【作者】 刘海波；

【导师】 丁自海；

【作者基本信息】 南方医科大学 ， 人体解剖与组织胚胎学， 2010， 博士

【摘要】 背景：下颌角肥大(prominent mandibular angle)导致的方脸畸形在东方人群中比较常见,这不太符合东方人要求的曲线优美(以下面部较狭小的椭圆形或叫鹅蛋形为美)的审美标准,被称之为不美脸型。近年来,随着人们物质文化生活水平的提高,人们对自身型体美的要求也在不断提高。要求通过手术来改变面部轮廓,塑造完美脸型的整形患者也越来越多。国内国外学者也对其进行了多方面的研究。目前,下颌角肥大整形的手术入路包括口内入路、口外入路和口内、口外联合入路,各有不同的优缺点。目前应用较为广泛,为医生和患者所普遍接受的是口内入路,但存在截骨的量不易准确控制,对器械的要求高,存在口腔感染因素,术后口腔护理不便等缺点。实际工作中,有部分患者因为口内入路的缺点而不愿采用口内切口,也有部分患者欲同时进行下颌角整形和面颈部除皱,此时耳后切口就比较适用。近年有学者应用耳后微创切口进行下颌角肥大整形手术,也取得了满意的疗效。但因其是在盲视下操作,有存在误伤正常组织的可能。近一个世纪以来,内镜技术和应用得到了很大的发展,从最开始用于临床诊断,到广泛应用于临床各个手术领域。内镜手术一般适用于有自然体腔部位,如卵巢手术、胆囊手术、结肠手术等。近年开始有学者将其应用到口内入路行下颌角肥大整形手术。以往,关于下颌角肥大整形的解剖研究不少,但缺乏有针对性的、符合内镜手术特点和耳后入路相关下颌角周围组织解剖学研究。行耳后微创切口时,比较容易伤到耳大神经的分支。作为颈丛最大的皮神经,耳大神经经常被用作神经移植的供体,如面神经的缺损修复等。耳大神经浅段主干位置相对比较恒定。耳大神经浅段位于颈外静脉后方,胸锁乳突肌浅面,被颈阔肌所覆盖,位置比较表浅,容易在手术当中受到损伤。在以往的研究中,主要集中在对耳大神经主干的研究,而对于其分支的研究比较少。近年来,随着手术要求日趋微创化,有学者认为,对耳大神经分支的损伤可在一定时期内导致其支配区域感觉缺失或不适,建议尽可能的保护好其分支,尤其是耳后分支。手术中只要对耳大神经分支有意识的加以区分辨认,游离保护,往往可以不用占用很多手术时间。目的：1.进行有针对性的符合内镜手术特点和耳后入路相关下颌角周围组织解剖学研究。通过标本解剖观察,为进行耳后切口内镜辅助下模拟手术提供参考。2.通过内镜技术的应用,在标本上探索耳后切口内镜辅助下下颌角肥大整形术的可行性,观察记录其镜下解剖结构,为应用到临床摸索经验。材料和方法：1.耳后切口内镜辅助下下颌角肥大整形术相关解剖学研究：新鲜头部标本两例,福尔马林防腐固定头部标本13例,其中男性9例,女性6例,由南方医科大学解剖教研室提供。解剖器械及测量仪器：常用手术刀、剪、镊子,双目显微镜、数码相机、数子显示游标卡尺(精度0.01mm)、量角器等。对头颈部标本按照原有解剖层次从浅入深进行细致解剖,观察耳后切口到达下颌角区域的合适入路层次和途经的重要解剖结构；测量耳根部到下颌角顶点的距离,面神经下颊支与下颌缘支之间在咬肌后缘处的距离；观察耳大神经的浅出点、位置、与颈外静脉的关系,及其分支分布情况；耳大神经各分支解剖到近耳廓处,用数码相机予以拍照记录：测量耳大神经的主干浅出段长度、宽度(以中点处测量值为准),耳大神经各个分支的长度、宽度(以中点处测量值为准),各分支到耳廓的近耳点到耳根部的距离,耳大神经主干的分支点到耳根的距离以及分支点与耳根连线与过分支点的水平线的夹角。利用统计学软件SPASS13.0对所测量的数值进行统计学分析,采用独立样本T检验方法分析数据。2.耳后切口内镜辅助下下颌角肥大模拟整形术：5例经福尔马林固定处理的防腐头颈部标本,由南方医科大学解剖教研室提供。器械：图像采集系统、监视器、冷光源,0°和30°长17cm、直径4mm的鼻窦内窥镜,眼科剪、骨膜剥离子、弯镊及常用手术器械。切口设计和操作：在耳垂中点后方沿着颅耳沟向上作一长约2cm的切口,向下颌角方向,钝性分离,同时插入内镜,通过内镜视野,在监视器的影像指引下操作,观察入路的层次解剖结构,照相记录。结果：1.下颌角最突点距耳根的距离在男性为(3.45±0.50)cm,在女性为(3.22±0.52)cm。从耳后切口到下颌角区,有两个潜在的层次空间作为手术入路,即SMAS与浅面皮肤、皮下组织层之间的层面,以及SMAS与深面腮腺咬肌筋膜之间的层面。在咬肌后缘,面神经下颊支、下颌缘支之间的距离在男性左侧为(2.75±0.29)cm,男性右侧为(2.82±0.28)cm,女性左侧为(2.79±0.30)cm女性右侧为(2.83±0.28)cm。走行于咬肌筋膜中的神经、血管与耳后入路关系密切的包括面神经下颊支、下颌缘支,以及咬肌后缘的下颌后静脉,面动、静脉靠近咬肌前缘,与下颌角距离较远,只要不过度向咬肌前缘游离,损伤的几率较小。下颌角、下颌支后缘与下颌后静脉紧密相邻,两者之间仅有骨膜及少量薄层脂肪组织相隔,下颌后静脉为耳后入路容易损伤的血管。下颌缘支一般位于下颌骨下缘上下一横指范围内。耳大神经源起第2、3颈神经,从颈丛发出以后,其深段走行于胸锁乳突肌深面,斜向外下方,在胸锁乳突肌后缘中点附近穿出深筋膜,到达皮下,在胸锁乳突肌表面斜行向前上方,到达胸锁乳突肌前缘后,走行于腮腺筋膜表面与颈阔肌深面之间,在下颌角水平附近分为3～4支,分别可称为耳后支、耳垂支和耳前支,分布到包括乳突区、耳廓颅侧、耳垂、耳垂前区的皮肤。大部分耳大神经走行于颈外静脉后方10mm左右,一部分与颈外静脉距离比较近,甚至紧贴着,呈伴行关系。大部分耳后静脉位于耳大神经深面,与下颌后静脉后支汇合成颈外静脉；有一部分耳大神经在颈外静脉后方走行一段后,先走行在耳后静脉深面,后移行至耳后静脉浅面,呈绕行状态。耳大神经耳前支发出后,越过耳垂下端,分布到耳垂前区的皮肤(18侧,占69.2%)；也有部分分支进入腮腺(8侧,占30.8%)。除去耳前分支,耳大神经在耳后可以找到3支分支,其中前两支共干者居绝大多数(21侧,占80.8%)；部分为后两支共干(4侧,占15.4%)；有1侧(占3.8%)分成4支,前后两两共干。统计分析结果：左侧耳大神经总干长度、耳后分支1和2的长度、主干分支点距耳根距离、耳后分支3的宽度在性别上有统计学差异(P<0.05),男性的测量值略大于女性,其余各值在性别上无统计学差异(P>0.05)；右侧耳大神经分支2的长度,各分支的近耳点距耳根的距离在统计学上有差异(P<0.05),其余各值在性别上无统计学差异(P>0.05)。2.在标本模拟手术中,切开皮肤后,向着下颌角方向作钝性分离,在皮下容易发现耳大神经的分支。将皮下通道分离扩展为约2cm宽,使通道内可以同时容纳内窥镜和剥离器械。在游离过程中,如果耳大神经分支的部位比较高,则可以看到其分支点,和与其相邻的耳后静脉。继续向前下游离,到达腮腺咬肌筋膜表面。沿着腮腺咬肌筋膜向前下方到达下颌角后缘区域,可能看到沿下颌角后缘下行的下颌后静脉。钝性分离咬肌表面筋膜,可显露部分咬肌,钝性分离咬肌,可到达下颌骨骨膜表面。到达下颌骨骨膜表面后,用长柄尖刀切开骨膜,可直达下颌骨骨质。然后沿骨面用骨膜剥离子向前剥离,必要时可离断部分咬肌。充分暴露下颌角内、外侧需要切除的范围。充分暴露下颌角内、外侧后,利用微型锯按照预先设计好的截骨范围锯除突出下颌角骨质,因操作空间狭小,可分多次锯除。结论：1.通过内镜辅助,从耳后入路行下颌角肥大整形术具有可行性；手术入路可从SMAS与皮肤、皮下组织层之间的层面,或者SMAS与深面腮腺咬肌筋膜之间的层面进行；术中应注意对耳大神经分支、面神经下颌缘支、下颌后静脉、面动静脉的保护。2.耳大神经主干具有较为恒定的位置和走行；耳大神经与颈外静脉的关系密切,临床手术中要加以重视；通过对耳大神经分支的测量统计,可以大致确定耳大神经分支在耳后的分布,为耳后切口手术设计、手术施行提供参考,减少耳大神经主干及分支的损伤；耳大神经分支可以作为耳后切口内镜辅助下下颌角肥大整形术手术入路分离层面参考标志。3.耳后切口内窥镜辅助下下颌角肥大整形手术是一种新的、有效的手术方式的尝试。具有创伤小,操作简单易行的特点。手术通道需要人为创建,无自然腔隙,须熟悉局部解剖,手术过程中要避免损伤耳大神经分支、面神经分支和下颌后静脉等。更多还原

