The frontotemporal peripheral nerves. Topographic variations of the supraorbital, supratrochlear and auriculotemporal nerves and their possible clinical significance

The peripheral topography of the supraorbital (SON) and supratrochlear (STN) nerves and the superficial temporal branch of the auriculotemporal nerve (ATN) was investigated in 10 cadavers. The aim was to define the optimal locations for anaesthetic nerve blocks, as well as to help surgeons prevent nerve injuries. Specific measurements on the nerve “exits” in relation to defined landmarks are presented. The variability of the supraorbital notches and peripheral branching of the dissected nerves suggests several methods for anaesthetic blocks in cases of surgical and clinical head pain. The optimum injection site for a selective SON block is 20-30 mm from the midline (range 15-33 mm) reinjection at 30-50 mm from the midline might complete inefficient nerve block. For selective SON block the distance between the main SON and STN branches (mean 15.3 mm) should also be considered. The ATN is best blocked at a point located at the level with and 10-15 mm (range 8-20 mm) anterior to the upper origin of the helix. Separate exits for the medial and lateral SON branches were observed in eight of the 20 nerves examined. Twenty of the 28 exits were foraminae completed by bony or connective tissue. In many cases both the SON and STN ascended close to the associated artery in six cases a tissue band covered the nerve and vessel at the orbital exit. Some of the observed structures associated with the nerve might be pain-generators, however the present study does not provide any evidence for such a hypothesis.     

Localization of important facial foramina encountered in maxillo-facial surgery

Knowledge of the location of foramina in the maxillo-facial region is necessary in clinical situations requiring regional nerve blocks and in open as well as endoscopic surgical procedures to avoid injury to corresponding nerves. In this study, measurements were taken on 79 adult dried human skulls to determine the position of the supraorbital, infraorbital, and mental foramina. Supraorbital foramina were found to be approximately 25 mm lateral to the midline, 30 mm medial to the temporal crest of the frontal bone, and 2-3 mm superior to the supraorbital rim. Additional exits for branches of the supraorbital nerve were present in 14% of skulls. The intersection of the zygomatico-maxillary suture with the inferior orbital rim was a readily palpable landmark for locating the infraorbital foramen. This foramen was approximately 7 mm inferior to the inferior orbital rim and 28.5-mm lateral to the midline. Mental foramina were on average, 25.8-mm lateral to the midline and about 13-mm superior to the inferior mandibular margin. Both the infraorbital and mental foramina were most often on a vertical line with the second premolar (Position 3). The distances of the foramina from the midline were similar on both sides demonstrating facial symmetry. In about 80% of skulls, the supraorbital, infraorbital, and mental foramina/notches were along the same vertical line. These measurements may be of value to clinicians in localizing and safeguarding these nerves and providing effective nerve blocks.     

带腓肠外侧皮神经及其营养血管筋膜皮瓣的应用解剖

目的 为带腓肠外侧皮神经及其营养血管筋膜皮瓣的临床应用提供解剖学基础.方法 在32例成人下肢标本上,对腓肠外侧皮神经及其营养血管进行解剖观测.结果 腓肠外侧皮神经在腓骨头平面上方 7.1±2.4cm处起于腓总神经,分布于小腿后外侧上半或上2/3的皮肤.其营养动脉主要为:腓肠外侧皮动脉:起自腘动脉,在腓骨头平面上方5.0±1.5cm处浅出,外径为0.9±0.3mm;肌间隔筋膜皮支:起自胫后动脉和腓动脉,分别在腓骨头平面下方9.2±3.8cm和15.8±3.8cm处浅出,外径为0.7±0.3mm和0.9±0.4mm.该营养动脉除在腓肠外侧皮神经周围或其内呈链式吻合外,还发出筋膜皮支与邻位的皮动脉连接.静脉血可沿伴行静脉或小隐静脉及其属支回流至深静脉.结论 以腓肠外侧皮神经及其营养血管为蒂,可设计成顺行或逆行转位筋膜皮瓣,修复邻近部位的软组织缺损.     

