Topographical Anatomy of the Chorda Tympani Nerve
3
Citation
12
Reference
10
Related Paper
Citation Trend
Abstract:
The topographical anatomy of the chorda tympani nerve (CTn) was investigated macroscopically in 45 ears of Japanese adult cadavers, aged 38-88 yr, with special reference to its topographical relationship to critical structures encountered in otorhinolaryngological practice such as the auditory tube and Wharton's duct. Fifteen cases of the “separated type” of CTn running independently along the posterior margin of the lingual nerve, which were noted in our previous study, were included among the 45 specimens. Major findings considered relevant to clinical practice are described below.1. The course of the CTn, passing inferiorly and medially in the petrotympanic fissure, was classified into 2 types: that traveling immediately anterior to and parallel with the auditory tube, and the becoming progressively more distant (inferior and anterior) to the auditory tube.2. Immediately after emerging from the petrotympanic fissure, the CTn cons istently communicated with the sympathetic plexus around the middle meningeal artery, and often issued twigs reaching the otic ganglion area.3. In cases where the CT n was trapped by tendinous tissue around the lateral pterygoid muscle (17.8%), the nerve merged into the lingual nerve from the medial or anterior aspect, and not from the usual posterior aspect, at the level of the mandibular notch.4. The lingual nerve sometimes (20.0%) showed a strongl y curved sigmoid course behind the mandibular ramus. Several buccal branches innervating the oral lining, without containing the CTn element, were issued at the anterior projecting protion of the sigmoid course.5. At the base of the oral cavity, the major CTn element traveled al ong the superior margin of the lingual nerve, therefore the CTn element was located away from the submandibular ganglion.6. A thick communicating branch on both sides of the lingual nerve was rarely observ ed under the mucous lining or in the mucous layers at the tip of the tongue. These findings suggest that morphological variations of the CTn should be considered during surgical procedures and for understanding the nature of related clinical symptoms.Keywords:
Chorda
Maxillary nerve
To define the anatomy of the corrugator supercilii muscle (CSM).Cadaver dissections following a preset approach.Anatomy laboratory at a medical school.Sixteen sides of 8 preserved cadaver heads were dissected. Inferiorly based trapdoor-type flaps were developed in the subgaleal plane. The bone origins of the CSM were first identified. The muscles were then followed to their insertions. The origin and outline of the muscles were plotted on the face of the cadaver. Following the measurements, we transferred the configuration of the CSM to the image of a computer-manipulated face of a model.The origin of the CSM has a wide base, spanning across 0.6 cm from the midline and the supraorbital notch/foramen. The area of the muscle origin measured 0.98 x 2.52 cm on the right side and 1.04 x 2.35 cm on the left side. The lateral extent of the CSM insertion measured 4.27 and 4.50 cm from the midline on the right and left sides, respectively.The CSM originates as 3 or 4 thin, rectangular, panellike muscle groups occupying a wide area across 0.6 cm from the midline and the supraorbital notch/foramen. The muscle groups travel parallel to one another in an oblique course without distinguishable oblique or transverse components.
