The Quadratojugal of Eryops studied by computed tomography and the morphological variability of foramina and canals in the quadratojugal of basal tetrapods

With respect to its large size and abundance, Eryops is an important representative of Permo‐Carboniferous basal tetrapods and one of the best‐known large temnospondyl amphibians of this period. This taxon forms a significant component of the Early Permian tetrapod fauna of Texas and New Mexico and here we describe a new record of skull remains, the first one from Brushy Creek (30 km northeast of Seymour) in Texas (Petrolia Formation, Wichita Group; Lower Permian – lower Artinskian). Our material, found in 2015, consists of a left nasal, a jaw fragment (premaxilla or maxilla), left quadratojugal fragments, and a partial left mandible. We used computed tomography methods (micro‐CT) for imaging both internal and external structures, for the first time, for Eryops. The quadratojugal presented here is exceptional compared to all known basal tetrapods in having four different internal foramina. CT data show that these foramina are interconnected by canals within the bone. This indicates that the morphology of the foramina and the course of the canals in the quadratojugal of basal tetrapods are more variable than hitherto thought. Anat Rec, 299:1073–1079, 2016. © 2016 Wiley Periodicals, Inc.     

胎儿胸椎间孔韧带的观测及意义

目的:通过胎儿胸椎间孔韧带的观测,为国人提供胎儿胸椎间孔韧带的解剖学资料。方法:选用足月胎儿尸体标本15具,解剖观察胸椎间孔韧带,用游标卡尺进行相关测量。结果:在30侧胸椎标本中未发现横孔上韧带和体横韧带,T1￣T12均发现横孔下韧带,其出现率从T1￣T12分别为10.0%、10.0%、23.3%、30%、46.7%、53.3%、76.7%、80.0%、80.8%、86.7%、90.0%、86.7%;T3￣T12横孔下韧带的长度随着椎骨序数的增加而有逐渐增加的趋势。结论:胎儿胸椎间孔韧带普遍存在,其为胸椎的正常组织结构,对胸椎神经根管内的结构具有固定、支持和保护作用。     

胎儿腰椎间孔韧带的观测及意义

目的:观察腰椎间孔韧带的形态,探讨其生理意义。方法:选用足月胎儿尸体标本11具,解剖观察腰椎间孔韧带,用游标卡尺进行相关测量。结果:在22侧腰椎标本中未发现横孔上韧带,L1、L2和L3横孔下韧带的宽度、厚度和长度分别为:L1:(1.4±0.4)mm、(0.4±0.2)mm、(2.8±0.5)mm,L2:(1.3±0.4)mm、(0.4±0.2)mm、(2.8±0.5)mm,L3:(1.6±0.1)mm、(0.4±0.1)mm、(2.8±0.9)mm,L4和L5椎间孔内未发现横孔下韧带;标本中未发现体横上韧带,体横下韧带分布于L3～L5椎间孔的外侧,其宽度、厚度和长度分别为:L3:(2.1±0.4)mm、(0.6±0.1)mm、(4.5±1.2)mm、L4:(2.0±1.2)mm、(0.4±0.2)mm、(5.7±0.8)mm,L5:(2.4±0.8)mm、(0.4±0.2)mm、(5.0±1.0)mm。结论:胎儿腰椎间孔韧带普遍存在,其为腰椎的正常组织结构。     

舌动脉的形态类型及其临床意义

目的：为临床应用提供舌动脉的形态学资料。方法：对７８例成人舌动脉剥制标本和铸型标本进行观察。结果：依据舌动脉变化最大的起始段形态，可分为上弓型（６９．１％），下降型（９．１％）、与面动脉共干型（２０．０％）和与甲状腺上动脉共干型（１．８％）四个类型。结论：舌动脉第一段的位置、形态个体差异很大，临床外科有关手术应予注意，第２～４段的位置和形态较为恒定。     

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。     

Ligaments of the lumbar neural foramina: A sectional anatomic study

The ligaments of the lumbar neural foramina have not been systematically described. We sectioned the lumbar spines of 15 cadavers in the sagittal plane with a cryomicrotome and identified the ligaments in the neural foramina. Fibrous ligaments were identified in every lumbar neural foramen. The most constant ligament was a band of fibrous tissue behind the anulus fibrosus and distinct from it, originating in one vertebral body and inserting in the next. Ligaments connecting the posterior disc margin and the superior articular process were found in 48% of the neural foramina. A band of fibrous tissue originating from the anulus fibrosus and inserting along the pedicle and superior articular process was found in 44% of the foramina. Three other distinct types of ligament were found less commonly. Ligaments, which some investigators believe may contribute to lateral spinal stenosis, are commonly present in the neural foramina.     