内镜经眉弓上锁孔入路的解剖学研究

目的 探索内镜经眉弓上锁孔入路暴露颅底中线区域的解剖结构,为临床该术式切除颅底中线区域肿瘤提供解剖学基础。 方法 内镜经眉弓上锁孔入路解剖5具成人尸头标本,观察该入路暴露的颅底中线区域脑组织、血管及神经。 结果 内镜经眉弓上锁孔入路可充分暴露前床突及其内侧前颅底硬脑膜、嗅沟及嗅神经;蝶鞍区可显露视神经、视交叉、视交叉前间隙、垂体上动脉、眼动脉、颈内动脉及其周围间隙;上斜坡区域可显露鞍背硬脑膜、乳头体、基底动脉末端、小脑上动脉、大脑后动脉、后交通动脉、动眼神经、滑车神经、三叉神经、面神经、前庭蜗神经及脑桥腹侧。 结论 内镜经眉弓上锁孔入路切除颅底中线区域肿瘤在解剖学上可行,临床上可作为常规显微镜手术及经鼻内镜入路手术的有效补充。     

Surgical anatomy of the superficial temporal artery to prevent facial nerve injury during arterial biopsy

To investigate the topographical relationship between the frontal branch of the superficial temporal artery (FSTA) and the temporal branch of the facial nerve (TFN) with the aim of preventing nerve injury during FSTA biopsy. Fifty‐seven hemifaces of 33 cadavers were dissected. Vertical lines drawn to the lateral orbital margin (LOM) and the superior root of the helix were used as the anterior and posterior reference positions, respectively. Horizontal lines drawn through the supraorbital margin and lateral canthus were used as the superior and inferior reference points, respectively. The depth and course relationships of the FSTA and TFN were examined. Midpoints between the FSTA and TFN are situated approximately 6.0 and 4.5 cm posterior to the lateral orbital margin at the levels of the lateral canthus and supraorbital margin, respectively. The TFN is generally situated 1–2 cm anteriorly and inferiorly to the FSTA in the temporal region. However, in two cases (3.6%), the TFN ran just underneath the FSTA with only a very small safe distance, making it highly vulnerable to iatrogenic injury. In conclusion, when performing an FSTA biopsy, the surgeon should not dissect below the superficial temporal fascia because there is an overlap between the course of the FSTA and the TFN in a minority of cases. Also, surgical incisions should be made outside the area delineated by an oblique line passing through the points 6.0 and 4.5 cm posterior to the lateral orbital margin at the levels of the lateral canthus and the supraorbital margin, respectively. Clin. Anat. 31:608–613, 2018. © 2017 Wiley Periodicals, Inc.     

Anatomic study of the distal supraorbital nerve

This investigation was designed to extend our present knowledge of the supraorbital n. (SO n.) distal to the supraorbital notch. It is based on 40 dissected hemi-faces and the position of the notch and the periosteal and frontalis cutaneous branches of the SO n. were studied. The notch was 33.05 mm from the midline on the right side and 30,70 mm on the left. The periosteal branch arises from the lateral frontalis cutaneous branch. Its ascends in an oblique direction laterally and ends in two terminal branches. The frontalis cutaneous branch, after a very short trunk, divides into two branches, medial and lateral. The medial or deep branch enters the corrugator supercilii m. between its fibers. Most frequently, it passes under the inferior fasciculus and superficial to the middle and superior ones. Leaving the corrugator m., it ascends medially into the frontalis m., supplying the median cutaneous frontalis region. The lateral or superficial branch crosses superficial to the corrugator supercilii m. to penetrate the frontalis m. in an ascending and lateral direction, supplying the lateral frontalis region. The two branches enter the frontalis m., displaying a zigzag pattern in order to adapt its length during expressive movements. They cross the frontalis region together with the SO a. and two veins supplying the nerve and the frontalis m. These anatomic data may explain some of the complications after surgery for ptosis and blepharospasm.     

High and low lateral approaches to the popliteal artery

Using a series of 20 dissections and two anatomic transverse sections of a lower limb, the authors investigated the lateral approaches to the popliteal artery. The high lateral approach (above the knee) is not very aggressive and gives access to the retro-genicular part of the popliteal artery. After cutaneous and fascial incision, a simple gap between the vastus lateralis and biceps femoris mm. allows easy exposure of the popliteal vessels after backward retraction of the sciatic nerve. The low lateral approach to the artery (below the knee) is very aggressive for the vessels, nerves, and ligaments of the area. It involves the resection of the upper fourth of the fibula and the isolation and protection of the common peroneal nerve Nevertheless, these lateral approaches must be known and used when classic approaches (medial and posterior) are impossible.     

