scholarly journals A review of the carotid artery and facial nerve canal systems in extant turtles

PeerJ ◽  
2021 ◽  
Vol 8 ◽  
pp. e10475
Author(s):  
Yann Rollot ◽  
Serjoscha W. Evers ◽  
Walter G. Joyce
Keyword(s):  
Facial Nerve ◽  
Morphometric Study ◽  
Circulation System ◽  
Geniculate Ganglion ◽  
Carotid Canal ◽  
Computed Tomography Scans ◽  
Canal Systems ◽  
Carotid Circulation ◽  
Palatine Artery ◽  
Shed Light

The cranial circulation and innervation systems of turtles have been studied for more than two centuries and extensively used to understand turtle systematics. Although a significant number of studies related to these structures exists, a broader comprehension of variation across the tree has been hindered by poor sampling and a lack of synthetic studies that addressed both systems together. We here provide new insights regarding the carotid circulation and facial nerve innervation systems in a broad set of extant turtles using CT (computed tomography) scans, which allow us to trace the canals these structures form in bone and understand the interaction between both systems. We document that the palatine artery, including the lateral carotid canal, is absent in all pleurodires and carettochelyids and was likely reduced or lost several times independently within Testudinoidea. We also highlight osteological correlates for the location of the mandibular artery. We finally summarize variation regarding the placement of the mandibular artery, location of the geniculate ganglion, placement of the hyomandibular and vidian nerves, and situations where we recommend caution when assessing canals in fossils. A morphometric study confirms that the relative sizes of the carotid canals are correlated with one another. Our results have the potential for building new phylogenetic characters and investigating the circulation systems of fossil taxa, which are expected to shed light on the evolution of the circulation system of turtles and clarify some unresolved relationships between fossil turtle clades.

scholarly journals A redescription of the Late Jurassic (Tithonian) turtle Uluops uluops and a new phylogenetic hypothesis of Paracryptodira

2021 ◽  
Vol 140 (1) ◽  
Author(s):  
Yann Rollot ◽  
Serjoscha W. Evers ◽  
Walter G. Joyce
Keyword(s):  
Computed Tomography ◽  
Phylogenetic Analysis ◽  
Late Jurassic ◽  
Internal Carotid ◽  
Circulation System ◽  
Phylogenetic Hypothesis ◽  
Micro Computed Tomography ◽  
Future Studies ◽  
Computed Tomography Scans ◽  
Palatine Artery

AbstractWe study the Late Jurassic (Tithonian) turtle Uluops uluops using micro-computed tomography scans to investigate the cranial anatomy of paracryptodires, and provide new insights into the evolution of the internal carotid artery and facial nerve systems, as well as the phylogenetic relationships of this group. We demonstrate the presence of a canalis caroticus lateralis in Uluops uluops, the only pleurosternid for which a palatine artery canal can be confidently identified. Our phylogenetic analysis retrieves Uluops uluops as the earliest branching pleurosternid, Helochelydridae within Pleurosternidae, and Compsemydidae including Kallokibotion bajazidi within Baenidae, which suggests at least two independent losses of the palatine artery within paracryptodires. We expect future studies will provide additional insights into the evolution of the circulation system of paracryptodires, as well as clarifying relationships along the turtle stem.

scholarly journals Resection of a Dumbbell-Shaped Facial Nerve Schwannoma With Preservation of Facial Nerve Function Through the Extended Middle Fossa Approach: 2-Dimensional Operative Video

2021 ◽  
Author(s):  
Kaith K Almefty ◽  
Wenya Linda Bi ◽  
Walid Ibn Essayed ◽  
Ossama Al-Mefty
Keyword(s):  
Facial Nerve ◽  
Cerebellopontine Angle ◽  
Internal Auditory Canal ◽  
Growth Patterns ◽  
Geniculate Ganglion ◽  
Nerve Function ◽  
Middle Fossa ◽  
Facial Nerve Function ◽  
Large Tumor ◽  
Middle Fossa Approach