Clinical anatomy of the orbitomeningeal foramina: variational anatomy of the canals connecting the orbit with the cranial cavity

Purpose

In addition to the optic canal and the superior orbital fissure, orbits are connected with the cranial cavity via inconstant canals including the orbitomeningeal foramen. This study has been carried out in order to define many anatomical and radiological details of the orbitomeningeal foramen that are relevant in the clinical practice.

Methods

Almost 1000 skulls and 50 computerized tomographies were examined to determine incidence, number, length, and caliber of the orbitomeningeal foramen as well as the topography of their orbital and cranial openings. A retrospective study of angiographies carried out on more than 100 children was performed to look for arteries candidate to run through the orbitomeningeal foramen.

Results

Orbitomeningeal foramina were detected in 59.46 % of skulls and in 54 % of individuals by computerized tomography. Orbits with two to five foramina were found. Canals were classified as M-subtype or A-subtype depending on their cranial opening. Large foramina, with the caliber ranging between 1 and 3 mm, were found in 12.17 % of orbitomeningeal foramen-bearing orbits. By computed tomography the average caliber measured 1.2 ± 0.3 and 1.5 ± 0.5 mm (p < 0.005) at the orbital and cranial openings, respectively (p < 0.005). Angiographies showed meningo-lacrimal and meningo-ophthalmic arteries, meningeal branches of the lacrimal and supraorbital arteries, and some unidentified arteries that could pass through the orbitomeningeal foramina.

Conclusions

Orbitomeningeal foramina are a common occurrence. When large they may house important arteries that can be the source of severe bleedings during deep dissection of the lateral wall of the orbit. Orbital surgeons should be aware of their existence.

     

成人胸椎间孔韧带的解剖学观测

目的 通过解剖观测成人胸椎间孔韧带.为国人提供胸椎间孔韧带的解剖学资料并探讨其临床意义.方法 选用成人尸体标本15具,解剖观察胸椎间孔韧带.用游标卡尺进行相关测量.结果 在30侧成人胸椎标本中未发现横孔上韧带和体横韧带.T1椎间孔内未发现横孔下韧带,T2～T12椎间孔内均发现横孔下韧带,其出现率从T2～T12呈逐渐增加...     

颈静脉孔的显微外科解剖学研究

目的:为颈静脉孔区病变的手术提供显微外科解剖学基础。方法:在手术显微镜下对２０例福尔马林固定的成人头颈部标本和１０例成人颅骨标本的颈静脉孔区进行显微解剖和观测。结果:静脉孔分成三部,即神经部、岩部、乙状部,岩部为接收岩下窦、舌下神经管静脉、岩斜裂静脉和椎静脉丛分支的静脉窦;乙状部接收乙状窦血流;神经部由位于结缔组织鞘中的舌咽、迷走、副神经所组成。颈静脉孔长(１３．４±１．１)ｍｍ,颈静脉孔乙状部宽(９．１±１．９)ｍｍ,颈静脉孔的乙状部高(７．３±２．２)ｍｍ,颈静脉孔的内、外口相距(１２．７±１．５)ｍｍ。颈静脉球具有下述特点:(１)静脉壁相当薄,不及乙状窦及颈内静脉壁一半的厚度 ;(２)连接多处的引流静脉;(３)完全位于骨质中且位置变异较大;(４)邻近重要结构等。高位颈静脉球出现率为１５%。结论:熟悉颈静脉孔区的显微解剖有利于手术中保护重要的神经和血管。     

