[Comparison of the results of tympanoplasty in the patients presenting with "dry" mesotympanitis obtained using different surgical approaches]

The objective of the present study was to compare the results of different surgical approaches to the treatment of tympanoplasty in the patients presenting with "dry" mesotympanitis. We compared the morphological and functional outcomes of tympanoplasty in 49 patients allocated to the three study groups. Group 1 was comprised of 28 patients that underwent tympanoplasty using the endaural (intrameatal) approach through an ear speculum. Group 2 consisted of 16 patients that underwent tympanoplasty using the endaural(intrameatal) approach through type A and B intercatilaginous incisions by the method of Heermann, Group 3 included 5 patients who underwent tympanoplasty using the postaural transcanal approach. The analysis of the outcomes of surgeries has demonstrated that the best morphological and functional results were obtained in the patients of groups 2 and 3.

[Criteria for the objective assessment of the dynamic state of the retraction pockets in the children presenting with excudative otitis media]

This publication continues the preceding paper entitled "Early diagnostics of the retraction pockets in the tympanic membrane of the children". The objective of the present work was to develop the criteria for the objective estimation of the dynamic state of the retraction pockets (RP) in the children at different stages of excudative otitis media. The secondary objective was to develop an approach to the early diagnostics of cholesteatoma of the middle ear. A group of 138 children at the age varying from 1 to 17 years was placed under dynamic observation for the purpose of drawing up the individual "photo-roentgenological passport of the retraction pockets". Special attention was given to RP-semiotics of different forms of the syndrome and its severity in accordance with the classification universally accepted by foreign researchers. The results of the dynamic observations were used to develop the indications for the early preserving surgical treatment. It was given to 16 children six of which presented with cholesteatoma. The original illustrative materials for all variants of the retraction pockets are presented.

[Functional examinations of the ear and auditory pathway]

Hearing is usually examined by means of pure tone and speech audiometry. Alternative examinations are required when the level of hearing defect needs to be more closely defined or hearing is being measured from a patient who is unable to give reliable feedback on a test sound. Neonatal hearing screening involves measuring of otoacoustic emissions generated in the cochlea of the inner ear or brain stem responses formed within the auditory pathway. Immittance measurements are used to evaluate the function of the middle ear. Most commonly used methods include tympanometry probing the mobility of the tympanic membrane and middle ear pressure, and acoustic reflex assessing the functionality of the ossicular chain.

Measurement of conductive hearing loss in mice

In order to discriminate conductive hearing loss from sensorineural impairment, quantitative measurements were used to evaluate the effect of artificial conductive pathology on distortion-product otoacoustic emissions (DPOAEs), auditory brainstem responses (ABRs) and laser-Doppler vibrometry (LDV) in mice. The conductive manipulations were created by perforating the pars flaccida of the tympanic membrane, filling or partially filling the middle-ear cavity with saline, fixing the ossicular chain, and interrupting the incudo-stapedial joint. In the saline-filled and ossicular-fixation groups, averaged DPOAE thresholds increased relative to the control state by 20-36 and 25-39 dB, respectively with the largest threshold shifts occurring at frequencies less than 20kHz, while averaged ABR thresholds increased 12-19 and 12-25 dB, respectively without the predominant low-frequency effect. Both DPOAE and ABR thresholds were elevated by less than 10 dB in the half-filled saline condition; no significant change was observed after pars flaccida perforation. Conductive pathology generally produced a change in DPOAE threshold in dB that was 1.5-2.5 times larger than the ABR threshold change at frequencies less than 30 kHz; the changes in the two thresholds were nearly equal at the highest frequencies. While mild conductive pathology (ABR threshold shifts of <10 dB) produced parallel shifts in DPOAE growth with level functions, manipulations that produced larger conductive hearing losses (ABR threshold shifts >10 dB) were associated with significant deceases in DPOAE growth rate. Our LDV measurements are consistent with others and suggest that measurements of umbo velocity are not an accurate indicator of conductive hearing loss produced by ossicular lesions in mice.

