颏舌肌前移术的应用解剖学研究

目的 :为颏舌肌前移术提供解剖学依据。方法 :选取 4 0具成人尸头 ,解剖下颌骨、颏舌肌和颏舌骨肌 ,观察颏舌肌和颏舌骨肌的起止点和走行 ,测量颏棘及其相关参数 ,然后采用SPSS10 .0统计软件进行分析。结果 :颏舌肌和颏舌骨肌分别起于上、下颏棘。上颏棘的高度 (5 .82± 0 .71)mm ,宽度 (6 .98± 1.35 )mm ,突度(2 .92± 0 .97)mm ;下颏棘高度 (5 .97± 1.39)mm ,宽度 (3.81± 0 .5 2 )mm ,突度 (0 .77± 0 .6 2 )mm。颏下点至下颏棘下缘的距离 (5 .11± 1.33)mm ,下中切牙根尖至上颏棘上缘的距离 (14 .38± 3.4 0 )mm ,颏棘处下颌骨的厚度(11.95± 1.5 9)mm。男性下中切牙根尖至上颏棘上缘的距离大于女性 ,差异具有统计学意义 (P <0 .0 1)。上、下颏棘宽度、突度的差异具有统计学意义 ,而高度的差异无统计学意义。结论 :颏舌肌与颏舌骨肌同时前移时 ,骨块下端切口线应距颏下点约 5mm ;颏舌肌单独前移时 ,骨块下端的切口线应距颏下点约 11mm。骨块上端的切口距颏下点约 18mm。两侧的垂直切口各距离中线约 4mm。以颏下点及中线作为标志来定位颏舌肌前移术中的骨切口线更加直观、可行和准确。     

Ⅰ型甲状成形术相关参数在喉标本和CT测量中的比较研究

目的探讨Ⅰ型甲状成形术相关参数通过喉标本和螺旋CT两种不同方法测量结果是否存在差异。方法对50例喉全切除术患者的喉体标本术后立即进行测量(均为单侧),并与术前通过螺旋CT多平面重建技术所测喉体相关参数结果进行比较研究,观察两种测量结果的差异是否具有统计学意义。结果所设6个参数通过两种方法测量结果差异均无统计学意义(P值均>0.05)。应用螺旋CT和喉标本两种方法测量所设参数的结果(x±s)分别为:甲状切迹至下缘的长度为(20.7±1.7)mm和(20.6±1.7)mm;声带的长度为(17.3±1.8)mm和(17.3±1.8)mm;斜线的长度为(28.6±3.2)mm和(29.1±2.7)mm;假设水平线的长度为(26.2±2.0)mm和(26.2±2.0)mm;声带前端至假设水平线在喉内的垂直距离为(4.5±0.6)mm和(4.5±0.7)mm;声带突至假设水平线在喉内的垂直距离为(10.8±1.1)mm和(10.9±1.1)mm。填入楔形假体在喉体内前、后端的宽度分别以4～5mm和8～9mm为宜。结论通过螺旋CT的多平面重建技术对喉体进行测量是准确可信的,是Ⅰ型甲状成形术术前设计开窗和假体大小的理想方法,解决了术中设计假体大小的滞后性。     

幼儿面神经的中耳手术解剖学研究

目的研究面神经隐窝入路手术相关的幼儿面神经解剖学特点,为开展幼儿中耳手术及人工耳蜗植入手术提供参考数值。方法对14具(28侧)幼儿尸头颞骨面神经隐窝及后鼓室结构进行解剖学观察,测量面神经隐窝入路手术相关的面神经解剖学特点和相关数值。结果面神经隐窝最小者1.82mm,但存在个体差异。鼓索神经到面神经锥曲段、垂直段的距离分别为(3.79±0.45)mm、(2.23±0.57)mm,锥隆起至面神经锥曲段、水平段、垂直段的距离分别是(2.79±0.60)mm、(2.17±0.42)mm、(3.90±0.59)mm,面神经垂直段至圆窗龛前缘中点的距离(4.83±0.70)mm。结论本文为幼儿中耳手术提供了有用的面神经相关参考数据,对手术中避免面神经等重要结构的损伤有重要意义。     

蝶腭孔的解剖学观察

目的为蝶腭孔相关手术提供解剖依据.方法观察106侧正中矢状切开颅骨蝶腭孔的位置、形状、大小,测量蝶腭孔的长径、宽径及孔中心至前鼻棘的距离.结果(1)蝶腭孔位于中鼻甲后端与蝶窦底之间,为圆形、椭圆形、不规则形,分为单孔、双孔、3孔;(2)平均长径左边是5.85±1.17mm,右边是6.09±1.31mm,平均宽径左边是3.91±0.97mm,右边是3.92±0.98mm;(3)孔中心至前鼻棘距离的平均值左是49.69±3.55mm,右是50.72±2.87mm.结论蝶腭孔的解剖学观测为临床提供了解剖资料.     