Foramen
Inferior oblique muscle
Cite
Citations (42)
Summary Background Anatomical landmarks in children are mostly extrapolated from studies in adults. Despite this, complex regional anesthetic procedures are frequently performed on pediatric patients. Sophisticated imaging techniques are available but the exact position, course and/or relationships of the structures are best understood with appropriate anatomical dissections. Maxillary nerve blocks are being used for peri‐operative analgesia after cleft palate repair in infants. However, the best approach for blocking the maxillary nerve in pediatric patients has yet to be established. Objective To determine the best approach for blocking the maxillary nerve within the pterygopalatine fossa. Methods In an attempt to define an optimal approach for maxillary nerve block in this age group three approaches were simulated and compared on 10 dried pediatric skulls as well as 30 dissected pediatric cadavers. The needle course, including depth and angles, to block the maxillary nerve, as it exits the skull at the foramen rotundum within the pterygopalatine fossa, was measured and compared. Two groups were studied: Group 1 consisted of skulls and cadavers of neonates (0–28 days after birth) and Group 2 consisted of skulls and cadavers from 28 days to 1 year after birth. Results No statistically significant difference ( P > 0.05) was found between the left and right side of each skull or cadaver. Only technique B, the suprazygomatic approach from the frontozygomatic angle towards the pterygopalatine fossa, exhibited no statistical significance ( P > 0.05) when other measurements made on the skulls and cadavers were compared. Technique A, a suprazygomatic approach from the midpoint on the lateral border of the orbit, as well as technique C, an infrazygomatic approach with an entry at a point on a vertical line extending along the lateral orbit wall, showed statistical significant differences when measurements of the skulls and cadavers were compared. Conclusions On the basis of these findings technique B produces the most consistent data for age groups 1 and 2 and supports the clinical findings recently reported.
Maxillary nerve
Pterygopalatine fossa
Cite
Citations (23)
Objective:To investigate the effect of hyalinized chorda tympani nerve canal in mastoid segment to landmark facial nerve in middle ear surgery by means of observing the location relationship between hyalinized chorda tympani nerve canal and facial nerve.Method:118 cases of cholesteatoma otitis media in our hospital undergoing tympanoplasty from 2008 to 2011 were retrospectively analyzed.In all the cases,the position of horizontal semicircular and fossa incus as well as the hyalinized chorda tympani nerve canal were used for landmark the height of facial ridge and vertical segment of facial nerve.Result:The chorda tympani nerve of 99 patients were higher than the vertical segment of the facial nerve which were not exposed,and the vertical segment of the facial nerve in 9 patients,which were exposed,were 1-2 mm lower and 2-3 mm ahead or backward than the chorda tympani nerve.The horizontal semicircular and fossa incus were broken in 9 patients,of whom the vertical segments of the facial nerve were 1-2 mm lower and 2-3 mm ahead or backward than the chorda tympani nerve.The chorda tympani nerve of 1 patient were lower than the exposed vertical segment of facial nerve.Conclusion:The hyalinized chorda tympani nerve canal in mastoid segment can landmark the positon of facial ridge,and it would be the complement to the traditional method of landmarking vertical segment of facial nerve,especially for those whose horizontal semicircular canal and fossa incus had been broken.
Chorda
Incus
Facial canal
Cite
Citations (0)
Objective To study the anatomy features and the location of the facial nerve during the temporal approaches.Methods The mastoidotympanectomy,the facial recess approaches,the facial nerve decompression,the middle cranial fossa approach and the infrelabyrine approach were simulated on 15 adult cadaveric specimens(30 sides).The topographical features and the relationship of facial nerve with the surrounding structures were explored.30 dry temporal bones were cut along the facial canal,for exploring the relationship of the facial canal and the surrounding structures.Results(1) The distance from the vertical part of the facial nerve to the glomus was about(3.58±1.33)mm,and to the sigmoid sinus(6.42±2.65)mm.(2) The air cells of lateral facial recess was found in 26 cases(86.67%),which is helpful for locating the facial recess and the facial nerve.(3) The lateral lap of the facial nerve was under the point between the posterior and middle 1/3 of the lateral semicircular canal about(1.70±0.33)mm.The vertical line connected this point to the anterior extremity of the conker's crista represented the vertical part of the facial nerve.(4) Geniculate ganglion located anteriorly to the cochleariform process about(2.48±0.23)mm.(5) The fundus of internal acoustic meatus was in the anterior aspect of the lateral point of the eminence of superior semicircular.The ramus lacrimales nervi petrosi superficialis majoris was the convenient signal for locating the labyrinthine segment of the facial nerve.Conclusions It is valuable for locating the facial nerve through its relationship with the surrounding structures,the topography and the features of substantia ossea surrounding the facial nerve,during the temporal approach.