The effects of childhood otitis media on the acoustic reflex threshold at age 15

Previous research has found that childhood otitis media leads to elevated adulthood acoustic reflex thresholds because of worsened audiometric thresholds in the stimulation ear, and abnormality of the tympanic membrane in the ear from which acoustic reflexes were measured. To confirm and expand this finding, our research utilized longitudinal data from 631 general-population-sampled children assessed between ages 5 and 15. Otitis media was assessed to age 9, audiometric thresholds were measured at age 11, and otoscopy and acoustic reflex thresholds testing were performed at age 15. Our findings support the earlier research, in that acoustic reflex threshold was higher in those with the worst experience of childhood otitis media. However, this was directly mediated not by audiometric threshold in the ear to which the stimulus was delivered, but by the amount of tympanic membrane abnormality in both the stimulus and probe ears. This appeared to have an effect independent of audiometric threshold. Furthermore, only those who suffered the worst, persistent, binaural childhood otitis media showed raised acoustic reflex thresholds.

Finite element modeling of sound transmission with perforations of tympanic membrane

A three-dimensional finite element (FE) model of human ear with structures of the external ear canal, middle ear, and cochlea has been developed recently. In this paper, the FE model was used to predict the effect of tympanic membrane (TM) perforations on sound transmission through the middle ear. Two perforations were made in the posterior-inferior quadrant and inferior site of the TM in the model with areas of 1.33 and 0.82 mm(2), respectively. These perforations were also created in human temporal bones with the same size and location. The vibrations of the TM (umbo) and stapes footplate were calculated from the model and measured from the temporal bones using laser Doppler vibrometers. The sound pressure in the middle ear cavity was derived from the model and measured from the bones. The results demonstrate that the TM perforations can be simulated in the FE model with geometrical visualization. The FE model provides reasonable predictions on effects of perforation size and location on middle ear transfer function. The middle ear structure-function relationship can be revealed with multi-field coupled FE analysis.

Infra-red thermometry: the reliability of tympanic and temporal artery readings for predicting brain temperature after severe traumatic brain injury

INTRODUCTION

Temperature measurement is important during routine neurocritical care especially as differences between brain and systemic temperatures have been observed. The purpose of the study was to determine if infra-red temporal artery thermometry provides a better estimate of brain temperature than tympanic membrane temperature for patients with severe traumatic brain injury.

METHODS

Brain parenchyma, tympanic membrane and temporal artery temperatures were recorded every 15-30 min for five hours during the first seven days after admission.

RESULTS

Twenty patients aged 17-76 years were recruited. Brain and tympanic membrane temperature differences ranged from -0.8 degrees C to 2.5 degrees C (mean 0.9 degrees C). Brain and temporal artery temperature differences ranged from -0.7 degrees C to 1.5 degrees C (mean 0.3 degrees C). Tympanic membrane temperature differed from brain temperature by an average of 0.58 degrees C more than temporal artery temperature measurements (95% CI 0.31 degrees C to 0.85 degrees C, P < 0.0001).

CONCLUSIONS

At temperatures within the normal to febrile range, temporal artery temperature is closer to brain temperature than is tympanic membrane temperature.

Estimating the operating point of the cochlear transducer using low-frequency biased distortion products

Distortion products in the cochlear microphonic (CM) and in the ear canal in the form of distortion product otoacoustic emissions (DPOAEs) are generated by nonlinear transduction in the cochlea and are related to the resting position of the organ of Corti (OC). A 4.8 Hz acoustic bias tone was used to displace the OC, while the relative amplitude and phase of distortion products evoked by a single tone [most often 500 Hz, 90 dB SPL (sound pressure level)] or two simultaneously presented tones (most often 4 kHz and 4.8 kHz, 80 dB SPL) were monitored. Electrical responses recorded from the round window, scala tympani and scala media of the basal turn, and acoustic emissions in the ear canal were simultaneously measured and compared during the bias. Bias-induced changes in the distortion products were similar to those predicted from computer models of a saturating transducer with a first-order Boltzmann distribution. Our results suggest that biased DPOAEs can be used to non-invasively estimate the OC displacement, producing a measurement equivalent to the transducer operating point obtained via Boltzmann analysis of the basal turn CM. Low-frequency biased DPOAEs might provide a diagnostic tool to objectively diagnose abnormal displacements of the OC, as might occur with endolymphatic hydrops.

