The muscular compliance of the auditory tube: a model-based survey

Comparative Evaluation of Eustachian Tube Changes in Oral Submucous Fibrosis Patients

Aim and Objective: Oral submucous fibrosis (OSMF) is a potentially premalignant disorder affecting the oral cavity and its adjacent structures. The present study was aimed at a comparative evaluation of eustachian tube (ET) changes in OSMF patients using audiometry and cone-beam computed tomography (CBCT). Materials and Methods: A total of 40 patients who were clinically diagnosed with OSMF were taken for the study and were graded into clinical and functional staging. After grading, the patients were subjected to audiometry to evaluate their hearing deficit. Subsequently, the patients were subjected to CBCT analysis for the evaluation of the length and volume of the ET. The length of ET was measured in the axial sections of the full-face CBCT images taken at the level of the root tip of the upper first molar. The radiolucency from the nasopharyngeal opening to the maximum distance was considered. The volume of ET was measured using third-party software (ITK-SNAP) in the radiolucent area. Result: The age group in which a higher number of OSMF cases were seen was between 41 and 50 years. There was mild to moderate hearing loss observed in the right and/or left ear, with little variation between right and left ear changes in audiometry. The CBCT analysis did not show a significant difference in the mean length of the eustachian tube when comparing OSMF cases with normal. However, as the disease worsened, the length on the right and left sides significantly decreased. Additionally, there was no statistically significant difference in the mean eustachian tube volume between disease cases and controls. According to the clinical subgrades, the overall volume decreased from lower grade to higher grade, but there was no discernible difference between the left and right ear. The volume on function sub-grading between the right and left ear, however, was significantly reduced. Thus, the length and volume of ET decreased as the disease severity increased, but the mild to moderate hearing loss found in different clinical and functional grades of OSMF cases was not statistically significant. Conclusion: Therefore, from the present study, it can be concluded that all OSMF cases should be evaluated for hearing deficit, and imaging of the eustachian tube should be part of the OSMF assessment for morphological changes of the ET that may cause hearing deficit.

Middle-ear effusion in children with cleft palate: congenital or acquired?

Objective

Cleft palates are one of the most common congenital malformations. Because of the loss of Eustachian tube function, middle-ear ventilation is reduced. The aim of this study was to determine if middle-ear effusions were present at birth or at the three-month audiological evaluation.

Method

A total of 53 children with a cleft palate were included. Data review included the results of newborn hearing screening, microscopic findings, a tympanometry, a free field audiometry and intra-operative findings.

Results

A total of 58.4 per cent of patients had a median, 26.4 per cent had a bilateral, 11.3 per cent had a unilateral and 3.8 per cent had a limited soft palate cleft. Newborn hearing screening showed a pass in 83.1 per cent of newborns bilaterally. The first ear microscopy showed a bilateral middle-ear effusion in 90.6 per cent of cases. During cleft surgery, bilateral paracentesis was performed in all cases, and in 90.6 per cent middle-ear effusion was sucked out.

Conclusion

The majority of children with a cleft palate do not present with middle-ear effusion at birth. It develops within several days or weeks of life.

Subjective and Objective Effectiveness of Eustachian Tube Balloon Dilatation for Patients With Eustachian Tube Dysfunction-Evaluation in a Pressure Chamber

INTRODUCTION

The Eustachian tube plays a crucial role in pressure equalization between the middle ear and ambient pressure for fast and large pressure differences. In patients with chronic Eustachian tube dysfunction, Eustachian tube balloon dilatation is increasingly used as surgical therapy. Subjectively, many patients report an improvement of the symptoms postoperatively. Hence, there is a need to objectively measure this effect.

METHODS

The objectivity of Eustachian tube balloon dilatation was evaluated using a precise method of measuring Eustachian tube function. In a hypo/hyperbaric pressure chamber, 23 ears in 13 patients were exposed to a standardized profile of compression and decompression before Eustachian tube balloon dilatation and 4 weeks afterwards. Standardized parameters of Eustachian tube function were determined and statistically compared before and 4 weeks after intervention. In addition, an Eustachian Tube Dysfunction Questionnaire-7 (ETDQ7) questionnaire was completed beforehand and 4 weeks postoperatively to determine subjective surgical success.

RESULTS

The results from the ETDQ7 questionnaire showed a significant improvement in symptoms after Eustachian tube balloon dilatation (p = 0.0002). Objective measurements results showed a significant reduction of the Eustachian tube opening pressure during pressure decrease 4 weeks after intervention (p = 0.0012).

