High-resolution computed tomography of the canals of the temporal bone: anatomic correlations

The aim of this study was to define precisely the imaging of the canals of the temporal bone by means of high-resolution computed tomography (HR CT). Based on 24 temporal bones removed from embalmed cadavers and investigated with HR CT, several canals were studied: the canal of the chorda tympani (CdT), the canal of the auricular branch of the vagus nerve (ABV), the canal of the tympanic nerve, the canal of the carotico-tympanic nerve and that of the lesser petrosal nerve. Anatomic correlations for six temporal bones were made to confirm the validity of our radiologic hypotheses. In CT, in axial sections OM 0°, the posterior canal of the CdT was visualized in 71% of cases, the ABV canal in 4%, the inferior tympanic canal in 12.5%, the carotico-tympanic canal in no cases and the canal of the lesser petrosal nerve in 50% (and in 75% with an incidence of OM+10°). In coronal incidence, the posterior canal of the CdT was seen in 20% of cases, the ABV canal in 25%, the inferior tympanic canal in 85%, the carotico-tympanic canal in 65% and that of the lesser petrosal nerve in 15%. The six anatomic comparisons confirmed the radiologic hypotheses in every case. These different structures are easy to identify in HR CT and are important to define so that any lesion (tumoral or vascular) developing in their vicinity may not be overlooked.     

颞骨内主要骨管的形态观测

目的　为颞骨各骨管相关疾病的影像诊断及手术治疗提供解剖学依据。方法　利用探针及游标卡尺测量 3 2块成的中国人颞骨各骨管的有关数据。结果　咽鼓管骨部长 10 4 0mm ,鼓室口 4 4 6mm× 3 5 8mm ,峡部开口 2 3 1mm× 1 4 5mm ;岩大神经管长 13 93mm ;鼓膜张肌半管长 11 86mm ;颈动脉管垂直段高 7 5 1mm ,水平段长 15 79mm ;岩鳞裂长 7 2 5mm ,鳞鼓裂长 13 88mm ,岩鼓裂管长 5 68mm ,岩鼓裂管颅底开口距下颌窝中央 7 4 2mm。结论　经乳突咽鼓管骨部手术扩张管腔时应防止损伤其毗邻结构 ;颅中窝手术在分离颞骨岩部前面覆盖的硬脑膜时 ,注意不要损伤岩大神经和膝神经节 ;颞下颌关节的病变通过穿行岩鼓裂管的结构可能会影响中耳的功能     

Evaluation of the temporal bone by anatomic sections and computed tomography

Summary Serial Computed Tomography (CT) scans of isolated temporal bones have been obtained in transverse planes at 1.5 mm intervals. Then gross anatomic sections of same temporal bones were taken at 3 mm. intervals in planes parallel to the CT scans. These CT and anatomic sections were evaluated comparatively.

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Evaluation de l'os temporal par coupes anatomiques et coupe TDM

Résumé Les coupes sériées au scanner d'os temporal isolé ont été faites dans le plan transversal tous les 1,5mm. Le même os a ensuite été coupé tous les 3mm dans des plans parallèles à ceux du scanner. Les deux séries de coupe sont ensuite analysées de façon comparative.

     

High-resolution computed tomographic study of the retrotympanum

Summary The aim of this study was to define the imaging of the retrotympanum precisely by means of high-resolution CT. Based on 66 scans of petrous bones performed in 49 patients observed in an otologic department, several retrotympanic structures were studied: the pyramidal eminence, ponticulus, subiculum, chordal ridge, tympanic sinus of Proctor, sinus tympani and recess of the facial n. The variations in morphology and depth were noted as well as the relationship between the pyramid and the facial canal. In a second phase the same anatomic structures were studied in 24 temporal bones removed from embalmed cadavers and investigated with the same radiologic technique. Anatomic correlations were made for six temporal bones to confirm the general applicability of our radiologic hypotheses. In CT the pyramidal eminence was visualised in 100% of cases, the chordal ridge in 52%, the ponticulus in 63% and the subiculum in 57%. As regards the different recesses, the sinus tympani was visualised in 95% of cases, the posterior tympanic sinus of Proctor in 38%, the fossula of Grivot in 47% and the facial recess in 80%. The mean depth of the sinus tympani was 2.7 mm and that of the tympanic sinus of Proctor was 1.65 mm; the fossula of Grivot was assessed as 2.1 mm and the facial recess as 2.2 mm. A better knowledge of these sinuses and their variations will aid the surgeon, particularly in a posterior tympanotomy or a retro-facial approach.

