Superior gluteal nerve: safe area in hip surgery

Injuries to the superior gluteal nerve are very bad complications in hip surgery. An exact knowledge of its course may be helpful in avoiding such problems. Nineteen half pelvises from ten male and female adult cadavers were dissected. Dissections revealed that the nerve divided into two (89.48%) or three (10.52%) branches after leaving the pelvis. The more caudal branch was responsible for innervation of tensor fascia latae. The distance and the angle from the entry points of all branches of the superior gluteal nerve into the deep surface of the gluteus medium and minimus muscles to the mid-point of the superior border of the greater trochanter were measured. The branch that innerved the tensor fascia latae was also followed. These data were subjected to several statistical tests. Based on these findings, and in order to prevent nerve damage, we propose to define a 2–3 cm safe area above the great trochanter.     

The course of the inferior gluteal nerve and surgical landmarks for its localization during posterior approaches to hip

The position of the inferior gluteal nerve (IGN) makes it vulnerable to iatrogenic injury during posterior and posterolateral approaches to the hip. Although the posterior approach has been reported to be the most frequently used technique, it is most likely to be associated with damage to the IGN. As there is scant information in the literature regarding the course and the anatomic relationships of the IGN, we aimed to investigate the anatomic course of the IGN and define the anatomical landmarks that can be used by surgeons during posterior approaches to the hip. Thirty-six gluteal regions from adult fixed cadavers were used for this study. A triangular-shaped anatomic area that contains the IGN was defined. This geometric area was formed by connecting the following points: posterior inferior iliac spine (PIIS) (apex), ischial tuberosity (IT) and greater trochanter (GT). This triangle can further be divided into two, the upper triangle being the “danger zone” since it contains the IGN and its branches. The closest mean distance between the point of IGN origin and the PIIS, IT and the GT was 3.2, 4.8 and 5.4 cm, respectively. In all specimens, the nerve entered the deep surface of the gluteus maximus approximately 5.4 cm from the apex of the GT and approached the GT as close as 0.8 cm, on average. Based on our study, dividing the gluteus maximus with standard techniques may damage the IGN. Posterior minimally invasive approaches to the hip should take into account the point of entry of the IGN into the gluteus maximus. Localization of the IGN by using the anatomic triangle defined in this study may decrease surgical morbidity.     

Does the direct lateral approach to the hip joint jeopardize the superior gluteal nerve?

The purpose of this anatomical study was to determine the location and course of the superior gluteal nerve in relation to the superior pole of the greater trochanter and the surgical pathway for the direct lateral approach to the hip joint. Twenty adult cadaveric lower extremities in ten patients (five male and five female) were carefully dissected to identify the location of the superior gluteal nerve and its terminal branches. The most inferior branch of the superior gluteal nerve was variable, could be asymmetrical, and was located 3–6.5 cm above the superior tip of the greater trochanter. During the lateral approach to the hip, it is recommended that the proximal extension be limited to 3 cm above the most superior aspect of the greater trochanter.     

Surgical anatomy of the superior gluteal nerve and landmarks for its localization during minimally invasive approaches to the hip

The superior gluteal nerve (SGN) is vulnerable to damage during total hip arthroplasty and various pelvic surgeries. Recently introduced minimally invasive approaches to the hip show promise for less muscle trauma compared to conventional approaches. However, the risk of damaging the SGN has not been well documented for such alternative approaches. Therefore, we aimed to investigate the anatomic course of the SGN and to define anatomical landmarks that may be used by surgeons during minimally invasive approaches to the hip. Twenty‐eight gluteal regions from 14 formalin‐fixed cadavers were dissected and the course and the distances of the SGN and its branches to the tip of the greater trochanter (GT) were measured. The landmarks for standardizing the course of the SGN included the posterior inferior iliac spine (PIIS), GT, and a line (PIIS‐GT) connecting these two points. The exit of the SGN was found to be at the medial one third of the PIIS‐GT line and 5.4 cm from the GT. Two branching patterns were noted. The branches of the SGN were distributed lateral to the PIIS‐GT line. On the basis of our study, the safe zone for the SGN was smaller than previously reported. Posterior, lateral, or anterolateral minimally invasive approaches to the hip should take into account the point of exit of the SGN and the area of distribution of its branches. A minimally invasive anterolateral approach may particularly compromise branches to the tensor fasciae latae muscle. Localization of the SGN and its branches using the anatomic landmarks defined in this study may decrease surgical morbidity. Clin. Anat. 26:614–620, 2013. © 2012 Wiley Periodicals, Inc.     