CONCLUSION

Eustachian tube balloon dilatation significantly reduced Eustachian tube opening pressure, in addition to subjective improvement of symptoms determined by ETDQ7.

[Diagnosis and treatment of Eustachian tube dysfunction]

The Eustachian tube protects against secretion, germs and sound pressure from the nasopharynx, it acts as a drain, and serves pressure equalization in both directions so that the ear drum and sound-conducting apparatus can vibrate optimally. The incidence of Eustachian tube dysfunction in adults is about 1%, in children almost 40%. Symptoms are often unspecific. For diagnosis, the Eustachian tube score (ETS-5) can be used in patients with a perforated ear drum, and the ETS-7 score in patients with intact ear drum. Adenoid hypertrophy is a frequent cause of obstructive tube dysfunction in children. Treatment of obstructive dysfunction includes steroid nasal sprays and regular performance of the Valsalva maneuver, as well as tube dilation with the Bielefelder balloon catheter. The patulous Eustachian tube is treated with saline nasal irrigation, estrogen-nasal ointment, and craniocervical manual therapy; causal treatments are evaluated.

Evidence and evidence gaps in the treatment of Eustachian tube dysfunction and otitis media

Evidence-based medicine is an approach to medical treatment intended to optimize patient-oriented decision-making on the basis of empirically proven effectiveness. For this purpose, a classification system has been established to categorize studies - and hence therapy options - in respect of associated evidence according to defined criteria. The Eustachian tube connects the nasopharynx with the middle ear cavity. Its key function is to ensure middle ear ventilation. Compromised ventilation results in inflammatory middle ear disorders. Numerous evidence-based therapy options are available for the treatment of impaired middle ear ventilation and otitis media, the main therapeutic approach being antibiotic treatment. More recent procedures such as balloon dilation of the Eustachian tube have also shown initial success but must undergo further evaluation with regard to evidence. There is, as yet, no evidence for some of the other long-established procedures. Owing to the multitude of variables, the classification of evidence levels for various treatment approaches calls for highly diversified assessment. Numerous evidence-based studies are therefore necessary in order to evaluate the evidence pertaining to existing and future therapy solutions for impaired middle ear ventilation and otitis media. If this need is addressed, a wealth of implications can be expected for therapeutic approaches in the years to come.

[The pressure-equalizing function of the Eustachian tube : Evaluation in a hypo-/hyperbaric pressure chamber]

BACKGROUND

The Eustachian tube connects the tympanic cavity (cavum tympani) and the nasopharynx, and enables pressure equalization between the middle ear and ambient pressure. Functional pressure compensation is very important for flying and diving in particular, due to non-physiologically large pressure differences.

OBJECTIVE

Evaluation of the pressure-equalizing function of the Eustachian tube is still a clinical challenge. This review article evaluates the existing data.

METHODS

Based on a selective literature search, different methods for evaluation of tube function are presented and evaluated, with special reference to evaluation of the pressure-equalizing function in a hypo-/hyperbaric pressure chamber.

RESULTS

The pressure chamber enables the dynamics of active and passive pressure compensation to be provoked and also permits accurate measurement of pressures in the millibar range.

CONCLUSION

A pressure chamber seems to be suitable to evaluate Eustachian tube function and therapeutic approaches to tube dysfunction. Further studies are needed to assess the value of the pressure chamber in combination with other functional tests.

Preoperative and Intraoperative Evaluation of the Eustachian Tube in Chronic Ear Surgery

This article discusses the authors' approach to the assessment of the eustachian tube using opening pressure measurement, endoscopic assessment of the protympanic segment of the eustachian tube, and Valsalva computed tomography. A possible algorithm for the evaluation of eustachian tube obstructive disorders is detailed both preoperatively and intraoperatively.

The role of the tensor veli palatini muscle in the development of cleft palate-associated middle ear problems

Objective

Otitis media with effusion is common in infants with an unrepaired cleft palate. Although its prevalence is reduced after cleft surgery, many children continue to suffer from middle ear problems during childhood. While the tensor veli palatini muscle is thought to be involved in middle ear ventilation, evidence about its exact anatomy, function, and role in cleft palate surgery is limited.

This study aimed to perform a thorough review of the literature on (1) the role of the tensor veli palatini muscle in the Eustachian tube opening and middle ear ventilation, (2) anatomical anomalies in cleft palate infants related to middle ear disease, and (3) their implications for surgical techniques used in cleft palate repair.