颏下岛状皮瓣的解剖学研究

目的:对颏下动脉、静脉及所供皮瓣进行解剖学研究。方法：测量21具成人尸体标本的颏下动脉、静脉及支配皮瓣的面积。结果：颏下动脉起点处外径（1.41±0.32）mm,颏下静脉的最大外径为（2.41±0.91）mm,皮瓣的长度为（78.2±13.9）mm,宽度为（55.6±5.4）mm。结论：颏下动脉是面动脉的一根恒定分支，血管行经长，位置表浅，口径粗，有恒定的伴行静脉，是良好的皮瓣供血动脉。     

鼻科学

20050322蝶腭孔的显微解剖学研究/贵平…//临床耳鼻咽喉科杂志.2004,18(10).60～608目的:通过对尸颅蝶腭孔的测量和观察,为经鼻内镜蝶腭孔相关手术提供解剖学依据。方法:应用显微解剖学方法对40侧正中线切开的尸颅蝶腭孔进行了位置、形状、大小及毗邻关系的观察与有关数据的测量。结果:将蝶腭孔分成3类,I类:孔位于上鼻甲、上鼻道的后方;Ⅱ类:孔位于中鼻甲或中鼻道的后端;Ⅲ类:I类加Ⅱ类。各类分别占35%5%、60%。孔上缘与蝶窦底间距离男(1.75±1.10)mm,女(1.13±0.55)mm,与蝶窦口距离男(9.80±3.27)mm,女(8.30±3.45)mm,孔的后缘与鼻咽部距…     

蝶窦、视神经管多层螺旋CT三维重建后的影象解剖学测量

目的：为经鼻内镜蝶窦手术、视神经管减压术提供影象解剖学基础。方法：利用螺旋CT三维重建技术对40例(80侧)鼻、鼻窦正常的受试者行蝶窦、视神经管有关解剖数据的影象学测量。结果：两侧视神经管各壁长度均值为：内侧壁12.08±0.62?mm，外侧壁10.16±1.73?mm,上壁9.16±1.17?mm,下壁10.24±1.35?mm。两侧视神经管及蝶窦有关径线均值为：视神经管颅口处：左右径5.57±0.95?mm，上下径4.53±0.78?mm；中部：左右径4.40±0.67?mm，上下径4.36±0.67?mm；眶口处：左右径5.09±0.85?mm，上下径5.90±0.98?mm；鼻小柱前缘中点到蝶窦前壁中点的距离：7.08±0.54?cm；蝶窦最大左右径：17.83±4.38?mm，最大上下径：18.40±3.76?mm，最大前后径：23.19±6.73?mm。结论：螺旋CT三维重建技术可以准确有效地测量蝶窦、视神经管的解剖结构，对经鼻内镜手术具有重要指导价值。     

前颅底肿瘤、类肿瘤病变手术入路的应用解剖研究

目的为前颅底肿瘤、类肿瘤病变的手术入路提供应用解剖学依据.方法测量30例干燥国人颅骨的鼻棘点、Dacryon点和颞额颧点至前颅底各结构的的连线长度;颞额颧点至颅中窝内各结构的连线长度,以及部分连线与正中矢状面所成的角度.结果1.鼻棘点至筛板前缘、筛板后缘、视神经交叉沟、鞍结节、前床突、视神经管眶口、视神经管颅内口、翼管口、蝶腭孔的距离分别为(49.6±3.8)mm、(54.8±3.5)mm、(66.3±3.9)mm、(67.9±3.3)mm、(71.8±3.5)mm、(61.0±3.3)mm、(66.4±3.6)mm、(64.3±3.6)mm、(47.5±2.8)mm.鼻棘点与筛板前缘、筛板后缘、鞍结节的连线与鼻底平面所成的夹角分别为;(77.4±4.0)°、(55.5±5.4)°、(40.5±3.5)°.2.Dacryon点至筛前、后孔、视神经管眶口、颅内口、前床突、筛板前、后缘、视神经沟、鞍结节、眶上裂外侧缘的距离分别为(16.2±2.2)mm、(28.6±2.3)mm、(34.7±2.5)mm、(42.6±3.4)mm、(49.8±3.1)mm、(12.7±1.7)mm、(28.5±2.8)mm、(43.7±3.7)mm、(47.9±3.2)mm、(37.4±2.8)mm.3.颞额颧点至眶下裂外端、翼上颌连接外侧下缘、翼上颌裂下端、翼突外侧板根部、圆孔、卵圆孔、棘孔、颈内动脉管内口外缘、前床突、鞍结节的距离分别为(28.8±3.0)mm、(67.6±4.3)mm、(58.5±3.6)mm、(61.0±3.9)mm、(50.0±3.8)mm、(58.6±4.3)mm、(61.7±4.7)mm、(64.0±3.9)mm、(57.5±3.5)mm、(64.0±3.6)mm.结论有关各种颅底手术入路的测量结果有助于设计手术入路和病变的术前诊断,并可为术中准确定位提供参考依据.     

