The canal of the posterior ampullar nerve: an important anatomic landmark in the posterior fossa transmeatal approach

Abstract The canal of the posterior ampullar nerve is located between the inferior part of the internal acoustic meatus and ampulla of the posterior semicircular canal. It permits a more accurate localisation of the underlying labyrinth in inner-ear surgery. An anatomical and radiological study was undertaken to determine the importance the relationship between the canal and the labyrinth. Ten dry and 10 cadaveric temporal bone dissections, together with 20 high resolution CT scans of the same temporal bones were studied in an attempt to describe the anatomy of the canal of the posterior ampullar nerve. The length of the canal of the posterior ampullar nerve, the length of internal acoustic meatus, and distances from porus acusticus to the singular foramen and the transverse crest, and from the singular foramen to the vestibule and transverse crest, and from operculum to the sigmoid sinus and to the porus acusticus were measured. During the transmeatal posterior cranial fossa approach using the canal of the posterior ampullar nerve as a landmark enables more bone to be safely removed from the internal acoustic meatus thus preserving hearing.     

内耳道底骨性结构、前庭神经与单孔神经骨管的Micro-CT影像解剖学实验研究

目的 探讨内耳道底骨性结构及前庭神经、单孔神经骨管（神经管）的Micro-CT影像解剖学特征。方法 取10%甲醛溶液固定的成人尸头标本6具（颞骨12侧）,其中男性4具、女性2具,具体年龄不详。对12侧颞骨均行Micro-CT扫描,再应用Mimics软件对内耳道底骨性结构及其中的神经管进行三维重建,之后进行影像解剖学观察,并分别测量前庭上神经、前庭下神经、单孔神经管相关解剖学参数。结果 经Micro-CT扫描及三维重建,内耳道底骨性结构及其内穿行的前庭神经和单孔神经管显示清晰。前庭上、下神经及单孔神经的解剖形态、位置及走行存在多种解剖变异以及多交叉分布现象。左右两侧前庭上神经管长度分别为（3.68±0.79）mm和（3.54±1.04）mm,起始处前后径分别为（2.03±0.76）mm和（1.83±0.68）mm、上下径分别为（1.75±0.35）mm和（1.72±0.43）mm,中点处的前后径分别为（0.89±0.19）mm和（1.13±0.29）mm、上下径分别为（1.58±0.26）mm和（1.69±0.58）mm;左右两侧前庭下神经管前后径分别为（0.44±0.07）mm和（0.50±0.29）mm,上下径分别为（0.53±0.11）mm和（0.76±0.38）mm。左右两侧单孔神经管直线长度分别为（3.97±0.68）mm和（3.85±0.69）mm,其内侧段长度分别为（2.54±0.70）mm和（2.26±0.82）mm、外侧段长度分别为（1.82±0.57）mm和（1.99±0.39）mm,内侧段直径分别为（0.67±0.10）mm和（0.66±0.09）mm、外侧段直径分别为（0.47±0.04）mm和（0.51±0.10）mm,内外段交角分别为128.82°±17.23°和127.51°±11.70°。以上各指标测量值侧别间比较,差异均无统计学意义（P值均>0.05）。结论 Micro-CT扫描及三维重建可清晰显示内耳道底骨性结构及前庭神经、单孔神经骨管等结构及其空间位置与走行;前庭神经和单孔神经骨管解剖形态及位置、走行均存在较大变异,但左右侧别间相关解剖学测量结果无差异。     

The subarcuate canaliculus and its artery--a radioanatomical study.

The anatomy of the subarcuate canaliculus (SAC), subarcuate fossa (SAF) and subarcuate artery (SAA) was studied in 12 cadavers and 35 dry temporal bones. Each cadaver was scanned with high resolution CT (HRCT) prior to microdissection. The SAC was always found to be a single canal located between the two arcs of the anterior semicircular canal in both microdissections and HRCT scans and the internal acoustic meatus was observed to be located just inferior to the SAC. The SAC was on average of 9.2 mm in length and 1 mm in width. The SAF was situated at a distance of 4.2 mm from the internal acoustic meatus, 3.5 mm from the groove for the superior petrosal sinus, 6.7 mm from the opening of the vestibular canaliculus and 11.5 mm from the most superior part of the jugular foramen. The SAA was found to originate from the anterior inferior cerebellar artery in 9 cadavers and from the internal auditory artery in 3 cadavers. The SAA always emerged from the main artery outside the internal acoustic meatus. It ran through the SAC as a single artery. This study investigated CT correlated anatomical aspects of the subarcuate canaliculus and its artery which is claimed to be responsible for the blood supply of the mastoid antrum, facial canal and bony labyrinth.     

