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Discomallear and maleomandibular ligaments: Anatomical study and clinical applications
Abstract
Phylogenesis, ontogenesis and anatomy show the existence of two discomallear and malleomandibular ligaments, arising from the first branchial arch and uniting the middle ear with the temporomandibular joint and to the mandible. The intra-articular discomallear ligament is the involuted tendon of the lateral pterygoid muscle on the primitive quadrato-articular joint. The malleomandibular ligament is the fibrous remnant of Meckel's cartilage. In the physiology of the temporomandibular joint, the discomallear ligament alone limits the anterior movement of the disc. Its stretching accompanies disco-condylar disunity, hyperlaxity and temporomandibular dislocation. The malleomandibular ligament, wrongly limited to its sphenomandibular part in classic anatomy, has no physiological role. However, it can be responsible for the dislocation of the ear ossicle chain after disarticulation or temporomandibular trauma. These two ligaments do not play any role in otological manifestations in dysfunction of the manducatory apparatus.
... a natomical study a nd clinical applications Cheynet et al. 2003 Franc ia Revisión Explicar la anatomía, la fisiología y las aplicacione s prácticas del los ligamentos di scomaleolar y maleo mandibular El liga mento disc omaleolar comie nza en la unión e ntre el tercio centra l y el tercio media l de la ba nda posterior del disco de la ATM, luego penetra en la parte lateral de la fisur a petrotimpánica y se fija en el proceso ante rior de l martillo. No tienen ningún papel en las manifestaciones otológicas de la ATM. ...
... Por otra parte, Coleman (1970) en su estudio observó al LDM como una estructura independiente, que presenta forma de cono y se extiende a posterior desde el disco y la cápsula de la ATM, atraviesa la FPT y se une al martillo y a la cara lateral cartílago de Meckel; además, afirma que sus fibras están adheridas a la fisura. Autores como Cheynet et al. (2003) y Kim et al. (2004), concuerdan con la descripción propuesta por Coleman (1970). Sin embargo, Ogütcen-Toller (1995) anexa que el LDM consta de dos capas o fibras. ...
... Por otro lado, Mérida-Velasco et al. (1999a), encontraron que el LDM comienza su desarrollo en la 8ª semana de gestación a partir de una banda de mesénquima que se extiende desde el cóndilo hasta la superficie lateral del cartílago de Meckel. Sin embargo, Ogütcen-Toller (1995) en su investigación encontró que el LDM se forma en la 10ª semana del desarrollo a partir del músculo pterigoideo lateral, lo cual es apoyado por Cheynet et al. (2003), en su revisión, donde alude que el LDM es un remanente del músculo pterigoideo lateral primitivo. ...
The temporomandibular joint (TMJ) has important functions for life; its proper functioning can be altered by temporomandibular disorders (TMD). The symptomatology of TMD is varied, including pain in the masticatory muscles, joint noises and less frequently some patients report auditory symptoms, suggesting the existence of a relationship between the TMJ and the middle ear; however, this relationship is not clear. Consequently, the present study aims to conduct a literature review to identify the known, unknown and controversial aspects of the relationship between TMJ and the middle ear in children and fetuses. A literature search was performed in databases using Boolean operators (AND/ OR) and key terms in English and Spanish. A total of 1080 articles were initially identified; duplicate articles were eliminated and inclusion and exclusion criteria were applied. Finally, a total of 14 articles were selected and reviewed in full text. The studies found focus on the histoembryological development of the TMJ and how that development occurs in conjunction with the middle ear components. Additionally, research on the origin, morphology, and function of the discomalleolar ligament, sphenomandibular ligament, and petrotympanic fissure as structures connecting the TMJ and middle ear was identified, but the results have been controversial. It is concluded that further studies are necessary to determine any anatomical and physiological relationship that may exist between the TMJ and the auditory system in fetuses and children.
... Ontogenetically, the tympanomandibular ligament was formed during the evolution for the passage from the aquatic life of reptiles to terrestrial adaptation, inducing important modification in morphology and physiology of the TMJ. Indeed, the several bones sagittally aligned, forming the reptilian lower jaw and articulating with cranial bone, have migrated toward the middle ear during phylogenesis, transforming themselves in the malleus and the incus [7]. ...
... These phylogenetic modifications left vestiges of primitive bones in the humans and can easily be seen in newborn. These vestiges are represented by tympanomandibular ligament which runs through the posterior region of petrotympanic fissure (Glaserian fissure) open in fetus and in newborn [7]. ...
... Discomalleolar ligament represents the vestiges of the primitive lateral pterygoid muscle which penetrates in the caudal end of Meckel's cartilage. During the development of newborn, the petrotympanic fissure closes almost completely leaving inside the discomalleolar ligament [7]. According to Pinto [8] and Rodriguez-V azquez et al. [6], this ligament is a triangular shaped band of connective tissue and it is located laterally in respect to the sphenomandibular ligament. ...
Discomalleolar ligament represents the vestiges of the primitive lateral pterygoid muscle which penetrates in the caudal end of Meckel's cartilage; during the development of newborn, the petrotympanic fissure close almost completely leaving inside the discomalleolar ligament. After entering in tympanic cavity, some fibers of the discomalleolar ligament insert to walls of cavity, other fibers continue with the lateral margin of the anterior ligament and insert in the neck of malleus; in contrast, other Authors demonstrated that discomalleolar ligament is an independent structure inserted in proximity of the neck of the malleus. Although the discomalleolar ligament can be considered as a structure of clinical importance, it is not described by anatomy textbooks. Moreover, it is likely that important correlations between temporomandibular diseases and otological symptoms exist. We have studied discomalleolar ligament submitting the specimens to the 3D volume rendering technique, light microscopy, reconstructing a wide light microscopic fields to analyze the real connection between retrodiscal connective tissue and middle ear, and immunofluorescence methods in order to analyze the consistence of ligament. We have shown two types of connections between TMJ and ear: first, with external acoustic meatus and, second, with middle ear through discomalleolar ligament. The different insertion represents a strong support in order to demonstrate that the TMJ disorders can determine variations of tension that are transmitted on the tympanic membrane provoking tinnitus in according to clinical features. Then, we propose that it is necessary to mention, also in anatomy textbook, the discomalleolar ligament as ligament distance of TMJ.
... Medially, it is divided into anterior portion (petrosquamous part) and posterior portion (petrotympanic part) by the lower extension of tegmen tympani which is the portion of petrous part of temporal bone [ Figure 1]. [17] The DML begins at the posterior band of TMJ disc, it runs posteriorly within joint cavity toward the bilaminar zone of the disc, then in the superior retrodiscal lamina. [18] The ligament then passes through the lateral part of PTF, while doing so, some of the fibers appear to insert themsleves on the sides of PTF. ...
... During its attachment to the malleus it may or may not joins the fibers of MML. [17] MML attaches itself at the level of anterior process of malleus in the middle ear cavity and with the lingula of the mandible via sphenomandibular ligament (SML). [19,20] The exact nomenclature of this ligament is not obvious but in majority of literature, it is synonymously called as sphenomandibular ligament or anterior ligament of malleus or tympanomandibular ligament. ...
... [22] Some other authors concluded that this ligament has no intermittent attachments and is therefore should be named as malleomandibular ligament, extending from malleus to lingula of the mandible. [5,13,17] MML lies medial to the DML. It runs horizontal, oblique anterior and medially in the middle ear cavity before it reaches to the Glaserian fissure. ...
... unite the mandible and TMJ with the middle ear have been identified as the discomalleolar ligament (DML) and the sphenomandibular ligament (SML) (Pinto, 1962;Burch, 1966;Rodr ıguez-V azquez et al., 1992Rodr ıguez-V azquez et al., , 1993Rodr ıguez-V azquez et al., , 1998Cesarani et al., 1991;Cheynet, 2003;Sencimen et al., 2008;Meng et al., 2011). The SML is also known as the malleomandibular ligament (MML), anterior ligament of the malleus (AML) and the tympanomandibular ligament (TML) ( Table 1). ...
... The SML is described as a fibrous remnant of Meckel's cartilage, and as such, in its completion, extends from the jaw to the middle ear. There is controversy concerning the derivation and even the factual existence of the discomalleolar ligament in the human adult (Harpman and Woollard, 1938;Pinto, 1962;Burch, 1966;Smeele, 1988;Loughner et al., 1989;Cheynet, 2003;Sencimen et al., 2008). A third ligament often discussed in the literature, the anterior ligament of the malleus (AML), specifically refers to the ligamentous attachments of the posterior (intratympanic) part of the SML to the malleus within the tympanic cavity ( Table 1). ...