Abstract Facial nerve schwannomas are rare and can arise from any segment along the course of the facial nerve.1 Their location and growth patterns present as distinct groups that warrant specific surgical management and approaches.2 The management challenge arises when the facial nerve maintains good function (House-Brackmann grade I-II).3 Hence, a prime goal of management is to maintain good facial animation. In large tumors, however, resection with facial nerve function preservation should be sought and is achievable.4,5  While tumors originating from the geniculate ganglion grow extradural on the floor of the middle fossa, they may extend via an isthmus through the internal auditory canal to the cerebellopontine angle forming a dumbbell-shaped tumor. Despite the large size, they may present with good facial nerve function. These tumors may be resected through an extended middle fossa approach with preservation of facial and vestibulocochlear nerve function.  The patient is a 62-yr-old man who presented with mixed sensorineural and conductive hearing loss and normal facial nerve function. Magnetic resonance imaging (MRI) revealed a large tumor involving the middle fossa, internal auditory meatus, and cerebellopontine angle.  The tumor was resected through an extended middle fossa approach with a zygomatic osteotomy and anterior petrosectomy.6 A small residual was left at the geniculate ganglion to preserve facial function. The patient did well with hearing preservation and intact facial nerve function. He consented to the procedure and publication of images.  Image at 1:30 © Ossama Al-Mefty, used with permission. Images at 2:03 reprinted from Kadri and Al-Mefty,6 with permission from JNSPG.

Anterior Facial Nerve Rerouting in Cranial Base Surgery: A Comparison of Three Techniques

1996 ◽  
Vol 115 (1) ◽  
pp. 82-88 ◽  
Author(s):  
Peter G. Von Doersten ◽  
Robert K. Jackler
Keyword(s):  
Facial Nerve ◽  
Jugular Foramen ◽  
Jugular Bulb ◽  
Cranial Base ◽  
Clinical Impression ◽  
Canal Wall ◽  
Posterior Aspect ◽  
Pivot Point ◽  
Carotid Canal ◽  
Canal Wall Down

Anterior rerouting of the facial nerve is a maneuver designed to enhance exposure of the jugular foramen and carotid canal during resection of cranial base tumors. Our clinical impression is that the degree of additional exposure afforded by moving the facial nerve varies considerably according to both anatomic variations and the technique used. Three possible techniques exist based on the extent of facial nerve mobilization and point of rotation: canal wall up-second genu pivot point (CWU-2G); canal wall down-second genu pivot point (CWD-2G); and canal wall down-first genu pivot point (CWD-1G). We anatomically studied 20 human cadaver heads to establish clinically relevant guidelines for the selective use of these techniques. At the level of the dome of the jugular bulb, the facial nerve mobilized anteriorly a mean of 4.2 mm for CWU-2G, 10 mm for CWD-2G, and 14 mm for CWD-1G. Detailed analysis of numerous measurements and rotation angles suggests that the typical exposure afforded by the various rerouting techniques is as follows: CWU-2G, complete exposure of the jugular bulb; CWD-2G, exposure of the jugular bulb and a mean of 6 mm of the posterior aspect of the carotid artery; and CWD-1G, exposure of the jugular bulb and entire carotid genu. Minimizing the amount of facial nerve manipulation needed to achieve sufficient surgical exposure helps optimize postoperative functional status.

scholarly journals Can MDCT Scan of the Temporal Bone Looking at Pneumatization Predict Surgical Vulnerability of the Facial Nerve?

2019 ◽  
pp. 014556131987952
Author(s):  
Mikail Inal ◽  
Nuray Bayar Muluk ◽  
Mehmet Hamdi Şahan ◽  
Neşe Asal ◽  
Gökçe Şimşek ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Facial Canal ◽  
Nerve Injuries ◽  
Mastoid Pneumatization ◽  
Computed Tomography Scans ◽  
Facial Nerve Injuries ◽  
Important Landmark ◽  
Facial Canal Dehiscence ◽  
Males And Females ◽  
Canal Dehiscence

Objectives: The aim of this study is to investigate the scutum–cochleariform process (CP) and scutum–promontorium distances according to the mastoid pneumatization condition. Methods: Two hundred temporal multidetector computed tomography scans (90 males and 110 females) were evaluated retrospectively. The scutum-CP and scutum–promontorium distances were measured. Facial canal dehiscence (FCD) in the tympanic segment and mastoid pneumatization were also evaluated. Results: The distances between scutum-CP and scutum–promontorium were not different between males and females and between right and left sides. Facial canal dehiscence in the tympanic segment was detected: 5.6% (right) and 7.8% (left) in males and 5.5% (right) and 10.0% (left) in females. Grade 4 (100%) pneumatization was detected mainly in 55.6% to 57.8% of the patients in both genders. Grade 0 (0%) pneumatization (sclerosis) was detected in 22.2% to 28.2% of both males and females. In more pneumatized mastoids, the scutum-CP and scutum–promontorium distances increased. In sclerotic mastoids, the scutum-CP and scutum–promontorium distances decreased. Facial canal dehiscence rates were not related to the mastoid pneumatization levels. Conclusion: Cochleariform process is an important landmark to localize the tympanic segment of the facial canal. In sclerosed mastoids, scutum-CP and scutum–promontorium distances decreased. There was no relationship between FCD rates and mastoid pneumatization levels. It may be due to the development of FCD that occurs during the intrauterine period. In endoscopic and classic ear surgeries, mastoid pneumatization must be evaluated preoperatively to avoid facial nerve injuries.

