耳后发际入路内镜辅助下颌下腺切除术的解剖研究

目的　为耳后发际入路内镜辅助下颌下腺切除术提供解剖学依据,并评价其可行性和安全性。 方法　新鲜尸体15具（30侧）,观测耳后发际区和颌下区的解剖层次及重要结构。新鲜尸体5具（10侧）,模拟内镜手术,术后解剖标本,观察有无神经、血管损伤。 结果　耳后发际区的分离层面在表浅肌肉腱膜系统与颈深筋膜浅层之间。胸锁乳突肌上部浅面,由后上至前下依次为枕小神经、耳大神经、颈外静脉。颌下区的分离层面在颈阔肌深面与下颌下腺鞘膜之间。下颌缘支出腮腺后：①66.7%行于下颌骨下缘之上（7.21±0.50）mm;②23.3%平行下颌骨下缘;③10％行于下颌骨下缘以下（9.43±0.32）mm。在咬肌前下角处,面神经下颌缘支均与面动脉和面静脉交叉,交叉点至下颌角距离分别为（29.86±2.77）mm和（25.71±3.32）mm。舌下神经经茎突舌骨肌和二腹肌后腹深面进入颌下区。舌骨舌肌浅面,自上而下分别是舌神经、下颌下腺导管、舌下神经。10侧模拟手术顺利完成,术中无重要结构损伤,无需中转切口。 结论　熟悉耳后发际区和颌下区的解剖层次、标志及参数,耳后发际入路内镜辅助下颌下腺切除术安全、可行。     

Mandibular landmarks as an aid in minimizing injury to the marginal mandibular branch: A metric and geometric anatomical study

Iatrogenic injury to the marginal mandibular branch is an important reason for medicolegal actions. The aim of this study was to determine the distance of the marginal mandibular branch to the inferior border of the mandible as well as variation of nerve position in relation to this border. The marginal mandibular branch was dissected carefully in a number of 36 facial halves. Three points were identified on the inferior border of the mandibular ramus: Point A at the angle of the mandible, Point B just anterior to the facial artery, and Point C, 2 cm anterior to Point B. A metric and geometric morphometric analysis, including thin-plate spline and relative warp analysis was done to determine the variation of nerve position in relation to these three bony landmarks. The metric study indicated a median distance from Point A to the nerve 2.3 mm inferior to Point A, 2.4 mm superior to Point B, and 10.7 mm superior to Point C. The shape analysis indicated that variation in the position of the nerve occurs most commonly at Points A and B. We conclude that these mandibular landmarks may assist surgeons in minimizing marginal mandibular branch injury and patient discomfort.     

面神经下颌缘支的应用解剖

目的了解面神经下颌缘支的正常层次解剖位置,为涉及面侧区和颌下区的美容外科手术提供临床应用解剖学资料。方法解剖33具（共66例）成人尸体标本的头颈部标本,观察了面神经下颌缘支的分支类型、走行、与面动脉的位置关系以及穿出腮腺处和与面动脉的交叉处的体表位置。结果面神经下颌缘支为1-2支,以单干型居多,约占58%,大多行于下颌骨下缘上方约占44%,行于骨下缘下方者占5%。未发现面神经下颌缘支不与面动脉交叉,位置在均下颌角下缘上、下方约0.5-1 cm范围内。面神经下颌缘支经过面动脉的浅面和深面者分别占89%和6%;面神经下颌缘支穿出腮腺处的体表位置分别在下颌角上方和下颌支后缘前方1 cm交点附近,面神经下颌缘支与面动脉交处距下颌支后缘约4 cm,距下颌骨下缘约1 cm。结论面神经下颌缘支的毗邻和行程关系较为复杂,了解其与周围结构的重要位置关系,可以减少美容外科手术因神经损伤造成下唇及口角功能障碍的发生。     

Surgical Anatomy of the Marginal Mandibular Nerve: A Systematic Review and Meta-Analysis