枕下远外侧经枕髁入路的应用解剖

目的：为枕下远外侧经枕髁入路提供应用解剖学基础。方法：在５例共１０侧正常人头颅标本上模拟枕下远外侧经枕髁入路逐层解剖和观测到达枕骨大孔区腹外侧。结果：应用此入路切除部分枕髁后可满意暴露枕骨大孔区腹外侧而对重要的神经血管的损伤最小。结论：正确的头位和切口设计、向外侧充分切除骨质、椎动脉内移、乙状窦外牵、上二条齿状韧带的切断及妥善保护重要的神经血管等是应用此入路成功的关键。     

Defining the anatomy of the neonatal lingual frenulum

The lingual frenulum is recognized as having the potential to limit tongue mobility, which may lead to difficulties with breastfeeding in some infants. There is extensive variation between individuals in the appearance of the lingual frenulum but an ambiguous relationship between frenulum appearance and functional limitation. An increasing number of infants are being diagnosed with ankyloglossia, with growing uncertainty regarding what can be considered “normal” lingual frenulum anatomy. In this study, microdissection of four fresh tissue premature infant cadavers shows that the lingual frenulum is a dynamic, layered structure formed by oral mucosa and the underlying floor of mouth fascia, which is mobilized into a midline fold with tongue elevation and/or retraction. Genioglossus is suspended from the floor of mouth fascia, and in some individuals can be drawn up into the fold of the frenulum. Branches of the lingual nerve are located superficially on the ventral surface of the tongue, immediately beneath the fascia, making them vulnerable to injury during frenotomy procedures. This research challenges the longstanding belief that the lingual frenulum is a midline structure formed by a submucosal “band” or “string” and confirms that the neonatal lingual frenulum structure replicates that recently described in the adult. This article provides an anatomical construct for understanding and describing variability in lingual frenulum morphology and lays the foundation for future research to assess the impact of specific anatomic variants of lingual frenulum morphology on tongue mobility. Clin. Anat. 32:824–835, 2019. © 2019 The Authors. Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.     

An assessment on spiral CT scan of the superior and inferior genial spinal foramina and canals

To characterise the superior as well as the inferior genial spinal foramen and their bony canal using a large CT data sample. The study included 555 mandibular spirals CT scans, taken from patients for pre-operative implant planning. Basic observation by three observers included the number of canals, their respective anatomical location and morphological variations. Furthermore, linear measurements were performed to describe the foramina and canal characteristics. On spiral CT scans, the superior and inferior genial spinal foramina were detected in 448 CT scans (81%). In 29% of the mandibular CTs, two or more midline canals were noted. 47% of the foramina were located in a position inferior to the genial spines; the others were located in a superior position. The mean (SD) lingual and buccal diameters of the canal structures were 0.73 (0.27) and 0.54 (0.29) mm, respectively with an average length of 3.94 (1.29) mm. The canal was located on average 7.40 (5.31) mm from the mandibular base at the lingual entrance and 7.96 (3.47) mm at the buccal canal end point. The average canal extended towards the buccal bone for an average 37% of the bone width. The results demonstrated the presence of both superior and inferior genial spinal foramina, with 29% of the individuals having double foramina. About 53% of the foramina was located superior to the genial spines. Considering its neurovascular content, these foramina should be carefully evaluated during pre-operative planning.     

中外结扎舌动脉的应用解剖

目的为口外舌动脉结扎提供解剖学资料。方法在30例经动脉灌注红色乳胶的成人尸体标本上,对舌动脉的起源、走行、分段和各段的重要毗邻等进行解剖观测。结果舌动脉单独起于颈外动脉者占66.7%,与面动脉共干者占23.3%,与甲状腺上动脉共干者占10.1%。舌动脉起始处的外径为(3.4±0.6)mm。起点至颈总动脉分叉处的距离为(1.1±0.5)cm。舌动脉全程可分为4段,即起始段、舌骨舌肌段、升段和水平段。舌骨舌肌段位置恒定,部位表浅,体表标志明确,血管周围无重要结构。结论舌动脉舌骨舌肌段是行口外舌动脉结扎最理想的部位。     