Functional effects of repeated pressure loads upon the tympanic membrane: mechanical stiffness measurements after simulated habitual sniffing

In experimental studies it was found that otitis media causes stiffness loss in the tympanic membrane, possible precursors to retraction pockets and cholesteatoma. Besides otitis media habitual sniffing behaviour is associated with the development of retractions. The present study aims to test the hypothesis that repeated sniffing manoeuvre may cause not only structural, epithelial tympanic membrane changes presumed to be possible precursors to retractions, but also tympanic membrane stiffness loss, another possible mediator for the development of retractions. An experimental model with a pressure chamber was used to mimic the pressure conditions for the tympanic membrane in habitual sniffers' ears. The stiffness properties of twelve Mongolian gerbil tympanic membranes were measured with moiré interferometry after varying time up to 12 days with repeated pressure loading. Three days later, lower overall displacement were obtained in two ears; after 7-12 days the displacement readings were normal. This study with maximum of 12 days of pressure loading did not verify the hypothesis that habitual "sniffing" impairs the stiffness of the tympanic membrane.

Transtympanic electrical stimulation for immediate and long-term tinnitus suppression

Tinnitus is a common symptom which often becomes disabling, affecting the emotional and psychosocial dimensions of life. There are many reports describing tinnitus suppression or attenuation through electrical stimulation of the ear, provided either by cochlear implants or by transtympanic stimulation. Our study project aims to assess the effects of electrical promontory stimulation (EPS) on persistent disabling tinnitus. We enrolled 11 patients affected by postlingual monoaural or binaural profound hearing loss and disabling tinnitus in the worse ear. EPS was performed with direct continuous positive current delivered by an active platinum-iridium needle electrode connected to a promontory stimulator device. The short-term effect on tinnitus was assessed during and immediately after the stimulation. Long-term effects were estimated after one month by comparing pre- and post-EPS Tinnitus Handicap Inventory (THI) scores. Immediately after EPS, five patients (45.4%) reported complete suppression and four (36.4%) reported attenuation of tinnitus. Two patients (18.2%) said it was unchanged. After one month, the THI score was reduced in five patients (45.4%) and remained unchanged in the other six patients (54.6%). The beneficial effects of EPS on tinnitus might be explained by interference with tinnitus generating circuits such as the dorsal cochlear nucleus and the inferior colliculus and by modification of cortical activity. EPS is to be considered a worthwhile attempt at tinnitus suppression, and could help select candidates for the positioning of an implantable electrical stimulator that might provide longer-term beneficial effect on tinnitus.

The value of transcranial cerebral sonography in diagnosing neurootological disorders

Transcranial cerebral sonography (TCCS) is a noninvasive technique that allows the clinician to detect abnormal intracranial-inner-ear fluid interactions in terms of nanoliter tympanic membrane displacements. The displacements recorded in TCCS are evoked either by the acoustic stapedius reflex or spontaneous movements generated by intracranial cardiovascular or by respiratory pressure waves transmitted through the inner ear to the stapes and thence to the tympanic membrane. Analysis of the amplitude and direction of these displacements has enabled neurosurgeons and neurologists to estimate cerebrospinal fluid pressures in patients evaluated by TCCS. This procedure allows for applications in neurootology, particularly in those patients who present with symptoms of pulsating tinnitus, dizziness and imbalance, or hearing loss. This study describes the application of TCCS tests in a series of patients whose diagnoses included perilymphatic fistula and a variety of neurological conditions such as idiopathic intracranial hypertension, type I Arnold-Chiari malformation, sigmoid sinus thrombosis, hydrocephalus, and cerebrovascular malformations. We conclude that both raised intracranial pressure and abnormal intracranial pressure waves are associated with common neurootological symptoms, including tinnitus, dizziness, and hearing dysfunction. Furthermore, TCCS is a valuable addition to neurootologists' test batteries.

Effect of static middle-ear and intracranial pressure changes on differential electrocochleographic response