Facial canal
Sigmoid sinus
Geniculate ganglion
Middle cranial fossa
Cadaveric spasm
Mastoid process
Meatus
Posterior Semicircular Canal
Cite
Citations (0)
Conclusion: The new method of facial recess enlargement through suspending, antedisplacing, and adhering the chorda tympani nerve to the posterior wall of the auditory canal can expose the round window, make electrode insertion easier, and preserve the function of the facial nerve and chorda tympani nerve. Objective: To describe and report cochlear implantation surgery in patients with narrow facial recess, including surgical technique and postoperative outcomes. Methods: Cochlear implantation surgery was performed in our hospital in 39 cases with narrow facial recess by enlarging the facial recess. To enlarge the distance between the facial nerve and chorda tympani nerve, the chorda tympani nerve was suspended. The chorda tympani was anteplaced and adhered to the posterior wall of the auditory canal. Results: Among the 39 cases, the narrowest distance between the facial nerve and the chorda tympani nerve was less than 1.0 mm. All patients successfully underwent cochlear implantation surgery. No injuries of the facial nerve, chorda tympani nerve, or the posterior wall of the auditory canal were reported in any of the patients. There were significant differences in the injuries of the facial nerve, chorda tympani nerve, and posterior wall of the auditory canal in these cases compared with previous approaches to this operation.
Chorda
Cochlear Implantation
Cochlear nerve
Cite
Citations (13)
Glossopharyngeal nerve
Chorda
Cranial nerves
Cite
Citations (15)
1) The functional components of the palatine nerve and a. chorda tympani are composed of visceral efferent and visceral afferent fibers. Branches of the palatine nerve and n. chorda tympani are distributed to the salivary glands and the mucous membrane of the mouth and pharynx and the lacrimal gland.The main trunk of the facial nerve is composed of special visceral efferent and somatic sensory fibers which supply muscles lying between the mandibular and the basis-phenoid bones, the m. tensor tympani lateralis, the skin and cutaneous muscle of the ventral aspect of the pharynx.2) N. canalis pterygoidei is similar in its anatomical structure to that of the domestic animals. It is formed by the union of n. petrosus superficialis major and n. petrosus profundus. N. petrosus profundus is composed of branches of ganglion cervicale craniale and ganglion petrosum, while n. petrosus superficialis major is a continuation of the palatine nerve.3) The point at which the chorda tympani branches out from the facial nerve in ducks is different from that of the chickens. In ducks the chorda tympani leaves the facial nerve on the ventral posterior border of the tympanic membrane, while in chickens this netve branches out from the geniculum of the facial nerve.4) Anastomoses of the facial nerve with the other nerves are as follows: a) Anastomosis with the sympathetic temporo-lacrimalis; b) Anastomosis with n. mandibularis of n. trigeminus via the chorda tympani; c) Indirect anastomosis with ganglion cervicale craniale and ganglion petrosum of the glossopharyngeal nerve via petrosus profundus; d) Anastomosis with n. maxillaris via n. salivalis; e) Anastomosis of the terminal branches of the facial nerve with the ventral branches of the second, third and fourth cervical nerves under the skin of the ventro-lateral aspect of the pharynx.5} In the domestic fowl the ganglion geniculi of the facial nerve has a special morphological structure: a) Ganglion geniculi of ducks is usually located in the initial part of the palatine nerve. The size of this ganglion gradually diminishes in old age and the nerve cells become scattered within the trunk of the palatine nerve; b) Ganglion geniculi of chickens is located just at the bifurcation of the trunk of n. fadalis and its branch-palatine nerve.6) The auditory nerve of the duck consists of five individual branches, but in chickens the branches distributed to the ampullae of the anterior and horizontal semicircular canals fuse with the facial nerve to form a single short trunk.