正常人面神经管垂直部与外耳道解剖位置关系的影像与临床研究

目的 观察、测量面神经管垂直部毗邻解剖关系及乳突的形态学指标,分析面神经管垂直部和外耳道后壁、外耳门后缘位置变化的相关性,探讨乳突气化程度与面神经管垂直部之间的关系及临床意义。 方法 1. 评价CT影像测量相关结构的正确性,采用64层螺旋CT对4具干颅标本进行扫描,在横断位测量面神经管垂直部至外耳道后壁、外耳门后缘的距离,在矢状平面上测量乳突的前后径（外耳道下壁最低点至乳突后缘的水平距离）和高度（外耳道下壁至乳突尖的垂直距离）;按影像层面锯开标本,对上述距离行实体测量。影像测量均值与实体测量均值的差异行显著性检验。2. 在体研究：随机入选无耳部疾患的118人（236侧）,其中男性55例（110侧）,女性63例（126侧）,行颌面部CT扫描。如上选择层面,并测量面神经管垂直部至外耳道后壁、外耳门后缘及乳突前后径和高度的距离,以乳突前后径与高度乘积的1/2定义为乳突面积,以乳突面积的大小来定义乳突气化程度,同时将乳突面积分别与面神经管垂直部至外耳道后壁、外耳门后缘距离分别进行相关和回归分析。 结果 1. 标本部分：各项指标的影像测量值与实体测量值差异无统计学意义（P>0.05）。2. 在体研究：各项指标测量结果侧别差异无统计学意义（P>0.05）,性别差异有统计学意义（P<0.05）。乳突面积与面神经管垂直部至外耳道后壁距离之间呈负相关性,且相关性有统计学意义;乳突面积与面神经管垂直部至外耳门后缘有相关性,但相关性无统计学意义。 结论 乳突发育气化好,面神经垂直部位置偏前。 CT检查可以明确面神经管垂直部与外耳道后壁的关系,有助于耳外科手术术式的选择以及对术中重要结构损伤的控制。     

收肌管下口处隐神经阻滞的应用解剖

目的　探讨收肌管下口处隐神经的精细解剖和体表定位。 方法　采用12具尸体标本20侧下肢对收肌管及其下口部位进行精细解剖和测量。 结果　收肌管下份隐神经在前内侧、股动脉居中、股静脉在后。在收肌管下口和稍上位置,膝降动、静脉和隐神经分别穿大收肌腱板出收肌管并伴行下行,隐神经在膝内侧缝匠肌腱和股薄肌腱之间穿深筋膜,伴大隐静脉下降至小腿和足内侧。收肌管下口分别距髌骨上缘（5.85±0.15）cm、髌骨底内侧缘（2.72±0.60）cm、股内侧皮肤表面（4.08±0.66）cm。 结论　髌骨上缘上5.85 cm、髌骨底内侧缘内2.72 cm、股内侧皮肤表面4.08 cm深处为收肌管下口隐神经阻滞的体表定位;股动脉是收肌管下口上隐神经阻滞的定位标志;膝降动脉的隐支是收肌管下口下隐神经阻滞的识别标志。     

The middle cranial fossa approach: an anatomical study

Hearing preservation surgery has become an option for an increasing number of patients with vestibular schwannomas due to diagnosis at an earlier stage. The middle cranial fossa approach represents one such surgical approach for resection of vestibular schwannomas with hearing preservation. We have undertaken an anatomical study of the middle cranial fossa approach to the internal auditory meatus using 20 fresh temporal bones. By simulating the surgical approach it was possible to analyze critically two of the main recognized subapproaches to the internal acoustic meatus. The results confirmed that the angle subtended by the facial nerve and "blue-lined" semicircular canal was much less than 60 degrees but equally important was the degree of individual variability. Furthermore the roof of the geniculate fossa was not infrequently dehiscent. The distance measured from the inner table of the craniotomy to the superior semicircular canal was on average 22 mm, similar to previous reports and utilized by some in their approach in this challenging surgery. From this anatomical study it appears that safe dissection of this area is facilitated by observing the more acute angle between the facial nerve and superior semicircular canal and by taking advantage of the relationship between the inner table and important landmarks.     