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Étude tomodensitométrique en haute résolution du rétrotympanum — Confrontations anatomiques

Résumé Le but de ce travail était de définir avec précision en tomodensitométrie haute résolution l'imagerie du rétrotympanum. A partir de 66 TDMs des rochers réalisés chez 49 patients suivis en ORL, plusieurs structures du rétrotympanum ont été étudiées : éminence pyramidale, ponticulus, subiculum, crête cordale, sinus tympanique de proctor, sinus tympani et récessus du facial. Les variations morphologiques et de profondeur ont été notées ainsi que le rapport entre la pyramide et le canal facial. Dans un deuxième temps, à partir de 24 temporaux prélevés sur cadavres embaumés, explorés selon la même technique radiologique, les mêmes structures anatomiques ont été étudiées. Des corrélations anatomiques pour 6 temporaux ont été réalisées pour confirmer l'ensemble de nos hypothèse radiologiques. En tomodensitométrie la visibilité de l'éminence pyramidale était obtenue dans 100% des cas, celle de la crête cordale dans 52% des cas, du ponticulus dans 63% des cas et du subiculum dans 57% des cas. Pour ce qui est des différents récessus, le sinus tympani était visible dans 95% des cas, le sinus tympani de Proctor dans 38% des cas, la fossette de Grivot dans 47% des cas et le recessus du facial dans 80% des cas. La profondeur moyenne du sinus tympani était de 2.7 mm, le sinus tympani de Proctor mesurait 1.65 mm, la fossette de Grivot était évaluée à 2.1 mm et le récessus du facial à 2.2 mm. La meilleure connaissance de ces sinus et de leur variation aidera le chirurgien en particulier pour une tympanotomie postérieure ou un abord rétro-facial.

     

A clinico-anatomic study of the auricular branch of the vagus nerve and Arnold’s ear-cough reflex

Summary The results of a clinico-anatomic study of the auricular branch of the vagus nerve (ABVN) and Arnold's ear-cough reflex are presented. The frequency of the ear-cough reflex was found to be 2.3% (12 out of 514 patients). It was bilateral in 3 cases (0.6%). The reflex was elicited by palpation of the postero-inferior wall of the external acoustic meatus (EAM) in 11 patients, and by palpation of the antero-inferior wall in one patient (0.2%). The reflex was frequently noticed to occur after a short latent period. The course of the ABVN inside the jugular foramen (JF), and distribution of the terminal branches of the ABVN in the external acoustic meatus were determined in 8 male cadavers (16 sides). In addition, the length of the mastoid canaliculus (MC) and the relationships of the ABVN with the facial nerve and stylomastoid foramen (SMF) were studied in both cadavers and 25 dry skulls (50 sides). High-resolution computed tomography (HRCT) scanning was also performed in all cadavers prior to microdissections. The ABVN emerged from the superior ganglion of the vagus nerve in all the cadavers. It ran between the internal jugular vein (IJV) and the bony wall of the jugular foramen. The ABVN was encased in a partial bony canal during its course from the jugular foramen to mastoid canaliculus in 18% of all specimens. The average length of the mastoid canaliculus was 5.6 mm (4.2–6.5), and it ran transversely towards the tympanomastoid suture 4.5 mm (4–5.1) above the stylomastoid foramen. The mastoid canaliculus was well demonstrated in all the HRCT scans.