Chorda
Glossopharyngeal nerve
Superior laryngeal nerve
Cite
Citations (1)
Ten cadavers were dissected to describe the cutaneous branches of the dorsal rami nerves that should be identified and protected throughout the thoracoplasty procedure.To identify the anatomic distribution of the cutaneous branches of the dorsal rami in the thoracic spine.The last anatomic description of cutaneous branches of the dorsal rami nerves dates back to the early 1900s.Ten cadavers were dissected. Each of the branches was followed deeper into the musculature of the back. The Steel 2-incision approach, the Geissele subcutaneous approach, and the subfascial/subtrapezial approach were then carried out on each cadaver.We determined the course traveled by each of these cutaneous branches of the dorsal rami. Medial branches traverse the paraspinal muscles running dorsally within a few millimeters of the midline before exiting beneath the trapezius. Lateral branches cross the top border of the inferior rib at an average of 6.8 mm from the tip of the transverse process and the lower border of the rib 27 mm from the tip of the transverse process.Both branches of the dorsal rami nerves are encountered during the posterior approaches used. Medial branches have the best chance for identification and preservation with the subtrapezial approach. Lateral branches can be identified and protected in each of the 3 posterior exposures.
Cadaveric spasm
Cite
Citations (1)
Abstract Aim The anatomy and even existence of a common tendinous origin of the extraocular eye muscles, or annulus of Zinn, has widely been debated in anatomical literature. This study explored the anatomical origins of the recti muscles, their course into the orbit and the dural connections of the common tendinous origin with the skull base. Method Twenty orbits of ten adult human cadavers were dissected. The orbital apex and its dural connections were photographed. Histological examination of apical specimens was performed. Results In all cadavers, extraocular muscles were observed to have a common tendinous origin at the orbital apex, continuous with dural connections extending into the skull base. Accessory slips of the medial rectus were observed across all cadavers. Dual heads of the lateral rectus were observed in fourteen orbits of seven cadavers. The origin of the levator palpebrae superioris appeared to be contiguous with the superior rectus at the common tendinous origin in all but one cadaver. Conclusions These results support the existence of a common tendinous origin of the extraocular muscles, that is continuous with the skull base dura. In addition, they support the existence of variations in orbital anatomy including dual or accessory muscle slips of the extraocular muscles.
Orbit (dynamics)
Apex (geometry)
Cite
Citations (0)
Infiltration of the equine maxillary nerve with local anaesthetic can be useful for both diagnostic and surgical procedures. The deep location and proximity of the nerve to surrounding vascular and orbital structures make an accurate, complication-free injection a challenge using traditional techniques reliant upon surface anatomical landmarks.To develop an ultrasound-guided injection technique of the maxillary nerve in equine cadavers and to evaluate its efficacy and potential for complications in vivo.Descriptive cadaver anatomical and clinical study.The relevant anatomy of the pterygopalatine fossa was reviewed in 6 cadaver heads from mature horses of a range of ages, breeds and genders. In an additional 13 cadaver heads, ultrasound-guided injection of 0.2 ml New Methylene Blue dye was performed on both left and right maxillary nerves (n = 26 attempts) in the pterygopalatine fossa. An independent observer dissected the area and recorded the number of times that dye successfully contacted the nerve, along with inadvertent penetration of other structures. The procedure was then performed on 8 clinical cases undergoing a variety of standing surgical procedures on the head.Dye was successfully deposited in contact with the nerve during all attempts on cadaver heads, with no penetration of the orbital cone, deep facial vein and maxillary artery or associated branches. In a single cadaver, a unilateral gas artefact in the masseter muscle prohibited an injection attempt. Analgesia of the maxillary nerve was achieved in <15 min in all clinical cases, with complete loss of ipsilateral cutaneous sensation over the rostral face. No gross or ultrasonographic abnormalities were detected following the procedure.Using ultrasonographic landmarks of the pterygopalatine fossa, local anaesthetic can be deposited around the maxillary nerve without the inadvertent penetration of adjacent vital structures.The technique allows for vascular structures to be visualised and avoided, which is currently not possible using traditional blind approaches.
Maxillary nerve
Maxillary artery
Pterygopalatine fossa
Cite
Citations (35)