颞骨岩部入路颅底手术有关的应用解剖

目的:为经岩部入路颅底手术提供解剖学参数.方法:观测成人的100例干燥整颅、20例颅底标本、15例尸头及36侧正常颅底CT资料;观测项目为与经岩部入路颅底手术有关的颞骨表面标志与岩部内重要结构的位置及其间距.结果:整颅及颅底内面各项测量结果左右侧比较U均<1.96,P均>0.05,颞骨内重要结构间及与表面标志间距离测量结果多数项目男女性间比较U均>1.96或>2.58,P<0.05或<0.01;颅中窝入路可以弓状隆起作标志寻认上骨半规管以确认内耳道,也可以岩大神经管裂孔为标志暴露面神经膝状神经节与迷路段确认内耳道底;磨除岩尖部骨质时可以颈动脉管后壁与内耳门内侧缘的连线作为界线.结论:颞骨表面标志点间距及颞骨岩部内重要结构间的位置关系可为经岩部入路颅底手术提供重要参考,有利于术中岩部重要结构的定位与保护.     

枕下乙状窦后入路内听道后壁磨除的显微解剖

目的 观测经枕下乙状窦后入路手术路径中,显微镜下磨除内听道后壁所涉及的重要解剖结构及相关解剖学参数,以指导术中安全磨除内听道后壁。方法 模拟枕下乙状窦后入路,对6具(12侧)国人湿性头颅标本显微镜下行磨除内听道后壁,以内听道内口后缘中点(P点)作为参照点,分别测量P点至弓状隐窝、后半规管、共脚、内听道底、前庭导水管外口、颈静脉孔的最短距离,对这些结构拍照记录,所得测量结果行统计学处理。结果 以内听道后壁作为参照平面,测得内听道干与后壁平面所呈夹角为47.3°±17.2°。以P点作为参照点,测得P点至弓状隐窝的最短距离(4.10±0.60)mm,P点至后半规管最短距离(7.39±0.44)mm,P点至共脚的最短距离(8.09±0.47)mm,P点至内听道底距离(9.08±0.59)mm,P点至前庭导水管外口(10.44±0.73)mm,P点至颈静脉孔最短距离(7.35±1.09)mm。结论 枕下乙状窦后入路磨除内听道后壁,其磨除长度不应超过7 mm,可减少半规管及共脚的损伤概率。熟悉磨除内听道后壁过程中容易损伤的结构,可避免损伤半规管、颈静脉球、前庭导水管外口及内淋巴囊等重要解剖结构。     

乙状窦后手术入路的显微解剖和虚拟解剖

目的 探索运用显微解剖和虚拟解剖的方法 研究乙状窦后手术入路,为该入路提供多种方式的形态学基础. 方法 10具(20侧)头颅固定标本,在显微镜下模拟乙状窦后入路手术,观察桥脑小脑三角内结构,并以岩上窦乙状窦汇合处、内耳门为基点进行相关测量;磨除内听道后壁,暴露其内结构;5例患者薄层CT和MRI影像数据,利用Dextroscope系统进行计算机三维重建,虚拟解剖乙状窦后入路手术过程. 结果 岩上窦乙状窦汇合处距三叉神经、面听神经复合体、舌咽神经、舌下神经穿硬膜处的距离分别是(38.50±2.64)mm、(27.80±2.25)mm、(32.70±2.11)mm、(44.30±2.05)mm;内耳门距三叉神经、展神经、小脑幕、舌咽神经穿硬膜处的距离分别是(5.68±1.55)mm、(13.80±1.81)mm、(5.00±0.66)mm、(6.34±1.24)mm.以面听神经复合体和舌咽神经为标志将桥脑小脑三角分为前、中、后3个间隙;在内听道后壁磨除后,该区结构层次充分显示.Dextroscope系统成功模拟乙状窦后手术入路,可显示星点、横窦乙状窦膝、颈静脉孔、内耳门、岩尖、基底动脉系统等结构及其空间关系. 结论 将桥脑小脑三角分为前、中、后3个间隙,有助于了解其内神经血管等结构的层次特点;以岩上窦乙状窦汇合处、内耳门为基点进行测量,可量化结构间的关系,有助于判断各间隙深浅、空间大小;识别内听道内的解剖标志,有利于手术时保护其内结构;通过Dextroscope系统能个体化显示局部结构,方便术前方案的设计.两种方法 各有优缺点,两者互补能提高对乙状窦后入路手术时桥脑小脑三角内结构的认识.     