臀下神经转位阴部神经的应用解剖

目的：为重建单纯脊髓圆锥或阴部神经损伤后的会阴部功能提供解剖学基础。方法：对成人尸体的臀下神经和阴部神经进行了观测。结果：臀下神经以1支(45．00％)或2支(46．67％)从盆腔穿出为多，其中85．00％穿梨状肌下孔；其穿出点的位置主要在髂后上棘与坐骨结节连线的中1／3(50．00％)或上、中1／3交界处(48．33％)。神经干的长大于3cm，与阴部神经穿出处相距仅约2cm。阴部神经出盆处主要在髂后上棘与坐骨结节连线中1／3(46．67％)或中、下1／3交界(50．00％)。结论：两神经出盆处位置接近，臀下神经的长度足以直接与阴部神经缝接，用脊髓起源节段高的臀下神经转位脊髓起源节段低的阴部神经，切实易行。     

The ramification of the superficial branch of the superior gluteal artery. Anatomical basis of a new gluteus maximus myocutaneous flap

Summary In order to design a new gluteus maximus myocutaneous flap, the ramification of the superficial branch of the superior gluteal artery was investigated in 56 sides of 33 Japanese cadavers. The superficial branch constantly divides into two main branches, which are called the ascending and transverse branches in this study. Of the ascending and transverse branches, one or both usually give off at least one well developed division running on the undersurface of the gluteus maximus muscle (98.2%). This division, which is called the intermediate branch in this study, generally reaches the superior edge of the muscle giving off only a couple of muscular branches and pierces the muscle and its deep fascia to supply skin (83.6%). Perforators of the intermediate branch constantly emerge from the fascia near the middle or lower one-third point on a line extending from the middle of the iliac crest to the tip of the greater trochanter.

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Les ramifications de la branche superficielle de l'artère gluteale supérieure. Bases anatomiques d'un nouveau lambeau myocutane de muscle grand fessier

Résumé Dans le but de créer un nouveau lambeau myocutané de muscle grand fessier, les ramifications de la branche superficielle de l'artère glutéale supérieure ont été étudiées chez 33 sujets japonais (56 cotés). La branche superficielle se divise de façon constante en deux rameaux principaux, qui seront appelés dans cette étude les branches ascendante et transverse. De l'une de ces deux branches, ou parfois des deux, naît souvent au moins un rameau bien développé courant sous le muscle grand fessier (98,2%). Cette branche de division, qui est nommée dans cette étude le rameau intermédiaire, atteint généralement la limite supérieure du muscle, en abandonnant seulement quelques rameaux musculaires, et perfore le muscle et son fascia profond pour vasculariser la peau (83,6%). Les branches perforantes du rameau intermédiaire traversent le fascia, de façon constante, au niveau du milieu ou du tiers inférieur d'une ligne tendue du milieu de la crête iliaque au sommet du grand trochanter.

     

臀部肌肉注射数字化解剖学研究

目的为临床上确定臀部肌肉内注射的最佳部位及深度提供数字化解剖学依据。方法 (1)23具防腐标本,解剖观测臀肌注射位置与血管干、坐骨神经的距离及软组织厚度;(2)6具明胶-氧化铅灌注的新鲜整尸标本,CT扫描后,行盆部三维重建。结果三分法臀部肌内注射点处的软组织总厚度为(6.63±1.06)cm,臀肌间隙至髂骨翼骨膜的距离为(4.37±0.62)cm,注射针体距臀上血管主干和坐骨神经的距离分别为(5.87±0.93)cm和(7.46±0.94)cm;十字法臀部肌内注射定位点距坐骨神经的距离为(3.63±0.68)cm。结论连线法臀部肌内注射简易而安全,但目前成人常用的注射针头(2.7～4.9cm)普遍偏短,建议选择针梗长6cm以上的针头。     

Anatomic basis of the transgluteal approach to the hip

Summary In order to define the technical modalities of the so-called transgluteal approach to the hip, the authors studied the structure and topography of the anatomic features encountered in this approach. The gluteus medius, gluteus minimus and vastus lateralis muscles are anatomically continuous by way of their tendinous fibers. The gluteus minimus muscle winds over the cranial and then anterolateral aspect of the capsule, to which it is bound by fibrous tracts and tendinous expansions; its terminal tendon blends its fibers with the anterior part of the tendon of the gluteus medius and enters into continuity with the superficial tendinous fibers of the anterior part of the vastus lateralis. The zone of junction of the three muscle structures is closely bound to the anterior aspect of greater trochanter. The caudal neurovascular trunk of the space between the gluteus medius and vastus lateralis is situated at a distance of 3 to 5 cm from the greater trochanter. The practical surgical implications are discussed, particularly as regards the methods of dissecting the anterior margin of the transgluteal incision, exposure of the capsule and preservation of the neurovascular pedicle, with reference to concepts published previously in studies elswhere.

