Endocranial petrosal anatomy ofBothriogenys(Mammalia, Artiodactyla, Anthracotheriidae), and petrosal volume and density comparisons among aquatic and terrestrial artiodactyls and outgroups

The present theory of eustachian tube function and middle ear ventilation posits that oxygen absorbed by the middle ear mucosa causes negative middle ear pressure which is relieved by periodic opening of the eustachian tube during swallowing and yawning. Measured by a PO2 sensor (Clark type) inserted into the middle ear cavity of normal adults through the eustachian tube, the partial oxygen pressure of the tympanic cavity was found 53.7 +/- 6.5 Torr (N:22). It was about one-third of ambient pressure (about 150 Torr), and showed no change when the eustachian tube was opened by swallowing. Our second study measured the effect of alterations in the systemic arterial blood oxygenation on middle ear gas exchange in 23 guinea pigs ventilated using 21% (room air), 50%, 70% and 100% oxygen at constant carbon dioxide blood gas tension. Partial oxygen tension (PO2) of middle ear cavity was measured by inserting a PO2 sensor into the tympanic bulla through a bore hole. The following results were obtained: (1) PO2 of the middle ear cavity was 39.3 +/- 2.2 Torr at room air, 42.2 +/- 0.84 Torr at 50%, 46.6 +/- 1.1 Torr at 70% and 54.5 +/- 3.7 Torr at 100% oxygen breathing. (2) There was a significant correlation between PO2 of the middle ear cavity and systemic arterial hyperoxygenation noted. Y = 30.79 + 0.056.X (r = 0.9440) (3) The rate of oxygen diffusion in the middle ear cavity was 2.665 x 10(-5) ml/min/cm2 and the rate of oxygen absorption in the middle ear space was 2.874 x 10(-5) ml/min/cm2. No significant difference between the rate of diffusion and that of absorption of oxygen in the middle ear cavity was noted. In our third study, electron microscopy shows that the submucosal capillaries of the human mastoid cells are structures which facilitate the intra- and extravascular transport of substances. It is known from these results that tympanic cavity pressure is kept equal to ambient pressure, or slightly higher to atmospheric pressure, by the respiratory function of the middle ear and mastoid cells so that outflow of air from the tympanic cavity to the pharyngeal orifice occurs during the ventilation of the eustachian tube at ambient pressure and inflow of air from the pharynx to the tympanic cavity is prevented in the absence of environmental pressure changes. The middle ear cavity has respiratory function, and in particular, such function of the mastoid cavity, which is larger in volume than the tympanic cavity, plays a significant role.(ABSTRACT TRUNCATED AT 400 WORDS)

US and MRI anatomy of fetal ear

The objective of the current study was to determine the anatomical features of the tympanic cavity in cattle and buffalo and to be recognize all parts of the tympanic cavity for its clinical purposes. There are general anatomical explanation about the middle ear in anatomy text book, however there are no studies in the literature on the morphology of the tympanic cavity in the buffalo, the region is important clinically as a frequent point of attachment for prostheses. As a recent studies have focused on the reconstruction of defects occurring in these tympanic cavity to aid in the development of new surgical technique. Twelve temporal bones from six heads of adult cattle and buffalo were used, the cavity had been investigated on both sides after dissection them, the features of the cavity were assessed with a measurement done by using digital veirenear calipers and measurement tap and photograph by a stereomicroscope. The result show that the tympanic cavity can be divided into three parts, dorsal (epitympanic recess) middle (proper tympanic cavity) and ventral (tympanic bulla), size communicating freely with each other. Epitympanic recess has handle the head of the malleus ,which embedded in the medial surface of tympanic membrane , the proper tympanic cavity has three ossicles are connected to each other , in buffalo being the most developed and the ossicles of the cattle are relatively small , but the incus is more pronounced. Malleus is intimately fused with the incus, it was therefore not possible to separate the malleus and incus. The proper tympanic cavity has tympanic membrane the membrane can be divided into pars flaccids and pars tensa, in buffalo was more development, large in size and oval in shape, with a darker color and thick, but in cattle was rectangle in shape, with a lighter color and thin comparative with buffalo. The tympanic cavity has two skeletal muscles (stapedius and tensor tympanic muscles), the stapedius muscle is ill developed and the greater part of the tensor tympanic muscle was tendinous in buffalo. The proper tympanic cavity has four opening, the external acoustic meatus, the fenestra ovals, the fenestra rotundum and the Eustachian tube. The first three opening are closed by membrane partitions, the Eustachian tube or the auditory tube is short, and (4-5) cm in length and this can clearly why the tympanic cavity of the animal is easily susptable for infections. The ventral of the tympanic cavity was sieve - like present large number of formation which continues with the air cell of the tympanic bulla, the cell which lie directly ventral to the proper tympanic cavity was communicate with those around the external acoustic meatus and facial canal .

