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Iwanaga J, Fukino K, Kitagawa N, Carrera A, Reina F, Manzanares-Cespedes MC, Hur MS, Reina MA, Tubbs RS. Newly revealed anatomy of the bucinator muscle: An anatomical and histological study. Ann Anat 2024; 255:152297. [PMID: 38936747 DOI: 10.1016/j.aanat.2024.152297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 06/13/2024] [Accepted: 06/24/2024] [Indexed: 06/29/2024]
Abstract
BACKGROUND Current anatomical knowledge of the origin of the bucinator muscle (BM), i.e., long thin attachments on the maxilla and mandible and the pterygomandibular raphe (PMR), is not supported by anatomical dissection of this muscle. The aim of this study was therefore to investigate the detailed morphology of the BM and associated structures and to discuss its function. METHODS The anatomy of the BM and related structures was investigated in 15 cadaveric heads using a surgical microscope and histological analysis. RESULTS The inferior fibers of the BM originated from a small retromolar area (internal oblique line), which shared a common tendon with the deep tendon of the temporalis. The superior fibers of the BM originated from the maxillary tuberosity. The middle fibers originated the pterygoid hamulus. No PMR was identified in any of the specimens, but the border between the BM and superior pharyngeal constrictor muscle (SC) was clear because the muscle fibers followed different directions. Some horizontal fibers were continuous between the BM and SC. CONCLUSIONS Our results suggest the need to revise established accounts of the origins of the bucinator (the maxillary tuberosity, conjoint tendon of the temporalis, and pterygoid hamulus without a pterygomandibular raphe. It also needs to be noted that some of its fibers merge directly with the SC.
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Affiliation(s)
- Joe Iwanaga
- Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, LA, USA; Department of Neurology, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, LA, USA; Department of Structural & Cellular Biology, Tulane University School of Medicine, New Orleans, LA, USA; Department of Neurosurgery and Ochsner Neuroscience Institute, Ochsner Health System, New Orleans, LA, USA; Department of Oral and Maxillofacial Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan; Dental and Oral Medical Center, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, Japan; Division of Gross and Clinical Anatomy, Department of Anatomy, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, Japan.
| | - Keiko Fukino
- Department of Oral and Maxillofacial Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Norio Kitagawa
- Department of Oral and Maxillofacial Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Ana Carrera
- Medical Sciences Department, Clinical Anatomy, Embryology and Neuroscience Research Group (NEOMA), Faculty of Medicine, University of Girona, Girona, Spain
| | - Francisco Reina
- Medical Sciences Department, Clinical Anatomy, Embryology and Neuroscience Research Group (NEOMA), Faculty of Medicine, University of Girona, Girona, Spain
| | - Maria Cristina Manzanares-Cespedes
- Human Anatomy and Embryology Unit. Experimental Pathology and Therapeutics Department, Faculty of Medicine and Health Sciences, University of Barcelona, Spain
| | - Mi-Sun Hur
- Department of Anatomy, Daegu Catholic University School of Medicine, Daegu, South Korea
| | - Miguel A Reina
- CEU-San Pablo University School of Medicine, Department of Anesthesiology, Madrid-Montepríncipe University Hospital, Madrid, Spain; Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL, USA
| | - R Shane Tubbs
- Department of Neurosurgery, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, LA, USA; Department of Neurology, Tulane Center for Clinical Neurosciences, Tulane University School of Medicine, New Orleans, LA, USA; Department of Structural & Cellular Biology, Tulane University School of Medicine, New Orleans, LA, USA; Department of Neurosurgery and Ochsner Neuroscience Institute, Ochsner Health System, New Orleans, LA, USA; Department of Anatomical Sciences, St. George's University, St. George's, Grenada; Department of Surgery, Tulane University School of Medicine, New Orleans, LA, USA; University of Queensland, Brisbane, Australia