Materials and methods

A literature search on the MEDLINE database was performed using a combination of the keywords “tensor veli palatini muscle,” “Eustachian tube,” “otitis media with effusion,” and “cleft palate.”

Results

Several studies confirm the important role of the tensor veli palatini muscle in the Eustachian tube opening mechanism. Maintaining the integrity of the tensor veli palatini muscle during cleft palate surgery seems to improve long-term otological outcome. However, anatomical variations in cleft palate children may alter the effect of the tensor veli palatini muscle on the Eustachian tube’s dilatation mechanism.

Conclusion

More research is warranted to clarify the role of the tensor veli palatini muscle in cleft palate-associated Eustachian tube dysfunction and development of middle ear problems.

Clinical relevance

Optimized surgical management of cleft palate could potentially reduce associated middle ear problems.

Imaging of the Eustachian tube and its function: a systematic review

Introduction

The Eustachian tube is a complex and inaccessible structure, which maintains middle ear ventilation to facilitate transmission of sound from the tympanic membrane to the cochlea. A renewed interest in treatments for eustachian tube dysfunction has led to a demand for methods of imaging the Eustachian tube, and assessing tube opening non-invasively. This review aims to summarise the use of imaging in the anatomical assessment of the Eustachian tube, and to explore how radiological techniques can be used to assess tube function.

Methods

A systematic review of the literature was performed with narrative data analysis.

Results

With high-resolution images, the soft and bony anatomy of the Eustachian tube can be assessed in detail. CT and MRI are best suited to identifying features associated with obstructive or patulous Eustachian tube dysfunction, though true assessments of function have only been achieved with contrast enhanced radiographs and scintigraphy. A single modality has yet to provide a complete assessment. No test has entered routine clinical use, but further development and research is underway.

Conclusion

Significant information can be gained from imaging the Eustachian tube, and as faster acquisition techniques are developed, it is possible that dynamic imaging of tubal opening could play an important role in the assessment of patients with ET dysfunction.

Characterizing the active opening of the eustachian tube in a hypobaric/hyperbaric pressure chamber

OBJECTIVE

Active and passive opening of the Eustachian tube (ET) enables direct aeration of the middle ear and a pressure balance between middle ear and the ambient pressure. The aim of this study was to characterize standard values for the opening pressure (ETOP), the opening frequency (ETOF), and the opening duration (ETOD) for active tubal openings (Valsalva maneuver, swallowing) in healthy participants.

DESIGN/PARTICIPANTS

In a hypobaric/hyperbaric pressure chamber, 30 healthy participants (19 women, 11 men; mean age, 25.57 ± 3.33 years) were exposed to a standardized profile of compression and decompression. The pressure values were recorded via continuous impedance measurement during the Valsalva maneuver and swallowing. Based on the data, standard curves were identified and the ETOP, ETOD, and ETOF were determined.

RESULTS

Recurring patterns of the pressure curve during active tube opening for the Valsalva maneuver and for active swallowing were characterized. The mean value for the Valsalva maneuver for ETOP was 41.21 ± 17.38 mbar; for the ETOD, it was 2.65 ± 1.87 seconds. In the active pressure compensation by swallowing, the mean value for the ETOP was 29.91 ± 13.07 mbar; and for the ETOD, it was 0.82 ± 0.53 seconds.

CONCLUSION

Standard values for the opening pressure of the tube and the tube opening duration for active tubal openings (Valsalva maneuver, swallowing) were described, and typical curve gradients for healthy subjects could be shown. This is another step toward analyzing the function of the tube in compression and decompression.

Visualization of the eustachian tube lumen with Valsalva computed tomography

OBJECTIVES/HYPOTHESIS

Assess the feasibility of using the Valsalva maneuver to visualize the cartilaginous eustachian tube lumen with computed tomography (CT) in subjects with no ear disease.

STUDY DESIGN

Prospective case series study.

METHODS

Thirty-eight consecutive patients undergoing CT of the sinuses for nose-related complaints with normal radiographic findings consented for a CT of the temporal bone while performing the Valsalva maneuver. Multiplanar reconstruction was performed along the axis of the tube. Images were assessed for visualization of the whole length of lumen of the tube, or partial visualization with ratio of visualized to nonvisualized segments.

RESULTS

The Valsalva maneuver allowed visualization of the whole length of the tube in 27/76 (35%) ears examined. It consistently visualized the distal one-third of the cartilaginous tube in 71/76 (94%) ears. Paradoxical collapse of the eustachian tube was present in three ears along with evidence of poor Valsalva technique.