In an animal model, we examined the extratympanic electrocochleographic response to static pressure changes (middle-ear pressure and intracranial pressure [ICP]) with attention to the summating potential (SP), action potential (AP), and the SP/AP ratio. With a closed middle ear, raised or lowered middle-ear pressure and raised or lowered ICP resulted in congruent increases of the SP and the SP/AP ratio, while the AP remained at a steady voltage. With a closed middle ear, raising or lowering ICP by positioning also had the effect of raising or lowering middle-ear pressure. With an open middle ear, raising or lowering middle-ear pressure resulted in congruent increases of the SP and the SP/AP ratio and, though the AP remained steady, it showed much higher voltage values. With an open middle ear, the baseline SP and baseline SP/AP ratio were reduced, but the reduction of the SP/AP ratio was mainly due to an increased AP. With an open middle ear, the SP, the SP/AP ratio, and the AP did not change appreciably during positioning-induced ICP changes. This suggests that ICP changes by positioning are not very effective in the rat when the middle ear is open. Thus, the effect of ICP changes with the middle ear closed are mainly due to positioning-induced pressure changes in the middle ear. Our findings confirm that static middle-ear pressure is critical for the cochlea and that good eustachian tube function is essential to keeping the pressure gradient across the round-window membrane as small as possible, the latter possibly assisted by a Windkessel function of the round-window membrane. However, relatively small pressure changes in the middle ear can overwhelm it, which suggests a very limited Windkessel function. In Ménière's disease, sensitivity to static pressure changes is possibly exaggerated. The insertion of a middle-ear ventilation tube, as practiced in treating selected cases of Ménière's disease, could restore Windkessel function. It has a stabilizing effect, as the inner ear appears less pressure-sensitive. This effect decreases Ménière's disease symptoms, but it is not without consequences. After the insertion of a middle-ear ventilation tube, a reduced SP/AP ratio is no evidence of improved inner-ear function. Its consequences are enlarged AP voltages, very likely loss of middle-ear dampening, and possible increased ringing.

[Hearing in children with a history of acute otitis media. Use of paracentesis]

The examination of 103 children aged 1 year to 5 years had acute otitis media purulenta. They were treated with paracentesis which had a positive effect on recovery of the acoustic function. It is shown that children with previous acute otitis media should be followed up to control recovery of hearing.

Multifield coupled finite element analysis for sound transmission in otitis media with effusion

In this paper, a newly constructed three-dimensional finite element (FE) model of the human ear based on histological sections of a left ear temporal bone is reported. The otitis media with effusion was simulated in the model with variable fluid levels in the middle ear. The interfaces among the air, structure, and fluid in the ear canal and middle ear cavity were identified and the acoustic-structure-fluid coupled FE analysis was conducted when the middle ear fluid level was varied from zero to full fill of the cavity. The results show how the displacements of the tympanic membrane and stapes footplate or the middle ear transfer function is affected by fluid in the cavity across the auditory frequencies. Comparison of model results with measured data in temporal bones indicates that this model has the capability to extend FE analysis into pathological ears such as otitis media with visualized fluid-air interfaces inside the middle ear structures.

Non-ossicular signal transmission in human middle ears: Experimental assessment of the "acoustic route" with perforated tympanic membranes

Direct acoustic stimulation of the cochlea by the sound-pressure difference between the oval and round windows (called the "acoustic route") has been thought to contribute to hearing in some pathological conditions, along with the normally dominant "ossicular route." To determine the efficacy of this acoustic route and its constituent mechanisms in human ears, sound pressures were measured at three locations in cadaveric temporal bones [with intact and perforated tympanic membranes (TMs)]: (1) in the external ear canal lateral to the TM, P(TM); (2) in the tympanic cavity lateral to the oval window, P(OW); and (3) near the round window, P(RW). Sound transmission via the acoustic route is described by two concatenated processes: (1) coupling of sound pressure from ear canal to middle-ear cavity, H(P(CAV) ) identical withP(CAV)P(TM), where P(CAV) represents the middle-ear cavity pressure, and (2) sound-pressure difference between the windows, H(WPD) identical with(P(OW)-P(RW))P(CAV). Results show that: H(P(CAV) ) depends on perforation size but not perforation location; H(WPD) depends on neither perforation size nor location. The results (1) provide a description of the window pressures based on measurements, (2) refute the common otological view that TM perforation location affects the "relative phase of the pressures at the oval and round windows," and (3) show with an intact ossicular chain that acoustic-route transmission is substantially below ossicular-route transmission except for low frequencies with large perforations. Thus, hearing loss from TM perforations results primarily from reduction in sound coupling via the ossicular route. Some features of the frequency dependence of H(P(CAV) ) and H(WPD) can be interpreted in terms of a structure-based lumped-element acoustic model of the perforation and middle-ear cavities.

Immune modulatory oligonucleotides in the prevention and treatment of OVA-induced eustachian tube dysfunction in rats

BACKGROUND

Otitis media with effusion (OME) is often associated with allergies. Immune modulatory oligonucleotides (IMO) mediate allergic inflammation and may therefore be efficacious in the treatment of airway inflammation.

OBJECTIVE

To evaluate the role of an IMO via transtympanic mucosal application in prevention and treatment of ovalbumin-induced OME.

DESIGN

Forty brown Norway rats were divided into control and treatment groups. Eustachian tube dysfunction was evaluated by passive opening pressures, passive closing pressures, active clearance of negative pressure, and mucociliary clearance transit time.