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Cho KH, Kim JH, Honkura Y, Yamamoto M, Murakami G, Rodríguez-Vázquez JF, Katori Y. Cochlear aqueduct revisited: A histological study using human fetuses. Ann Anat 2024; 253:152236. [PMID: 38417484 DOI: 10.1016/j.aanat.2024.152236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 12/04/2023] [Accepted: 02/20/2024] [Indexed: 03/01/2024]
Abstract
BACKGROUND AND AIM The cochlear aqueduct (CA) connects between the perilymphatic space of the cochlea and the subarachnoid space in the posterior cranial fossa. The study aimed to examine 1) whether cavitation of the CA occurs on the subarachnoid side or the cochlear side and 2) the growth and/or degeneration of the CA and its concomitant vein. METHODS We examined paraffin-embedded histological sections from human fetuses: 15 midterm fetuses (crown-rump length or CRL, 39-115 mm) and 12 near-term fetuses (CRL, 225-328 mm). RESULTS A linear mesenchymal condensation, i.e., a likely candidate of the CA anlage, was observed without the accompanying vein at 9-10 weeks. The vein appeared until 15 weeks, but it was sometimes distant from the CA. At 10-12 weeks, the subarachnoid space (or the epidural space) near the glossopharyngeal nerve rapidly protruded into the CA anlage and reached the scala tympani, in which cavitation was gradually on-going but without epithelial lining. However, CA cavitation did not to occur in the anlage. At the opening to the scala, the epithelial-like lining of the CA lost its meningeal structure. At near-term, the CA was often narrowed and obliterated. CONCLUSION The CA develops from meningeal tissues when the cavitation of the scala begins. The latter cavitation seemed to reduce tissue stiffness leading, to meningeal protrusion. The so-called anlage of CA might be a phylogenetic remnant of the glossopharyngeal nerve branch. A course of cochlear veins appears to be determined by a rule different from the CA development.
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Affiliation(s)
- Kwang Ho Cho
- Department of Neurology, Wonkwang University School of Medicine and Hospital, Institute of Wonkwang Medical Science, Iksan, Republic of Korea.
| | - Ji Hyun Kim
- Department of Anatomy, Jeonbuk National University Medical School, Jeonju, Republic of Korea.
| | - Yohei Honkura
- Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
| | - Masahito Yamamoto
- Department of Anatomy, Division of Basic Medical Science, Tokai University School of Medicine, Japan.
| | - Gen Murakami
- Division of Internal Medicine, Cupid Clinic, Iwamizawa, Japan.
| | | | - Yukio Katori
- Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan.
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Cho KH, Homma KI, Kim JH, Murakami G, Rodríguez-Vázquez JF, Abe H. Growth of muscles and nerves in the upper eyelid: a morphometrical and immunohistochemical study using term human fetuses. Surg Radiol Anat 2024; 46:317-326. [PMID: 38372770 DOI: 10.1007/s00276-024-03308-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 01/18/2024] [Indexed: 02/20/2024]
Abstract
BACKGROUND There is no information about muscle growth in eyelids with infrequent blinking in fetuses. METHODS To examine the muscle and nerve morphology, we morphometrically and immunohistochemically examined sagittal sections of unilateral upper eyelids obtained from 21 term fetuses (approximately 30-42 weeks of gestation) and, for the comparison, those from 10 midterm fetuses (12-15 weeks). RESULTS The approximation margin of the upper eyelid always corresponded to the entire free margin in midterm fetuses, whereas it was often (18/21) restricted in the posterior part in term fetuses. Thus, in the latter, the thickness at the approximation site to the lower lid often ranged from 0.8 to 1.6 mm and corresponded to 18-56% of the nearly maximum thickness of the lid. In the lower part of the upper eyelid, a layer of the orbicularis oculi muscles often (14/21) provided posterior flexion at 90-120° to extend posteriorly. Nerve fibers running along the mediolateral axis were rich along the approximation surface at term, but they might not be reported in the upper eyelid of adults. CONCLUSION Being different from adult morphologies, the term eyelid was much thicker than the approximation surface and it carried a flexed muscle layer and transversely-running nerve. The infrequent blinking in fetuses seemed to provide a specific condition for the muscle-nerve growth. Plastic and pediatric surgeons should pay attention to a fact that infants' upper eyelid was unlikely to be a mini-version of the adult morphology.