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Bases anatomiques de la voie d'abord transglutéale de la hanche

Résumé Afin de préciser les modalités techniques de la voie d'abord dite transglutéale de la hanche, les auteurs ont étudié la structure et la topographie des éléments anatomiques interposés sur cette voie d'accès. Les muscles moyen fessier, petit fessier et vaste latéral sont en continuité anatomique par leurs fibres tendineuses. Le muscle petit fessier s'enroule sur le versant crânial puis latéro-ventral de la capsule à laquelle il s'amarre par des tractus fibreux et des expansions tendineuses, son tendon terminal échange des fibres avec la partie ventrale du tendon du moyen fessier et se met en continuité avec les fibres tendineuses superficielles de la partie ventrale du vaste latéral. La zone de jonction tendineuse des trois formations musculaires est étroitement amarrée au versant ventral du grand trochanter. Le pédicule vasculo-nerveux caudal de l'espace moyen fessier-vaste latéral est situé à une distance de 3 à 5 cm du sommet du grand trochanter. Les déductions chirurgicales pratiques sont présentées, concernant en particulier les modalités de préparation de la berge ventrale de l'incision transglutéale, l'exposition de la capsule, et la préservation du pédicule vasculo-nerveux, avec référence aux notions exposées dans des travaux déjà publiés ailleurs.

     

臀区穿支皮瓣的应用解剖学研究

目的:为臀区穿支皮瓣的临床应用提供解剖学基础。方法:6具(12侧)动脉灌注明胶-氧化铅混悬液的新鲜成人整尸标本,解剖观测臀区外径≥0.5mm的穿支,测量其管径及其走行、分支、分布情况等。取下整个臀区被覆组织拍摄X线片,观测皮动脉的数量以及彼此之间的吻合情况等。利用Photoshop与ScionImage分析穿支供血的趋向性及每个分支的供血面积等。结果:臀上、臀下动脉直径≥0.5mm的穿支数量分别为平均(5±2)支和(8±4)支,所有的臀上动脉和90%的臀下动脉的分支都是肌皮穿支,这些穿支的平均内径为(0.6±0.1)mm。臀上、臀下动脉穿支在皮肤的平均分布范围分别是(69±56)cm2和(177±38)cm2。臀上动脉穿支主要分布在髂后上棘和大转子的连线的内侧2/3;而臀下动脉的穿支多在臀区与臀皱褶平行的水平中部1/3处。结论:臀区的皮肤穿支密集,营养皮肤面积较大,以臀上、臀下动脉穿支为蒂设计的穿支皮瓣可用于乳房重建,骶骨、髋骨及会阴区重建等。     

The superior laryngeal nerve loop and its surgical implications

Summary Based upon findings from 60 cadavers (120 sides), the incidence of superior laryngeal nerve loop, connecting the cervical sympathetic chain and the superior laryngeal nerve and its branches, the external and internal laryngeal nerve, was 98.3% (118 out of 120 sides). In most cases the loop connected the sympathetic chain and the external laryngeal nerve. The external laryngeal nerve was looped, and not linear as traditionally thought. The loop could be divided into three categories, V-shaped, U-shaped and mixed, and subdivided into 5 types and 17 subtypes according to morphological variation. The loop without exception innervated not only the cricothyroid muscle, but also the thyroid gland. The loop is one of the origins of the thyroid nerve. It seems that for thyroid surgery the loop, when lower in position, should be carefully separated from the superior thyroid vessels before the latter are ligated, in order to preserve a normal nerve supply to the muscle as well as to the part of the gland that remains after surgery.