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Etude anatomo-clinique de la branche auriculaire du nerf vague et du réflexe de toux otogène d'Arnold

Résumé Les résultats d'une étude anatomo-clinique concernant la branche auriculaire du nerf vague (BANV) et le réflexe de toux otogène d'Arnold sont exposés. Un réflexe de toux otogène a été trouvé dans 2,3 % des cas (12 cas sur 514). Il était bilatéral dans 3 cas (0,6 %). Le réflexe a été provoqué par la palpation de la paroi postéro-inférieure du méat acoustique externe dans 11 cas. Il a été provoqué après la palpation de sa paroi antéro-inférieure dans 1 cas (0,2 %). Il faut noter que le réflexe est souvent apparu après une brève période de latence. Le trajet de la BANV à l'intérieur du foramen jugulaire et la distribution des branches terminales de la BANV dans le méat acoustique externe ont été précisés sur 8 sujets mâles (16 côtés). De plus, la longueur du canalicule mastoïdien, les rapports de la BANV avec le nerf facial et le foramen stylo-mastoïdien ont été étudiés à la fois sur des sujets anatomiques et sur 25 crânes secs (50 côtés). Une tomodensitométrie à haute résolution a également été réalisée sur tous les sujets anatomiques avant les microdissections. La BANV émergeait du ganglion supérieur du nerf vague sur tous les sujets. Elle passait entre la veine jugulaire interne et le canal osseux du foramen jugulaire. La BANV était enchâssée dans un canal osseux partiel durant son trajet depuis le foramen jugulaire jusqu'au canalicule mastoïdien dans 18 % des cas. La longueur moyenne du canalicule mastoïdien était de 5,6 mm (4,2 – 6,5), et il se dirigeait transversalement vers la suture tympano-mastoïdienne à 4,5 mm (4 – 5,1) au-dessus du foramen stylomastoïdien. Le canalicule mastoïdien a été bien mis en évidence sur toutes les tomodensitométries.

     

面神经管及邻近结构在横断薄层切片与高分辨率计算机断层摄影图像的对照

目的:为面神经及耳科病变的影像诊断和手术治疗提供解剖学基础。方法:15例成人头部标本,以眦耳线(CML)为基线,获得间隔为1.0mm,厚度为1.0mm的高分辨率计算机断层摄影(HRCT)图像,扫描后的头部标本按原定位截取以耳颞区为中心的组织块并将其制成厚为1.0mm的连续横断簿层切片。标本切片与HRCT图像对照,对颞骨内面神经、听小骨、骨半规管、前庭、耳蜗等结构进行观测。结果:面神经膝状神经节(GG)多位于外半规管层面;匙突多与锤砧关节位于同一层面;锥隆起多位于鼓岬层面。结论:面神经水平段起始部、OG、面神经迷路段三者在外半规管层面内呈倒"V"字型排列;面神经垂直段位于面神经隐窝深面,面神经隐窝、锥隆起、锥隐窝三者在鼓岬层面内从内向外呈"ω"字型排列。     

Variability of the pulmonary oblique fissures presented by high-resolution computed tomography

The purpose of the study was to evaluate the radiological anatomy of oblique fissures (OFs) on high-resolution computed tomography (HRCT) scans. We retrospectively reviewed HRCT scans of 144 patients with normal lung parenchyma. The uppermost level of OFs with respect to the ribs, configuration (concave, straight, convex and others), orientation (medial or lateral facing), rotation and completeness of OFs were recorded. The most cranial level of the left OF was seen between the third and sixth ribs, and all but one were seen above or at the same level as the right OF. The uppermost extent of the OF was between the third and fourth intercostal space and seventh rib on the right lung. Only 2.2% of the right and 1.6% of the left OFs followed a parallel course to the ribs. The configuration of the OFs was generally concave in the upper zones (85.8% on the right and 72.1% on the left) and convex in the middle and lower lung zones (79.3% on the right and 73.9% on the left); 62.5% of the right and 59.7% of the left OFs were incomplete. Suprahilar portions of both OFs (98.9% on the right and 96.7% on the left) and the infrahilar portion of the right OF (54.2%) were generally facing laterally, whereas the infrahilar portion of the left OF was facing medially (80.9%). Angles of the MFs differed at the upper and lower levels. We detected reversal of 21 OFs in their craniocaudal course. In conclusion, the radiological anatomy of the right OF differs from the left OF. The uppermost extent of the left OF is almost always higher than the right. Thus, higher position of the right OF compared with the left almost always indicates a pathological process. Assessment of the angles of the OFs or comparison of the two sides cannot be used for the diagnosis of parenchymal disease like atelectasis. Occasionally, the classical propeller-like configuration is disrupted by the reverse course of the caudal part of the OF.     

