosis and follow after the end of mandibular distraction, it helps us to correct skeletal deformities more precisely and finally obtain a good and stable occlusion. Open bite is a common complication following mandibular osteodistraction which may be attributed to the forces of masticatory muscles. Open bite was found in 5 of 11 patients after DO, but it was corrected well by orthodontic treatment. Treatment of TMJ ankylosis with secondary dentofacial deformities remains a great challenge for oral surgeons. Distraction osteogenesis, which induces new bone formation along the vector of pull without requiring the use of bone graft, has become a valuable method for treating the TMJ ankylosis patients with micrognathia. However, no single method has brought out an ideal treatment result. In most cases, various techniques, such as arthoplasty, orthognathic surgery and DO, should be combined to deal with this serious problem. Although some surgeons used to release the ankylosis and correct the secondary deformities simultaneously, we prefer to select a staged approach for the treatment plan. Like the current cases reported here, we have applied a two-stage protocol, composed of arthoplasty as the initial surgery, followed by orthodontic treatment, and correction of mandibular deficiency with DO and genioplasty for the treatment of the ankylosis patients with dentofacial deformities. Our experience suggests that this combined treatment not only restore oral and respiration functions but also improve the patient’s aesthetic appearances. Conflict interestNone declared.References1. ANANTANARAYANAN P, NARAYANAN V, MANIKANDHAN R, KUMAR D. Primary mandibular distraction for management of nocturnal desaturations secondary to temporomandibular joint ankylosis. Int J Pediatr Otorhinolaryngol 2008: 72:385-389.2. CASCONE P, AGRILLO A, SPUNTARELLI G, ARANGIO P, IANNETTI G. Combined surgical therapy of temporomandibular joint ankylosis and secondary deformity using intraoral distraction. J Craniofac Surg 2002:13:401-409.3. CHANG EW, LAM SM, KAREN M, DONLEVY JL. 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Sleep apnea in mandibular hypoplasia. Plast Reconstr Surg 1982:70:213-216.15. RAO K, KUMAR S, KUMAR V, SINGH AK, BHATNAGAR SK. The role of simultaneous gap arthroplasty and distraction osteogenesis in the management of temporo-mandibular joint ankylosis with mandibular deformity in children. J Craniomaxillofac Surg 2004: 32: 38-42.16. SANTOS JUNIOR JF, ABRAHAO M, GREGORIO LC, ZONATO AI, GUMIEIRO EH. Genioplasty for genioglossus muscle advancement in patients with obstructive sleep apnea-hypopnea syndrome and mandibular retrognathia. Braz J Otorhinolaryngol 2007:73:480-486.17. SWENNEN G, SCHLIEPHAKE H, DEMPF R, SCHIERLE H, MALEVEZ C. Craniofacial distraction osteogenesis: a review of the literature: Part 1: clinical studies. Int J Oral Maxillofac Surg 2001:30:89-103.18. ZHU SS, HU J, LI J, LUO E, LIANG X, FENG G. Free grafting of autogenous coronoid process for condylar reconstruction in patients with temporomandibular joint ankylosis. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008:106: 662-667.Address: Jing HuDepartment of Oral and Maxillofacial SurgeryWest China College of StomatologySichuan UniversityChengdu 610041People’s Republic of China Tel: +86 28 8550 2334E-mail: drhu@vip.sohu.com