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L'anse du nerf larynge supérieur, étude anatomique et applications chirurgicales

Résumé La fréquence d'une anse du nerf laryngé supérieur réalisant une anastomose entre la chaine sympathique cervicale et le nerf laryngé supérieur et/ou ses branches (rameau laryngé externe et ingerne), est de 98,3 % (118/120). Ce résultat s'appuie sur l'étude de 60 cadavres. Dans la plupart des cas, l'anastomose se fait entre la chaine sympathique cervicale et le rameau laryngé externe. Ce rameau laryngé externe a un trajet curviligne et non linéaire conformément aux données classiques. Il existe trois catégories d'anses : en "V", en "U" et mixte ; on peut également les subdiviser en 5 types et 17 sous-types en fonction des variations morphologiques. Cette anse innerve constamment non seulement le muscle cricothyroïdien mais aussi la glande thyroïde dont elle fournit une partie de l'innervation. Lors de la chirurgie thyroïdienne, si l'anse est en position basse, les nerfs doivent être soigneusement disséqués et séparés des vaisseaux thyroïdiens supérieurs avant ligature de ces derniers de façon à conserver l'innervation normale du muscle et de la partie restante de la glande.

     

An applied anatomical study of the superior laryngeal nerve loop

The aim of this study was to provide some specific information about the morphology and topography of the superior laryngeal n., its branches, and its anastomoses with the cervical sympathetic chain, as well as its relations with the thyroid gland. Sixty adult cadavers, ie 120 superior laryngeal nn., were dissected and analysed. An anastomotic loop connecting the cervical sympathetic chain and the distal laryngeal n. was present in 111 of the 120 cases. The morphology of this loop made it possible to define 5 different groups. This study supplies information valuable in thyroid surgery.     

带尺侧上副动脉尺神经转位的解剖及临床意义

目的为临床上带血管蒂的尺神经移植在健侧颈7移位治疗臂丛根性撕脱伤中的应用提供解剖学依据。方法取新鲜经动脉灌注红色乳胶的成人上肢标本22侧进行显微解剖,观察尺神经外部营养动脉的来源。另取患骨肿瘤而截肢新鲜成人上肢6侧作仅保留尺侧上副动脉的尺神经游离,采用动脉灌注墨汁和尺神经组织切片的方法,观察尺侧上副动脉对尺神经内部血供营养的范围。结果尺神经在腋部由胸外侧或腋动脉的分支供应,在内侧肌间隔后方由尺侧上副动脉供应,在尺神经沟由尺侧上副动脉与尺侧返动脉后支的吻合支供应,在前臂由尺侧返动脉和尺动脉的分支供应。尺侧上副动脉灌注墨汁后,尺神经腕部、手背支及腋部的神经束内微血管被墨汁充填。结论以尺侧上副动脉的起始处为血管蒂部旋转点,尺神经可提供平均为(46.5±2.6)cm的有血供的移植长度,可经胸前皮下隧道逆向转位与对侧颈7神经根吻合。以尺侧上副动脉为血供的尺神经移植的设计是合理的。     

腰椎前路手术中保护生殖股神经的临床解剖学

目的　为腰椎前路手术中避免生殖股神经(Genitofemoral nerve, GFN)损伤提供解剖学依据。 方法　 在15具成年尸体标本上选择易于触及的椎间盘中点为标志,观察GFN在腰大肌中走行、分支的形态特点及穿出点位置,测量并进行统计学处理。 结果　GFN穿出腰大肌的位置主要集中在L3~4节段;GFN自腰大肌内穿出前未分支者占83.33%（25侧）,穿出前已分支者占16.67%（5侧）;根据GFN的走行分3型： Ⅰ型,在腰大肌内远离腰椎体走行;Ⅱ型,紧贴腰椎体走行;Ⅲ型,生殖支和股支分别穿出腰大肌,且两支在腰大肌内隔有肌纤维组织。 结论　在显露L2-4椎体前外侧时容易损伤GFN。Ⅰ型剥离腰大肌时紧贴椎体并向外侧牵开肌肉;Ⅱ型及Ⅲ型采用经腰大肌入路劈开肌纤维束,可避免损伤GFN。     