On the functional compartmentalization of the normal middle ear. Morpho-histological modelling parameters of its mucosa

Previous studies on the morphology of the inner ear (semicircular canals and cochlea) in the Sima de los Huesos hominin sample have provided important results on the evolution of these structures in the Neandertal lineage. Similarly, studies of the anatomy of the external and middle ear cavities of the Sima de los Huesos hominins have also provided important data on the auditory capacities of this European Middle Pleistocene population. The present contribution provides unpublished data on three new middle ear variables from the Sima de los Huesos fossils and compares these data with values from samples of Pan troglodytes, Homo neanderthalensis and Homo sapiens. The results of this analysis are combined with those obtained in previous studies to characterize the anatomy of the outer, middle and inner ear in the Sima de los Huesos fossils, as well as to establish the order of appearance of the features that characterize Neandertal ears. As in other cranial structures, the ear region in the Sima de los Huesos show a mosaic evolutionary pattern that includes primitive traits, others shared exclusively with Neandertals, and others that are specific to the Sima de los Huesos hominins. Neandertals and Sima de los Huesos hominins share two exclusive features of the middle ear that are among the first characteristics of the Neandertal lineage: a long tympanic cavity and a large entrance and exit of the mastoid antrum. Along with these traits, the Sima de los Huesos hominins present two specialized features: large volumes of the tympanic cavity and the mastoid antrum. Finally, the middle ear of the Neandertals is characterized by the presence of small angles between the tympanic axis and the plane of the oval window.