【Abstract】 Background:In the east,the people who had square face,because of prominent mandibular angle were very common.It didn’t fit the beauty standard of the people,who thinked that the oval-shaped face was beautiful. Nearly, As the improving of the people’s material and cultural living standards, there were more and more people had come to do the plasty operation to change the facial contour for the purpose of beauty.There were many researches about this in the world.To the approach for prominent mandibular angle plastic surgery,there were intraoral approach,extraoral approach and combined intraoral, extraoral approach.Each approach had its own advantages and disadvantages.The intraoral approach was used widely now,but it had the disadvantages such as,the requiring for instrument was high,to control the scope of osteotomy was not easy,the possibility of oral cavity infection and the inconvenience after the operation.So there were people who didn’t want to do the operation with intraoral approach for those reasons.When the people want to do both the face lifting and the prominent mandibular angle contouring surgery on the same time,the postauricular incision approach was suitable.During the last centuries,the techniques and clinical applicaton of endscope have enjoyed great development.It was used for clinical diagnose in the first time,then used in a lot of regions of clinical operations.The endscope was used in the operation on the body where it had nature celom generally, such as operation on oarium,gallbladder,colon and so on. Endoscopically assisted prominent mandibular angle contouring surgery with intraoral approach was used widely.Some doctors did prominent mandibular angle contouring surgery with postauricular minimal incision and achieved satisfactory results.nearly,but it did with bad visual fields,the opportunity to hurt the normal tissues was existed.There were many anatomy studies about the operation,but for the endoscopically assisted prominent mandibular angle contouring surgery with postauricular incision was absence.When did the operations with postauricular minimal incision,the branches of the great auricular nerve were very easy to be hurted. As the great cutaneous nerve of the cervical plexus, the great auricular nerve(GAN) was used for the neural transplantation donors,such as it was used for repairing the facial never injury.The shalloe section of the GAN is traveling steadily.It is covered by platysma,behind the external jugular vein,above the sternomastoid muscle and it is easy to hurt during the operation.The early researchs were focus on the nerve trunk of the great cutaneous nerve and little about the branches of the nerve.Some doctors suggested to study and protect the branches of the great cutaneous nerve,because the injury to the GAN would lead to some sensory losses,especialy the posterio branches.It would not take a long time to protect the branches during the operations. Objective:1.To do the anatomy research with the tissues about the mandibular angle aimed at the purpose to operate endoscopically assisted prominent mandibular angle contouring surgery with postauricular minimal incision.2. Try to operate endoscopically assisted prominent mandibular angle contouring surgery with postauricular minimal incision on the cadavers,to make sure the feasibility,to observe the anatomy structures through the endoscope.Methods:1. The clinical anatomical study to the endoscopically assisted prominent mandibular angle contouring surgery with postauricular