Lingual foramina on the mandibular midline revisited: a macroanatomical study

The purpose of the present study was to determine the incidence, size, location, course, and content of the foramina and bony canals located on the lingual side of the mandibular midline. Fifty dry human mandibles were morphometrically analyzed by measuring the distances of these midline foramina from the mandibular base and the dimensions of these foramina and their bony canals. In addition, macro- and microanatomical dissection was performed on 12 intact cadaver mandibles. The macroanatomic midline foramina were classified into superior and inferior genial spinal foramina according to their vertical location with respect to the genial spines. This study showed that out of 50 dry mandibles, 49 (98%) had at least one midline lingual foramen; only one lacked a true midline foramen. Evaluation of the microanatomical dissections indicated a clear neurovascular bundle in both superior and inferior genial spinal foramina and canals. For the superior canal, the content was found to derive from the lingual artery and the lingual nerve. For the inferior canal, however, the arterial origin was submental and/or sublingual, while the innervation derived from a branch of the mylohyoid nerve. In conclusion, different kinds of lingual foramina have been identified according to their location. The superior and inferior genial spinal foramina have different neurovascular contents, determined by their anatomical location above or below the genial spines.     

收肌管下口处隐神经阻滞的应用解剖

目的探讨收肌管下口处隐神经的精细解剖和体表定位。方法采用12具尸体标本20侧下肢对收肌管及其下口部位进行精细解剖和测量。结果收肌管下份隐神经在前内侧、股动脉居中、股静脉在后。在收肌管下口和稍上位置,膝降动、静脉和隐神经分别穿大收肌腱板出收肌管并伴行下行,隐神经在膝内侧缝匠肌腱和股薄肌腱之间穿深筋膜,伴大隐静脉下降至小腿和足内侧。收肌管下口分别距髌骨上缘(5.85±0.15)cm、髌骨底内侧缘(2.72±0.60)cm、股内侧皮肤表面(4.08±0.66)cm。结论髌骨上缘上5.85 cm、髌骨底内侧缘内2.72 cm、股内侧皮肤表面4.08 cm深处为收肌管下口隐神经阻滞的体表定位;股动脉是收肌管下口上隐神经阻滞的定位标志;膝降动脉的隐支是收肌管下口下隐神经阻滞的识别标志。     

迷路后桥脑小脑三角区内镜手术的应用解剖研究

目的：评价内镜在桥脑小脑三角区手术中的应用价值。方法：对5例10侧成人尸头进行大体解剖，熟悉桥脑小脑三角区诸结构解剖关系；在10例20侧成人尸头上模拟迷路后径路内镜手术，将镜下结构按解剖位置分为面神经、三又神经、舌咽神经三个区域，重点观察各区域各组颅神经之间、神经和血管之间关系；在15例标本上，于颞骨岩部后骨板平面测量内耳门外缘距后半规管外缘、颞骨表面距离，内耳门下缘距舌咽神经距离。结果：10例标本通过内压小脑均能成功导入内镜进行模拟手术；内耳门及第7、8颅神经可作为内镜手术的解剖标志。内耳门外缘距颞骨表面距离为（33．82±2．80）mm，距后半规管后缘距离为（13．24±2．55）mm，下缘距舌咽神经距离为（6．26±1．05）mm。结论：迷路后径路桥小脑角区内镜手术完全可行，较显微镜手术而言具有微创、能多角度观察病变区域、更清晰分辨血管神经关系等优点，更适合耳科医生采用，但需熟悉和掌握有关解剖知识以及内镜操作技巧。     

下颌神经管的解剖结构

背景:在下颌后牙种植术中,由于下颌神经管走行于下颌骨体内,有时可损伤下齿槽神经,因而制约了牙种植术的应用。 因此,牙种植术的应用需详细了解下颌神经管的解剖结构。 目的：观察下颌神经管在下颌骨内的走行及管内的解剖结构。 方法：共纳入15具成人牙下颌骨标本与4具新鲜下颌骨动脉灌注标本。纳入对象均牙列完整,后牙无缺失,牙槽骨无吸收。测量15具成人牙下颌骨标本下颌管走行及其管腔各径长度,包括下颌管横径与纵径,下颌管至上下内外缘距离。观察4具新鲜下颌骨动脉灌注标本管内下颌神经管内神经、血管位置关系。 结果与结论：下颌管内缘至舌侧骨板的距离比下颌管外缘至颊侧骨板距离短(P < 0.01);下颌管上缘至牙槽嵴顶的距离较下颌管下缘至下颌骨下缘的距离大(P < 0.01)。表明下颌管在下颌骨体部走行中偏舌侧、偏下颌骨下缘。下颌神经管在下颌骨体部的部分横径小于纵径(P < 0.05),亦即下颌管截面形态为上下径略长的椭圆形。神经管横纵径于前后牙位区差异无显著性意义。实验还发现在暴露的下颌管腔中下牙槽神经及伴随血管有一层被膜包绕成神经血管束,血管位于神经上方,而且位置恒定,并发出小分支包绕神经。结果提示,下牙槽血管神经束在下颌管内走行中血管位于神经之上。     