... Varying degrees of attachment of the ligament to the spine of the sphenoid have been observed (Cameron, 1915;Burch, 1966;Loughner et al., 1989). Some authors maintain that the ligament has no intermintent attachments and is therefore a true malleomandibular ligament, extending from the lingula of the mandible, through the tympanic bone, and then to the epitympanic region where it attaches to the malleus (Burch, 1966;Toledo Filho et al., 1985;Rodr ıguez-V azquez et al., 1992;Cheynet et al., 2003). ...
In the human, two ligaments derived from the first embryonic pharyngeal (branchial) arch that unite the mandible and temporomandibular joint (TMJ) with the middle ear have been identified as the discomalleolar ligament (DML) and sphenomandibular ligament (SML), also known as the malleomandibular ligament (MML), anterior ligament of the malleus (AML), and tympanomandibular ligament (TML). Neither of these structures has been previously described in the dog. The homologue of the human sphenomandibular ligament (SML) exists in the dog and is represented as a fibrous remnant of Meckel's cartilage. In the newborn puppy, the ligament is a true malleomandibular ligament (MML), extending from the medial mandible to the rostral process of the malleus with no intermittent attachments. In the adult dog, the ligament is entrapped within a bony passageway, likely due to the development and ossification of the tympanic bulla, making it difficult to grossly view the complete course of the ligament. The majority of the ligamentous fibers attach near the tympanic bulla in the adult dog, thus this portion of the ligament has been named the tympanomandibular ligament (TML). Those fibers of the ligament not attaching near the tympanic bulla appear to continue through a canal, located between the tympanic annulus and the surrounding tympanic bone, to become continuous with a connective tissue sheet within the cavity of the middle ear that has attachments to the malleus and incus. Tension on the adult canine TML did not result in movement of the malleus. Anat Rec, 2014. © 2014 Wiley Periodicals, Inc.
... The formation of a disc is therefore only possible due to the initial development of the condylar. The disc is associated with the discomallear ligament, which corresponds to a remnant of the lateral pterygoid muscle, which attaches to the caudal end of Meckel's cartilage during embryonic development (Ogutcen-Toller, 1995;Cheynet et al. 2003). In reptiles and birds this muscle inserts on the quadrato-articular joint. ...
... As has already been mentioned, this occurs relatively late in marsupials, at around P20, but a late break is also observed in the placental tree shrew (Tupaia), where Meckel's remains connecting the ear to the jaw until around P14, and is thought to function as a skeletal support (Zeller, 1987). In humans, Meckel's cartilage breaks down by the 8th month of gestation (Cheynet et al. 2003). In clinical cases where the temporomandibular joint does not develop, Meckel's remains continuous (Herring, 1993). ...
... During development, the stretch of Meckel's cartilage from the molar primordium to the malleus undergoes an unusual transformation to form a fibrous ligamentous structure (Harada & Ishizeki, 1998), which develops into the sphenomandibular and anterior malleolar ligaments (Ogutcen-Toller, 1995;Cheynet et al. 2003). The sphenomandibular (also known as the malleomandibular) is involved in TMJ movement by limiting the distension of the mandible and preventing dislocation and forms between the sphenoid bone and dentary. ...
Having three ossicles in the middle ear is one of the defining features of mammals. All reptiles and birds have only one middle ear ossicle, the stapes or columella. How these two additional ossicles came to reside and function in the middle ear of mammals has been studied for the last 200 years and represents one of the classic example of how structures can change during evolution to function in new and novel ways. From fossil data, comparative anatomy and developmental biology it is now clear that the two new bones in the mammalian middle ear, the malleus and incus, are homologous to the quadrate and articular, which form the articulation for the upper and lower jaws in non-mammalian jawed vertebrates. The incorporation of the primary jaw joint into the mammalian middle ear was only possible due to the evolution of a new way to articulate the upper and lower jaws, with the formation of the dentary-squamosal joint, or TMJ in humans. The evolution of the three-ossicle ear in mammals is thus intricately connected with the evolution of a novel jaw joint, the two structures evolving together to create the distinctive mammalian skull.
... The AML, which contains muscle fibers 12,13,18 , spans from the mallear neck, which is just above the anterior process, to the anterior wall of the tympanic cavity near the petrotympanic fissure (PTF). The other ligaments, derived from the perichondrial sheath of Meckel's cartilage, continue into the SML like the AML 11,19 . The AML, first described by Pinto in 1962, was thought to be a muscle inserting into the malleus 34 ; but it is now considered to be a fibroelastic ligament. ...
... Investigators renamed the AML the malleomandibular ligament (MML) and it was identified as a tympanic part of the SML because the remaining bundles of this fibrotic tissue join the SML just after passing through the PTF 38 . DML is a free ligament, lying between the malleus and the TMJ 11 , that was shown to be structurally different from the AML in an adult cadaver study 24 . ...
... Several studies have investigated whether ligamentous structures between the middle ear and the TMJ cause otological symptoms 11,24,27 . The latter could occur in anterior disc displacements with reduction due to the tension of the DML and the movement of the malleus 23,27,32 . ...
The aim of this paper is to investigate the anatomical topography and the relationship between the ligaments, malleus and temporomandibular joint (TMJ) and to determine the role of these ligaments on the movement of the malleus. The malleus, incus, petrotympanic fissure (PTF), chorda tympani, anterior malleolar ligament (AML), discomallear ligament (DML), malleomandibular ligament, sphenomandibular ligament and articular disc were explored in 15 skulls. Traction and tension tests were carried out to clarify their role in malleolar movement. In 12 of the cases, two separate ligaments were connected to the anterior of the malleus, whereas a single ligament from the anterior of the malleus to the PTF was observed in 3 cases. In 12 cases, the DML united the retrodiscal tissues. In the other 3 cases, the medial and the lateral parts of the ligament were connected to the retrodiscal tissue after passing through the PTF. The thickness of the ligaments differed among specimens. When tension was applied to the DML no malleolar movement occurred, but when the AML was overstretched, significant movement was observed in 5 cadavers; little movement in 6 cadavers, and no movement in 4 cadavers. This study suggests that extreme stretching of the condyle in conjunction with the ligaments between the ossicles of the inner ear and the TMJ could be the reason for unexplained otological problems.
... 12 The arrangement of the discomalleolar ligament and its relationships with the malleus of the middle ear have been pointed out in fetuses 13,14 and in adults. [15][16][17][18] The studies carried out by Gross et al 19 pointed out that there was a greater proportion of elastic fibrae in the inner region of the upper lamina of the bilaminar zone. Our observations indicate that this region corresponds to the discomalleolar ligament. ...
... It has been suggested that this ligament would limit the anterior discal movements in movements at maximum aperture and propulsion. 17 The excessive tension of the discomalleolar ligament may provoke auditory symptoms. 15 However, other authors are doubtful that this will occur. ...
... 15 However, other authors are doubtful that this will occur. 17,18 The retroarticular region during the fetal period has been systematized by us. 7,13,14 The retroarticular region in fetuses is limited by the posterior part of the articular disc (bilaminar zone) and the anterior site of ossification of the tympanic bone. ...
The aim of this work was to clarify the arrangement of the posterior segment of the temporomandibular joint capsule and its pertinent relationships.
The temporomandibular region was dissected bilaterally in 20 adult cadavers. Natural stained latex was injected into 16 cadavers through the external carotid artery to facilitate the dissection of the arterial vessels.
The posterior segment of the joint capsule is made up of the so-called "bilaminar zone" of the articular disc. The upper internal portion of the posterior segment of the capsule was reinforced by the discomalleolar ligament. The retroarticular space was filled with loose connective tissue and the anterior branches of the anterior tympanic artery were distributed throughout the posterior segment of the joint capsule.
The posterior segment of the temporomandibular joint capsule corresponds to the bilaminar zone of the articular disc. The structures of the retroarticular space are extracapsular.
... 5,8,12,14 On the other hand, different opinions exist about histological characteristics of these ligaments. 6,8,9,12,[14][15][16][17] Various investigators have recognized AML to be consisted of muscular fibers, fibrotic tissue bands, fibro-elastic bands and lastly collagenous fibers since the last century. 3,6,14,16,17 The DML is a free ligament, lying between the malleus and the TMJ, 5,8,12,18 which was shown to have a total structural difference from the AML. ...
... 6,8,9,12,[14][15][16][17] Various investigators have recognized AML to be consisted of muscular fibers, fibrotic tissue bands, fibro-elastic bands and lastly collagenous fibers since the last century. 3,6,14,16,17 The DML is a free ligament, lying between the malleus and the TMJ, 5,8,12,18 which was shown to have a total structural difference from the AML. 19 These ligaments were exposed to various traction and stretching tests in the cadaveric studies to discover whether they were responsible for mallear mobility by experimental simulation of discal or condylar translation. ...
Objectives: To examine histological aspects of the ligaments between the middle ear and temporomandibular joint and suppose a theoretical role of their structural characteristics on mobility of mallear ossicle.