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Affiliation(s)
- Kwang Ho Cho
- Department of Neurology, Wonkwang University School of Medicine and Hospital, Institute of Wonkwang Medical Science, 895, Muwang-ro, Iksan-si, Jeollabuk-do, 54538, Republic of Korea.
| | | | - Ji Hyun Kim
- Department of Anatomy, Jeonbuk National University Medical School, Jeonju, Republic of Korea
| | - Gen Murakami
- Division of Internal Medicine, Cupid Clinic, Iwamizawa, Japan
| | | | - Hiroshi Abe
- Emeritus Professor of Akita University School of Medicine, Akita, Japan
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Yamamoto M, Hirota Y, Watanabe G, Taniguchi S, Murakami G, Rodríguez-Vázquez JF, Abe SI. Development and growth of median structures in the human tongue: A histological study using human fetuses and adult cadavers. Anat Rec (Hoboken) 2024; 307:426-441. [PMID: 36939757 DOI: 10.1002/ar.25198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 03/21/2023]
Abstract
Glossectomy is a surgical procedure performed to remove all or part of the tongue in patients with cancer. The removal of a significant part of the tongue has a marked effect on speech and swallowing function, as patients may lose not only the tongue muscles but also the median lingual septum (MLS). Therefore, to achieve successful tongue regeneration, it is necessary to investigate the developmental processes of not only the tongue muscles but also the MLS. This study was conducted to clarify the mutual development of the tongue muscles and the MLS in human fetuses. Serial or semi-serial histological sections from 37 embryos and fetuses (aged 5-39 weeks) as well as nine adults were analyzed. The MLS appeared at Carnegie stage 15 (CS15), and until 12 weeks of gestation, abundant fibers of the intrinsic transverse muscle crossed the septum in the entire tongue. However, in near-term fetuses and adults, the contralaterally extending muscles were restricted to the deepest layer just above the genioglossus muscle. This finding indicates that the crossing transverse muscle showed the highest density at mid-term. A thorough understanding of both the MLS and the tongue muscles is necessary for successful tongue regeneration.
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Affiliation(s)
| | | | - Genji Watanabe
- Department of Anatomy, Tokyo Dental College, Tokyo, Japan
| | | | - Gen Murakami
- Department of Anatomy, Tokyo Dental College, Tokyo, Japan
- Division of Internal Medicine, Cupid Clinic, Iwamizawa, Japan
| | | | - Shin-Ichi Abe
- Department of Anatomy, Tokyo Dental College, Tokyo, Japan
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Cho KH, Honkura Y, Kim JH, Hayashi S, Kitamura K, Murakami G, Rodríguez-Vázquez JF. Topohistology of the cranial nerves IX-XII at the cranial base and upper parapharyngeal space: A histological study using human fetuses. Anat Rec (Hoboken) 2023. [PMID: 38009864 DOI: 10.1002/ar.25355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/17/2023] [Accepted: 11/10/2023] [Indexed: 11/29/2023]
Abstract
The topographical relationships among the lower cranial nerves, internal carotid artery (ICA), and internal jugular vein (IJV) in the upper parapharyngeal neurovascular bundle remain obscure. Thus, details of the anatomy were examined in human fetus histology. We observed the horizontal histological sections from 20 midterm (9-18 weeks) and 12 near-term (28-40 weeks) fetuses. At the external skull base, the glossopharyngeal nerve crosses the anterior aspect of the IJV to reach the medially located Hyrtl's fissure in the petrous temporal bone. The nerve crossed the anterior aspect of the ICA medially near or below the first cervical nerve root. Below the hypoglossal nerve canal, the accessory nerve crosses the anterior or posterior aspects of the IJV and moves laterally. During the half-spiral course, the hypoglossal nerve was tightly attached to the posterolateral-anterior aspects of the vagus nerve and surrounded by a common nerve sheath. The glossopharyngeal ganglia sometimes extended inferiorly to the level of the hypoglossal nerve canal but were absent along the inferior course. The inferior vagal ganglion rarely extends above the occipital condyle. The superior cervical sympathetic ganglion occasionally extends above the first cervical nerve root. The IJV (or ICA) descends to the lateral (or medial) margins of the parapharyngeal neurovascular bundle. The glossopharyngeal (or accessory) nerve crosses the ICA (or IJV) to exit the bundle at the base of the skull (or below the hypoglossal nerve canal). The glossopharyngeal and vagus inferior ganglia differ at each site.