舌动脉的解剖特点与舌根中线部分切除术的关系

目的观察舌动脉的走行、比邻及其主干与舌表面各标志的关系,以指导舌根中线手术,提高手术安全性。方法8具（16侧）颌面部发育正常成人尸头标本,颈总动脉灌注红色乳胶。①解剖观察舌动脉的起源、走行;②以舌骨舌肌为界将舌动脉分为3段,对各段的长度及其邻近结构进行观测。③以舌盲孔、舌盲孔前5mm和10mm、舌盲孔后10mm及舌根与会厌谷粘膜分界处为标志,分别测量舌动脉主干距舌中线及舌表面的距离。结果舌动脉全长为(92.88±13.53)mm;其中第1段为(40.44±5.79)mm,第2段为(18.33±3.32)mm,第3段为(38.33±7.74)mm。舌动脉主干在舌盲孔前10mm和5mm、舌盲孔、舌盲孔后10mm、舌根与会厌谷分界处距舌中线的距离分别为(7.78±3.15)mm,(8.56±3.57)mm、(11.00±4.95)mm、(13.00±3.28)mm、(15.22±3.11)mm,距舌表面的距离分别为(22.56±7.81)mm、(22.11±6.74)mm、(21.44±5.59)mm、(16.56±5.57)mm、(2.56±0.73)mm。结论舌骨大角上方10mm范围内为寻找舌动脉的首选位置,在行舌根中线部分切除术时,在舌根与会厌谷粘膜分界处最易伤及舌动脉主干,切除范围在舌中线两侧7mm、舌表面下10mm范围内,可防止舌动脉的损伤。     

部分迷路切除行小脑桥脑角区手术的临床解剖学测量

目的　为临床上保留半规管功能和听力处理小脑桥脑角区病变提供解剖学资料。方法　在 2 0例40侧国人成人尸头上模拟单纯后半规管切除及后、上半规管切除处理小脑桥脑角区病变 ,对暴露的范围进行解剖测量 ,比较相关数据。结果　岩上窦下缘至颈静脉球顶的垂直线距离为 (15.0 2± 3 .69)mm (7.80～ 2 1.3 0 ) ,乙状窦内侧至内淋巴管起始处的水平距离为 (10 .62± 2 .0 9)mm (6.2 0～ 16.80 ) ,颞骨岩部后硬脑膜至外半规管后壶腹后缘的水平距离为 (6.2 1± 1.78)mm (3 .80～ 10 .10 ) ,至后半规管中点后缘水平距离为 (4.0 7± 1.2 6)mm (2 .10～6.60 )。乙状窦内侧至内听道口后缘中点水平距离为 (19.89± 3 .10 )mm (14 .70～ 2 4.60 ) ,岩骨后硬脑膜至上半规管前壶腹后缘间水平距离为 (12 .60± 2 .73 )mm (8.2 0～ 19.10 )。结论　颞骨径路处理小脑桥脑角区病变同时保留听力和平衡功能是可能的 ,相对而言 ,后上半规管切除比单纯后半规管切除所得的术野大 ,暴露好且操作相对简单 ,不易发生并发症     