A 28-year-old man presented with right-sided facial paralysis that had been worsening over the past eight months. He was initially diagnosed with Bell's palsy and treated with oral steroids and antiviral medication immediately after symptom onset, but experienced minimal improvement. He has a known history of conductive hearing loss in the right ear since age five due to a traumatic tympanic membrane perforation from q-tip use and subsequently underwent tympanoplasty at that time. He denied otalgia, otorrhea, vertigo, or tinnitus. Physical examination showed grade 6/6 paralysis on the right side. Audiogram from two months before presentation ago is shown in Figure 1. What is your diagnosis?Figure 1: Audiogram showing moderate-to-severe conductive hearing loss on the right side. Hearing loss, paralysis.Figure 2: Axial (horizontal) CT of the right temporal bone showing the cholesteatoma involving the middle ear, cochlea, and internal auditory canal. Hearing loss, paralysis.Figure 3: Axial (horizontal) CT of the right temporal bone showing cholesteatoma 1.2 mm above Figure 2 showing the involvement of the tympanic (middle ear) facial nerve by the cholesteatoma. Hearing loss, paralysis.Figure 4: Coronal (vertical parallel to ear) CT of the right temporal bone demonstrating that the cholesteatoma has eroded the tegmen tympani. The cholesteatoma appears to have originated medial to the malleus. Hearing loss, paralysis.Figure 5: Sagittal (vertical parallel to face) CT of the right temporal bone further highlighting the erosion of the tegmen tympani as the cholesteatoma extended medially to the cochlea and internal auditory canal. Hearing loss, paralysis.Figure 6: Sagittal (vertical parallel to face) CT Temporal bone showing the involvement of the cochlea 2 mm medial to the image in Figure 5. Hearing loss, paralysis.DIAGNOSIS: IATROGENIC CHOLESTEATOMA The most concerning aspect of this patient's presentation is the duration of his facial paralysis. Although Bell's palsy is the most frequent diagnosis for facial paralysis, the physician must begin to consider other etiologies and obtain imaging with MRI of the internal auditory canals (IACs) if the paralysis persists beyond six months. The majority of patients with facial paralysis are diagnosed with Bell's palsy, also called idiopathic facial nerve paralysis. By definition, the exact cause of Bell's palsy is unknown; however, it is believed that a large number of cases are due to edema in and around the facial nerve and is caused by the herpes simplex virus (HSV). HSV, which also causes cold sores, has been found to be present within the geniculate ganglion of affected individuals. Viral replication and reactivation within the ganglion are thought to cause edema and subsequent compression of facial nerve fibers, resulting in blockage of electrical conduction and subsequent facial paralysis. The surrounding bony architecture of the facial nerve helps to explain this phenomenon. As it courses through the labyrinthine segment of the temporal bone (the narrowest portion of the fallopian canal measuring approximately 0.68 mm), the facial nerve is completely surrounded by bone, and therefore vulnerable to compression in the event of swelling. The extent of nerve injury depends on both the degree of inflammation and how quickly treatment with steroids and antivirals can be given to reduce swelling. In cases of mild edema, there is transient compression and blockage of nerve conduction until the inflammation subsides. However, in more severe cases the nerve fibers may be crushed and rapidly degenerate. In these cases, axon regeneration usually occurs, but the new nerve fibers may not reach the intended target muscles. This results in synkinesis, in which voluntary movement in one facial muscle group causes involuntary activity of another. For example, a patient may experience involuntary blinking when trying to smile. In the case of this patient, we obtained a CT scan of the temporal bones given the history of conductive hearing loss and previous surgery (Figs. 2, 3, 4, 5). On the right side, we see bony erosion with soft tissue opacification within the petrous and mastoid temporal bone segments, including regional involvement of the labyrinthine and tympanic segments of the facial nerve, basal turn of the cochlea, vestibule, IAC, tegmen tympani, and middle ear cavity including the ossicles. Though initially treated for Bell's palsy, our patient was ultimately diagnosed with a middle ear cholesteatoma that invaded the skull base and involved the facial nerve. The diagnosis was confirmed surgically. Cholesteatomas are benign masses comprised of abnormal squamous epithelium within the temporal bone. Over time, these masses can grow large enough to cause local bony destruction with surrounding inflammation and granulation tissue. Cholesteatomas are often classified into congenital and acquired types (primary or secondary). In the primary acquired type, cholesteatomas typically arise in the setting of chronic tympanic membrane (TM) retraction. Alternatively, secondary acquired cholesteatomas occur in the setting of TM perforation with epithelial migration into the middle ear space. Given the patient's history of q-tip injury and subsequent surgery, the cholesteatoma was most likely caused by traumatic implantation of squamous epithelium or iatrogenic, i.e., caused by the surgeon not removing or implanting squamous epithelium from the middle ear. Facial nerve palsy due to cholesteatoma has been rarely reported in the literature.1 While the mechanism by which cholesteatoma causes facial nerve palsy remains unclear, several theories have been proposed. The first hypothesis is that direct compression by the cholesteatoma is responsible for causing nerve edema and subsequent ischemia. A second hypothesis is that direct contact between the cholesteatoma and facial nerve promotes an inflammatory reaction that leads to injury. This theory is supported by histological studies showing degeneration of the epineurium in facial nerve segments exposed to cholesteatoma or granulation tissue.2 A third hypothesis is that nerve injury is mediated by neurotoxic or enzymatic substances secreted by the cholesteatoma, although the significance of these factors remains controversial.3 It is important to accurately diagnose and treat cholesteatomas, as they have a strong propensity to become infected and erode through local bony structures.4 The infections and associated pathogens in cholesteatoma can be especially hard to eradicate as they are frequently polymicrobial and resistant to antibiotics. Skull base invasion of cholesteatomas carries an increased risk of deafness, facial paralysis, and intracranial complications given their location. In this patient, we see the cholesteatoma is already eroding the cochlea, creating an increased likelihood of sensorineural hearing loss in the right ear. After evaluating the extent of the disease on CT scan, surgical treatment is undertaken with the goals of removing all of the cholesteatoma and repairing damaged structures when possible. Various surgical approaches can be used, depending on the involved structures as well as surgeon comfort level. In this patient, a right middle cranial fossa or translabyrinthine approach could be undertaken. Generally, when the hearing is intact, the best approach is the middle cranial fossa. The translabyrinthine approach is reserved for non-serviceable hearing patients. If the facial nerve function does not return, the patient may receive a hypoglossal-facial jump graft. In the future, a medical device in development may allow restoration of function for the patient.5-6 BONUS ONLINE VIDEOS: VISUAL DIAGNOSIS Read this month's Clinical Consultation case, then watch the accompanying videos from Hamid R. Djalilian, MD, to review the patient's imaging for yourself. Video 1. Axial (horizontal) CT of the right temporal bone showing the extent of the cholesteatoma in the axial plane and involvement of tympanic facial nerve and geniculate ganglion. Video 2. Coronal (vertical parallel to ear) CT of the right temporal bone showing the extent of the cholesteatoma in the coronal plane and invasion of the tegmen and IAC. Video 3. Sagittal (vertical parallel to face) CT of the right temporal bone showing the extent of the cholesteatoma in the sagittal plane and invasion of the cochlea. Video 4. Axial (horizontal) CT of the left temporal bone showing the normal anatomy of the facial nerve in the axial plane. Video 5. Coronal (vertical parallel to ear) CT of the left temporal bone showing the normal anatomy of the tegmen tympani. Video 6. Sagittal (vertical parallel to face) CT of the left temporal bone showing the normal cochlear anatomy in the sagittal plane. Watch the patient videos online at thehearingjournal.com