The anatomy of the hip abductor muscles

The anatomy of the hip abductors has not been comprehensively examined, yet is important to understanding function and pathology in the gluteal region. For example, pathology of the hip abductor muscle‐tendon complexes can cause greater trochanteric pain syndrome, and may be associated with gluteal atrophy and fatty infiltration. The purpose of this study was to investigate the detailed morphology of gluteus medius (GMed), gluteus minimus (GMin), and tensor fascia lata (TFL), and determine whether the muscles comprised anatomical compartments. The gluteal region from 12 cadavers was dissected and data collected on attachment sites, volume, fascicular and tendinous anatomy, and innervation. Three sites of GMed origin were identified (gluteal fossa, gluteal aponeurosis, and posteroinferior edge of the iliac crest) and the distal tendon had lateral and posterior parts. GMed was the largest in volume (27.6 ± 11.6 cm³; GMin 14.1 ± 11.1 cm³; TFL 1.8 ± 0.8 cm³). Fascicles of GMin originated from the gluteal fossa, inserting onto the deep surface of its distal tendon and the hip joint capsule. TFL was encapsulated in the fascia lata, having no bony attachment. Primary innervation patterns varied for GMed, with three or four branches supplying different regions of muscle. Distinct secondary nerve branches entered four regions of GMin; no differential innervation was observed for TFL. On the basis of architectural parameters and innervation, GMed, and GMin each comprise of four compartments but TFL is a homogenous muscle. It is anticipated that these data will be useful for future clinical and functional studies of the hip abductors. Clin. Anat. 27:241–253, 2014. © 2013 Wiley Periodicals, Inc.     

喉上神经外支和甲状腺上动脉的应用解剖

目的　解剖并观察喉上神经外支（external laryngeal nerve, ELN）和甲状腺上动脉（superior thyroid artery,STA）之间的比邻关系,为手术中保护ELN提供解剖学基础。 方法　成年尸体标本57具（114侧）,在6倍大视场显微镜下解剖并观察ELN、STA的比邻关系。 结果　本组标本中颈交感链（cervical sympathetic chain,CSC)与ELN吻合成袢（CSC-ELN loop)者,占78.9% （90侧）。在27.7%（25侧）低位CSC-ELN loop中,血管和神经的位置关系可分为4类：①STA分支与CSC-ELN loop重叠;②STA腺支穿过CSC-ELN loop;③CSC-ELN loop环甲肌支与STA喉支伴行;④STA的分支与CSC-ELN loop分支相互交叉。 结论　STA与CSC-ELN loop之间的关系十分复杂。有鉴于此,在甲状腺和/或颈部手术中,我们特提出两个手术保护措施：①应单支游离并结扎STA;②在处理STA的前内侧分支时,应注意避免损伤ELN/CSC-ELN loop的环甲肌支。     

Anatomical bases of the transhiatus approach to the greater splanchnic nerve

Summary The level of origin and mode of constitution of the greater splanchnic nerve and its relations in the posterior mediastinum were studied. The aim of this work was to identify the anatomical basis of the transhiatus approach to the right and left greater splanchnic nerves. The azygos venous system was seen to be the main anatomical relation of these nerves. The results of this study should allow the surgeon to perform total bilateral neurotomy.

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Bases anatomiques de l'abord trans-hiatal des nerfs grands splanchniques

Résumé La hauteur et le mode de constitution des nerfs grands splanchniques ainsi que leurs rapports dans le médiastin postérieur ont été étudiés pour préciser les bases anatomiques de l'abord trans-hiatal des nerfs grands splanchniques. Le système veineux azygos constitue le rapport essentiel. Le but de ce travail est de permettre une neurectomie bilatérale complète.

     

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.     

髋关节后侧入路应用解剖

目的:为髋关节后侧手术入路及如何避免易损伤结构提供解剖学依据。方法:对60侧成尸下肢标本,参照手术进路的层次对相关结构和神经血管进行解剖观测。结果:1.臀大肌的神经和血管及其分支均从肌深面入肌,入肌点均在臀大肌前缘后方。2.在竖脊肌起点外侧缘与大转子尖连线上距大转子尖距离:臀上血管神经束上支为(105.8±29.6)mm;臀上血管神经束下支为(78.6±36.8)mm。3.坐骨神经半腱肌支上支入肌点与坐骨结节距离为(102.6±56.2)mm;坐骨神经股二头肌支最上支入肌点与坐骨结节距离为(127.1±50.5)mm;坐骨神经半膜肌支上支入肌点与坐骨结节距离为(135.6±85.1)mm。结论:1.从大转子尖向上分离臀中肌臀小肌时不要超过大转子尖与髂嵴连线的下1/2,最安全应在1/3以内,以免损伤臀上血管神经束下支。2.切断梨状肌的位置越贴近大转子越不易损伤坐骨神经,梨状肌肌腱残留长度在保证吻合的情况下越短越好。     