Methods: The ligaments were obtained by microdissection of middle cranial fossa on both sites of 15 cadavers fixed in formalin solution and were sectioned longitudinally (7-10 µm thickness). The sections were stained with Verhoff’s Van Gieson’s stain (VVG) for demonstration of elastic fibers and visualized at X2.5 and X10 magnifications under light microscopy.
Results: Anterior mallear ligament (AML) and sphenomandibular ligaments (SML) were consisted of collagen fibres in analyzed specimens. The discomallear ligament (DML) was constituted of rich collagenous fibres. One specimen of DML harvested between petrotympanic fissure and retrodiscal-capsular intersection site contained elastic fibers dispersed in cotton-bowl appearance between collagen fibers. In the light of functional tests performed in previous studies, it could be extrapolated that presence of elastic fibers in the DML may prevent excessive forces conducted to mallear head by elongation of elastic fibers.
Conclusions: Collagenous fibres have no ability to stretch along their axis which may lack compensatory mechanism to prevent mallear head mobility. (Eur J Dent 2009;3:280-284)
... [5] Meckel's cartilage breaks down by the 8 th month of gestation. [6] The transformation process to a ligamentous fate such as sphenomandibular and anterior malleolar ligaments start close to the malleus and then toward the dentary. [6] These lesions presented as a single, white, hard, round, horn-or club-shaped mass with a smooth surface, and the size was 1-2 mm in diameter. ...
... [6] The transformation process to a ligamentous fate such as sphenomandibular and anterior malleolar ligaments start close to the malleus and then toward the dentary. [6] These lesions presented as a single, white, hard, round, horn-or club-shaped mass with a smooth surface, and the size was 1-2 mm in diameter. Most of the lesions were asymptomatic. ...
When the small white mass is found at the anterior wall of the bony external auditory canal (EAC) just in front of the short process of the malleus, the differential diagnosis of cartilaginous choristoma (CC) besides exostosis, osteoma, and keratoma should be included. CC of bony EAC is not as rare as it has been thought to be. Furthermore, it is very surprising that the term chondroma has been wrongly used to describe CC in many previous studies. In this report, I present my clinical experience with four patients with CC in the bony EAC and discuss the clinical importance of CC in differential diagnosis.
... There exists an intimate relationship of the caudal ligament, capsule and disc with the external acoustic meatus, the tympanic part of the temporal bone and the petrotympanic fissure that links the TMJ and middle ear in horses. This does not appear to have been documented previously in the horse, but has in man (Schmolke 1994;Cheynet et al. 2003). Cheynet et al. (2003) also described 2 ligaments, the discomallear and malleomandibular, from the TMJ to the malleous of the middle ear. ...
... This does not appear to have been documented previously in the horse, but has in man (Schmolke 1994;Cheynet et al. 2003). Cheynet et al. (2003) also described 2 ligaments, the discomallear and malleomandibular, from the TMJ to the malleous of the middle ear. ...
The minute anatomy of the temporomandibular joint (TMJ) in horses is poorly documented in the literature.
To examine in detail the anatomy of the normal equine TMJ and the relationship of the joint to adjacent structures.
The anatomy of the TMJ was examined in 12 equidae using dissections, synovial and vascular injections and frozen and plastinated sections. Relevant structures were photographed.
Rostral and caudal compartments were identified in the dorsal and ventral synovial pouches of the TMJ. Lateral and caudal ligaments were identified and attachments of the masticatory muscles over the TMJ were documented. Direct relationships between the TMJ and components of the ear were found, and the vascular supply described.
This joint is related to some components of the ear as in man, and has its own peripheral vascular supply. Potential relevance: A knowledge of the detailed anatomy of the equine TMJ is a prerequisite to interpreting the imaging techniques, and will enable improved diagnosis of TMJ pathologies.
... Stapedius and TT muscle contraction is produced during many normal events. Also, they can be stimulated by the CNS in centrifuge auditory inhibition control (olivocochlear efferent system), protecting and filtering auditory afferent conduction towards the CNS through contracting these muscles and by additional inner ear hair cell modification (Chan & Reade, 1994). Such combined stapedial and TT muscle mechanisms normally work by discriminating, fine-tuning, and improving external vocalization; reducing the masking effect of autogenous sounds (pre-vocalization contraction); enhancing transient stimuli against continuous background noise; and responding to strong external stimuli, protecting against possible acoustic trauma. ...
... The discomalleolar and anterior malleolar ligaments are responsible for such bone communication and connection; they are attached to the ossicular chain (malleus) and may create a biomechanical connection between the middle ear and the mandible (Alkofide et al, 1997;Burch, 1966;Ogutcen-Toller, 1995;Rodriguez et al, 1992). These ligamental structures may be stretched by a TMJ disorder, which could affect middle-ear ossicular equilibrium; although, there is controversy about their ability to disturb the ossicular chain (Cheynet et al, 2003;Eckerdal, 1991;Kim et al, 2004;Rodriguez et al, 1992). According to Eckerdal (1991), the range of movement of these ligaments depends on the fibrous connection on the walls of the petrotympanic fissure, thereby corroborating Coleman's findings (Coleman, 1970). ...
The literature has closely observed otic symptoms (and other craniofacial complaints) in temporomandibular disorders; however, there is little evidence for an association between the two. This review tries to provide an integrated biological basis for otic symptoms in temporomandibular disorders from both anatomical and physiological points of view; it also attempts to enlarge the view of one of the ranges of central and peripheral mechanisms involved. The pathophysiology of common symptoms is integrated within different health specialties through basic science. This review is not based on a structured selection of randomized controlled trials; rather, it deals with perspectives of otic symptoms triggered or exacerbated by stomatognathic dynamics.
... This hypothesis remains controversial. Studies in multiple species have suggested connections between the developing lateral pterygoid muscle and malleus via the forming disc, while others find no such connection (Cheynet et al., 2003;Coleman, 1970;Harpman & Woollard, 1938;Pinto, 1962;Rodríguez-Vázquez et al., 1998). Using human tissue, Ögütcen-Toller and Juniper (1993) were able to identify a band of connecting mesenchyme between the developing lateral pterygoid and Meckel's cartilage (which forms the malleus) in 10-week-old human tissue. ...
A jaw joint between the squamosal and dentary is a defining feature of mammals and is referred to as the temporomandibular joint (TMJ) in humans. Driven by changes in dentition and jaw musculature, this new joint evolved early in the mammalian ancestral lineage and permitted the transference of the ancestral jaw joint into the middle ear. The fossil record demonstrates the steps in the cynodont lineage that led to the acquisition of the TMJ, including the expansion of the dentary bone, formation of the coronoid process, and initial contact between the dentary and squamosal. From a developmental perspective, the components of the TMJ form through tissue interactions of muscle and skeletal elements, as well as through interaction between the jaw and the cranial base, with the signals involved in these interactions being both biomechanical and biochemical. In this review, we discuss the development of the TMJ in an evolutionary context. We describe the evolution of the TMJ in the fossil record and the development of the TMJ in embryonic development. We address the formation of key elements of the TMJ and how knowledge from developmental biology can inform our understanding of TMJ evolution. This review describes the evolution of the novel mammalian novel jaw joint (temporomandibular joint [TMJ]) in the fossil record and the development of the TMJ in embryonic development. It addresses the formation of key elements of the TMJ and how knowledge from developmental biology can inform the understanding of TMJ evolution.
... Extraarticular ligaments, formed at a distance from the articular capsule include sphenomandibular, stylomandibular, pterygomandibular ligaments, and tractus angularis. Of particular clinical interest are discomalleoar (Pinto's) and malleomandibular ligaments (part of the sphenomandibular ligament), which connect the structures of the middle ear and the mandibular condyle or articulating disc, thus forming a morphological background for the development of tinnitus in patients with functional problems of TMJ, in particular those of the cervicocranio-mandibular system [43,44]. ...
(1) Background and Objectives: The aim of this narrative review was to analyze the neuroanatomical and neurophysiological basis of cervicogenic pain in cervico-cranial pain syndromes, focusing particularly on cervico-orofacial syndromes as a background for the proper diagnosis and non-surgical treatment. Relevant literature on the topic from past 120 years has been surveyed. (2) Material and Methods: We surveyed all original papers, reviews, or short communications published in the English, Spanish, Czech or Slovak languages from 1900 to 2020 in major journals. (3) Results: The cervicogenic headache originates from the spinal trigeminal nucleus where axons from the C1–C3 cervical spinal nerves and three branches of the trigeminal nerve converge (trigeminocervical convergence) at the interneurons that mediate cranio-cervical nociceptive interactions. The role of the temporomandibular joint in the broad clinical picture is also important. Despite abundant available experimental and clinical data, cervicogenic orofacial pain may be challenging to diagnose and treat. Crucial non-surgical therapeutic approach is the orthopedic manual therapy focused on correction of body posture, proper alignment of cervical vertebra and restoration of normal function of temporomandibular joint and occlusion. In addition, two novel concepts for the functional synthesis of cervico-cranial interactions are the tricentric concept of mouth sensorimotor control and the concept of a cervicogenic origin of bruxism. (4) Conclusions: Understanding the basis of neuroanatomical and neurophysiological neuromuscular relations enables an effective therapeutic approach based principally on orthopedic manual and dental occlusal treatment.