颞骨手术相关的面神经临床解剖学研究

目的探讨颞骨手术中面神经的解剖学特点及手术中的定位方法。方法 (1)在15例尸头标本上(30侧)模拟完壁式乳突根治术,面神经隐窝入路,面神经减压手术,迷路下入路,颅中窝入路内耳道等手术,观察面神经形态及其与周围结构的关系;(2)30例干颞骨标本采用断面方法观察面神经管与周围主要结构之间的关系。结果 (1)面神经垂直段中点距离乙状窦前壁(6.42±2.65)mm,距离颈静脉球外侧壁(3.58±1.33)mm。(2)面神经隐窝外侧气房明显存在者86.67%(26例),不明显者13.33%(4侧),面神经隐窝外侧气房可以定位面神经与面神经隐窝。(3)在外半规管中后1/3交点下方(1.70±0.33)mm可定位面神经锥段,向下与二腹肌嵴前端连线是面神经垂直段位置。(4)膝神经节位于匙突前(2.48±0.23)mm。(5)弓状隆起外侧端前方是内耳道底位置,岩浅大神经方便定位面神经迷路段。结论利用面神经与周围结构的关系,根据面神经走行特点及面神经管周围颜色、骨质改变在颞骨部位手术中能够快速准确的定位面神经,同时也可以将面神经作为其它手术的重要标志。     

面神经颞支的应用解剖

目的确定面神经颞支的数量、走行和分布情况,为涉及面侧区和颞区的美容外科手术提供解剖学资料。方法解剖33具(66侧)成人尸体标本,探明颞支支数及走行;测量面神经颞支各分支越过颧弓下缘、外眦角等部位的距离。结果面神经颞支有4个分支,分别称为颞支Ⅰ、Ⅱ、Ⅲ、Ⅳ。除颞支Ⅳ经腮腺前缘浅出外,其余均经上缘浅出。浅出后它们立即到达颧弓浅面,其中颞支Ⅰ主要发支到达额肌深面;颞支Ⅱ主要到达额肌与眼轮匝肌交界部深面。颞支Ⅲ、Ⅳ主要发支到达眼轮匝肌深面。测量得到面神经颞支各分支越过颧弓下缘处距外眦角的距离男性分别为3.8cm、3.5cm、2.9cm、和2.8cm;女性分别为3.6cm、3.3cm、2.7cm、2.6cm。面神经颞支各分支发出部位距颧弓下缘的距离男性分别为3.0cm、3.8cm、4.0cm、4.2cm;女性分别为2.7cm、3.3cm、3.3cm、3.7cm。结论面神经颞支根据性别具有基本确定的走行及分布,为相关的美容外科手术提供了解剖学依据。     

Variations of the celiac trunk investigated by multidetector computed tomography: Systematic review and meta-analysis with clinical correlations