Morphometric study of Intratemporal course of facial nerve in relation to pneumatization of temporal bone—An original study

2018 ◽  
Vol 67 (2) ◽  
pp. 110-114 ◽  
Author(s):  
Vishram Singh ◽  
D. Krishna Chaitanya Reddy ◽  
David Victor Kumar I. ◽  
B.K.S. Chauhan ◽  
Sridhar Reddy
Keyword(s):  
Facial Nerve ◽  
Temporal Bone ◽  
Original Study ◽  
Morphometric Study

Facial nerve preservation in geniculate ganglion hemangiomas

2014 ◽  
Vol 134 (9) ◽  
pp. 974-976 ◽  
Author(s):  
Xiaofeng Ma ◽  
Dong Chen ◽  
Li Cai ◽  
Daowen Wang
Keyword(s):  
Facial Nerve ◽  
Geniculate Ganglion ◽  
Nerve Preservation ◽  
Facial Nerve Preservation

scholarly journals Memoirs: The Chorda Tympani and Middle Ear in Reptiles, Birds, and Mammals

1915 ◽  
Vol s2-61 (242) ◽  
pp. 137-160
Author(s):  
EDWIN S. GOODRICH
Keyword(s):  
Facial Nerve ◽  
Middle Ear ◽  
Proximal Region ◽  
Geniculate Ganglion ◽  
Chorda Tympani ◽  
Tympanic Cavity ◽  
Gill Slit ◽  
Lower Region ◽  
Lower Jaw ◽  
Dorsal Edge

A comparison of the development of the various structures of the middle-ear region in the lizard, duck, and mammal, shows a remarkable uniformity in their origin and relation. The first gill-pouch separates off from the epidermis from below upwards; at its dorsal edge is an epiblastic proliferation contributing to the geniculate ganglion. The tympanum is formed between the outer epidermis and an outgrowing diverticulum of the hinder lower region of the first gill-pouch. The chorda tympani is a post-trematic branch of the facial nerve, developing behind the first or spiracular gill-slit, and passing down to the lower jaw between the tympanum and the closing spiracle. The relation of these parts to the skeleton and blood-vessels is (with the exception mentioned below) constant throughout the Amniota, and is only intelligible on the view of Reichert that the proximal region of the columella corresponds to the stapes, the quadrate to the incus, and the articular to the malleus. In the chick the chorda tympani develops as a pre-trematic branch of the facial nerve from its first appearance. In adult gallinaceous birds the chorda passes down directly from the geniculate ganglion in front of the tympanic cavity. This exceptional position is probably due to some secondary modification at present unexplained.

Effect of stimulation of nucleus raphe dorsalis on carotid blood flow. I. The monkey

1985 ◽  
Vol 248 (2) ◽  
pp. R257-R262 ◽  
Author(s):  
P. J. Goadsby ◽  
R. D. Piper ◽  
G. A. Lambert ◽  
J. W. Lance
Keyword(s):  
Facial Nerve ◽  
External Carotid ◽  
Blood Flows ◽  
Beta Adrenoceptor ◽  
Alpha Adrenoceptor ◽  
Adrenoceptor Antagonist ◽  
Muscarinic Cholinergic ◽  
Raphe Dorsalis ◽  
Carotid Circulation ◽  
Stimulation Of

The dorsal raphe nucleus (DRN) and surrounding midbrain of 16 anaesthetized monkeys were stimulated electrically, and carotid blood flows were measured with electromagnetic flow probes. Stimulation of the DRN caused a frequency-dependent decrease (vasodilatation) in both internal and external carotid vascular resistance, which was abolished in both circulations by bilateral section of the facial nerve intracranially. These vasodilator responses were unaltered by intravenous administration of muscarinic cholinergic or by alpha- or beta-adrenoceptor antagonists. A postdilatation constrictor response, observed in the external carotid circulation, was blocked by the alpha-adrenoceptor antagonist phentolamine. It is concluded that projections of the DRN through the greater superficial petrosal branch of the facial nerve mediate vasodilatation in both internal and external carotid circulations.

Sign in / Sign up

Export Citation Format

Share Document