RESULTS

Rats who underwent IMO treatment required 50% less pressure to open and close the eustachian tube (P < 0.05) and were able to actively clear 50% more negative pressure than the ovalbumin-control rats (P < 0.001). The treatment rats' mucociliary clearance time was half that of the control group (P < 0.001).

CONCLUSION

IMO via transtympanic application can prevent and treat allergy-induced eustachian tube dysfunction in rats. IMO may offer substantial promise in the future management of OME.

Outer- and middle-ear contributions to presbycusis in the Brown Norway rat

This paper examines the contribution of the outer and middle ears to the hearing loss associated with presbycusis in Brown Norway rats. Animals were formed into two groups; young adults (2-3 months old) and aged animals (approximately 34 months old). Auditory brainstem response (ABR) thresholds were obtained with the outer ear intact or surgically removed. Tympanic membrane (TM) velocity transfer functions were measured from the umbo with the outer ear removed. The length of the auditory meatus, TM surface area, and TM thickness were quantified. The ABR thresholds were 17-26 dB less sensitive in the aged animals between 8.0 and 40.0 kHz when the outer ear was intact. A significant and reliable reduction in the aged rat velocity transfer function of 5-8 dB occurred between 10.0 and 32.0 kHz, while the low frequency velocity response was only a few decibels greater in the younger animals. The ABR threshold differences between young adult and aged ears were compensated by removing the outer/middle ear effects of aging to reveal a purely sensorineural component of presbycusis. The outer and middle ear effects were calculated directly when the ABR and TM velocity data were obtained with the outer ear removed. The outer ear intact condition was modeled in order to compare the ABR data obtained with the outer ear intact with the TM velocity data obtained with the outer removed. With either procedure, removal of the age-related contributions of the outer and middle ear to the ABR threshold resulted in similar age-related ABR threshold shifts between the two age groups. The pure sensorineural threshold shift component of the ABR response was restricted to frequencies between 5.0 and 20.0 kHz and reached a maximum of approximately 15 dB. These results support the conclusion that there is an outer- and middle-ear contribution to the threshold loss defining presbycusis.

Pathogenesis of sinus cholesteatoma

The aim of the present study was to provide evidence for the establishment of sinus cholesteatoma, defined as postero-superior pars tensa retraction extending into the posterior tympanum and tympanic sinuses.

BACKGROUND

There is clinical evidence for formation of a retraction, but there is a lack of explanation for the transition from a retraction pocket to an active and expanding sinus cholesteatoma. Epidemiological studies on incidence of postero-superior retractions of pars tensa and follow-up studies on patients with similar pars tensa retractions were performed. Additionally, expression of proliferation marker and analysis of basement membrane were studied in samples of sinus cholesteatoma. The prevalence of pars tensa pathology was between 9.2 and 24% of investigated ears. In children with manifest secretory otitis there were some sinus cholesteatomas and 5-6% severe retractions, some of those became pre-cholesteatomas, requiring treatment and controls. Immunohistochemistry of sinus cholesteatomas showed that proliferating keratinocytes were very often found within epithelial cones growing towards the underlying stroma. These growth cones exhibit focal discontinuities of the basement membrane especially in areas of intense subepithelial inflammation. As a possible explanation based on clinical and immunohistochemical findings, we propose a four-step concept for pathogenesis of sinus cholesteatoma combining the retraction and proliferation theory: (1) The retraction pocket stage. (2) The proliferation stage of the retraction pocket, subdivided in (a) Cone formation, (b) Cone fusion. (3) Expansion stage of attic cholesteatoma. (4) Bone resorption.

The influence of ventilation tube design on the magnitude of stress imposed at the implant/tympanic membrane interface

The design of ventilation tubes or grommets is thought to have a considerable influence on their performance. A computational model (finite element method) was used to investigate the significance of four design parameters of a commonly used design of ventilation tube. The design parameters were: the length of the shaft, the diameter of the flanges, the thickness of the flanges, and the material type. A statistical analysis technique, known as a factorial analysis of variance, was used to examine the importance of the four design parameters on the dynamical behaviour of the middle ear with the implant in situ and on the magnitude of stress induced at the implant/tympanic membrane interface. We predicted that the ventilation tube alters the frequency response of the middle ear; specifically the shaft length and the thickness of the flanges were found to have a significant effect upon the vibratory pattern at the umbo. A reduced length of tube and an increased size of flange were also found to be significant for minimising membrane stress (both with P<0.001). Thus, design parameters of critical influence on optimising performance were identified.