In recent years multidetector computed tomography (MDCT) has been used to investigate vascular anatomy for scientific and diagnostic purposes. These studies allow for much larger sample sizes than traditional cadaveric studies. The aim of this research was to perform a systematic review and meta-analysis on studies investigating the variations of the celiac trunk using MDCT. Major medical databases were used to find studies investigating celiac trunk anatomy using MDCT. Extracted information included demographic details, number of normal celiac trunks, and number of each variant celiac trunk. Using a random effects meta-analysis the pooled prevalence of each variation was calculated. A total of 36 studies from 14 countries and four continents were included in the meta-analysis. The total number of subjects included was 17,391. The total prevalence of variant celiac trunks was 10.85%. The different types of celiac trunk variations with their prevalences were: gastrosplenic trunk (3.46%), hepatosplenic trunk (3.88%), hepatogastric trunk (0.24%), absent celiac trunk (0.28%), celiacomesenteric trunk (0.46%), hepatosplenomesenteric trunk (0.26%), gastrosplenomesenteric trunk (0.07%), and celiacomesenteric anastomosis (0.09%). A total of 61 cases (0.19%) were either not described or not described adequately to be included in our classification. Major variations of the celiac trunk are not uncommon and should be anticipated before radiological and surgical interventions. Knowledge of celiac trunk anatomy is important in hepatopancreatobiliary surgery, transplantology, and interventional radiology.     

面神经颞骨内段斜矢状断层切片与HRCT图像对照研究

目的探讨颞骨内面神经管各段及邻近结构在斜矢状断面上的形态规律及影像学表现,为该区影像诊断及外科手术提供形态学依据。方法取15例成人颞骨利用火棉胶包埋薄层切片技术制作成层厚1.00mm的斜矢状位连续薄层断面标本,并与之对应的HRCT扫描图像进行对照研究。结果斜矢状断面可良好显示颞骨内面神经管及其邻近结构对面神经膝部,面神经水平段及垂直段、前庭导水管等结构显示最好。面神经垂直段全长(14.95±1.31)mm,面神经第二膝转折处夹角约(108.01±10.23)°,薄层断面与HRCT图像有良好的对应关系。结论斜矢状面扫描是补充横断、冠状面扫描缺陷的一个重要扫描方法;结合切片、HRCT进行对照研究,为颞骨内疾病的影像学诊断和临床手术提供准确的断层形态资料。     

Petrosal anatomy and inner ear structures of the Late Jurassic Henkelotherium (Mammalia, Cladotheria, Dryolestoidea): insight into the early evolution of the ear region in cladotherian mammals

The petrosal anatomy and inner ear structure of Jurassic cladotherian mammals represent the ancestral morphological conditions (groundplan) from which modern therian mammals (marsupials and placentals) have evolved. We present the reconstruction of the petrosal and inner ear features of the Late Jurassic dryolestoid mammal Henkelotherium guimarotae from high-resolution computed tomography and three-dimensional imaging analysis. This study of Henkelotherium revealed a combination of derived and primitive features, including: cladotherian apomorphies, such as the promontorial sulcus for the internal carotid artery and reduced lateral trough; trechnotherian characters, such as an enclosed cochlear canaliculus for the perilymphatic duct, post-promontorial tympanic sinus and caudal tympanic process; in addition to plesiomorphic mammalian features, such as the cavum supracochleare and prootic canal. The inner ear of Henkelotherium shows a division between the utricle and saccule, a cochlear canal coiled through at least 270°, a distinctive primary bony lamina for the basilar membrane, and a secondary bony lamina. The development of the primary and secondary bony laminae in the cochlear canal is suggested here to be correlated with the concurrent coiling of the bony canal and membranous duct of the inner ear cochlea, apomorphies of the more inclusive cladotherian clade that also represent the ancestral morphotype of modern therian mammals. Because these features are crucial for high-frequency hearing in extant therian mammals, their early appearance in Late Jurassic cladotherians suggests a more ancient origination for high-frequency hearing in mammalian history than previously thought.     