... Although the research of Schmolke [13] carried out on human cadavers has concluded, that it was not possible to distinguish the distal disk as a part of a separated structure, Merida-Velasco et al. [10] reported that after examination of 20 cadavers they have identified two separated laminae and retroarticular region filled with venous plexus. The authors confirmed the presence of discomalleolar ligaments in that region and agreed with suggestion about limitation of the range of opening function by those ligaments [14]. Apparently, that part of the joint capsule is still not fully explored. ...
The temporomandibular joint (TMJ), being an almost well-known anatomical structure but its diagnosis may become difficult due to sounds accompanying joint movement. One example is temporomandibular joint hypermobility (TMJH), which still requires comprehensive study. TMJH is a rare disorder; however, its prevalence at the level of around 4% is still significant. We propose a diagnostic method of TMJH based on the digital time-frequency analysis of sounds generated by TMJ. The volunteers were diagnosed using the RDC/TMD questionnaire and auscultated with the Littmann 3200 electronic stethoscopes on both sides of the head simultaneously. Recorded TMJ sounds were transferred to the computer via Bluetooth® for numerical analysis. The research reveals characteristic time-frequency features in acoustic signals which can be used to detect TMJH. This can help differentiate other disc displacements from joint hypermobility.
... 7 The discomalleolar ligament can restrict anterior discal movements in extreme movements (maximal opening and propulsion). 23 Because the TMJ disc is connected to the middle ear by the discomalleolar ligament, this connection is disrupted by discectomy operation. This situation suggests the potential for discectomy procedures to affect hearing, leading to the design of the present study. ...
Purpose
Discectomy is 1 of the preferred TMJ surgical procedure for the treatment of internal derangements when conservative and minimally invasive treatments have failed. The purpose of the current study is to investigate whether a TMJ discectomy operation influences auditory function and clinical variables.
Materials and Methods
This prospective study was composed of patients who underwent a TMJ discectomy operation between 2016 and 2020. Auditory function was evaluated with pure tone audiometry, tympanometry, and acoustic reflex tests at preoperatively (T0), postoperative first week (T1), first month (T2) and third month (T3). Clinical parameters including maximum mouth opening (MMO) and TMJ pain were also evaluated at T0, T1, T2, T3 and sixth month (T4).
Results
The study consisted of 17 patients (5 males, 12 females) with a mean age of 42.65. A significant reduction in VAS pain scores and MMO values compared to baseline values was achieved in all follow up periods (PT0-T1= .001; PT0-T2/T3/T4 < .001). In pure tone audiometry, a significant increase in T1- T0 comparisons at 1000 Hz, 2000 Hz, 6000 Hz, 8000 Hz frequencies and pure tone average (P = .008; P = .005; P = .012; P = .002; P = .001) was observed. In T3-T0 comparisons, a statistically significant decrease was observed in pure tone thresholds at 125 Hz and 8000 Hz frequencies (P = .008; P = .01). There was no statistically significant difference in middle ear pressure and compliance values at T1, T2 and T3 compared to T0 (P ˃ .05). Type C tympanogram was seen in 3 patients at T1 and in 1 patient at T2. Acoustic reflex tests were positive in all patients.
Conclusion
Although mild changes occurred in auditory tests in the early postoperative period, TMJ discectomy procedure has no permanent effect on auditory function.
... The sphenomandibular ligament connects the lingula of the mandible, situated at the periphery of the mandibular foramen and the spine of the sphenoid, hanging from the cranial base, from which it continues as an anterior ligament of the malleus to the middle ear cavity and attaches itself to the malleus. In adulthood, the connection between the mandible and the middle ear is still apparent, as trauma to the jaw joint can potentially cause dislocation of ear bones [35]. After the dentary bone undergoes intramembranous ossification, secondary ossification centres appear in the key points of articulation and mechanical force-in the condylar, coronoid, and angular pro-cesses of the mandible-where they initiate endochondral ossification. ...
The mandibular and hyoid arches collectively make up the facial skeleton, also known as the viscerocranium. Although all three germ layers come together to assemble the pharyngeal arches, the majority of tissue within viscerocranial skeletal components differentiates from the neural crest. Since nearly one third of all birth defects in humans affect the craniofacial region, it is important to understand how signalling pathways and transcription factors govern the embryogenesis and skeletogenesis of the viscerocranium. This review focuses on mouse and zebrafish models of craniofacial development. We highlight gene regulatory networks directing the patterning and osteochondrogenesis of the mandibular and hyoid arches that are actually conserved among all gnathostomes. The first part of this review describes the anatomy and development of mandibular and hyoid arches in both species. The second part analyses cell signalling and transcription factors that ensure the specificity of individual structures along the anatomical axes. The third part discusses the genes and molecules that control the formation of bone and cartilage within mandibular and hyoid arches and how dysregulation of molecular signalling influences the development of skeletal components of the viscerocranium. In conclusion, we notice that mandibular malformations in humans and mice often co-occur with hyoid malformations and pinpoint the similar molecular machinery controlling the development of mandibular and hyoid arches.
... The manifestations of these syndromes are devastating in physical but also psychological aspects and highlight the clinical importance of investigating MC. In addition, understanding the developmental origins of the MC derived anterior malleolar ligament helps to explain why temporomandibular joint (TMJ) trauma can be associated with dislocation of the ear bones (Cheynet et al., 2003). The anatomy only makes sense in the light of an understanding of the development and evolution of the structures. ...
Meckel’s cartilage was first described by the German anatomist Johann Friedrich Meckel the Younger in 1820 from his analysis of human embryos. Two hundred years after its discovery this paper follows the development and largely transient nature of the mammalian Meckel’s cartilage, and its role in jaw development. Meckel’s cartilage acts as a jaw support during early development, and a template for the later forming jaw bones. In mammals, its anterior domain links the two arms of the dentary together at the symphysis while the posterior domain ossifies to form two of the three ear ossicles of the middle ear. In between, Meckel’s cartilage transforms to a ligament or disappears, subsumed by the growing dentary bone. Several human syndromes have been linked, directly or indirectly, to abnormal Meckel’s cartilage formation. Herein, the evolution, development and fate of the cartilage and its impact on jaw development is mapped. The review focuses on developmental and cellular processes that shed light on the mechanisms behind the different fates of this cartilage, examining the control of Meckel’s cartilage patterning, initiation and maturation. Importantly, human disorders and mouse models with disrupted Meckel’s cartilage development are highlighted, in order to understand how changes in this cartilage impact on later development of the dentary and the craniofacial complex as a whole. Finally, the relative roles of tissue interactions, apoptosis, autophagy, macrophages and clast cells in the removal process are discussed. Meckel’s cartilage is a unique and enigmatic structure, the development and function of which is starting to be understood but many interesting questions still remain.
... The correlation between DML and articular disc can be also confirmed by the fact that the organogenetic development of DML is closely linked to development of Meckel's cartilage [35]. In fact, the DML corresponds to the remnant of the primitive lateral pterygoid muscle that penetrates the caudal end of the Meckel's cartilage [8,9]. Phylogenetically, the malleus is part of the primitive jaw joint and derives from dorsal region of Meckel's cartilage. ...
Background
Several anatomic relationships between the ear and the temporo-mandibular joint have been proposed to account for the presence of tinnitus during temporo-mandibular disorders. Among the otomandibular structures, the discomallear ligament (DML) is interposed between the malleus and the retrodiscal capsular complex. The aim of present paper was to study through dissection the frequency and morphology of DML, to characterize its type of collagen, and to evaluate the DML on routine computed tomography (CT).
Methods and results
The study has been conducted on five un-embalmed adult cadavers, and in all cases, the DML was present (100%). It was constituted mainly by fibers of collagen I, with abundant elastic fibers. On CT exams of 40 patients with no reported pathology of the ear, on axial images, a dense structure, going from the upper end of the petrotympanic fissure to the neck of the malleus, was present in all the cases. In 90%, it showed a triangular shape, in 5% a rectangular shape, and in 5% a curved course. The mean length of the antero-medial side was 2 ± 0.6 mm and that of the antero-lateral side was 1.63 ± 0.5, and the mean area was 1.29 ± 0.83 mm².
Conclusion
The DML could represent an anatomical structure that joining the temporo-mandibular joint and the malleus may play a role in the otologic symptoms during temporo-mandibular disorders.