The high number of marginal mandibular nerve (MMN) anatomical variants have a well-known clinical significance due to the risk of nerve injury in several surgical procedures. The aim of this study was to find and systematize the available anatomical data concerning this nerve. The PubMed and Scopus databases were investigated in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. All studies reporting extractable data on the origin, course, splitting, anastomosis and relationship of the MMN with the mandible or the facial vessels were included. We included 28 studies analyzing 1861 halves. The MMN had one (PP = 35% 95% CI:18–54%), two (PP =35% 95% CI:18–54%), three (PP = 18% 95% CI:0–35%), or four branches (PP = 2% 95% CI:0–8%). Anastomosis with the great auricular nerve, transverse cervical nerve, mental nerve, and other branches of the facial nerve were defined. The origin of the MMN in relation to the parotid and the mandible was variable. The MMN nearly always crossed the anterior facial vein laterally (PP = 38% 95% CI:9–72% if single, PP = 57% 95% CI:22–90% when multiple); its relation with other vessels was less constant. At least one branch of the MMN was found below the inferior border of the mandible (IBM), with a PP of 39% (95% CI:30–50%). The MMN has high anatomical variability and it is more often represented by one or two branches; its origin is frequently described at the parotid apex and above the IBM, although in its course at least one branch often runs below the IBM. Its most frequent anastomosis is with the buccal branch of the facial nerve. Clin. Anat., 33:739–750, 2020. © 2019 Wiley Periodicals, Inc.     

腮腺内下颌后静脉与面神经关系的解剖学研究

为了避免腮腺外科手术过程中损伤面神经，对３１具成年尸体（５７侧）腮腺内下颌后静脉与面神经关系进行解剖学研究。结果如下：下颌后静脉直径５．６±１．０ｍｍ。下颌后静脉位于面神经上、下干（或上、中、下干）内侧有５０侧（８７．８％）；位于面神经上干内侧，而在下干外侧有７侧（１２．３％）。依据下颌后静脉横过面神经不同部位，又分成若干亚型。其中较为常见者为下颌后静脉在面神经总干分支点与下干分支点之间的内侧横过（３３．３％）。在２６具双侧解剖的尸体中，有４例（１５．４％）下颌后静脉与面神经关系左、右侧不同     

A method for locating the marginal mandibular branch of the facial nerve in the neck

In order to avoid injury to the marginal mandibular branch of the facial nerve during surgery in the face and neck, a simple method for locating this branch was devised. The anatomical relations between the marginal mandibular nerve and both the facial artery and vein were analyzed in 19 dissection preparations. The following distances were considered: (1) the angle of the mandible to the intersection point nerve-vein; (2) mandibular angle to the facial artery; (3) inferior mandibular margin to the intersection point nerve-vein; (4) facial artery to the intersection point projection nerve-vein; (5) facial artery to the intersection point projection nerve-vein on the inferior mandibular margin; and (6) facial vein to the facial artery. These data are useful for an easier localization of the marginal mandibular nerve in the submandibular region. All reference points employed are easily detected in a living subject.     

Anatomical study of the zygomatic and buccal branches of the facial nerve: Application to facial reanimation procedures

The facial nerve is responsible for any facial expression channeling human emotions. Facial paralysis causes asymmetry, lagophthalmus, oral incontinence, and social limitations. Facial dynamics may be re‐established with cross‐face‐nerve‐grafts (CFNG). Our aim was to reappraise the zygomaticobuccal branch system relevant for facial reanimation surgery with respect to anastomoses and crossings. Dissection was performed on 106 facial halves of 53 fresh frozen cadavers. Study endpoints were quantity and relative thickness of branches, correlation to “Zuker's point”, interconnection patterns and crossings. Level I and level II branches were classified as relevant for CFNG. Anastomoses and fusion patterns were assessed in both levels. The zygomatic branch showed 2.98 ± 0.86 (range 2–5) twigs at level II and the buccal branch 3.45 ± 0.96 (range 2–5), respectively. In the zygomatic system a single dominant branch was present in 50%, two co‐dominant branches in 9% and three in 1%. In 66% of cases a single dominant buccal twig, two co‐dominant in 12.6%, and three in 1% of cases were detected. The most inferior zygomatic branch was the most dominant branch (P = 0.003). Using Zuker's point, a facial nerve branch was found within 5 mm in all facial halves. Fusions were detected in 80% of specimens. Two different types of fusion patterns could be identified. Undercrossing of branches was found in 24% at levels I and II. Our study describes facial nerve branch systems relevant for facial reanimation surgery in a three‐dimensional relationship of branches to each other. Clin. Anat. 32:480–488, 2019. © 2019 Wiley Periodicals, Inc.     