A computed tomography and magnetic resonance imaging study of the variations of the sciatic nerve branches of the pediatric knee: Implications for peripheral nerve blockade

In pediatric patients, peripheral anesthetic blockade of the sciatic nerve is useful for postoperative pain relief after orthopedic procedures of the lower limb. The identification of the sciatic and its branches relative to the surrounding anatomical structures of the knee significantly contribute to the successful nerve blockade. However, reports have demonstrated complications arising from the inadequate and inconsistent understanding of the anatomy of the nerves in the knee region. In addition, the paucity of information regarding the location of the nerves of the knee throughout the pediatric development needs to be addressed in order for peripheral nerve blockades to become more readily used among the pediatric population. This clinical imaging study therefore aimed to document and analyze the relative morphometric relationship of the nerves in the knee region throughout the different stages of pediatric development. The locations of the sciatic, tibial, and common fibular nerves were measured in relation to relevant anatomical structures in 142 pediatric magnetic resonance imaging and computed tomography. A strong correlation was found between age and the distance from the common fibular nerve to the semitendinosus muscle, and thus can be used to predict stature. Significant differences were found between males and females, specifically after puberty, suggesting that sexual dimorphism emerges more distinctively at puberty. In order to predict the location of the nerves at the popliteal fossa, a regression formula using the patient's age and bicondylar width was created. These finding may have significant implications for popliteal approach of the sciatic nerve blockade in pediatric patients. Clin. Anat. 32:836–850, 2019. © 2019 Wiley Periodicals, Inc.     

Anatomical topography of the mandibular symphysis in the Korean population: A computed tomography analysis

The objective of this study was to reveal the topography of the mandibular symphysis according to gender and age in the Korean population using computed tomography (CT) to provide a mean anatomical database for the safety zone during block bone harvesting. The following parameters were measured in CT images taken from Korean subjects: interforaminal distance (ID), vertical distance between the inferior mandibular border and the apices of the anterior teeth (VD), and horizontal distance between the labial cortical bone and the apices of the anterior teeth (HD). Differences between genders and among age groups, and the correlations among measurements were analyzed. A total of 973 images (411 males and 562 females; mean age = 41.2 years) were selected. The overall mean ID, VD, and HD were 55.38 ± 5.13, 22.16 ± 3.84 and 5.21 ± 1.70 mm, respectively. The ID and VD were significantly larger in males than in females (P < 0.001), and ID was significantly smaller in the youngest age group than in other age groups (P < 0.001), while HD differed significantly only between the youngest and oldest groups (P < 0.05). There was a weak positive correlation between ID and HD (γ > 0.10). This study provides information on the topography of the mandibular symphysis in the Korean population based on a large number of CT images. In general, gender seemed to influence the symphyseal dimensions strongly, whereas the influence of age was limited. Clin. Anat. 592–597, 2014. © 2013 Wiley Periodicals, Inc.     

An image of sudden death: utility of routine post-mortem computed tomography scanning in medico-legal autopsy practice

Post-mortem computed tomography (CT) is an established technique at Victorian Institute of Forensic Medicine (VIFM) used to assist pathologists in determining cause and manner of death. It also plays an important role in identification of deceased individuals as exemplified by the 2009 “Black Saturday” Victorian bushfires in which the remains of 164 individuals were subjected to disaster victim identification procedures. CT scanning is now explicitly incorporated into the Victorian Coronial legislation (Coroners Act 2008), and is an important component of the preliminary examination process whereby a pathologist reviews the circumstances of a death, any pre-existing medical history, whole body CT images, the external appearances of the body and expedited (overnight) toxicological screen results, so that a recommendation to the Coroner may be formulated regarding the likely cause of death and necessity for autopsy. This process has seen a reduction in autopsies from a mean of 62% over the last 5 years to 47% of admissions in less than 12 months. VIFM pathologists perform the primary interpretation of CT images in consultation with a radiologist. A process of quality audit has been instituted in order to detect systematic errors in this interpretation, in addition to a structured education programme directed to correct those errors. New imaging techniques, notably whole body CT angiography and dual energy CT have the prospect of even more substantial forensic application.     