Diagnosis and treatment of the otitis externa and media

Hearing is one of the fundamental sense. Ear also known as the vestibulocochlear organ, is subdivided into three parts namely external, middle and inner ear. Auricle and external acoustic meatus comprise external ear. Sound waves are transmitted from the external ear to the middle ear. In dogs, breed-specific variances of external ear is noticeable. The auricle has a funnel-like shape which helps in sound collection. Auricle is divided into the proximal conchal cavity and distally located scapha. Anthelix divides the conchal cavity from the scapha and is located close to the conchal cavity. External acoustic meatus is made up of a proximal osseous portion and a distal cartilaginous portion. The cartilaginous portion of carnivores is relatively long and curved which hampers the passage of the straight otoscope for examination. The tympanic membrane consist of two parts, namely the pars flaccida and the pars tensa. The middle ear comprises the auditory ossicles (malleus, incus and stapes), muscles and auditory tube. Tympanic cavity is contained in the petrous temporal bone and has dorsal (epitympanicum), middle (mesotympanicum) and ventral (hypotympanicum) section. Auricular ossicles are located in the dorsal portion. The tympanic membrane is located on the lateral wall of the middle portion. The tympanic bulla is known as the ventral hypotympanicum. Internal ear has membranous and osseous labyrinth. The membrane labyrinth is filled with endolymph and includes the vestibular labyrinth which houses the receptor organ for balance and cochlear labyrinth containing the organ of hearing. The osseous labyrinth consists of vestibule, semicircular canals and cochlea. While defects in the inner ear may result in sensorineural hearing loss, defects in the outer, middle, and middle ear can cause conductive hearing loss. Therefore, it is crucial to research the anatomy and physiology of the ear. This chapter's main objective is to explore the fundamental anatomy and physiology of numerous components of the canine ear that plays a vital role in hearing.


 This 24-year-old woman presented to ENT outpatients with an enlarging swelling in the right external auditory canal. A radical mastoidectomy for chronic suppurative otitis media with cholesteatoma had previously been undertaken at another institution. On clinical examination there was an otologic mass that was tender on probing.
 High resolution imaging of the temporal bones and a subsequent MRI brain confirmed the mass was a temporal lobe encephalocele.
 A temporal lobe encephalocele is where a segment of the temporal lobe invaginates through a defect in the tegmen tympani. The brain is separated from the middle ear and mastoid process by an exceptionally thin layer of bone – the tegmen tympani. Damage to the tegmen compromises the barrier with the brain and may occur for a number of reasons. This includes congenital, traumatic, post-infectious, malignant invasion, post-radiation therapy and post-surgical causes.1 When this occurs the brain may extrude through the defect resulting in a temporal lobe encephalocele. 
 A bony defect alone, whatever the cause, is insufficient to always result in an encephalocele. Even with dehiscence of the tegmen the dura is capable of supporting the brain issue without herniation. Only when the integrity of the dura is compromised does an encephalocele occur.2 This may be due to the underlying disease process (such as cholesteatoma causing an intracranial abscess) or both purposeful (opening dura to drain an adjacent intracranial abscess) /non-purposeful surgical intervention. Mainstream microsurgical techniques however have lowered the incidence of dural violation.3
 Historically, infection was a major cause, but with the ready availability of antibiotics and prompt management, the key contemporary cause is iatrogenic, following mastoid surgery. However, the overall incidence is uncommon following otologic surgery. In a review of 25 years of middle ear/mastoid encephalocele cases 77% were identified to be iatrogenic in origin.4 
 This patient presented with the finding of a mass observed in the external auditory canal. Less common findings at attendance include tympanic perforation, cholesteatoma, otorrhoea and meningitis.4 
 The key to diagnosis hinges on cross-sectional imaging: combined imaging with CT to assess the osseous structures and MRI for soft tissue review. The high-resolution CT (HRCT) of the temporal bones illustrates a large defect in the right tegmen tympani with a large soft tissue lesion occupying the post-surgical mastoid cavity abutting the tympanic membrane. (Figures 1A, B) The defect of 15mm in the tegmen was more than double the average of 7.2mm reported elsewhere.4 The MRI confirms the defect in the tegmen with the protrusion of a knuckle of the right temporal lobe and its overlying meninges through the defect into the mastoid cavity. The dumb-bell appearance is typical with the narrower neck at the site of the tegmental dehiscence. The extruded brain occupies the post-operative middle ear cavity. (Figures 2 A, B and C) The defect size and volume of herniated brain can be accurately assessed, both of which may be key determinates of the type of surgical procedure.
 Revision mastoidectomy with repair of the tegmen defect and dural integrity using a combined intracranial-mastoid approach is planned as a joint case with neurosurgical colleagues.
 References
 