[Audiological assessment in 79 patients with tympanosclerosis]

OBJECTIVE

To conduct audiological assessment in patients with tympanosclerosis.

METHODS

A retrospective review was conducted in 79 patients with tympanosclerosis (involving 79 ears) with complete records, including 30 patients (30 ears) with fixed Malleus-incus complex, 29 (29 ears) with fixed stapes, and 20 (20 ears) with fixations of both the stapes footplate and the Malleus-incus complex. Audiometry was performed for all the patients one or two days before operation, and the audiological features of the patients were compared between the 3 groups.

RESULTS

Most of the patients (65.8%) suffered conductive hearing loss, 32.9% had mixed deafness, and one patient had sensorineural hearing loss. No statistically significant differences was noted in the speech frequency (0.5, 1, and 2 kHz) air conduction pure tone average (PTA) or the air-bone gap (ABG) in the 3 groups (P<0.05).

CONCLUSION

Most of the patients with tympanosclerosis suffer conductive hearing loss, and the severity of hearing loss is not associated with the site of tympanosclerosis.

Middle ear atelectasis: what causes it and how is it corrected?

Many options are available to manage a patient who has atelectatic ears. Establishing normal middle ear ventilation and aeration is the cornerstone to successful control of these ears. Often, medical management with nasal steroids and decongestants is all that is needed. If recurrent infections have weakened the tympanic membrane progressively, or the middle ear environment is so severe that medical management does not correct the problem, then surgical correction is often necessary. This article explores the pathogenesis of middle ear atelectasis and explains a classification system to help the clinician determine the best course of management.

Acoustic shock injury (ASI)

CONCLUSION

The potential severity and persistence of ASI symptoms has significant clinical and medico-legal implications. With the rapid growth of call centres around the world, professionals providing tinnitus and hyperacusis therapy are increasingly likely to encounter some or all of the cluster of ASI symptoms in their clients.

BACKGROUND

Acoustic shock injury (ASI), occurring as a result of exposure to a sudden unexpected loud sound, has been observed to cause a specific and consistent pattern of neurophysiological and psychological symptoms. These include aural pain, tinnitus, hyperacusis/phonophobia, vertigo and other unusual symptoms such as numbness or burning sensations around the ear. A range of emotional reactions including trauma, anxiety and depression can develop. Call centre staff using a telephone headset or handset are vulnerable to ASI because of the increased likelihood of exposure, close to their ear(s), of sudden unexpected loud sounds randomly transmitted via the telephone line.

DISCUSSION

This paper presents an overview of a study of 103 people exposed to 123 acoustic incidents, and of the proposed neurophysiological mechanism of ASI, in particular tonic tensor tympani syndrome (TTTS). An understanding of TTTS has the potential to provide insight into the neurophysiological and psychological development of tinnitus and hyperacusis and the association with high levels of emotional trauma and anxiety.

REHABILITATION

ASI rehabilitation is discussed.

Correlations between rapid maxillary expansion (RME) and the auditory apparatus

OBJECTIVE

To evaluate the effects of rapid maxillary expansion (RME) on conductive hearing loss and maxillary constriction.

MATERIALS AND METHODS

A total of 25 subjects (15 girls and 10 boys, aged between 6 years 8 months to 8 years 2 months) with conductive hearing loss and maxillary constriction were studied. Audiogram, tympanogram, and video-otoscopy were used to investigate the anatomical and physiological modifications of the bony and muscular structure of the maxilla and the auditory apparatus. The records were taken before maxillary expansion (T0), after expansion (7-14 days; T1), and after the retention period (8 months after expansion; T2).

RESULTS

After expansion, the audiometric records indicated an improvement in hearing levels for higher frequencies but not for lower ones. After the retention period, there was a functional improvement in all patients for all frequencies. The recovery of the tympanic membrane's elasticity occurred only after retention, as shown by the standard model tympanogram, which was still flat after expansion.

CONCLUSIONS

The auditory function in patients with conductive hearing loss may be corrected through correction of the palatal anatomy, which influences the muscular function of the tubal ostia and allows a normal activity of the tympanic membrane and the auditory apparatus. Positive effects on conductive hearing loss are possible additional benefits of RME treatment, but this does not indicate that patients with conductive hearing loss without an accompanying maxillary constriction should consider this as a treatment approach.