The third vascular route of the inner ear or the canal of Cotugno: Its topographical anatomy,fetal development,and contribution to ossification of the otic capsule cartilage

Three vascular routes to the inner ear are known: (a) through the internal acoustic meatus with the vestibulocochlear nerve; (b) from the endolymphatic duct aperture; and (c) along the canal of Cotugno (CC) inserted into the vestibular part of the ear from the superior or brain side. The third is believed to contain only veins. Examinations of 33 human embryos and fetuses at 6–40 weeks demonstrated that (a) the CC appeared as a recess of epidural mesenchymal tissues at the superior aspect of the otic capsule cartilage in embryos and it was inserted deeply to issue multiple peripheral divisions inferolaterally and posteriorly at midterm; (b) the CC consistently passed through a ring of the superior or anterior semicircular canal and contained both, the arteries from the vestibulocochlear nerve origin at the midbrain and the vein draining into the sigmoid sinus or petrosal sinuses; and (c) the CC appeared not to contribute to ossification of the otic capsule cartilage but, after endochondral ossification of the internal ear, woven bone development occurred along a smooth interface of the CC with the ossified ear. In contrast, another interface between the developing bone and the residual cartilage of the otic capsule was rough and wavy with many short bony columns, called osseous globules. In addition, the endolymphatic duct accompanied veins but no arteries. Our results show that the CC is a major vascular route to the vestibular part of the otic capsule cartilage, but its role appears to be limited after ossification.     

Pathways for the vestibulo-ocular reflex excitation arising from semicircular canals of rabbits

Summary In anesthetized albino rabbits, ampullary branches of the vestibular nerve were stimulated electrically. Prominent and stable reflex contraction was induced in extra-ocular muscles by applying single current pulses of relatively long duration, 3–5 msec. Survey with a glass microelectrode revealed that, during application of relatively wide pulses to a canal, primary vestibular fibers discharged impulses repetitively at a rate as high as 300–1400/sec and that after being transmitted across second-order vestibular neurons these impulses built up summated EPSPs in oculomotor neurons, large enough to trigger off motoneuronal discharges. From each semicircular canal, prominent reflex contraction was evoked selectively in two muscles; from the anterior canal in the ipsilateral superior rectus and contralateral inferior oblique; from the horizontal canal in the ipsilateral medial rectus and contralateral lateral rectus; and from the posterior canal in the ipsilateral superior oblique and contralateral inferior rectus. Acute lesion experiments indicated that signals for this excitation reached IIIrd and IVth nuclei via three different pathways; from the anterior canal through the ipsilateral brachium conjunctivum, from the horizontal canal through the ipsilateral fasciculus longitudinalis medialis and from the posterior canal through the contralateral fasciculus longitudinalis medialis.This work was supported by a grant from Educational Ministry of Japan (844021).     

Morphometric measurements from various reference points in the orbit of male Caucasians