 McMurphy AB, Oghalai JS. Repair of iatrogenic temporal lobe encephalocele after canal wall down mastoidectomy in the presence of active cholesteatoma. Otol Neurotol. 2005 Jul;26(4):587-94. PMID:16015151
 
 
 
 Neely JG, Kuhn JR. Diagnosis amd treatment of iatrogenic cerebrospinal fluid leak and brain herniation during or following mastoidectomy. Laryngoscope 1985 Nov;95(11):1299-300. PMID:4058205
 
 
 
 Glasscock ME 3rd, Dickins JR, Jackson CG, Wiet RJ, Feenstra L.
 
 Surgical management of brain tissue herniation into the middle ear and 
 mastoid. Laryngoscope. 1979 Nov;89(11):1743-54. DOI:10.1288/00005537-197911000-00005 PMID:502695
 
 
 Jackson CG, Pappas DG Jr, Manolidis S, Glasscock ME 3rd, Von Doersten PG, Hampf CR, Williams JB, Storper IS. Brain herniation into the middle ear and mastoid: concepts in diagnosis and surgical management. Am J Otol. 1997 Mar;18(2):198-205. PMID:9093677
 

ANATOMY AND PHYSIOLOGY OF THE MIDDLE EAR The ear is composed of structures at three levels the outer, middle and inner ear. The middle ear comprises the tympanic membranes, tympanic cavity, ossicles and the auditory tube, and transmits sound to the inner ear. The major difference between the cat and dog lies in the structure of the middle ear. Whereas the mesotympanic cavity and epitympanic recess of the middle ear of the dog are partially separated by a bony shelf from the larger ventromedial hypotympanic cavity, the cat’s tympanic chamber is separated into two almost distinct cavities communicating through a small slit-like opening in the bony separation, which widens into a distinct foramen caudally (Fig. 1).This separation gives rise to the characteristic ‘double shell’ profile of the tympanic structures visible on anteroposterior radiographic views (Fig. 2). The lining of the cat’s tympanic chambers is reported to contain more abundant ciliated and secretory cells than the dog. A number of nerves pass through the tympanic chamber and their distribution within the middle ear is similar to that of the dog; the facial nerve and the vestibulocochlear nerve reach the internal auditory meatus in close association. The facial nerve lies exposed in the dorsal aspect of the tympanic cavity. On entering the middle ear, the tympanic plexus (facial nerve mixed with vagal branches) distributes widely across the bony promontory. Sympathetic postganglionic fibres (from the first cervical nerve) pass through the bulla. In the cat, the tympanic plexus is reported to be more exposed, or possibly more sensitive to, iatrogenic trauma.