... The PTF transmits the discomalleolar ligament (DML), the anterior ligament of the malleus (ALM), the chorda tympani, and the posteromedial branches of the anterior tympanic artery [6,14,21]. The two ligamentous structures originate in the malleolar neck and its anterior process [5]. ...
Purpose
The purpose of the current study is twofold. First, to investigate the variability of the petrotympanic fissure’s (PTF) morphology in anatomized human cadaveric specimens using multi-detector computed tomography (MDCT), and second, to compare the resulting measurements to investigate the possibilities of applying MDCT in the determination of PTF morphology in living humans.
Methods
Specimens (n = 15) containing the temporal bone and TMJ were obtained from embalmed adult female (53.3%) and male (46.7%) cadavers and imaged using a helical 16-row scanner. Afterwards, cryosections were obtained and morphometric parameters were measured. Degree of agreement between both determinations was investigated and morphometric variables were also compared between PTF types.
Results
Three different types of PTF were identified. Type 1 was a wide tunnel-shaped structure. It was found in 20% of the cases. Type 2 was wide in the entrance but gradually narrows to the tympanic cavity. It was found in 46.7% of specimens. Finally, type 3, which was observed in 33.3% of the cases, was wide at the entrance of the mandibular fossa, followed by a middle region with flat-shaped tunnel structure and a narrow exit. The PTF’s vertical diameters at the mandibular fossa, midpoint, and tympanic cavity and the width at the mandibular fossa all were significantly greater in type 1 specimens.
Conclusions
MDCT is suitable for investigating the variable morphology of human PTF and its association with middle ear’s and TMJ pathologies.
... Furthermore, in 1962 Pinto [9] showed that there is a close relationship between the structures of TMJ and the middle ear. This was mainly attributed to the presence of the anterior malleolar ligament (AML), and the disco malleolar ligament (DML) [10][11][12]. Both ligaments exit the tympanic wall anteriorly from the malleus' anterior process directed towards the PTF [13][14][15][16]. ...
Objectives
The purpose of the present study was: a) to examine the visibility and morphology of the petrotympanic fissure on cone-beam computed tomography images, and b) to investigate whether the petrotympanic fissure morphology is significantly affected by gender and age, or not.
Material and Methods
Using Newtom VGi (QR Verona, Italy), 106 cone-beam computed tomography examinations (212 temporomandibular joint areas) of both genders were retrospectively and randomly selected. Two observers examined the images and subsequently classified by consensus the petrotympanic fissure morphology into the following three types: type 1 - widely open; type 2 - narrow middle; type 3 - very narrow/closed.
Results
The petrotympanic fissure morphology was assessed as type 1, type 2, and type 3 in 85 (40.1%), 72 (34.0%), and 55 (25.9%) cases, respectively. No significant difference was found between left and right petrotympanic fissure morphology (Kappa = 0.37; P < 0.001). Furthermore, no significant difference was found between genders, specifically P = 0.264 and P = 0.211 for the right and left petrotympanic fissure morphology, respectively. However, the ordinal logistic regression analysis showed that males tend to have narrower petrotympanic fissures, in particular OR = 1.58 for right and OR = 1.5 for left petrotympanic fissure.
Conclusions
The current study lends support to the conclusion that an enhanced multi-planar cone-beam computed tomography yields a clear depiction of the petrotympanic fissure's morphological characteristics. We have found that the morphology is neither gender nor age-related.
... 4 Interestingly, the sphenomandibular ligament extends to the middle ear through the petrotympanic (Glaserian) fissure and the anterior canaliculus of the chorda tympani (Huguier's canal). 2 The coexistence of the bilateral ossification of this ligament and the TMJ is similar to the double jaw articulation of mammalian reptiles. This shows that mutations in the genes involved in the signalling of BMP may have played a part in the evolutionary transition between the jaw articulation of the plesiomorphic tetrapod articularquadrate and the mallealincudal joint in the middle ear of mammals. ...
... A TMJ disorder may stretch the DML and AML, thereby affecting middle ear structure equilibrium (Eckerdal;Cheynet et al., 2003;Kim et al., 2004;Wright & Bifano, 1997). The spread of forces through cranial bone sutures was treated by Libin in 1987(Libin, 1987 and suggested that ligaments common to neighbouring structures could become tensioned during normal physiological mobilisation and in abnormal temporal bone trauma. ...
The disco-malleolar and anterior malleolar ligaments are common to the middle ear, the temporomandibular joint and the jaw, all of them sharing a common embryological origin; these ligaments' morphometric and functional aspects were studied in 23 temporal bones. Experimental design: The epitympanum roof and the temporomandibular joint roof were elevated by micro-dissection of the middle cranial fossa, exposing both disco-malleolar and anterior malleolar ligaments and their association with the malleus, the temporomandibular joint disc and the mandibular lingula. Principal observations: Both ligaments start in the malleus and take anterior and divergent routes towards the temporomandibular joint and lingula, passing through Huguier's canal. The disco-malleolar and anterior malleolar ligaments' mean lengths were 6.88 mm (SD 0.81) and 4.22mm (SD 1.17), respectively, no statistically significant difference being revealed between the sides. Temporomandibular joint disc traction was applied for verifying malleus mobility; malleus movement was observed when applying disco-malleolar traction in 30.5% of the samples. Correlation was observed between malleus movement and disco-malleolar length (R2=-0.499, p<0.05). Both ligaments common to the stomatognathic system and middle ear were present in all specimens. Conclusions: There was an anatomical and functional relationship between human TMJ and the middle ear.
... Several small attempts to draw attention to the problem have resulted in publications on inaccuracies in NA and TA but unfortunately no author reviewed it as a whole (Ajayi et al., 2013;Bartoska et al., 2013;Benninger, 2013;Benninger and Delamarter, 2013;Cheynet et al., 2003;Davidge et al., 2010;Ercoli et al., 2005;Ferreira et al., 2011;Grodinsky and Holyoke, 1938;Guidera et al., 2012;Hromada and Voboril, 1968;Isik et al., 2014;Kachlik et al., 2008bKachlik et al., , 2010aKodama et al., 1987;Krmpotić-Nemanić and Vinter, 2003b;Krmpotić-Nemanić et al., 2003;Lengelé and Scalliet, 2009;Lobo and Menezes, 2011;Loukas et al., 2007;Matusz, 2010Matusz, , 2011Mirilas and Skandalakis, 2002;O'Brien et al., 2013;Paraskevas, 2011;Pauza et al., 1997;Ribas, 2010;Rodríguez-Hernández et al., 2011;Rohrich et al., 2008;Saleh et al., 2012;Schurter and Letterman, 1976;Shokrollahi et al., 2014;Skandalakis et al., 2006;Starmühler, 2011;Tran-Dinh, 1987;Vavilov and Kosourov, 2004;Voboril, 1985;Vojniković et al., 2013;Wendell-Smith, 2000b;Ziyal et al., 2005). ...
... In literature on temporomandibular morphology, however, there is mention of two ligaments that originate from the temporomandibular joint region, travel through the petrotympanic fissure and finally attach to the anterior side of the malleus: the discomallear ligament (DML) and a separated branch of the sphenomandibular ligament (SpML; Kim et al., 2004;Sencimen et al., 2008). The DML connects the malleus to the articular disc of the temporomandibular joint (Cheynet et al., 2003;Kim et al., 2004;Rowicki and Fig. 9. Superior views of the incudal lenticular processes of all samples. The views are in perspective but the scale bars are always in the plane of the pedicle of the lenticular process. ...
A multitude of morphological aspects of the human middle ear (ME) were studied qualitatively and/or quantitatively through the postprocessing and interpretation of micro-CT (micro X-ray computed tomography) data of six human temporal bones. The samples were scanned after phosphotungstic acid staining to enhance soft-tissue contrast. The influence of this staining on ME ossicle configuration was shown to be insignificant. Through postprocessing, the image data were converted into surface models, after which the approaches diverged depending on the topics of interest. The studied topics were: the ME ligaments; morphometric and mechanical parameters of the ossicles relating to inertia and the ossicular lever arm ratio; the morphology of the distal incus; the contact surface areas of the tympanic membrane (TM) and of the stapes footplate; and the thickness of the TM, round window of the cochlea, ossicle joint spaces, and stapedial annular ligament. Some of the resulting insights are relevant in ongoing discussions concerning ME morphology and mechanical functions, while other results provide quantitative data to add to existing data. All findings are discussed in the light of other published data and many are relevant for the construction of mechanical finite element simulations of the ME. J. Morphol., 2015. © 2015 Wiley Periodicals, Inc.
© 2015 Wiley Periodicals, Inc.
... La inserción en la espina del esfenoides no fue observada en ningún caso. Esta diferencia anatómica entre LDM y el LMA estaría dada por su origen embriológico, el LDM corresponde al remanente primitivo del músculo pterigoideo lateral, mientras que el LMA es el remanente fibroso del cartílago mandibular (Cheynet et al., 2003), compartiendo su origen estructural con el ligamento esfenomandibular (Rodríguez-Vázquez et al., 1992). Con el desarrollo la fisura petrotimpánica se cierra, sirviendo de límite entre ambos ligamentos (Cheynet). ...