颏下逆行带蒂岛状皮瓣的应用解剖研究

目的 为颏下逆行带蒂岛状皮瓣修复颜面部皮肤软组织缺损的可行性及手术操作提供解剖学依据.方法 解剖20例40侧福尔马林固定、颈总动脉灌注红色乳胶的成人头颈标本及4例灌注汞溴红、2例灌注亚甲蓝的新鲜成人头颈标本,测量相关动脉的外径及相关标志点之间的距离(以-x±s表示);观察两侧面动脉之间、面动脉与颞浅动脉及眼动脉终术之间的吻合情况,观察面动、静脉的行程要点及其与面神经各分支之间的位置关系,观察面静脉与相关静脉之间的吻合情况.结果 颏下动脉、上唇动脉、下唇动脉起点处的外径(-x±s,以下同)分别为(1.42±0.30)mm、(1.34±0.35)mm、(1.34±0.27)mm.下唇动脉起点至颏下动脉起点直线距离为(35.19±9.18)mm,实际距离为(50.13±13.79)mm;上唇动脉起点至颏下动脉起点直线距离为(64.99±5.24)mm,实际距离为(92.09±8.73)mm.双侧面动脉之间、面动脉与颞浅动脉及眼动脉终末之间有丰富的吻合.在下颌缘水平,面动、静脉相贴伴行,面神经下颌缘支跨过其浅面;在下颌缘水平以上,面静脉行于面动脉后外约1 cm处,面神经颊支经面静脉表面于面动、静脉之间人表情肌.面静脉通过内眦静脉与眼静脉、面深静脉与上颌静脉之间有良好的交通.结论 以颏下逆行带蒂岛状皮瓣修复颜面部皮肤软组织缺损在解剖上具有可行性,建议皮瓣的旋转点选择在口角或口角以下平面.     

不同性别阻塞性睡眠呼吸暂停低通气综合征患者与上气道影像学相关性的研究

目的探讨上气道影像学在不同性别阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者病情严重程度中的预测作用。方法对163例经多导睡眠监测(PSG)确诊为OSAHS患者(男98例,女65例),行平静呼吸时上气道CT扫描,测量舌骨下缘距下颌骨下缘(颏下点)的垂直距离(D-HM)、舌骨最前点距下颌骨下缘(颏下点)的距离等CT参数,并进行各测量值与睡眠呼吸暂停低通气指数(AHI)、最低动脉血氧饱和度(LSaO_2)的相关性分析。结果 (1)AHI。男性患者14.2~52.3次/h,平均(36.22±5.64)次/h;女性患者9.6~46.4次/h,平均(29.38±3.90)次/h;(2)LSaO_2。男性患者48%~79%,平均(63.93%±10.51%);女性患者59%~87%,平均(70.92%±9.17%);(3)各研究平面的最小前后径、左右径及面积与AHI的大小均呈负相关,与LSaO_2呈正相关,且男性OSAHS患者AHI、LSaO_2与腭后区最小截面积相关性更明显(r=-0.441,P0.01),而女性OSAHS患者AHI、LSaO_2与舌后区最小截面积相关性更明显(r=-0.403,P0.01);(4)不同性别之间舌骨下缘距下颌骨下缘(颏下点)的垂直距离(D-HM)、舌骨最前点距下颌骨下缘(颏下点)的距离差异具有统计学意义(P0.01);(5)对部分OSAHS患者行改良UPPP手术,术后3个月,男性OSAHS患者总有效率为84.31%,女性OSAHS患者总有效率为58.06%,CT测量值男性OSAHS患者有4个数值与术前相比有统计学意义,而女性患者有1个数值与术前相比有统计学意义。结论 OSAHS患者上气道CT的测量指标可对OSAHS病情的严重程度有一定预测作用,且不同性别之间的测量数值差异有统计学意义,需根据性别的不同来制定个体化诊疗意见。     

Computer-aided 3-D temporal bone anatomy for cochlear implant surgery

To define anatomical relationships important in cochlear implantation, computer-aided three-dimensional reconstruction and measurement of middle and inner ear structures in six normal temporal bones were performed. Our findings were as follows: 1. When viewed from the posterior hypotympanotomy (facial recess) approach, the inferior 10% to 30% of the round window (RW) membrane was visible in only half the cases. 2. The most inferior portion of the basal turn of the scala tympani was not only inferior but also slightly anteriorly behind the RW membrane in more than half the cases. 3. The shortest distances from the aperture of the RW niche and from the margin of the RW to the stapes head were 2.38 +/- 0.33 and 2.15 +/- 0.22 mm, respectively. 4. The distance between the RW and the most inferior portion of the basal turn scala tympani was 5.15 +/- 0.34 mm. 5. The direction of the electrode advancement lay at a sharp angle to the inferior part of the RW (mean 31.9 +/- 3.6 degrees). 6. The direction from the RW to the most inferior portion of the basal turn scala tympani lay 16.0 +/- 5.3 degrees anteroinferior to the direction of the advancement of the electrode to the RW. 7. The distance between the margin of the RW and the basilar membrane of the cochlea was 0.58 +/- 0.10 mm at the superior aspect of the RW, and was 1.23 +/- 0.12 mm at the lateral aspect of the RW. 8. Dissecting away less than 1 mm (mean 0.7 +/- 0.27 mm) of the RW margin inferiorly or inferolaterally was enough to permit straight insertion of the electrode in most cases.     