CONCLUSIONS

Valsalva CT consistently allows visualization of the lumen of the distal one-third of the eustachian tube in a majority of patients with no eustachian tube-related complaints. This technique might be helpful in localizing eustachian tube pathology in patients with obstructive tube symptoms.

New insights into mechanism of Eustachian tube ventilation based on cine computed tomography images

There is debate concerning the mechanism of Eustachian tube (ET) ventilation. While a mechanism of complete opening has been advocated previously, sequential contraction of the levator veli palatini and medial pterygoid muscles followed by the tensor veli palatini and lateral pterygoid muscles may produce a transient sequential opening mechanism, allowing an air bolus to traverse the ET. This may explain confusion surrounding sonotubometry reports that not every swallow leads to sound passage in normal subjects. We hypothesize that the ET may not need to open completely when ventilating the middle ear; rather, a discrete air bolus can pass through it. Five normal and five disordered subjects underwent low-radiation dose cine computed tomography (CT) scans of the ET. Sixteen contiguous 2.5 mm slice locations were chosen through a 4 cm area in the nasopharynx that were parallel to and encompassed the entire ET. Twelve images were acquired at each slice over 4.8 s during swallowing and other tasks. Serial images were analyzed. An air bolus was observed passing through the ET in the normal subjects, but not the subject with ET dysfunction. Medial and lateral pterygoid contractions were also observed. A new hypothetical mechanism of transient sequential ET ventilation is presented. This is not a definitive conclusion, as the number of scans taken and maneuvers used was limited. Improved understanding of ET ventilation may facilitate management of middle ear disease as treatment evolves from ventilatory tube placement to ET manipulation.

Deleterious sucking habits and atypical swallowing in children with otitis media with effusion

OBJECTIVE

The aim of this study was to investigate the possible correlation between otitis media with effusion, bad sucking habits and atypical swallowing in children affected by otitis media with effusion.

METHODS

65 children, aged from 7 to 12 years, observed in the ENT Department of the "La Sapienza" University of Rome, were enrolled in the study group (group A). All children were affected by otitis media with effusion for more than 3 months. As control group, 60 healthy children, aged from 7 to 12 years were identified (group B). All the children underwent medical history, with evaluation of the sucking habits, ENT examination, tympanometry, orthodontic examination and evaluation of swallowing. In the orthodontic examination the variables analyzed were: maximum mouth opening, right and left mandibular lateral movements and mandibular protrusion. Atypical swallowing was considered to occur when lip activity produced strong tension in the perioral musculature, and/or the tip of the tongue was placed or pushed against the anterior teeth during swallowing.

RESULTS

In the group A, atypical swallowing was found in 33/65 subjects out of the 65 children (50.7%). In the control group (group B) 16/60 children (26.6%) showed atypical swallowing. Compared with group B, deleterious sucking habits were significantly higher (p<0.05) in the study group (28/65 vs. 12/60). In both the study and control group, deleterious sucking habits were present in almost all children with atypical swallowing (28/33 in group A and 12/16 in group B).

CONCLUSIONS

Our data suggest a correlation between otitis media with effusion, deleterious sucking habits and prevalence of atypical swallowing.

Effects of Velopharyngeal Dysfunction on Middle Ear of Repaired Cleft Palate Patients

Objective

Cleft palates are strongly associated with the development of otitis media due to the anatomic and functional defect of the soft palate musculature and the associated alterations of velopharyngeal muscle insertion on tubal cartilage, or even intrinsic alterations of the cartilage, which affects eustachian tube function. This study will assess velopharyngeal muscle adequacy after palatoplasty through videonasoendoscopy and verify if there is a correlation with otologic status.

Design

Transversal study.

Setting

Otorhinolaryngology and cleft palate outpatient service of the Hospital de Clinicas de Porto Alegre (HCPA), Porto Alegre, Brazil.

Patients

Seventy-three patients with cleft palate or cleft lip and palate between the ages of 6 and 12 years who had already undergone palatoplasty.

Interventions

Videonasoendoscopy for evaluation of velopharyngeal function and videotoscopy to assess middle ear status.

Main Outcome Measures

Severity scale for videonasoendoscopic and videotoscopic findings.

Results

There was no significant correlation between the videonasoendoscopic and the videotoscopic scores in the population studied.