The nerve supply of zygomaticus major: Variability and distinguishing zygomatic from buccal facial nerve branches

The zygomaticus major (ZM) is important for the human smile. There are conflicting data about whether the zygomatic or buccal branches of the facial nerve are responsible for its motor innervation. The literature provides no precise distinction of the transition zone between these two branch systems. In this study, a definition to distinguish the facial nerve branches at the level of the body of the zygoma is proposed. In the light of this definition, we conducted an anatomical study to determine how the source of innervation of the ZM was distributed. A total of 96 fresh‐frozen cadaveric facial halves were dissected under loupe magnification. A hemiparotidectomy was followed by antegrade microsurgical dissection. Any branch topographically lying superficial to the zygoma or touching it was classed as zygomatic, and any neighboring inferior branch was considered buccal. The arborization of the facial nerve was diffuse in all cases. In 64 out of 96 specimens (67%, 95% CI: 56% to 76%), zygomatic branches innervated the ZM. Buccal branches innervated ZM in the other 32 facial halves (33%, 95% CI: 24% to 44%). There were no differences in respect of sex or facial side. All facial halves displayed additional branches, which crossed the muscle on its inner surface without supplying it. In 31 specimens, a nerve branch ran superficial to ZM in its cranial third. According to our classification, the zygomaticus major is innervated by zygomatic branches in 67% of cases and by buccal branches in 33%. Clin. Anat. 31:560–565, 2018. © 2018 Wiley Periodicals, Inc.     

下颌角肥大整形术相关解剖

目的 精细解剖下颌角周围软组织结构及下颌神经管,为下颌角肥大整形术提供解剖学参考。 方法 20例大体标本,观察及测量面动静脉、面神经下颌缘支及咬肌区的血管和神经。据下颌骨表面骨性标志定位5条径线,测量该5条径线上下颌神经管在下颌骨中的位置。计算各软组织结构和下颌神经管的安全范围。 结果 面动脉距下颌角点为23.18～36.28 mm,距咬肌前缘为-9.51～9.27 mm。面静脉距离下颌角点为17.79～32.03 mm。面神经下颌缘支贴近下颌角部及下颌骨下缘走行,距离下颌角点为-8.57～10.70 mm,而咬肌前缘下颌缘支距下颌骨下缘为-8.83～11.06 mm。咬肌的血供主要有面动脉咬肌支、颈外动脉咬肌支、上颌动脉咬肌支及面横动脉咬肌支这四大来源。咬肌神经多与咬肌动脉伴行进入咬肌。下颌神经管在5个截面中距离下颌骨外侧点分别大于10.50 mm、14.72 mm、15.60 mm、8.53 mm、6.74 mm。 结论 在剥离下颌角区软组织时,注意对咬肌前缘面动脉、面神经下颌缘支及下颌角点附近面神经下颌缘支的保护。去除咬肌的最佳层次为咬肌深层中份最厚点及中下份。而在截骨或劈骨时,根据下颌神经管的安全范围,可在下颌骨颊侧骨板快速画出一条指导性的安全线。     

The facial artery of the common marmoset (Callithrix jacchus)

The facial artery and its ramifications in 7 adult common marmosets (Callithrix jacchus) were studied by the plastic injection method. The findings obtained are discussed in comparison with those for other primates. In the submandibular region, the facial artery arose from the external carotid artery at the height of the atlas via the linguofacial trunk on 10 of the total of 14 sides examined and independently on the other 4 sides. This common trunk always gave rise to the superior thyroid artery. The facial artery passed anterolaterally between the styloglossus muscle and the intermediate tendon of the digastricus muscle, giving off the styloglossal and the submandibular glandular branches, and anteroinferiorly medial to the pterygoideus medialis muscle. In a position anterior to this muscle, the submental artery and masseteric branch were derived. The submental artery gave off the medial pterygoid, the digastric, the cutaneous, the sublingual glandular and the mylohyoid branches, and then continued up to the median line, where it terminated to supply the genioglossus muscle. In the facial region, the facial artery passed anterosuperiorly along the anterior margin of the masseter muscle on 12 sides and away from it forwards on 2 sides, giving off the premasseteric branch in one of these 2 sides. It gave rise to the cutaneous, the buccal and the buccinator branches, the inferior labial artery and the communicating branch with the zygomatic artery. It terminated to divide into the superior labial and the naris lateral arteries, although the latter was lacking on 4 sides. The inferior labial artery gave off the mandibular marginal, the inferior labial marginal and the inferior labial glandular branches and terminated to anastomose with the mental artery. The superior labial artery divided into the superficial and deep branches, each of which continued as a nasal septal branch. The facial artery of the common marmoset usually ascended along the anterior margin of the masseter muscle and did not reach the medial angle of the eye.     