Morphometric study of the medial aspect of the human maxillary sinus with special reference to the nasal fontanelle

OBJECTIVE: The purpose of this study was to clarify configurations of the nasal fontanelle (NF) from the morphometrical point of view, especially variations of its four margins (anterior, posterior, superior, and inferior), for clinical application. METHODS: We used 136 sides of hemi-sectioned heads that were obtained from 119 donated Japanese cadavers (66 men and 53 women with an average age of 77.6+/-12.0). After mucosal examination, the specimens were boiled with a small amount of powdered soap and treated with protease. The residual mucous membrane was then gently removed. These specimens were originally made for our previous study describing variations of the uncinate process (Isobe M, Murakami G, Kataura A. Variations of the uncinate process of the lateral nasal wall with clinical implications, Clin. Anat. 1998;11:295-303). Different series of measurements were conducted based on surgical approaches and angles of observation. RESULTS: The superior margin of the NF is difficult to identify because the ethmoidal infundibulum, which leads the anterior end of the margin upward, often interrupts the superior margin. Because the inferior and posterior margins are modified by thin paper-like bony structures and because the anterior margin is disturbed by variations of the lacrimal bone and/or the inferior turbinate, they are also difficult to identify. Knowing these variables, we evaluated the NF morphometrically. The NF was located 12.6+/-4.3 mm posterior to the anterior nasal spine and 6.6+/-2.2 mm anterior to the sphenopalatine foramen. The size of the NF was 17.9+/-3.2 mm (anteroposterior axis) x 11.5+/-3.0 mm (inferosuperior axis). The lowest orbital floor was located 10 mm below the superior margin of the anterior NF (-10 mm), and the distance was therefore measured as -3.7+/-2.4 mm on average. Viewed from the maxillary sinus, the location of the NF varied along the anteroposterior axis, whereas it was located consistently at the most superior portion of the medial aspect of the sinus wall. CONCLUSION: During endoscopic sinus surgery for tumor resection in the maxillary sinus, a large and primary window should be prepared in the posterior NF, including partial removal of the uncinate process. Preparation of an additional window in the inferior meatus is preferable to enlargement of the primary window. Approaching the anterior NF should be avoided, if possible, due to its complicated configuration as well as its proximity to the orbital floor.     

Anatomic measurements for the endoscopic modified Lothrop procedure

BACKGROUND: The aim of this study was to introduce preoperative radiographic frontal recess and sinus anatomic measurements to assist in the selection of patients considered for the modified Lothrop procedure. METHODS: Data were collected from sagittally reconstructed computed tomography (CT) scans of seven cadaver heads. Four anatomic parameters for measurement were defined as follows: (1) thickness of the nasal beak (desirable < 10 mm); (2) midsagittal distance from nasal beak to skull base (adding 1 and 2 provides the anterior-posterior (AP) space at the cephalad margin of the frontal recess; desirable, > or = 15 mm); (3) accessible dimension (in a parasagittal plane through the frontal ostium; the distance between two lines drawn parallel to the plane of the anterior skull base and perpendicular to the line of the insertion of the nasal endoscope during surgery; the posterior line is drawn at the skull base and the anterior line is drawn at the posterior margin of the nasal beak; the distance between the lines indicates the space available for instrumentation; desirable, > 5 mm); (4) AP dimension of each frontal sinus. RESULTS: The average and the range of each parameter measured were as follows: (1) nasal beak thickness = 8.0 mm (5.0-10.4 mm); (2) nasal beak-skull base = 7.9 mm (2.5-14.1 mm); (3) accessible dimension, 6.1 mm (0.9-9.6 mm); (4) AP diameter of the frontal sinus, 9.7 mm (5.2-14.1 mm). Four specimens were considered candidates for modified Lothrop and three were not. CONCLUSION: Preoperative radiographic frontal recess and sinus anatomic measurements may assist in the selection of patients considered for the endoscopic modified Lothrop procedure.     