Discussion and Conclusions

Intrinsic defects of the eustachian tube cartilage and of the insertion of the velopharyngeal muscles seem to contribute to the evolution of otitis media in patients with cleft palate, in addition to the actual defect of the soft palate. There was no correlation between the severity of the otoscopic findings and the degree of velopharyngeal dysfunction.

Involvement of pterygoid venous plexus in patulous eustachian tube symptoms

CONCLUSIONS

The pterygoid venous plexus (PVP) is an important factor in the mechanism of eustachian tube (ET) closure under conditions that can cause increased venous pressure in the head, such as during neck compression and postural change from the sitting/standing to the recumbent position.

OBJECTIVES

The symptoms of patulous ET are usually improved by neck compression or postural change (from sitting/standing to recumbent position). Venous congestion around the ET and/or gravitational change may be involved in the changing degree of symptoms, but its mechanism is not understood. This study investigated whether the PVP is involved.

MATERIALS AND METHODS

The dimensions of soft tissues surrounding ET were measured on magnetic resonance images before and after neck compression.

RESULTS

The lateral pterygoid muscle became enlarged after neck compression. Simultaneously, the volume of venous plexus observed between the medial pterygoid muscle and tensor veli palatini muscle was increased. Such enlargement was probably due to blood pooling in the PVP, resulting in protrusion of the ET anterior wall to the luminal side, and decreased ET patency.

Evaluation of Eustachian tube function by sonotubometry: results and reliability of 8 kHz signals in normal subjects

Sonotubometry allows an assessment of the Eustachian tube (ET) function under physiological conditions. The reliability of the application of an 8 kHz pure-tone signal was investigated. In 40 normal subjects (80 ears) sonotubometric studies were performed with a custom-made device. ET opening was provoked by swallowing, yawning and Valsalva manoeuvre. An opening was detected in all patients but not in all manoeuvres. Four characteristic sonotubogram types were found. Most common was the spike-type (60%). The double-peak and the plateau-shaped curves occurred in 17% each. The finding of an descendant curve was rare (5%). Of 623 measurements, only in 55% manouvres a positive sonotubometric result was found despite the fact that the patients reported an opening in all cases. The median opening time in dry swallowing, liquid swallowing, yawning and Valsalva was found to be 486, 355, 1,263 and 1,250 ms. A median sound increase of 16.0, 13.8, 15.0 and 15.0 dB was recorded for these manoeuvres. There was a statistic significant difference (P < 0.02) between the increase in sound intensity of liquid and dry swallowing. There was also a statistic significant difference found for the duration of the forced manoeuvres Valsalva and yawning as compared to dry and liquid swallowing (P < 0.0001). The use of an 8 kHz pure-tone signal showed a limited sensitivity for the detection of ET openings. This is mainly due to noise pollution, but also because of an altered positioning and/or dislocation of the probes and compression of the nostrils. The application of an 8 kHz signal is therefore not reliable enough for the use in practice. Further technical refinements and the use of alternative signals are necessary for a broader clinical application.

Imaging of muscular denervation secondary to motor cranial nerve dysfunction

The effects of motor cranial nerve dysfunction on the computed tomography (CT) and magnetic resonance imaging (MRI) appearances of head and neck muscles are reviewed. Patterns of denervation changes are described and illustrated for V, VII, X, XI and XII cranial nerves. Recognition of the range of imaging manifestations, including the temporal changes in muscular appearances and associated muscular grafting or compensatory hypertrophy, will avoid misinterpretation as local disease. It will also prompt the radiologist to search for underlying cranial nerve pathology, which may be clinically occult. The relevant cranial nerve motor division anatomy will be described to enable a focussed search for such a structural abnormality.

Pathophysiology of the Eustachian tube--relevant new aspects for the head and neck surgeon

OBJECTIVES

The impact of cranio-maxillofacial procedures upon Eustachian tube function is still largely unknown. The aim of this presentation is to depict new aspects of Eustachian tube function and to demonstrate its importance to cranio-maxillofacial surgery.

METHODS

Two different groups of patients were examined both clinically and by MRI of the Eustachian tube region. One of these groups comprised 15 adult patients with a history of cleft palate; another consisted of 32 patients with a history of a so-called patulous Eustachian tube.

RESULTS

Clinical and MRI-findings revealed that the problem of persistent chronic middle ear disease with cleft palate patients depends crucially on the integrity of the pterygoid hamulus and of the tensor veli palatini muscle after cleft palate repair. The masticatory muscles on the other hand also play an important role in Eustachian tube function in non-cleft patients.