经颈外静脉穿刺置管的应用解剖

在80侧成人尸体上进行了颈外静脉应用解剖学研究.它的合成类型共分6型,其中以下颌后静脉后支、耳后静脉后支和耳后静脉合成面静脉后再注入者较多(46.3％);属支除常见的颈横静脉、颈前静脉外,尚有头静脉注入:其末端以注入锁骨下静脉较多(58.7％).颈外静脉自甲状软骨上缘至汇入其它静脉的注入点的平均长为77.5±1.5mm,颈横神经在锁骨上方62.1±1.2mm处横越颈外静脉深面.文中讨论了经颈外静脉穿刺置管的部位和术中注意问题.     

Branching pattern of the external branch of the superior laryngeal nerve and its clinical importance

The external branch of the superior laryngeal nerve gives off many branches above the upper pole of the thyroid gland. Differentiating the branch innervating the cricothyroid muscle from the others may be important during surgery. Therefore, we aimed to demonstrate the branching pattern of this nerve in detail. In 34 human cadavers (59 sides), branches of the nerve were exposed and measurements related to them and neighboring structures were made. A cricothyroidal branch was present on all sides. This branch pierced the inferior pharyngeal constrictor muscle 3.9-17.6 mm above, 3.1-9.9 mm below, or at the level of the upper pole of the thyroid gland. On all sides, the nerve provided one or two thyroidal branches. The thyroidal branch was generally thinner than the cricothyroidal branch. But they were equal in size on three (5%) sides. The external laryngeal nerve provided two or three pharyngeal branches on all sides. These branches arose from the nerve 3.5-12.7 mm from the upper pole of the thyroid gland. Although the branch was generally thinner than the cricothyroidal branch, both branches were equal on four (6.7%) sides. Two cardiac branches were observed on two (3.3%) left sides. In conclusion, the cricothyroidal branch was generally thicker than the other branches. But on seven (11.8%) sides, thyroidal or pharyngeal branches and the cricothyroidal branch were equal in size. These data may be important during surgery as the surgeon may confuse the cricothyroidal branch with other branches of the external laryngeal nerve.     

面神经颊支的应用解剖

目的：观测分析面神经颊支的分支类型及其与腮腺管之间的解剖关系，为腮腺区手术提供解剖学基础。方法：60例成人头部标本，观测面神经颊支的分支类型、行程、神经与腮腺管的位置关系。结果：面神经颊支以双干型多见(58．3％)，三干型次之(28．3％)。神经多行于腮腺管浅面(73．3％)。腮腺管走行在颊支之问的占61．7％，导管距上颊支垂直距离约4．86mm；腮腺管走行在神经下方者占11．7％，距下颊支的垂直距离约1．71mm；腮腺管走行在神经上方者占26．7％，距上颊支的垂直距离约2．56mm。结论：面神经颊支多行于腮腺管浅层，与腮腺管关系十分密切，腮腺区手术时循颊支向后追踪面神经是比较安全、有效的方法，容易掌握。     

颈腮区手术中耳大神经的临床解剖学观察

目的 研究耳大神经的应用解剖学,为颈腮区相关手术提供临床解剖资料。方法 选取安徽医科大学第一附属医院耳鼻咽喉头颈外科2010年11月—2013年10月45例（52侧）头颈腮腺区手术病例进行前瞻性研究,在手术中观察耳大神经出肌点的位置、行程、分支点、分支及其与颈外静脉之间的关系。其中全颈淋巴结清扫术25例（32侧）、腮腺恶性肿瘤手术4例、咽旁间隙肿瘤16例。结果 耳大神经多于胸锁乳突肌后缘中点上下10mm范围内穿出占94．2％（49／52）,并多以单干形式上行,在胸锁乳突肌前缘、腮腺尾部以及下颌角下方10mm左右分成前、中、后3个终支。耳大神经伴行于颈外静脉的后方上行（间距不超过20mm）。结论 耳大神经解剖变异较大,其主干与颈外静脉关系密切,手术时尽可能避免耳大神经损伤。     