CT anatomic measurement of the optic canal and its clinical significance]

OBJECTIVE: To probe into the normal anatomy of the optic canal and its clinical significance. METHODS: The optic canals of 200 normal subjects were examined by thin layer CT scan in axial nd coronal positions. The distance and anatomic relationship with circumferentral structure were measured. RESULTS: In average: (1) The transverse diameter of the optic canal was (3.57 +/- 0.61) mm, the longitudinal diameter was (4.82 +/- 0.38) mm, the length of the inner wall was (12.62 +/- 2.59) mm, the length of the outer wall was (10.18 +/- 2.19) mm, and the length of the optic canal was (11.46 +/- 2.35) mm. The angle between optic canal and the middle line of the skull was 34.34 degrees +/- 6.48 degrees, the angle between optic canal and the intraorbital optic was 10.69 degrees +/- 6.48 degrees. The thickness of the inner wall was (0.68 +/- 0.46) mm. It showed no significant difference between the two sides of the optic canal in diameters(P > 0.05). (2) The optic canal, the superior orbital fissure and the inferior orbital fissure were respectively shown as track, crack and gorge type in CT axial pictures, while in the coronal pictures, they were respectively shown as butterfly eyes, horizontal fissure and vertical fissure type. (3) The relationship of the posterior ethmoid sinus and the optic canal was: anterocanal(42.00%), semicanal(27.5%), whole-canal(18.75%), sella turcica(9.75%) and circumcanal(2.00%). (4) The relationship of the position of the sphenoidal sinus and the optic canal was: I degree sphenoidal sinus(20%), II degree (63%) and III degree (17%). (5) The incidence of the bony defect of the inner optic canal wall was 25.5%. The range of the defect was (5.07 +/- 2.52) mm. CONCLUSION: It's a reliable way to show the relation of the optic canal and circumcanal by CT, and it is of important value in operation.     

国产颏棘环钻系统行颏舌肌前移术

目的探讨国产颏棘环钻系统行颏舌肌前移术的可行性。方法2005年6月～8月对3例阻塞性睡眠呼吸暂停低通气综合征（obstructive sleep apnea hypopnea syndrome,OSAHS）患者行悬雍垂腭咽成形术（uvulopalatopharyngoplasty,UPPP）,同时采用颏棘环钻系统（genial bone advancement trephinesystem,GBAT system）行颏舌肌前移术。结果颏棘环钻系统颏舌肌前移术的手术时间30分钟～1小时,术中未发生下前牙根尖损伤、颏神经损伤及下颔骨骨折等并发症,术后无口底血肿,伤口感染等。结论应用国产颏棘环钻系统行颏舌肌前移术具手术时间短、创伤小、操作容易等优点。     

A temporal bone study of the jugular fossa]

This study was performed to elucidate the anatomic variations of the jugular fossa (JF) on the basis of examination of 120 human temporal bones. Observations were made of temporal bones sectioned along a plane including the cochlea, the JF, and long axis of the internal auditory canal. The position of the upper margin of the JF was classified according to its relation to the tympanic cavity, the cochlea, and the internal auditory canal. The height of the upper margin of the JF was classified as follows. Low type; inferior to the level of the external auditory canal. Middle type; between the level of the external auditory canal and the cochlea. High type; superior to the level of the cochlea. The results revealed that 58 ears were of low type, 46 middle type, and 16 high type. Middle and high type comprised 62 ears, thus in 52% of ears the upper margin of the JF was situated superior to the external auditory canal. The relation between the JF and the cochlea was classified as follows. Medial type; medial to the medial margin of the cochlea. Lateral type; lateral to the medial margin of the cochlea. The results showed that 74 ears were of medial type, and 46 lateral type. Therefore, in 62% of ears the upper margin of the JF was situated medial to the medial margin of the cochlea. Forty-seven ears of medial type were of middle or high type. Ears of lateral type included none of high type. The jugular bulb diverticulum was observed in 32 ears, which consisted of 3 of low type, 13 middle type, 16 high type. When the upper margin of the JF was positioned higher, the JF was in a more medial position. However, no defect of the bony labyrinth was observed. In conclusion, it is considered that protrusion of the jugular bulb into the tympanic cavity was not caused by the abnormally high position of the JF, but by its lateral displacement. Distances from the JF to the surrounding structures were as follows; to the tympanic membrane 5.58 +/- 2.43mm (mean +/- S.D.), to the tympanic cavity 2.94 +/- 1.92mm, to the cochlea 4.93 +/- 2.20mm, and the internal auditory canal 5.82 +/- 2.38mm.