Terminología Anatómica is currently the international standard for anatomical terminology, and establishes an internationally accepted and unified nomenclature for several anatomical structures. However, International Anatomical Terminology (IAT) is not always used correctly in scientific literature. The purpose of this review is to examine scientific literature in order to determine whether the terms that refer to the sphenomandibular ligament of the temporomandibular joint (TMJ) are being used correctly. Scientific books and articles were reviewed, and the terms used were compared with those established by the IAT. Our study found differences between the terms actually used (Synonyms) to refer to the sphenomandibular ligament and to the anatomical structures where the ligament originates and where it is inserted and those established by the IAT in Latin, English and some terms translated into Spanish. The use of eponyms and synonyms found, creates difficulties in communication between scientists and in the learning process of undergraduate students, who frequently use textbooks.
... A TMJ disorder may stretch the DML and AML, thereby affecting middle ear structure equilibrium (Eckerdal;Cheynet et al., 2003;Kim et al., 2004;Wright & Bifano, 1997). The spread of forces through cranial bone sutures was treated by Libin in 1987(Libin, 1987 and suggested that ligaments common to neighbouring structures could become tensioned during normal physiological mobilisation and in abnormal temporal bone trauma. ...
The disco-malleolar and anterior malleolar ligaments are common to the middle ear, the temporomandibular joint and the jaw, all of them sharing a common embryological origin; these ligaments' morphometric and functional aspects were studied in 23 temporal bones. Experimental design: The epitympanum roof and the temporomandibular joint roof were elevated by micro-dissection of the middle cranial fossa, exposing both disco-malleolar and anterior malleolar ligaments and their association with the malleus, the temporomandibular joint disc and the mandibular lingula. Principal observations: Both ligaments start in the malleus and take anterior and divergent routes towards the temporomandibular joint and lingula, passing through Huguier's canal. The disco-malleolar and anterior malleolar ligaments' mean lengths were 6.88 mm (SD 0.81) and 4.22mm (SD 1.17), respectively, no statistically significant difference being revealed between the sides. Temporomandibular joint disc traction was applied for verifying malleus mobility; malleus movement was observed when applying disco-malleolar traction in 30.5% of the samples. Correlation was observed between malleus movement and disco-malleolar length (R2=-0.499, p
... 149 These ligamental structures may be stretched by a TMJ disorder, which could affect middle ear oscicular equilibrium; although, there is controversy about their ability to disturb the oscicular chain. 150,151,152,153 The spread of forces through cranial bone sutures was treated by Libin in 1987 and suggested that ligaments common to neighbouring structures could become tensioned during normal physiological mobilization and in abnormal temporal bone trauma. 154 Retrodiscal tissue elasticity can normally act as an energy buffer in spreading movement from the TMJ to the middle ear by such common ligaments; however, TMJ disc luxation or oedematous pressure from an inflammatory disorder could certainly cause tension on the malleus through Huguier's canal. ...
... A TMJ disorder may stretch the DML and AML, thereby affecting middle ear structure equilibrium (Eckerdal;Cheynet et al., 2003;Kim et al., 2004;Wright & Bifano, 1997). The spread of forces through cranial bone sutures was treated by Libin in 1987(Libin, 1987 and suggested that ligaments common to neighbouring structures could become tensioned during normal physiological mobilisation and in abnormal temporal bone trauma. ...
... On the other hand, different opinions exist about histological characteristics of these ligaments.6,8,9,12,14–17 Various investigators have recognized AML to be consisted of muscular fibers, fibrotic tissue bands, fibro-elastic bands and lastly collagenous fibers since the last century.3,6,14,16,17 ...
To examine histological aspects of the ligaments between the middle ear and temporomandibular joint and suppose a theoretical role of their structural characteristics on mobility of mallear ossicle.
The ligaments were obtained by microdissection of middle cranial fossa on both sites of 15 cadavers fixed in formalin solution and were sectioned longitudinally (7-10 mum thickness). The sections were stained with Verhoff's Van Gieson's stain (VVG) for demonstration of elastic fibers and visualized at X2.5 and X10 magnifications under light microscopy.
Anterior mallear ligament (AML) and sphenomandibular ligaments (SML) were consisted of collagen fibres in analyzed specimens. The discomallear ligament (DML) was constituted of rich collagenous fibres. One specimen of DML harvested between petrotympanic fissure and retrodiscal-capsular intersection site contained elastic fibers dispersed in cotton-bowl appearance between collagen fibers. In the light of functional tests performed in previous studies, it could be extrapolated that presence of elastic fibers in the DML may prevent excessive forces conducted to mallear head by elongation of elastic fibers.
Collagenous fibres have no ability to stretch along their axis which may lack compensatory mechanism to prevent mallear head mobility.
Objective
The aim of the current clinical study was to test the hypothesis that chronic suppurative otitis media (CSOM) might be significantly associated with signs of temporomandibular joint (TMJ) internal derangement.
Methods
The study involved 79 patients with CSOM and 79 control subjects. The TMJ was clinically examined in both groups.
Results
Signs of internal derangement of the TMJ(s) were found in 67.1% of CSOM patients versus 26.6% of control subjects (p = .001).
Conclusion
CSOM may be associated with the extension of the inflammatory process into the TMJ, thereby predisposing to internal derangement of the joint.
The temporomandibular joint is one of the most complex structures in the human body. Understanding the form is a prerequisite to understanding the function. This chapter is devoted to presenting the details of TMJ anatomy.
The Discomaleolar Ligament is a structure that is not described in the classic texts of anatomy despite being described for the first time by Rees, Pinto and later by various authors as a ligamentous structure of fibroelastic tissue that connects the neck and the anterior process of the malleus through the petrotympanic cleft to the mid-superior part of the capsule of the temporomandibular joint (TMJ), the articular disc and the sphenomandibular ligament. Several studies have reported the clinical implications of the discomaleolar ligament and the relationship between temporomandibular disorders and symptoms associated with the middle ear. The aim of this study was to conduct a review of studies that describe the discomaleolar ligament and determine if an anatomically and functionally independent structure and its relation to the middle ear is considered. A search was performed of scientific literature identified articles where the anatomical structures associated with the temporomandibular joint and the middle ear were identified, 24 articles were selected according to the selection criteria. The results obtained in the studies selected in this review suggest the existence of a lamina or fibrous fascicle that connects the TMJ disc with the malleolus of the middle ear, which would validate the presence and relationship between the discomaleolar ligament and middle ear disorders.
Objectives:
To describe objective tinnitus complicated with transient low-tone hearing loss coinciding with mouth opening, which was related to the connection between the mandibular fossa and middle ear space.
Patients:
A 41-year-old man presented with tinnitus, ear fullness, and hearing loss in the left ear on mouth opening.
Main outcome measures:
Clinical case records, audiological data, and radiological analyses including computed tomography (CT) and magnetic resonance imaging.
Results:
Hearing thresholds on the affected side, which were evaluated with mouth opening, showed elevations of approximately 20 dB in the frequencies below 1000 Hz. Again, peak pressure on the tympanogram deviated negatively to -220 mmH2O under mouth opening without changing peak amplitude. CT showed a connection between the mandibular fossa and middle ear space, as revealed by a gas collection around the joint capsule evaluated in two phases (with and without mouth closing). Ear symptoms resolved after myringotomy.
Conclusions:
Although an influence of temporomandibular disorder (TMD) on tinnitus perception has been debated, whether this association is causal or fortuitous has remained contentious. The present case showed a unique feature of tinnitus attributed to a connection between the mandibular fossa and middle ear space.
Jane Nixon MA VetMB BSc MRCVS, examines this vital, but often overlooked connection
1.
Epidemiologic data indicate a frequent association between temporomandibular joint disorders and tinnitus.
2.
It is extremely unlikely that tinnitus is Directly caused by a mechanical relationship between the masticatory system and the middle ear.
3.
Increased muscle tension of masticatory muscles may cause clonus of the palatine muscle via reflex muscle hypertension.
4.
Increased muscle tension of masticatory muscles can influence tinnitus via somatosensory afferents.
5.
In certain patients, occlusional appliances have been shown to normalize increased muscle tension and improve tinnitus, even if evidence for their efficacy is limited.