Anatomic study of the superficial sural artery and its implication in the neurocutaneous vascularized sural nerve free flap

Combined extended nerve and soft tissue defects of the upper extremity require nerve reconstruction and adequate soft tissue coverage. This study focuses on the reliability of the free vascularized sural nerve graft combined with a fasciocutaneous posterior calf flap within this indication. An anatomical study was performed on 26 cadaveric lower extremities that had been Thiel fixated and color silicone injected. Dissection of the fasciocutaneous posterior calf flap involved the medial sural nerve and superficial sural artery (SSA) with its septocutaneous perforators, extended laterally to include the lateral cutaneous branch of the sural nerve and continued to the popliteal origin of the vascular pedicle and the nerves. The vessel and nerves diameter were measured with an eyepiece reticle at 4.5× magnification. Length and diameter of the nerves and vessels were carefully assessed and reported in the dissection book. A total of 26 flaps were dissected. The SSA originated from the medial sural artery (13 cases), the popliteal artery (12 cases), or the lateral sural artery (one case). The average size of the SSA was 1.4 ± 0.4 mm. The mean pedicle length before the artery joined the sural nerve was 4.5 ± 1.9 cm. A comitant vein was present in 21 cases with an average diameter of 2.0 ± 0.8 mm, in 5 cases a separate vein needed to be dissected with an average diameter of 3.5 ± 0.4 mm. The mean medial vascularized sural nerve length was 21.2 ± 8.9 cm. Because of inclusion of the vascularized part of the lateral branch of the sural nerve (mean length of 16.7 ± 4.8 cm), a total of 35.0 ± 9.6 cm mean length of vascularized nerve could be gained from each extremity. The free vascularized sural nerve graft combined with a fasciocutaneous posterior calf flap pedicled on the SSA offers a reliable solution for complex tissue and nerve defect. Clin. Anat. 26:903–910, 2013. © 2012 Wiley Periodicals, Inc.     

带桡神经浅支及其营养血管筋膜皮瓣的应用解剖

目的:为带桡神经浅支及其营养血管筋膜皮瓣的临床应用提供形态学基础.方法:在32例成人上肢标本上,观测了桡神经浅支浅段及其营养血管、以及该血管与筋膜皮肤的供血关系.结果:桡神经浅交浅段的血供主要来自桡动脉的肌皮支或皮支,其中以桡动脉显露段的粗大皮支,鼻咽壶段的茎突返支及虎口区的皮动脉较为恒定,起点外径分别为0.8mm、0.7mm及0.6mm:穿出深筋膜前长分别为0.8cm、1.1cm及0.5cm.皮动脉的神经支在神经旁或神经干内相互沟通形成纵向链状血管网,并借吻合支与皮动脉筋膜皮支构成的皮下血管网、筋膜血管网等连接.结论:可设计成带桡神经浅支及其营养血管的顺行或逆行筋膜皮瓣,转位修复邻近部位的软组织缺损.     

The relationship of the posterior inferior cerebellar artery to cranial nerves VII-XII

The posterior inferior cerebellar artery (PICA) is the largest branch of the vertebral artery. It usually arises at the anterolateral margin of the medulla oblongata close to the lower cranial nerves. The PICA had the most complex relationship to the cranial nerves of any artery and it is frequently exposed in approaches directed to the fourth ventricle. The aim of this article is to describe the anatomical relationship of the PICA to the lower cranial nerves. In this study, 12.5% of PICAs passed between the glossopharyngeal and vagus nerves, 20% between the vagus and accessory nerves, and 65% through the rootlets of the accessory nerve. The lateral medullary segment of the PICA showed a lateral loop which in 20% specimens pressed against the inferior surfaces of the facial and vestibulocochlear nerves. The lateral medullary segment of the PICA in 20% specimens passed superior to the hypoglossal nerve, in 47.5% through the rootlets of the hypoglossal nerve, and in 30% inferior to the hypoglossal nerve. The findings on the relationship of the PICA to the lower cranial nerves could be helpful in microsurgery of this region.     