incision.15 cadavers(6 females,9 males) offered by Department of anatomy,School of basic medical sciences,Southern medical university were used in the study.Instument:scalpel,scissors,forceps,binocular microscopes,digital camera, digital vernier,protractor.With neck specimens, detailed dissected from shallow to deep-level according to the original anatomy, to observe important anatomical structures from the postauricular incision to the mandibular angle, and the appropriate approach of the regional level. To measure the distance between root of the ear to the mandibular angle vertices, distance between facial lower buccal nerves and marginal mandibular branch at the masseter muscle trailing edge.To study the point where the great cutaneous nerve emerges from sternomastoid muscle,it’s traveling line,the relationship with the external jugular vein, the branches’s traveling line.To measure the length of the GAN trunk, the each length and width of the GAN’s branches after the auricle, the distance from the point where the GAN divided into branches to the below end point of the auricle, the angle between the line 1 (from the point where the GAN divided into branches to the below end point of the auricle)and line2(the horizon line passing through the point where the GAN divided into branches), the distance from the points where the branches traveling into the auricle to the below end point of the auricle.The software Spass13.0 was used for data statistics.The Independent-sample T Test was used to analysis the datas.2. Endoscopically assisted prominent mandibular angle contouring surgery with postauricular incisionFive cadavers offered by Department of anatomy,School of basic medical sciences,Southern medical university were used in the study.Instument:Image acquisition system,PC monitor,luminescence source,endscopes(4cm×17cm,0°and 30°),eye scissors,periosteal strippings,bending forceps,and so on.The incision design and operation:Cut the skin with postauricular minimal incision,the incision’s length was about 2cm,then separated the tissues bluntly with endoscope assisted.Through the endoscope assisted, the anatomical structures were observed on the PC monitor and the photos were taken.Results:1. After section of the skin,the branches of the great auricular nerve could be found easily. Separating the tissues bluntly with endoscope assisted, then to made a internal port with 2cm width.In some of cases,we could find the point where the great auricular nerve divide into 3 or more branches and the posterior auricular vein nearly during the oprations.Along the surface of the parotid gland fasciae to surface of the mandibular angle,we may find the retromandibular vein nearly in the area.Then incised the periosteum with sharp pointed scalpel and stripped the periosteum with periostotome. Then stripped the region where the masseter muscle stick to the mandibular angle.To make sure that the mandibular angle was exposed fully include superficial surface and deep surface of the angle, before cut the prominent mandibular angle.Then cut off some bone of the mandibular angle with the minimal saw.lt could be saw for a few times,for the operation field was limited. All these were done with endoscope assisted.2. The distance between root of the ear to the mandibular angle vertices was (3.45±0.50) cm in males,and (3.22±0.52) cm in females.There were two approach room for the operation, one was between the skin and the SMAS,another one was between the SMAS and masseteric