In the present study, the human discomallear ligament (DML) was observed in structures at both macroscopic and cone beam computed tomography levels. Assessments were made regarding the distribution of calcitonin-gene-related peptide (CGRP), protein gene-product (PGP) 9.5, and substance P (SP) of the DML based on immunohistochemical analyses of the anatomical properties of jaw movements using 27 Japanese human cadavers (mean, 79.3 +/- 8.6 years; male, 74.9 +/- 8.0; female, 82.8 +/- 7.5). The DML of the anterior region was connected to the TMJ disc. The DML of the posterior region was attached to both the head and the anterior process of the malleus through the petrotympanic fissure, which formed a narrow channel. The structure of the petrotympanic fissure through the DML was attached to the malleus, and this structure was associated with the mobility of the malleus. In the anterior and posterior parts of the disc-associated connective tissue of the DML, CGRP-, PGP9.5- and SP-positive nerve fibers were located around numerous blood vessels, a condition which may be correlated with chronic pain syndrines disorders and the auditory system.
1.
Damage in the external, middle, or internal ear can contribute to the emergence of tinnitus because of the hearing loss it
causes.
2.
The two components of the external ear are the auricle and the outer auditory canal.
(a)
The occlusion of the ear canal produces an alteration in sound transmission that may cause tinnitus to develop.
(b)
Ear canal inflammation may cause tinnitus.
3.
The middle ear is an impedance transformer and the site of several pathologies that all may cause tinnitus.
(a)
Acute otitis is accompanied by fever, strong pain in the ear, conductive hearing loss, and discharge from the ear.
(b)
Otitis media with effusion is a chronic presence of seromucous secretions in the middle ear cavity without signs of acute
inflammation.
(c)
Otitis media is an inflammation of the middle ear causing conductive hearing loss.
(d)
Cholesteatoma is a mass of keratinizing squamous cells or epithelial debris that may occur in the middle ear cavity; it can
erode body structures.
(e)
Otosclerosis involves a bony formation around the stapes, impeding its motion.
4.
The first symptom of otosclerosis is often tinnitus.
5.
Tinnitus often occurs in association with hearing loss of cochlear origin.
(a)
Acoustic trauma is one of the most common risk factors for the development of tinnitus and one of the major causes of permanent
sensorineural hearing loss.
(b)
Administration of ototoxic drugs can cause hearing loss, tinnitus, and vertigo or dizziness.
(c)
Age-related changes can cause tinnitus and hearing loss.
(d)
Tinnitus is one of the three symptoms that define Ménière’s disease.
(e)
Changes (decrease) in cochlear blood perfusion can lead to cochlear damage with hearing loss and tinnitus.
(f)
Abrupt change in barometric pressure (barotraumas) can cause damage to the cochlea and may lead to tinnitus.
6.
Hearing loss due to ear diseases may trigger a series of reactions in the central nervous system, which leads to the tinnitus.
7.
Head trauma can lead to tinnitus, and balance disorders are very common after mild to severe head traumas.
The petrotympanic fissure, a narrow slit in the temporal bone, allows the temporomandibular joint (TMJ) and the middle ear to communicate. Both the chorda tympani and the ligament cross the fissure between the posterior region of the joint disk and the malleolar ossicle. The parasympathetic fibers of the chorda tympani spread into the major salivary glands and are responsible for the taste sensibility on the anterior two-thirds of the tongue. After chronological identification of 30 human skulls, petrotympanic fissures were macroscopically and stereomicroscopically analyzed for the presence and disposition of ossification areas. Digitalized images were analyzed using computer program UTHSCSA ImageTool 3.0 (developed by the Department of Dental Diagnostic Science at The University of Texas Health Science Center, San Antonio, Texas). The total extension of the fissures and ossification areas was measured. The macroscopic analysis did not constitute an appropriated method for this evaluation and the ossification of the fissures increased with aging, suggesting its influence on the causes of otalgia in cases of TMJ dysfunction.
This study was carried out on histological aspects of the extratympanic portion of the discomallear ligament (DL) in adult humans. The temporomandibular joint (TMJ) was dissected bilaterally in 20 cadavers; in 15 cases the articular disc (AD) and the retroarticular tissue were extirpated. The extratympanic portion of the DL had the shape of a base-down triangle, in relation to the AD, and an upper vertex, in relation to the petrotympanic fissure. In five cases, the base, measured bilaterally, had an average length of 6.4 mm, while the distance from the base to the upper vertex averaged 9.3 mm in length. The extratypanic portion of the DL is an intrinsic ligament of the TMJ, composed of collagen fibres and abundant elastic fibres. We propose that this ligament could act as a tensor of the synovial membrane in movements of the TMJ.
The association of temporomandibular joint (TMJ) disorders with aural symptoms, such as tinnitus, otic fullness, and subjective decrease of hearing acuity, is a well-established clinical observation. Although several hypotheses have been made about the otic-conductive origin of these complaints, conventional 226-Hz tympanometry has failed to demonstrate any middle ear abnormalities. The aim of this study was to evaluate patients with TMJ disorders with multiple frequency tympanometry (MFT).
Prospective clinical study.
Outpatient clinic.
The population of this study consisted of 40 patients with unilateral TMJ disorders diagnosed for longer than 1 month.
After verifying that there were no abnormal otoscopic findings, 226-Hz tympanometry, conventional pure-tone audiometry, brainstem auditory evoked potentials, and MFT were performed.
Resonant frequency (RF) values.
With the exception of MFT, no abnormal audiologic findings were revealed. The ear ipsilateral to the lesion demonstrated significantly higher (p = 0.002) RF values in comparison to the contralateral ear. The difference in RF values was more obvious in patients aged 45 years or younger.
The results of this study imply an increase in the stiffness of the middle ear, which has not been detected by conventional tympanometry. This represents the first concrete documentation of minor alterations in the conductive properties of the middle ear and seems to support the various hypotheses on the middle-ear origin of aural complaints in patients with TMJ disorders. Further studies are needed before a clear insight on the presumably multifactorial pathophysiology of these complaints can finally be reached.
Orthodontists are fully prepared to treat the problems of occlusion that they are called upon to deal with every day. On the other hand temporo-mandibular joint disorders present more obscure difficulties from the point of view of detection and diagnosis as well the management of their treatment. That is why a profound understanding of the anatomical and physiological functioning of the temporo-mandibular joint has become indispensable for today's orthodontists who are now asked to detect and diagnose an assortment of TMJ disturbances whose etiology may vary greatly. By performing a rigorous diagnostic procedure, based on a thorough clinical examination supported by careful axiographic and radiological studies, of temporo-mandibular malfunctioning and its underlying etiological causes, which are primarily dento-alveolar and occlusal in nature, orthodontists will be able to adopt an appropriate therapeutic approach that might be purely orthodontic or multi-disciplinary and carried out with the collaboration of specialists in occlusion, oral surgery, and even osteopathy.
EDP Sciences, SFODF, 2010.
Studies on the anterior ligament of the Malleus and the Spheuo-mandibular ligament have shown that these structures survive in the adult and represent fibrous vestiges of the Cartilage of Meckel. The Cartilage of Meckel has the form of an elongated X, whose dorsal branches terminate at the anterior apophysis of the Malleus and the spine of the sphenoid. The ventral superior branch terminates at the Lingula mandibulae and the ventral inferior branch continues up to the mental symphyis. It would seem that the termination of each of these brabches represents a bony structure of enchondral origin. The lesser portions of the structure become transformed into ligamentary vestiges.
The sphenomandibular (tympanomandibular) ligament develops from Meckel's cartilage between the future petrotympanic fissure and the mandibular lingula. The superior attachment of this ligament has been described to attach to the sphenoidal spine.
Fifty‐one cadaver half heads were dissected to study the superior attachment of this ligament. Forty‐five of the 51 ligaments were found to be attached in the area of the petrotympanic fissure, not directly to the sphenoidal spine. Six of the specimens had a thin fibrous slip which fanned out medially to the sphenoidal spine.
Twelve additional cadaver specimens were decalcified and cut in various planes through the temporomandibular joint. All specimens showed a fibrous continuation of the ligament through the petrotympanic and/or squamotympanic fissures with an attachment to the malleus in the middle ear. When tension was applied to the ligament the malleus was seen to move.
A 115 mm human fetus head was dissected. A ligamentous structure was seen to run from the medial side of the mandibular ramus to the future squamotympanic fissure area. When observed microscopically the ligament was continuous through the fissure and attached to the malleus.
In this reported case, a variant petrotympanic fissure--opening at the height of the orifice of the Eustachian tube into the hypotympanon--was identified by high resolution computed tomography (CT) as the possible cause of a tympanic membrane perforation. Inner ear function was preserved by an otosclerotic stapes which prevented destruction of the labyrinth. The perforation was closed by a myringoplasty and was to be followed by a stapedectomy after six months to restore normal hearing. Surgeons performing temporomandibular joint arthroscopy should be aware that in a small percentage of patients a variant anatomy of the tympanic plate exists and, therefore, great care must be exercised in the manipulation of instruments near this structure. A preoperative high resolution CT with thin slices of the temporal bone might allow identification of these high risk patients.