下颌后静脉的应用解剖分析

目的研究下颌后静脉的解剖学特点,为避免下颌角截骨术中因血管损伤而出血提供解剖学依据。方法选取30具经过甲醛溶液固定的成年人尸体作为解剖对象。对其下颌后静脉的解剖位置、组成、回流以及和周围组织的毗邻关系进行研究。结果大部分的下颌后静脉（91.38%）是由上颌静脉以及颞前静脉合成,其与下颌角的关系主要以紧密结合型为主（70.69%）,其起始部位的外径为（5.62±2.58）mm,长度为（43.93±21.18）mm,在下颌支的后缘周围静脉的长度为（41.94±7.79）mm,在下颌体的下缘周围静脉的长度为（19.87±3.68）mm。结论下颌后静脉是管壁较薄、管径较大的血管,在下颌角截骨术中容易被破损。因此,在手术中必须熟悉其解剖结构,术中仔细操作,避免伤及下颌后静脉。     

Is the high submandibular transmasseteric approach to the mandibular condyle safe for the inferior buccal branch?

Purpose  

There are basically 3 main approaches for extra-articular mandibular condyle fractures: low cervical, retromandibular and preauricular. These include a risk of facial palsy affecting the marginal mandibular branch. We use a high submandibular transmasseteric approach featuring masseter section 10–20 mm above the mandibular basilar edge. Our null hypothesis was that both the marginal mandibular and the inferior buccal branches are not more at risk than in other surgical approaches.     

An anatomical study of the levator veli palatini and superior constrictor with special reference to their nerve supply

We dissected 50 head halves of 25 Japanese cadavers (10 males, 15 females) to investigate the innervations of the levator veli palatini (LVP) and superior constrictor pharyngis. The branches supplying the LVP were classified into the following three types according to their origins: supplying branches that originated from the pharyngeal branch of the glossopharyngeal nerve (type I, four sides, 8%), branches that originated from a communicating branch between the pharyngeal branches of the glossopharyngeal and vagus nerves (type II, 36 sides, 72%), and those that originated from the pharyngeal branch of the vagus nerve (type III, 10 sides, 20%). In previous studies, supplying branches of type I were seldom described. Regarding the innervation of the superior constrictor, some variations were observed, and we consider it likely that there is a close relationship between these variations and the type of innervation of the LVP.     

Anatomic landmarks of the buccal branches of the facial nerve

The aim of this study was to classify the buccal branches of the facial nerve in relation to the parotid duct and its relevance to surgical procedures such as rhytidectomy and parotid gland surgery. In this study, 30 cadaver heads (60 specimens) were dissected. The vertical and horizontal relationships between the buccal branches of the facial nerve and tragus, and parotid duct were recorded and analyzed. The buccal branches of the facial nerve were classified into four types: Type I: a single buccal branch of the facial nerve at the point of emergence from the parotid gland and inferior to the parotid duct. Type II: a single buccal branch of the facial nerve at the point of emergence from the parotid gland and superior to the parotid duct. Type III: buccal and other branches of the facial nerve formed a plexus. Type IV: two branches of buccal branch; one superior and one inferior to the duct at the point of emergence from the parotid gland. The buccal branches of the facial nerve are very vulnerable to surgical injury because of its location in the midface. For this reason, the surgeons who are willing to operate on this area should have a true knowledge about the anatomy of these branches.     

Variations in the anatomy of the posterior auricular nerve and its potential as a landmark for identification of the facial nerve trunk: a cadaveric study

The posterior auricular nerve (PAN) is the first extracranial branch of the facial nerve trunk. It innervates the posterior belly of the occipitofrontalis and the auricular muscles and contributes cutaneous sensation from the skin covering the mastoid process and parts of the auricle. This study was carried out to provide a detailed account of its anatomy and to ascertain its reliability as a surgical landmark for the facial nerve. Eleven facial sides from six formalin-fixed cadavers were dissected. The course and arborisation pattern of the PAN was observed, and its position of emergence from the facial nerve trunk (FNT) was measured. The PAN arose from the posterolateral aspect of the FNT 1.6-11.1 mm from the stylomastoid foramen (5.4 ± 3.3 mm). It arose as a single branch (45.4%), or from a common trunk that divided into two (36.4%) or three branches (18.2%), with the other branches passing into the parotid gland. The PAN continued deep (63%), or lateral to the mastoid process (9.1%), or through the tissue of the parotid gland (27.3%). In all cases the PAN ran in a consistent, superficial location posterior to the external auditory meatus. The PAN takes a variable course; however, its consistent location behind the external auditory meatus makes it easily identifiable in superficial dissection, and therefore a potential surgical landmark for identifying the FNT.