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Affiliation(s)
- Kwang Ho Cho
- Department of Neurology, Wonkwang University School of Medicine and Hospital, Institute of Wonkwang Medical Science, Iksan, Republic of Korea
| | - Yohei Honkura
- Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Ji Hyun Kim
- Department of Anatomy, Jeonbuk National University Medical School, Jeonju, Republic of Korea
| | - Shogo Hayashi
- Department of Anatomy, Division of Basic Medical Science, Tokai University School of Medicine, Tokyo, Japan
| | - Kei Kitamura
- Department of Histology and Embryology, Tokyo Dental College, Tokyo, Japan
| | - Gen Murakami
- Division of Internal Medicine, Cupid Clinic, Iwamizawa, Japan
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Martínez-Sanz E, Catón J, Maldonado E, Murillo-González J, Barrio MC, Paradas-Lara I, García-Serradilla M, Arráez-Aybar L, Mérida-Velasco JR. Study of the functional relationships between the buccinator muscle and the connective tissue of the cheek in humans. Ann Anat 2023; 246:152025. [PMID: 36375681 DOI: 10.1016/j.aanat.2022.152025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/17/2022] [Accepted: 11/02/2022] [Indexed: 11/13/2022]
Abstract
BACKGROUND The buccinator muscle derives from the mesenchyme of the second pharyngeal arch. In adults, it has a quadrilateral shape, occupying the deepest part of the cheek region. Its function is complex, being active during swallowing, chewing, and sucking. To our knowledge, there are no studies that have specifically analyzed the relationship of the buccinator muscle fibers and neighboring connective tissue of the cheek in humans, neither during development nor in adults. Such relationships are fundamental to understand its function. Thus, in this study the relations of the buccinator muscle with associated connective tissue were investigated. METHODS The buccinator muscle region was investigated bilaterally in 41 human specimens of 8-17 weeks of development. Moreover, four complete adult tissue blocks from human cadavers (including mucosa and skin) were obtained from the cheek region (between the anterior border of the masseter muscle and the nasolabial fold). All samples were processed with standard histological techniques. In addition, subsets of sections were stained with picrosirius red (PSR). Furthermore, immunoreactivity against type I and III collagen was also studied in adult tissues. RESULTS The buccinator muscle showed direct relationships with its connective tissue from 8 to 17 weeks of development. Collagen fibers were arranged in septa from the submucosa to the skin through the muscle. These septa were positive for type I collagen and presented elastic fibers. Fibrous septa that were positive for type III collagen were arranged from the lateral side of the muscle to the skin. CONCLUSIONS The intimate relationship between buccinator muscle fibers and cheek connective tissue may explain the complex functions of this muscle.
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Affiliation(s)
- Elena Martínez-Sanz
- Department of Anatomy and Embryology, Faculty of Medicine, Complutense University of Madrid, Plaza de Ramón y Cajal, s/n, Ciudad Universitaria, 28040 Madrid, Spain
| | - Javier Catón
- Department of Anatomy and Embryology, Faculty of Medicine, Complutense University of Madrid, Plaza de Ramón y Cajal, s/n, Ciudad Universitaria, 28040 Madrid, Spain.
| | - Estela Maldonado
- Department of Anatomy and Embryology, Faculty of Medicine, Complutense University of Madrid, Plaza de Ramón y Cajal, s/n, Ciudad Universitaria, 28040 Madrid, Spain
| | - Jorge Murillo-González
- Department of Anatomy and Embryology, Faculty of Medicine, Complutense University of Madrid, Plaza de Ramón y Cajal, s/n, Ciudad Universitaria, 28040 Madrid, Spain
| | - María Carmen Barrio
- Department of Anatomy and Embryology, Faculty of Optics and Optometry, Complutense University of Madrid, Calle de Arcos de Jalón, 118, 28037 Madrid, Spain
| | - Irene Paradas-Lara
- Department of Anatomy and Embryology, Faculty of Optics and Optometry, Complutense University of Madrid, Calle de Arcos de Jalón, 118, 28037 Madrid, Spain
| | - Moisés García-Serradilla
- Department of Anatomy and Embryology, Faculty of Optics and Optometry, Complutense University of Madrid, Calle de Arcos de Jalón, 118, 28037 Madrid, Spain
| | - Luis Arráez-Aybar
- Department of Anatomy and Embryology, Faculty of Medicine, Complutense University of Madrid, Plaza de Ramón y Cajal, s/n, Ciudad Universitaria, 28040 Madrid, Spain
| | - José Ramón Mérida-Velasco
- Department of Anatomy and Embryology, Faculty of Medicine, Complutense University of Madrid, Plaza de Ramón y Cajal, s/n, Ciudad Universitaria, 28040 Madrid, Spain
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