梨状肌上孔内血管损伤致臀内上部坏死的解剖学基础

目的:分析研究髋关节手术损伤臀上血管后并发臀内侧上部坏死的解剖学基础。方法:在40侧经动脉内灌注红色乳胶标本,解剖观察梨状肌上孔、臀上血管神经走行及分支分布,髂内动脉造影观察吻合情况。结果:梨状肌上孔为半圆形,中点高(11.6±2,4)mm,下界宽(22.3±4.2)mm;梨状肌上孔内侧缘骨壁厚(7.5±1.2)mm;臀上动脉外径厚(2.3±1.3、)mm;外径宽(4.8±1.0)mm;臀上动脉深支分布臀中小肌;浅支外径厚(0.9 0.6)mm;外径宽(2.7±0.8)mm,分布臀大肌内侧上部。臀上静脉1支型占30.0％,2支型占70.0％;臀上静脉浅支外径厚(0.6±0.2)mm,外径宽(0.9±0.6)mm。结论:术中将臀大肌向内推臀上动、静脉挤压至梨状肌上孔内侧缘骨壁上,致臀上血管断裂,并发臀内侧上部软组织坏死。     

Topographic anatomy of the deep temporal nerves, with references to the superior head of lateral pterygoid

Summary Commonly, the nerve branches from the anterior mandibular nerve trunk pass between the roof of infratemporal fossa and the superior head of lateral pterygoid. However, varied courses of the mandibular nerve branches can be frequently observed. The purpose of this study was to clarify the positional relationships and the clinical relevance of the course variations of the branches of the anterior mandibular nerve trunk with reference to the surrounding anatomical structures. Thirty-six hemi-sectioned heads were studied in detail. In 20 cases, the posterior deep temporal nerve had a common trunk with the masseteric nerve and was then divided anteriorly (15 cases) or posteriorly (five cases). In 16 cases, the posterior deep temporal nerve arose from the mandibular nerve trunk independently. Based on the branching patterns of the middle deep temporal nerve, type A (one twig of the middle deep temporal nerve) was most frequent and occurred in 41.7%. Similarly, type B (two twigs), type C (three twigs) and type D (four twigs) were observed in 36.1%, 16.7%, and 5.5%, respectively. The twigs of the middle deep temporal nerve, which pierced the muscle fibers of the superior head of lateral pterygoid, were found in 21 cases (58.3%). Cases in which the middle deep temporal nerve pierced through all areas of the superior head were most frequent (56.5%). These results suggest that the piercing patterns of the middle deep temporal nerve show there is a possibility that it may be compressed during the actions of the superior head of lateral pterygoid.

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Electronic Supplementary Material The French version of this article is available in the form of electronic supplementary material at http://dx.doi.org/10.1007/[s00276-003-0171-5].

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Anatomie topographique des nerfs temporaux profond, et notamment de leurs rapports avec le chef supérieur du muscle ptérygoïdien latéral

Résumé Habituellement, les rameaux nés du tronc antérieur du nerf mandibulaire passent entre le toit de la fosse infra-temporale et le chef supérieur du muscle ptérygoïdien latéral. Cependant, des trajets variés des branches du nerf mandibulaire peuvent être fréquemment observés. Le but de cette étude était de clarifier les rapports et l'importance clinique des variations de trajet des branches du tronc antérieur du nerf mandibulaire par rapport aux structures anatomiques environnantes. 36 demi-têtes ont été étudiées en détail. Dans 20 cas, le nerf temporal profond postérieur naissait d'un tronc commun avec le nerf massétérique, puis se divisait en avant (15 cas) oui en arrière (5 cas). Dans 16 cas, le nerf temporal profond postérieur naissait indépendamment du tronc du nerf mandibulaire. Sur la base des modes d'origine du nerf temporal profond moyen, le type A (une seule racine) était la plus fréquente et survenait dans 41,7% des cas. De même, les types B (2 racines) C (3 racines) et D (4 racines) étaient observés respectivement dans 31.6%, 16.7%, et 5.5%. Les branches du nerf temporal profond moyen traversaient les fibres musculaires du chef supérieur du muscle ptérygoïdien latéral dans 21 cas (58.3%). Les cas dans lesquels le nerf temporal profond moyen traversait toutes les zones du chef supérieur étaient les plus fréquents (56,5%). Ces résultats suggèrent que les modes de traversée du nerf temporal profond moyen montrent la possibilité qu'il soit comprimé au cours de l'action du chef supérieur du muscle ptérygoïdien latéral.