CONCLUSION

The maxillofacial surgeon should be aware that he holds a key position for preventing as well as treating Eustachian tube pathophysiology.

Endoscopic examination of the eustachian tube: a step-by-step approach

OBJECTIVE

The aim of this study was to develop a step-by-step approach for endoscopic examinations of the eustachian tube on awake patients and to report anatomic and functional findings.

STUDY DESIGN

Prospective study.

SETTING

University hospital.

PATIENTS

Convenience sample of seven individuals without a history of ear disease.

INTERVENTION

Diagnostic transnasal-transpharyngeal videoendoscopy of the eustachian tube with 30- and 70-degree rigid Hopkins rod endoscopes, 2.5- and 0.8-mm, 0-degree flexible fiber endoscopes performed under local anesthesia in 12 eustachian tubes.

MAIN OUTCOME MEASURES

Utility of the various endoscopes for the diagnosis in the different parts of the eustachian tube; quality of vision and the patient's comfort during the procedure.

RESULTS

The 2.5-mm flexible endoscope was most useful for examination of the pharyngeal ostium and the cartilaginous lumen of the tube. The isthmus region could only be passed using an 0.8-mm fiberscope. In all cases, it was possible to insert the endoscope into the middle ear cavity. Eleven of the 12 tube examinations showed normal findings. The mobility of the tubal cartilage could be visualized with sufficient quality. In 50% of all examinations, application of local anesthesia via a tube catheter was necessary to make the procedure tolerable.

CONCLUSION

The presented approach allows an assessment of both anatomic and functional changes to the eustachian tube in awake patients. The assessment of middle ear structures is limited. To ensure a comfortable and safe procedure, the use of topical anesthesia in a supine position and, in certain cases, additional anesthesia via eustachian tube catheter is recommended.

Endoskopische Untersuchungen der Eustachi-Röhre

BACKGROUND AND OBJECTIVE

Endoscopy of the eustachian tube allows direct examination of endoluminal alterations in the course of the organ. The aim of this study was to describe anatomic and functional findings in healthy awake subjects.

PATIENTS/METHODS

Ten eustachian tubes in six healthy individuals with no history of tube dysfunction were examined under local anesthesia using different types of rigid and flexible endoscopes.

RESULTS

Nine of ten tubes presented with no pathologic finding. The motility of the tube cartilage could be visualized in all cases and showed a wide variety. Prior anesthesia of the mucosa with the subject in the supine position, if necessary supplemented by a tube catheter, rendered the procedure more comfortable.

CONCLUSION

The eustachian tube shows a wide spectrum of anatomic and functional varieties in normal subjects. The method allows comprehensive evaluation of anatomic and functional stenoses of the eustachian tube. The transnasal-transpharyngeal approach allows only limited evaluation of the middle ear structures.

Sectional anatomy of auditory tube

BACKGROUND AND PURPOSE

The auditory tube connects the tympanic cavity with nasopharynx. Due to its structure and position it is difficult to demonstrate the auditory tube in its whole length, and to study its topography on anatomical specimens. The purpose of our study was to present sectional anatomy of auditory tube in order to facilitate understanding of its structure and topography.

MATERIALS AND METHODS

We utilised serial sections of cadaveric head in four planes: transverse, oblique, frontal and sagittal.

RESULTS

The osseous part of the auditory tube was demonstrated on transverse sections, and most of the cartilaginous part on oblique sections of head and neck. The tensor veli palati muscle was found to consist of bilaminar muscle sheet: the outer part originating from the skull base and the inner part originating from lateral cartilaginous lamina and membranous part of the tube. Topographic relations seen on four section planes were described in detail.

CONCLUSION

The structure, course and topography of auditory tube are well demonstrated on sectional images. Detailed knowledge of sectional anatomy of the auditory tube is important for interpretation of corresponding computerised tomographic and magnetic resonance images, and in understanding the disorders and diseases affecting middle ear and mastoid.

Funktionsuntersuchungen der Tuba Eustachii

The Eustachian tube regulates the homeostasis of the middle ear. Problems with its function are predominantly found in childhood. As a consequence, otitis and hearing impairment occur. The most important muscle is the tensor tympani muscle. The complexity of the functional anatomy and physiology are reasons why no function test alone is capable of fulfilling all diagnostic needs. The predictive value of the various Eustachian tube function tests for the outcome of a tympanoplasty is not yet clear. An overview of clinically and scientifically relevant tests for the Eustachian tube function is provided.