外踝术中腓肠神经和腓浅神经的应用解剖

目的　探讨外踝术中腓肠神经和腓浅神经损伤的风险 ,并分析损伤后感觉缺失情况。方法　在解剖显微镜下对 5 0侧常规防腐固定成年尸体的腓肠神经和腓浅神经及其分支作解剖 ,观测和绘图。结果　 2 4 % (12侧 )的腓浅神经或足背中间皮神经浅出点在外踝前缘水平 ,10 % (5侧 )的腓肠神经横切过外踝尖 ,78% (39侧 )的标本可识别来自这两条神经的踝支 (其中 2 8%同时具有两个来源 ) ,腓肠神经管理 38% (19侧 )标本的足及足趾的外侧半。结论　外踝术中很容易损伤来自腓肠神经和腓浅神经的踝支 (可能性为 78% ) ,损伤神经主干的风险较小 ,但有 2 4 %的可能损伤在外踝前缘浅出的腓浅神经或足背中间皮神经 ,10 %的可能损伤外踝尖处的腓肠神经 ,而且损伤后感觉缺失范围差异很大 ,腓肠神经具有比解剖学以往描述的更重要的意义     

Anatomical variations of the sural nerve

An anatomical study of the formation of the sural nerve (SN) was carried out on 76 Thai cadavers. The results revealed that 67.1% of the SNs were formed by the union of the medial sural cutaneous nerve (MSCN) and the lateral sural cutaneous nerve (LSCN); the MSCN and LSCN are branches of the tibial and the common fibular (peroneal) nerves, respectively. The site of union was variable: 5.9% in the popliteal fossa, 1.9% in the middle third of the leg, 66.7% in the lower third of the leg, and 25.5% at or just below the ankle. One SN (0.7%) was formed by the union of the MSCN and a different branch of the common fibular nerve, running parallel and medial to but not connecting with the LSCN, which joined the MSCN in the lower third of the leg. The remaining 32.2% of the SNs were a direct continuation of the MSCN. The SNs ranged from 6-30 cm (mean = 14.41 cm) in length with a range in diameter of 3.5-3.8 mm (mean = 3.61 mm), and were easily located 1-1.5 cm posterior to the posterior border of the lateral malleolus. The LSCNs were 15-32 cm long (mean = 22.48 cm) with a diameter between 2.7-3.4 mm (mean = 3.22 mm); the MSCNs were 17-31 cm long (mean = 20.42 cm) with a diameter between 2.3-2.5 mm (mean = 2.41 mm). Clinically, the SN is widely used for both diagnostic (biopsy and nerve conduction velocity studies) and therapeutic purposes (nerve grafting) and the LSCN is used for a sensate free flap; thus, a detailed knowledge of the anatomy of the SN and its contributing nerves are important in carrying out these and other procedures.     

后踝上皮瓣血供的解剖观察及临床应用

目的 探讨后踝上皮瓣的解剖特点,总结后踝上皮瓣治疗足踝部软组织缺损的临床经验,为后踝上皮瓣的临床应用提供依据。方法 2012年8—10月收集8侧新鲜成人下肢标本,股动脉灌注红色乳胶,解剖观察胫后动脉在小腿下段内侧的皮穿支及其营养腓肠神经、腓肠外侧皮神经的情况;观察腘窝外侧皮动脉穿出部位、走行、分布及与胫后动脉踝上穿支吻合情况,测量腘窝外侧皮动脉长度及直径。回顾性分析2007年2月—2012年6月兰州军区兰州总医院全军创伤骨科中心采用后踝上皮瓣移植修复的15例足踝部软组织缺损患者的临床资料,其中男11例,女4例;年龄18～49 岁,平均33岁;创面位于小腿下1/3段3例,足踝部7例,足底负重区5例。15例患者均采用后踝上皮瓣移植修复;术后观察患者皮瓣成活情况,创面完全愈合后1个月,有骨折者骨折临床愈合后3个月采用美国矫形足踝协会(AOFAS)评分系统评定踝关节功能。结果 8侧下肢标本观察示,胫后动脉在小腿下段发出2～4支肌间隙皮动脉,均有分支向外上方走行,供应腓肠神经及腓肠外侧皮神经,并与腘窝外侧皮动脉间有确定的吻合支;均见腘窝外侧皮动脉,起于股骨内外髁连线上方(1.8±0.47)cm处,于腘窝后正中线外侧(1.1±0.14)cm处穿出深筋膜并沿腓肠肌外侧头表面下行;腘窝外侧皮动脉均与腓肠外侧皮神经伴行,腘窝外侧皮动脉全长(14.21±3.89)cm、直径(1.23±0.24)mm。临床应用后踝上皮瓣移植修复足踝部软组织缺损15例,移植皮瓣全部成活13例,2例远端部分坏死。12例患者获随访6～18个月,平均11个月。患者皮瓣质地及外观良好,术后踝关节功能优8例,良4例。结论 后踝上皮瓣血管蒂位置相对隐蔽,外伤后不易损伤,且修复范围大,成活率高,是治疗足踝部软组织大面积缺损的一种较好的选择。     