The aim of this study was to determine the morphometric variations from various reference points to decrease risks in orbital surgery. Sixty-two orbits obtained from 31 skulls of male adult Caucasians were measured with a millimetric compass. On the medial orbital wall, the midpoint of the anterior lacrimal crest was the reference point; from this point we measured distances of 23.9+/-3.3 mm, 35.6+/-2.3 mm, 41.7+/-3.1 mm and 6.9+/-1.5 mm respectively to the anterior ethmoidal foramen, posterior ethmoidal foramen, midpoint of the medial aspect of the optic canal and posterior lacrimal crest. On the same wall, distances from the plane of the anterior and posterior ethmoidal foramina to the ethmoido-maxillary suture and distance from the posterior ethmoidal foramen to the anterior ethmoidal foramen and midpoint of the medial margin of the optic canal were 14.9+/-2.3 mm, 9.8+/-2.9 mm and 6.8+/-2.2 mm respectively. On the inferior orbital wall, the main reference point was the infraorbital foramen, and from this point to the midpoints of the lateral margin of the fossa for the lacrimal gland, inferior orbital fissure, inferior orbital rim and inferior aspect of the optic canal was 23.8+/-7.2 mm, 31.9+/-3.9 mm, 6.7+/-1.9 mm and 50.3+/-3.2 mm respectively. On the superior orbital wall, the distances from the supraorbital foramen to the midpoints of the superior orbital fissure, fossa for the lacrimal gland and superior aspect of the optic canal were 45.7+/-3.6 mm, 26.0+/-2.5 mm and 45.3+/-3.2 mm respectively. Furthermore, on the same wall, the distance from the posterior ethmoidal foramen to the midpoint of the superior orbital fissure was 14.6+/-2.8 mm. Finally, on the lateral orbital wall the frontozygomatic suture was the reference point. From this point distances to the midpoints of the fossa for the lacrimal gland, superior orbital fissure, lateral aspect of the optic canal and inferior orbital fissure were 17.5+/-2.1 mm, 37.7+/-3.6 mm, 44.9+/-2.5 mm and 33.4+/-3.1 mm respectively.     

乙状窦后进路骨窗和乳突孔定位的解剖学研究

目的：对乙状窦后手术进路的骨窗和乳突孔进行定位,为临床手术操作提供应用解剖基础。方法：采用干性颅骨１８具,福尔马林固定的头颅标本１２具分别进行骨窗及乳突孔的定位测量和桥小脑角结构距骨窗的距离测定。结果：经外耳道下极水平向后４．３５ｃｍ定位圆心“０”点,以１．３５ｃｍ为半径所 圆即为骨窗的位置。将骨窗分为四个象限,其中乳突孔在前上、后上、后下象限公别为６０．５％、３０．２％和９．３％。结论：作者设计     

Evolutionary changes in the cochlea and labyrinth: Solving the problem of sound transmission to the balance organs of the inner ear

This review article examines the evolutionary adaptations in the vertebrate inner ear that allow selective activation of auditory or vestibular hair cells, although both are housed in the same bony capsule. The problem of separating acoustic stimuli from the vestibular end organs in the inner ear has recently reemerged with the recognition of clinical conditions such as superior canal dehiscence syndrome and enlarged vestibular aqueduct syndrome. In these syndromes, anatomical defects in the otic capsule alter the functional separation of auditory and vestibular stimuli and lead to pathological activation of vestibular reflexes in response to sound. This review demonstrates that while the pars superior of the labyrinth (utricle and semicircular canals) has remained fairly constant throughout evolution, the pars inferior (saccule and other otolith, macular, and auditory end organs) has seen considerable change as many adaptations were made for the development of auditory function. Among these were a relatively rigid membranous labyrinth wall, a variably rigid otic capsule, immersion of the membranous labyrinth in perilymph, a perilymphatic duct to channel acoustic pressure changes away from the vestibular organs, and different operating frequencies for vestibular versus auditory epithelia. Even in normal human ears, acoustic sensitivity of the labyrinth to loud clicks or tones is retained enough to be measured in a standard clinical test, the vestibular-evoked myogenic potential test.     

蝶腭孔、翼管前口的应用解剖及临床意义

目的 为鼻内窥镜翼管神经切断术等临床应用提供解剖学依据。方法 用15个30侧经防腐处理的成人头颅标本，经正中矢状面剖开，解剖观察测量蝶腭孔、翼管前口及穿过的血管、神经。结果 19例(63．33％)蝶腭孔位于中鼻甲后端前方平均8．09mm；11例(36．67％)位于在中鼻甲后端前上方平均7．24min。蝶腭孔呈圆形24例，直径平均3．25mm；呈卵圆形6例，最大径平均4．92mm穿过蝶腭孔的动脉有蝶腭动脉，或其分支鼻后外侧动脉和鼻中隔后动脉。翼管前口位于蝶腭孔后方约7mm，呈圆形漏斗状，横径约3mm，略向外下方开口，距离鼻小柱平均71．72mm，有翼管神经和翼管动脉穿过。结论 经鼻腔暴露翼管前口及翼管神经，以及进入翼腭窝处理上颌动脉末端的分支时，蝶腭孔及其周围骨质菲薄的部位是理想的手术入路部位。