基于CT三维重建的成人第5掌骨的形态学及临床意义

目的 通过对成人第5掌骨CT三维重建数据进行测量,探讨人类第5掌骨形态学特点及临床意义,为临床手术和器械设计提供依据。方法 对医学影像工作站内留存的114例第5掌骨CT扫描进行三维重建,基于三维模型测量第5掌骨长度、掌骨头半径、掌骨弓半径和1/2掌骨弓圆心角、掌骨头偏心距和偏心比及髓腔狭部内径。结果 成人掌骨长度（51.55±3.01）mm,掌骨头半径（6.59±0.49）mm,掌骨弓半径（99.58±26.83）mm,1/2掌骨弓圆心角（15.90±3.36）°,掌骨头偏心距平均（0.49±0.26）mm,掌骨头偏心比平均（7.4±3.9）%,髓腔峡部内径平均（2.28±0.77）mm。结论 男性掌骨长度、掌骨头半径、掌骨头偏心距及髓腔峡部内径大于女性,其余指标性别间差异无显著性;左右手之间差异也无显著性。     

A computerized tomography study of the morphological interrelationship between the temporal bones and the craniofacial complex

The hypothesis that the temporal bones are at the center of the dynamics of the craniofacial complex, directly influencing facial morphology, has been put forward long ago. This study examines the role of the spatial positioning of temporal bones (frontal and sagittal inclination) in terms of influencing overall facial morphology. Several 3D linear, angular and orthogonal measurements obtained through computerized analysis of virtual models of 163 modern human skulls reconstructed from cone-beam computed tomography images were analyzed and correlated. Additionally, the sample was divided into two subgroups based on the median value of temporal bone sagittal inclination [anterior rotation group (n = 82); posterior rotation group (n = 81)], and differences between groups evaluated. Correlation coefficients showed that sagittal inclination of the temporal bone was significantly (P < 0.01) related to midline flexion, transversal width and anterior-posterior length of the basicranium, to the anterior-posterior positioning of the mandible and maxilla, and posterior midfacial height. Frontal inclination of the temporal bone was significantly related (P < 0.01) to basicranium anterior-posterior and transversal dimensions, and to posterior midfacial height. In comparison with the posterior rotation group, the anterior rotation group presented a less flexed and anterior-posteriorly longer cranial base, a narrower skull, porion and the articular eminence located more superiorly and posteriorly, a shorter posterior midfacial height, the palatal plane rotated clockwise, a more retrognathic maxilla and mandible, and the upper posterior occlusal plane more inclined and posteriorly located. The results suggest that differences in craniofacial morphology are highly integrated with differences in the positional relationship of the temporal bones. The sagittal inclination of the temporal bone seems to have a greater impact on the 3D morphology of the craniofacial complex than frontal inclination.     

Response properties of the pharyngeal branch of the glossopharyngeal nerve for umami taste in mice and rats

Many studies have reported the mechanism underlying umami taste. However, there are no investigations of responses to umami stimuli taste originating from chemoreceptors in the pharyngeal region. The pharyngeal branch of the glossopharyngeal nerve (GPN-ph) innervating the pharynx has unique responses to taste stimulation that differs from responses of the chorda tympani nerve and lingual branch of the glossopharyngeal nerve. Water evokes robust response, but NaCl solutions at physiological concentrations do not elicit responses. The present study was designed to examine umami taste (chemosensory) responses in the GPN-ph. Response characteristics to umami taste were compared between mice and rats. In mice, stimulation with compounds eliciting umami taste (0.1 M monosodium l-glutamate (MSG), 0.01 M inosine monophosphate (IMP) and the mixture of 0.1 M MSG + 0.01 M IMP) evoked higher responses than application of distilled water (DW). However, synergistic response of a mixture of 0.1 M MSG + 0.01 M IMP was not observed. In rats, there is no significant difference between the responses to umami taste (0.1 M MSG, 0.01 M IMP and the mixture of 0.1 M MSG + 0.01 M IMP) and DW. Monopotassium glutamate (MPG) was used in rats to examine the contribution of the sodium component of MSG on the response. Stimulation with 0.1 M MPG evoked a higher response when compared with responses to DW. The present results suggest that umami taste compounds are effective stimuli of the chemoreceptors in the pharynx of both mice and rats.