The discal apparatus represent the intra-articular part of the lateral pterygoid muscle tendon, which is differentiated in front of articular surfaces. It is involved in craniomandibular shock absorbing, joint proprioception, and also plays an important part in both condylar growth and morphogenesis. This is to emphasize the different roles of this apparatus, which should be religiously preserved, its lesions being, most of the time, irreversible and cause of TMJ disorders.
• Complaints of diminished hearing or reduced speech discrimination frequently accompany temporomandibular dysfunction. There is no consensus as to the mechanism of their occurrence or the alteration of these symptoms with the treatment. We studied 12 subjects with internal derangement of the temporomandibular joint (treated surgically) and nine subjects with myofascial pain disorder (treated medically), and we found no difference between the groups in pretreatment audiometric findings or in their degree of otologic symptoms. Similarly, there were no differences in posttreatment audiometric measures and there were no significant treatment effects. Furthermore, there was no correlation between subjects' complaints of reduced hearing sensitivity or discrimination and audiometric results. The apparently significant reduction in symptoms experienced by some subjects in the absence of audiometric change suggests the operation of unmeasured factors in their response to treatment.
(Arch Otolaryngol Head Neck Surg. 1992;118:1208-1213)
The posterior attachment of the temporomandibular joint disc is a highly compliant tissue, capable of large volumetric fluctuations. Its structure and volume at any moment are a function of condylar position. The posterior attachment appears to function as a device for rearrangement of liquids. The liquids are blood, tissue fluid, and synovial fluid.
Morphological traits of the petrotympanic fissure, a soft tissue containing connection between the middle ear and the temporomandibular joint, are described. The description is based on sagittal histological sections of 67 petrous bones with the proximal part of the mandible. The morphological pattern of the soft tissues within the petrotympanic fissure does not, other than in association with exceptional anatomic conditions, support the opinion that forces may be transferred from the joint to the middle ear. The petrotympanic fissure is mainly to be looked upon as a reminder of earlier evolutionary stages. It may also call attention to a developmentally caused special neurological pattern where the innervation of chewing muscles and some middle ear and pharyngeal muscles are closely related to each other. Taking the developmental facts into account in the clinical situation, it may not be so confusing that a primary pathological stimulus in the chewing apparatus and its muscles may, secondarily, manifest itself as ear symptoms. This symptomatology is known as the "otomandibular syndrome."
The condyle is not responsible for the growth of the body of the mandible, as the latter does not extend in length caudally at the expense of the ascending rami (through the classical relocation phenomenon), but does so deep to these, at the level of the lower insertions of the sphenomandibular ligaments (i.e., from the inlet inner border of the inferior dental canals). Philogenetically and ontogenetically, its appearance reflects the adaptation of the mandible of mammals to the morphologic and functional changes that took place in their cephalic skeleton (more erect posture, more vigorous mastication). Its chief role in man is to stabilize the mandibular body and to allow it to be properly mobilized, although contributing also to its forward and downward movements (namely in its posterior aspect). As such, it plays an active role in mandibular growth, and this role varies according to the primary "potential" of the condylar cartilage. Such primary-type potential for condylar growth may be adequately assessed by studying the shape of the mandible, as well as through an analysis of craniofacial architecture. Most of the conventional diagrams depicting mandibular growth are defective. Another figurative system has to be innovated, that will differentiate each skeletal unit--body, condyle, coronoid process, angle, alveolodental arch--, the sum of which confers the shape, the size, and the multiple variations to the mandible as a whole.
Damage to structures within the middle ear during surgical manipulation of the temporomandibular joint (TMJ) has been reported. Two structures are proposed as possible intermediaries in this trauma: the discomalleolar ligament (DML), which passes from the malleus to the medial retrodiscal tissue of the TMJ, and the anterior malleolar ligament (AML), which connects the malleus with the lingula of the mandible via the sphenomandibular ligament (SML). It has been hypothesized that when tension is applied to the DML and/or AML, the resulting movement of the malleus could cause damage to the tympanic membrane and associated structures. The objective of this study was to determine whether tension applied to the DML and/or the AML could cause movement of the malleus. With the use of a superior medial approach through the middle cranial fossa, the ligaments connecting the malleus with the mandible were examined in 52 adult/human cadaveric half-heads. Tension applied directly to the SML resulted in movement of the malleus in three specimens. Similar tension applied to the DML did not cause movement of the malleus. Histologic evidence showed a continuity of fibers between the SML and AML. When the mandibular condyle was distracted inferiorly, tension was demonstrated in the SML. The results indicate that the AML via the SML has the potential to cause middle ear damage and is more likely to do so than the DML.
The ligamentous structures connecting the temporomandibular joint region and the middle ear were investigated in adult cadavers by the superior approach through the middle cranial fossa. As a result, two ligaments—the continuation of the sphenomandibular ligament with the malleus and the discomalleolar ligament—were present. They passed through the petrotympanic fissure and attached individually to the neck of the malleus, although the discomalleolar ligament was said to become discontinuous with the malleus in older fetal life. Thus, what is called the anterior ligament of the malleus was actually composed of these two ligaments. The discomalleolar ligaments varied greatly in size with cadaver. The authors discuss the liagments' possible contribution to the presence of the aural symptoms related to temporomandibular joint dysfunction.
The presence of aural symptoms in patients with temporomandibular joint dysfunction has been known for a long time. Although many suggestions have been made as to their cause, none has yet proved adequate. In this article reports are given on four patients with temporomandibular joint dysfunction presenting with aural symptoms, the pertinent literature is reviewed, and a new theory of their causation is discussed.
The anterior process of the malleus has been recognized and its unique embryological development described for some time. However, most authorities, while describing it in the fetus and the child, claim that it atrophies with age and offer no theory as to its function. This study examined the horizontal serial sections of whole temporal bones of 50 ears, from donors of various ages from a 24 week fetus to extreme old age. Measurements indicate that, while the anterior process of the malleus seems to get smaller with increasing age, its anatomical consistency would indicate a physiological function. It is proposed that the anterior malleal process, in conjunction with the anterior malleal ligament, acts as the fulcrum of the axis of rotation of the malleus/incus complex and also acts as a damper to resonant oscillations of the complex at low frequencies.
This article documents the existence of three structures that traverse through the petrotympanic fissure. These structures are the mandibular malleolar ligament, the chorda tympani nerve and the anterior tympanic artery. The mandibular malleolar ligament or the disk-malleolar ligament originates on the anterior process of the mallous. It traverses through the petro-tympanic fissure and attaches to the posterior portion of the capsule and disk of the temporomandibular joint. The chorda tympani nerve supplies sensory feeling to the posterior two thirds of the tongue. The anterior tympanic artery supplies blood to the area of the tympanic membrane. Clinical experience with implants that impinge or cover ear problems and other symptoms. Removal of these implants and placements with devices that do not cover these structures often relieve these symptoms.
The case of a 37-year-old woman who suffered a condylar dislocation into the middle cranial fossa is reported. The mechanisms of injury, the problems of clinical diagnosis and the management are discussed.
The evolution of the mandible shows two characteristic features: transformation of the angular, articular and square bones in reptiles into the tympanic bone, malleus and incus of the middle ear respectively; and specific volume expansion of the tooth-bearing bone which in mammals comprises the entire mandible. Posture, locomotion and mastication are the basic evolutionary factors which simultaneously provoked 1) a displacement of the temporal regions, 2) a transformation of the face lowering and widening the lower jaw and 3) an elongation of the sutures uniting the different bones in the reptile jaw bone, progressively leading to their separation and transversal orientation. These transformations were accentuated in the biped. Thus in man the temporomandibular joint is in a very lateral and elevated position near the mastoids. The mandibular condyls are elongated transversally with a medial cantilever. The medial part of the meniscus is drawn medially by the lateral pterygoid while the lateral part is drawn laterally by the temporal and masseter fibers. The ramus is oriented vertically and lies close to the cervical spine. The dental arches are displaced posteriorly on the bone and have lost their anterior abutment. The strongest occlusal forces are displaced to the posterior part of the arches and are transmitted vertically to the intra-articular meniscus. All these phenomena are termed extreme adaptations and the temporomandibular joint would (apparently) suffer if the evolution continued. The architectural features of temporomandibular joint overload can be deducted by comparison with the "ideal" architectural conditions for the craniofacial equilibrium.
Surgery is sometimes indicated in cases of recurrent temporomandibular joint dislocation (luxation). Among the panel of available techniques, therapeutic arthroscopy with retrodiscal tissue and oblique protuberance coagulation has been used to prevent new episodes. Therapeutic arthroscopy was used for 6 patients. Outcome was considered to be satisfactory in 66% with a mean 3.1-year follow-up. This technique can be recommended as first line therapy when surgery is indicated. In case of failure, eminectomy is scheduled.
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L'articulation temporo-mandibulaire et son vrai-faux ménisque [thesis no
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