BackgroundEustachian tube (ET) dysfunction is associated with middle ear pathologies; however, the quantitative relationship between ET opening and pressure equalization remains insufficiently characterized. Computational fluid dynamics (CFD) offers a robust tool for analyzing middle ear pressure dynamics, particularly in elucidating pressure equilibrium mechanisms under partial ET opening conditions.ObjectiveThis study aimed to investigate pressure dynamics in the tympanic cavity, mastoid antrum, and air cells during ET opening using CFD, to compare pressure distributions between full and partial openings, and to determine whether partial opening can achieve equilibration equivalent to full opening.MethodsEight normal temporal bones were reconstructed from high-resolution computed tomography scans of four healthy adults. ET openings were simulated at 10%, 30%, 50%, and 100% patency using CFD, and results were validated against in vivo Tubomanometry data. Pressure variations in the tympanic cavity, mastoid antrum, and air cells were monitored throughout the process. Mesh independence was verified to ensure reliability, and statistical analyses were conducted using SPSS 27.0, with P < 0.05 considered significant.ResultsCFD simulations revealed distinct pressure dynamics within the ET–middle ear system. Airflow velocity peaked at the narrow isthmus, generating a localized pressure drop. Effective middle ear pressure equilibration—across the tympanic cavity, antrum, and mastoid air cells—was achieved with partial ET opening in most cases: 30% opening sufficed for full equilibration in two ears, while 50% opening achieved complete equilibration in six. This equivalence to full patency was consistently observed during pressurization, stabilization, and depressurization phases.ConclusionEffective middle ear pressure equilibration can be achieved with partial ET opening (50%) in most cases (75% of ears). These findings provide valuable insight into middle ear physiology and its response under pathological conditions, offering a theoretical basis for optimizing the management of ET dysfunction.

To evaluate the osseous structures of the external acoustic meatus, tympanic cavity, and tympanic bulla of llamas (Lama glama) by use of computed tomography (CT) and establish measurement values for use in detection of abnormalities associated with the external or middle ear in llamas. 10 adult llama heads without any evidence of ear disease. Heads of 10 healthy llamas euthanized by use of a captive bolt striking the dorsal aspect of the skull were collected. Transverse images of the heads were acquired with 1-mm slice thickness, and images were reconstructed in sagittal and dorsal planes. Measurements of the bony structures of the external and middle ear of each head were obtained. The osseous external acoustic meatus curved ventrally as it tracked medially. Its narrowest portion was located at the level of the tympanic annulus. The tympanic bulla conformation differed widely from the bubble-shaped tympanic bulla in dogs and cats. The bulla was divided by the stylohyoid fossa into a larger caudolateral and a smaller caudomedial process; its interior had a honeycombed structure with pneumatized cells similar to the honeycombed appearance of the human mastoid process. Results provided new information regarding the shape and dimensions of the osseous external and middle ear structures in adult llamas without ear disease. Specific landmarks for location of the external acoustic meatus, tympanic cavity, and tympanic bulla in relation to each other were identified. Knowledge of the CT appearance of normal structures will help clinicians to identify changes attributable to middle ear otitis, external ear canal stenosis, or congenital malformations of the ear in this species.

Otitis media with effusion (OME) accounts for 15-17% of the total number of recorded diseases of the middle ear. Surgical methods have become much more common. One of the factors affecting the tactics and effectiveness of treatment OME is the degree of viscosity of the effusion. Modern diagnostic methods do not allow to reliably identify cases of OME with high effusion viscosity. To study the possibilities of optical coherence tomography (OCT) in the diagnosis of OME and a non-invasive study of effusion viscosity. An analysis of the results of the examination of 29 patients who underwent surgical treatment for OME - tympanostomy. A control group of 30 patients without middle ear pathology. The study used a spectral OCT with a non-contact probe designed specifically for studies of the structural middle ear. Quantitative analysis of the results using open source ImageJ. Objectification of the degree of viscosity of the effusion was carried out by means of viscometry. A comparative analysis of the intensity of the optical signal in the external auditory canal (EAC) and in the tympanic cavity (TC) was performed, as well as a comparison of the signal from viscous and fluid effusion. In all patients with OME, during the OCT study, an optical signal with a higher intensity was recorded in TC than in the EAC. In all cases, in the control group in the TC, an optical signal was recorded that was identical in intensity with the signal in the EAC. When measuring the degree of viscosity of the effusion, 17 cases of OME were characterized as effusion of a low degree of viscosity, 12 cases - effusion of extreme viscosity. When comparing the average intensity of the optical signal of the OCT images of viscous and liquid effusion, a statistically significant difference was revealed, p<0.001. OCT makes it possible to detect light scattering from large scatterers - cell structures characteristic of low viscosity effusion. In addition, OCT allows you to register an optical signal from small scatterers - high molecular weight structures that are present in large quantities in viscous effusion. A correlation was found between the intensity of the optical signal in the TC and the degree of viscosity of the middle ear effusion. Based on OCT data, it is possible to determine the indications for surgical treatment of OME by detecting viscous exudate.