ⅨⅩⅪ脑神经和颈静脉孔的显微解剖研究

目的：通过颈静脉孔以及Ⅸ、Ⅹ、Ⅺ脑神经的显微解剖研究，对重要结构进行量化分析，为手术提供解剖依据，并进一步澄清颈静脉孔的概念。方法：用10例成人尸头，在手术显微镜下对双侧重点观察了颈静脉孔的分隔，脑神经和颈静脉球的关系，同时对25例干性颅骨标本进行了大体测量。结果：Ⅸ和Ⅹ、Ⅺ脑神经之间有纤维(80％)或骨桥(20％)形成的不完全分隔，仅在1例干性颅骨标本中发现颈静脉孔被完全分隔为两个部分。Ⅸ、Ⅹ、Ⅺ脑神经全部位于颈静脉孔的前内侧，它们在孔内有各自单独的神经鞘膜，出孔后和颈内动脉、颈内静脉有共同的纤维包膜。在颈静脉球和颈内静脉的连接部，舌咽神经被一致密的结缔组织纤维固定在颈内动脉上。结论：颈静脉孔内的结构分成神经部，岩部和乙状部是比较合理的，有助于更好地理解颈静脉孔区特殊结构。Ⅸ、Ⅹ、Ⅺ脑神经在孔内的结构较为疏松，这种特点为术中辨认和神经保护提供了依据。     

Clinical and surgical anatomy of the liver: A review for clinicians

The liver is the largest gland in the body occupying 2.5% of total body weight and providing a host of functions necessary for maintaining normal physiological homeostasis. Despite the complexity of its functions, the liver has a homogenous appearance, making hepatic anatomy a challenging topic of discussion. To address this issue, scholars have devoted time to establishing a framework for describing hepatic anatomy to aid clinicians. Work by the anatomist Sir James Cantlie provided the first accurate division between the right and left liver in 1897. The French surgeon and anatomist Claude Couinaud provided additional insight by introducing the Couinaud segments on the basis of hepatic vasculature. These fundamental studies provided a framework for medical and surgical discussions of hepatic anatomy and were essential for the advancement of modern medicine. In this article, the authors review the normal anatomy and physiology of the liver with a view to enhancing the clinician's knowledge base. They also provide a convenient model to assist with understanding and discussion of liver anatomy. Clin. Anat. 27:764–769, 2014. © 2014 Wiley Periodicals, Inc.     

Anatomy of the lingual nerve: Application to oral surgery

The purpose of this research is to obtain morphological information about the traveling route, branching pattern, and distribution within the tongue of the lingual nerve, all of which are important for oral surgical procedures. Using 20 sides from 10 Japanese cadaveric heads, we followed the lingual nerve from its merging point with the chorda tympani to its peripheral terminal in the tongue. We focused on the collateral branches in the area before reaching the tongue and the communication between the lingual and hypoglossal nerves reaching the tongue. The collateral branches of the lingual nerve were distributed in the oral mucosa between the palatoglossal arch and the mandibular molar region. Two to eight collateral branches arose from the main trunk of the nerve, and the configuration of branching was classified into three types. More distally, the lingual nerve started to communicate with the hypoglossal nerve before passing the anterior border of the hyoglossus muscle. Nerve communications were also found in the main body and near the apex of the tongue. A thorough understanding of the collateral branches near the tongue, and the communication with the hypoglossal nerve inside the tongue, will help to prevent functional disorders from local anesthesia and oral surgical procedures associated with the lingual nerve. Clin. Anat. 32:635–641, 2019. © 2019 Wiley Periodicals, Inc.     

The clinical anatomy of accessory mental nerves and foramina

Since three‐dimensional computed tomography was developed, many researchers have described accessory mental foramina. The anatomical and radiological findings have been discussed, but details of accessory mental nerves (AMNs) have only been researched in a small number of anatomical and clinical cases. For this article, we reviewed the literature relating to accessory mental foramina (AMFs) and nerves to clarify aspects important for clinical situations. The review showed that the distribution pattern of the AMN can differ according to the position of the accessory mental foramen, and the reported incidence of AMFs differs among observation methods. A review of clinical cases also revealed that injury to large AMF can result in paresthesia. This investigation did not reveal all aspects of AMNs and AMFs, but will be useful for diagnosis and treatment by many dentists and oral and maxillofacial surgeons. Clin. Anat. 28:848–856, 2015. © 2015 Wiley Periodicals, Inc.