fascia. The distance between facial lower buccal nerves and marginal mandibular branch at the masseter muscle trailing edge was (2.75±0.29) cm at left side of males, (2.82±0.28) cm at ringht side of males, (2.79±0.30) cm at left side of females, (2.83±0.28) cm at right side of females.The lower buccal branches,marginal mandibular branches, retromandibular vein,facial vein,facial artery was located in the masseteric fascia and was easily to hurt during the operation. The retromandibular vein was much close to the mandibular angle,the marginal mandibular branches were located one finger upper or inferior of the bottom edge of the mandibular.The great auricular nerve may originate from the anastomotic loop between the second and third cervica nerves, or directly from the latter.Immediately after its origin,it passes around the posterior margin of the sternocleidomastoid muscle and then proceed antero-superioly to parotid capsule and then divides into anterior and posterior terminal branches.In most of the cases, the GAN was about 10mm behind the external jugular vein.In few of the cases,the GAN was very closer to the external jugular vein. In most of the cases, the GAN was nealy above the posterior auricular vein,but the GAN winded around the posterior auricular vein In some of cases. The GAN divides into 3-4 branches in the plane of mandibular angle,those were called anterior auricular branch, lobe branch and posterior branch by some scholars.The anterior auricular branch spreaded into the skin(18sides,64%) or parotid(10sides,36%).There were three or more branches after the ear.In most of the cases,the first two branches had common trunk(23sides,82.1%).In some of the cases,the last two branches had common trunk.At one side there was four branches,each two had common trunk.In the left side,the middle length of the GAN trunk, length of the GAN’s branches(NO1,NO2), the distance from the point where the GAN divided into branches to the below end point of the auricle after the auricle, and the width of NO3 GAN’s branches had statistic difference between sex (P<0.05); In the right side, the length of the GAN’s branches(NO2)and each of the distance from the points where the branches traveling into the auricle to the below end point of the auricle had statistic difference between sex (P<0.05).Conclusion:1.With endoscopically assisted,to do the prominent mandibular angle contouring surgery was practicable;The approach could from the space between skin and SMAS,or the space between SMAS and parotid gland fascia; Pay attention to the GAN’s branches, marginal mandibular branches, retromandibular vein,facial vein,facial artery during the operation.2. The GAN has a constant traveling line and place.The relationship between the GAN and the external jugular vein was very close in some of the cases,which shoud arouse high attention by the operators.The study about the GAN branches would help the operators to design the postauricular incision,protect the GAN and it’s branches during the operations. The GAN’s branches could be the mark to the surgery approach space.3.It was a new and effective way to do the operation of endoscopically assisted prominent mandibular angle contouring surgery with postauricular minimal incision. The trauma was limited and the process was not complicated.During the operation,in order to prevent injury to the branches of the great auricular nerve, branches of the face nerve, and the retromandibular vein,the anatomical structures should be mastered.更多还原