Even in ancient times the existence of an open pathway between the ear and the respiratory tract was assumed. Up to the middle ages, however, Aristotle's idea that the air in the ear is an innate part of the body prevailed. The first anatomical description of the tube was given by Eustachius (1563). He still adhered to the concept of "innate air" and regarded the tube only as a pathway for draining pathological matter from the tympanic cavity. Duverney (1683) realized that an important function of the tube was replacing and adjusting the pressure of the air in the tympanic cavity. He thought that the tube is permanently open, thus offering a vent to the air, when the tympanic membrane is moving inwards and outwards. Valsalva (1704) discovered a muscle for opening the tube, and he presumed that in hearing this muscle would come into action. He described the maneuver that is named after him as a method to expel pus from the tympanic cavity into the external auditory canal. E.G. Guyot, a postmaster in Versailles, was the first to try catheterization of his own Eustachian tube via the mouth. Cleland (1741) inserted the catheter via the nose, and Wathen (1756) after studies on corpses described in detail the technique how to carry out this procedure. The therapeutic application of Eustachian catheterization as practiced by physicians such as Itard (1821) centered around irrigation with water and medications as well as inflation of various fumes. Deleau (1836) later advocated a douche of pure air and, in analogy to the auscultation of the lung, described the different noises that could be perceived during this procedure. Numerous models of pumps were constructed for this air douche, which became one of the most widely used therapeutical means in otology. There were also lethal incidents caused by cutaneous emphysemata. Toynbee realized that at rest the tube is closed and that there is a constant absorption of air in the tympanic cavity. The tube would be opened only by the act of swallowing and air would then be allowed to enter to equalize pressure. He believed that the maneuver he described, namely swallowing while the nostrils are closed, would produce a positive pressure in the tympanic cavity. He died when he applied these maneuvers in order to press fumes of chloroform or cyanic acid into his ears to treat his tinnitus. Politzer could demonstrate that after Toynbee's maneuver the middle ear is left with a negative pressure, and consequently, in 1861-63, he devised his own method for actively inflating the middle ear. The history of these events is described in detail and illustrated by a number of figures and anecdotal episodes.

ConclusionsThe characteristic features of the Hh specimen conformed to those of other Pleistocene human fossils, indicating strong cranial structures and a heavy mandible. The mastoid was large and suggested a powerful sternocleidomastoid muscle. The inner ear and tympanic cavities were similar in size and orientation, suggesting that their functions were probably similar. Our observations suggest that the left ear of this Hh specimen was healthy. The large canaliculo–fenestral angle confirms that this ancestor was bipedal. It also strongly suggests that Hh individuals were predisposed to develop certain pathologies of the labyrinth capsule associated with bipedalism, in particular otosclerosis.ObjectiveWe studied a temporal bone of Homo heidelbergensis (Hh) in order to investigate the clinical and physiological implications of certain morphological features, especially those associated with the evolutionary reorganization of the inner ear.Material and methodsThe bone, found in a breach of a cave near Málaga in southern Spain, together with Middle–Upper Pleistocene faunal remains, is >300 000 years old. Four analytical methods were employed. A 3D high-resolution surface laser scan was used for anatomical measurements. For the sectional analysis of the middle and inner ears of Hh we used high-resolution CT, simultaneously studying a normal temporal bone from Homo sapiens sapiens (Hss). To study the middle and inner ear spaces we used 3D reconstruction CT preceded by an intra-bone air shielding technique. To examine the tympanic cavities and measure the canaliculo–fenestral angle, we used a special minimally invasive endoscopic procedure.ResultsThe surface, sectional and 3D CT examinations showed that the Hh specimen was generally more robust and larger than the Hss specimen. It had a large glenoid fossa. The external meatus was wide and deep. The middle ear, and especially the mastoid, was large and widely pneumatized. There were no appreciable differences in the position and size of the labyrinthine spaces and tympanic cavity. The dimensions of the semicircular canals were similar to those of the Hss specimen. Endoscopy revealed normal, healthy tympanic walls and an ossicle fragment in the atticum that probably belonged to the body of the malleus. The diameters of the fallopian duct and the tympanic opening of the Eustachian tube were large. The canaliculo–fenestral angle was ≈114°.