国人眼眶容积及骨性径线测量

目的　为眼眶手术安全和眼眶重建术提供形态学资料。方法　应用摩立逊定位仪、游标卡尺等工具对 30例骨性眼眶进行解剖测量。结果　眶外侧缘点至眶上裂距离为 35 2 5mm ;眶外侧缘点至视神经孔外侧缘距离为 4 8 4 0mm ;眶下点至眶上裂距离为 4 5 6 2mm ;眶下点至眶下裂距离为 19 5 8mm ;眶下点至视神经孔外侧缘距离为 5 2 0 8mm ;眶内侧缘点至筛前孔距离为 18 5 9mm ;眶内侧缘点至筛后孔距离为 32 4 9mm ;眶内侧缘点至视神经孔内侧缘距离为 4 1 15mm ;眶上切迹至眶上裂距离为 39 0 4mm ;眶上切迹至视神经孔上缘距离为 4 5 93mm ;眶上缘中点至视神经孔上缘距离为 4 7 13mm ;眶下点至眶上裂距离为 4 5 35mm ;眶下缘中点至视神经孔外缘距离为 4 9 6 4mm ;眶深为 4 9 6 4mm ;颅最大长度为 175 34mm ;眶容积为 2 7 0 0ml。结论　同一个体双侧眼眶除了眶下点至视神经孔外侧缘距离右眼大于左眼 (P =0 0 16 )外 ,其他无显著差异 ;眶深与颅最大长度无直线相关关系。     

Landmarks for the identification of the cutaneous nerves of the occiput and nuchal regions

Although surgical procedures are often performed over the posterior head and neck, surgical landmarks for avoiding the cutaneous nerves in this region are surprisingly lacking in the literature. Twelve adult cadaveric specimens underwent dissection of the cutaneous nerves overlying the posterior head and neck, and mensuration was made between these structures and easily identifiable surrounding bony landmarks. All specimens were found to have a third occipital nerve (TON), lesser occipital nerve (LON), and greater occipital nerve (GON), and we found that the TON was, on average, 3 mm lateral to the external occipital protuberance (EOP). Small branches were found to cross the midline and communicate with the contralateral TON inferior to the EOP in the majority of sides. The mean diameter of the main TON trunk was 1.3 mm. This trunk became subcutaneous at a mean of 6 cm inferior to the EOP. The GON was found to lie at a mean distance of 4 cm lateral to the EOP. On all but three sides, a small medial branch was found that ran medially from the GON to the TON approximately 1 cm superior to a horizontal line drawn through the EOP. The GON was found to pierce the semispinalis capitis muscle on average 2 cm superior to the intermastoid line. The mean diameter of the GON was 3.5 mm. The GON was found to branch into medial and lateral branches on average 0.5 cm superior to the EOP. The LON was found to branch into a medial and lateral component at approximately the midpoint between a horizontal line drawn through the EOP and the intermastoid line. The main LON trunk was found on average 7 cm lateral to the EOP. In specimens with a mastoid branch of the great auricular nerve (GAN), this branch was found at a mean of 9 cm lateral to the EOP. The main trunk of this branch of the GAN was found to lie on average 1 cm superior to the mastoid tip. Easily identifiable bony landmarks for identification of the cutaneous nerves over the posterior head and neck can aid the surgeon in more precisely identifying these structures and avoiding complications. Although the occipital nerves were found to freely communicate with one another, avoiding the main nerve trunks could lessen postoperative or postprocedural morbidity. Moreover, clinicians who need to localize the occipital nerves for the treatment of occipital neuralgia could do so more reliably with better external landmarks.     

带臂外侧上皮神经及其营养血管筋膜皮瓣的应用解剖

目的:为带臂外侧上皮神经及其营养血管筋膜皮瓣提供解剖学基础.方法:32例经灌注红色乳胶的成人上肢标本,对臂外侧上皮神经及其营养血管等进行了较详细的应用解剖学研究.结果:臂外侧上皮神经在均由腑神经发出,起点横径为1.5±0.4mm,在三角肌深方斜向外下3.6±1.1cm从该肌后缘中1/3浅出肌间隔,分为上支和下支,分布于三角肌后部、外侧部和臂外侧上部.该神经的营养血管起源于旋肱后动脉,起点外径为0.9±0.4mm;其行程、分支和分布均同在神经,供血范因为14.8×9.8cm~2,并与周围的皮动脉存在丰富吻合.结论:带臂外侧上皮神经及其营养血管筋膜皮 瓣可视受区需要设计成游离瓣或旋转瓣,用于修复邻近部位、手或颌面部缺损.     

Anatomic bases of ankle arthroscopy: study of superficial and deep peroneal nerves around anterolateral and anterocentral approach

We studied the anatomy of the anterolateral and anterocentral portal sites for ankle arthroscopy with reference to the superficial peroneal nerve (SPN) in 29 cadavers (51 ankles) and the deep peroneal nerve (DPN) in 11 cadavers (21 ankles). In relation to the level of division into the medial and intermediate cutaneous nerves and their terminal branches, we classified the structure of the SPN surrounding the ankle into five types. We also identified the point where the SPN and the DPN cross the level of the talocrural joint. 32% of specimens had different SPN division types on the two sides and there was an average of 2 nerves at the level of the talocrural joint. Branches of the SPN were found lateral to the edge of the peroneus tertius tendon in 11.8% of specimens, and at its lateral edge in 27.5%. The DPN and some branches of the SPN were positioned around the lateral edge of the extensor hallucis longus tendon. We consider that the anterolateral portal should be made at least 2 mm lateral to the peroneus tertius tendon to avoid injury to the SPN, since the diameter of the scope is 2.7 mm. The anterocentral portal is unsuitable for arthroscopy due to a high risk of injury to the DPN and branches of the SPN.     

肘关节镜三种远端前外侧入路对周围神经损伤风险比较

目的：比较肘关节镜3 种远端前外侧入路穿刺后对前臂外侧皮神经及桡神经（ 深支）的影响。 方法：选用 新鲜冰冻的成人肘关节标本,关节镜下对3 种入针点（ 肱骨外上髁远端3 cm,前方1 cm ;肱骨外上髁远端2 cm, 前方2 cm ;肱骨外上髁远端1 cm,前方1 cm）进行定位、穿刺克氏针,并在肘关节屈曲90°时,解剖、测量与 前臂外侧皮神经及桡神经（ 深支）的最短距离。结果：3 种入路距前臂外侧皮神经的最短距离分别为（18.51±2.07） mm、（19.14±1.53）mm、（21.95±1.83）mm,距桡神经（ 深支）的最短距离分别为（7.18±1.17）mm、（7.59±0.88） mm、（9.22±1.51）mm。后一入路点（ 肱骨外上髁远端1 cm,前方1 cm）距2 条神经的距离为最短,且与前2 者 的差异具有统计学意义。结论：肘关节镜前外侧入路（ 肱骨外上髁远端1 cm,前方1 cm）距前臂外侧皮神经及桡 神经（ 深支）的最短距离最远,建立远端前外侧入路时选此入路穿刺比较安全。     

Vascular branches from cutaneous nerve of the forearm and hand: Application to better understanding raynaud's disease

Cutaneous nerves have branches called vascular branches (VBs) that reach arteries. VBs are thought to be involved in arterial constriction, and this is the rationale for periarterial sympathectomy as a treatment option for Raynaud's disease. However, the branching patterns and distribution areas of the VBs remain largely unclear. The aim of the present study was to investigate the anatomical structures of the VBs of the cutaneous nerves. Forty hands and forearms were examined to assess the branching patterns and distribution areas of the VBs of the superficial branch of the radial nerve (SBRN), the lateral antebrachial cutaneous nerve (LACN), the medial antebrachial cutaneous nerve (MACN), and the palmar cutaneous branch of the ulnar nerve (PCUN). VBs reaching the radial and ulnar arteries were observed in all specimens. The branching patterns were classified into six types. The mean distance between the radial styloid process and the point where the VBs reached the radial artery was 34.3 ± 4.8 mm in the SBRN and 38.5 ± 15.8 mm in the LACN. The mean distance between the ulnar styloid process and the point where the VBs reached the ulnar artery was 60.3 ± 25.9 mm in the MACN and 43.8 ± 26.0 mm in the PCUN. This study showed that the VBs of the cutaneous nerves have diverse branching patterns. The VBs of the SBRN had a more limited distribution areas than those of the other nerves. Clin. Anat. 31:734–741, 2018. © 2017 Wiley Periodicals, Inc.