Three-dimensional finite element analysis of Eustachian tube function under normal and pathological conditions

Central Auditory Processing Abilities in Children with Non-Syndromic Cleft Lip and Palate: An Electrophysiological Study

BACKGROUND

The present study compared the central auditory processing abilities using electrophysiological tests in children with non-syndromic cleft lip and palate (NSCLP) and their age-matched control group.

METHOD

Thirty children aged 7 to 15 years were recruited for the study. Participants were divided into 2 groups. The clinical group (children with NSCLP) comprised 15 children, while the control group (craniofacially typical peers) comprised 15 children with normal hearing sensitivity and auditory processing skills. Electrophysiological tests, including auditory brainstem responses (ABR), binaural interaction component (BIC) of ABR, auditory late latency responses (ALLR), and P300 were assessed.

RESULTS

The results showed deviant responses in ABR, BIC, and ALLR in children with NSCLP compared to craniofacially typical counterparts. However, no significant difference was observed in P300 between the two groups.

CONCLUSION

Children with NSCLP may be at a higher risk of central auditory processing disorder due to their abnormal neural transmission in the auditory nervous system. Also, assessing auditory processing abilities in children with NSCLP should include electrophysiological tests in the test battery for additional information regarding neural transmission.

Eustachian Tube Balloon Dilation in Children: Short- and Long-Term Outcome

OBJECTIVE

Eustachian Tube Balloon Dilation (ETBD) represents an innovative therapeutic approach for chronic Eustachian tube dysfunction (CETD), a common disease in children. Some evidence of a benefit of ETBD in the adults exist in contrast to sparse reports in children. The objective was to analyze short- and long-term outcome of ETBD in children with CETD.

METHODS

A retrospective chart-review was performed in a cohort of 19 children (mean age 13 years, 7-17) who underwent ETBD. The following parameters were analyzed: tubomanometry (R-value), tympanogram, hearing (CPT-AMA, Air-bone gap [ABG]), Eustachian Tube Score (ETS and ETS-7), and Eustachian Tube Disease questionnaire (ETDQ).

RESULTS

Twenty-four ears were dilated (in 5 patients subsequently after successful first intervention) and grouped as A (17) without and B (7) with additional T-tube insertion. Most children suffered from either chronic otitis media with effusion or chronic perforation (12, 63%), the remainder comprising recurrent otitis media, adhesive otitis media and CETD with barotrauma. Mean duration of symptoms were 7/8.2 years and mean follow-up 13.7/11.1 months. Eighty percent of patients reported a subjective benefit. Accordingly, the R-value, ETS, and ETS-7 were significantly (P < .05) improved. Tympanometry, CPT-AMA and ABG showed a positive trend, but the result was not significant. Tympanic retraction remained largely the same; a spontaneous closure of a chronic tympanic perforation was seen in 1 of 3 cases.

CONCLUSIONS

The high subjective benefit and some significant objective improvement warrants further analysis of ETBD as part of the therapeutic management in pediatric CETD.

Impact of palatoplasty techniques on tympanic membrane findings and hearing prognosis in children with cleft palate

OBJECTIVE

Children with cleft palate (CP) are at high risk of developing otitis media with effusion (OME) due to Eustachian tube (ET) dysfunction. Palatoplasty has been reported to decrease the frequency of middle ear disease and improve ET function, and although various techniques have been developed, there is no consensus on the differences in the impact of different techniques on the middle ear. The purpose of this study was to determine the differential effects of palatoplasty on middle ear function and hearing.

METHODS

We performed a retrospective observational survey of pediatric patients who underwent palatoplasty for CP between June 2010 and October 2018 at Tohoku University Hospital. Cases were divided into three groups depending on the palatoplasty procedures performed: the push-back palatoplasty group, the two-flap palatoplasty group, and the Furlow double-opposing Z-plasty group. We examined the differences in clinical characteristics between patients who underwent each procedure. The primary outcome variable was tympanic membrane (TM) findings, and the secondary outcome was hearing test results.

RESULTS

Children who underwent the two-flap palatoplasty had a higher tympanostomy tube (TT) insertion rate and a higher total number of TT insertions than those who underwent the Furlow double-opposing Z-plasty or the push-back palatoplasty. The TM retraction rate tended to be lower in the Furlow double-opposing Z-plasty group than in the push-back palatoplasty group or the two-flap palatoplasty group. The hearing test results at the last visit were not significantly different among the three groups.

CONCLUSIONS

Children who underwent the two-flap palatoplasty had a higher rate of TT insertions, potentially increasing the risk of TM perforation. In contrast, the Furlow double-opposing Z-plasty group had a lower tendency for TM regression, possibly due to improved ET function and reduced incidence of OME. It is important to understand the advantages and disadvantages of each technique before selecting one suitable for the child's cleft and arch width. Additionally, it is important to conduct regular follow-up of TM findings and hearing test results even after palatoplasty.

Effects of RME on Hearing in UCLP Patients: A Pilot Study

OBJECTIVE

To assess the changes in hearing after rapid maxillary expansion (RME) and at the end of 6 months retention period in complete unilateral cleft lip and palate (UCLP) patients using pure tone audiometry and tympanometry test.

DESIGN

Prospective pilot study.

SETTING

Tertiary health care teaching hospital in New Delhi.

PATIENTS

This study was conducted on 6 UCLP patients in the age range of 6-14 years with normal ear anatomy. All 6 patients had undergone primary repair of cleft lip and palate and required no more than 5 mm expansion in the intermolar region.

INTERVENTION

RME was done using a Hyrax expander with daily activation of one-quarter turn per day for a period of 15-20 days (0.25 mm per day).

MAIN OUTCOME MEASURE

Audiometry and tympanometry readings at the baseline as compared to the post expansion and at the end of 6 months retention period.

RESULTS

There were no significant changes in the hearing levels on the audiometry test after RME on the cleft side (p-value -0.51) and the noncleft side ear (p-value -0.26). No significant changes were observed in the middle ear volume on the tympanometry test after RME on the cleft side (p-value -0.09) and the noncleft side ear (p-value -0.28).

CONCLUSION

There was no improvement or deterioration in the hearing levels after RME and at the end of 6 months retention period in UCLP patients as evaluated using pure tone audiometry and tympanometry test. Hence RME may be undertaken in UCLP patients safely in terms of hearing is concerned.

CT Imaging of Eustachian Tube Balloon Dilation: Method Development on Cadaver Heads

Objective: To develop a methodology for the measurement of balloon dilation (BD) effects on Eustachian Tube (ET) structure using Computerized Tomography (CT) images. Methods: The BD of the ET was performed on three cadaver heads (five ears) through the nasopharyngeal orifice. The axial CT images of the temporal bones were obtained before dilation, while an inflated balloon was in the lumen of ET, and after balloon removal in each ear. Utilizing Dicom images captured by the ImageJ software 3D volume viewer function, the anatomical landmark coordinates of the ET were matched with their pre- and post-dilation counterparts, and the longitudinal axis of the ET was captured with serial images. The histograms of the regions of interest (ROI) and three different lumen width and length measurements were obtained from captured images. The densities of air, tissue, and bone were determined with histograms as a baseline to determine the BD rate as a function of increased air in the lumen. Results: The small ROI box included the area of prominently dilated ET lumen after BD and best represented the visually obvious changes in the lumen, compared to the ROIs that extended the wider areas (longest and longer). Air density was the outcome measure for comparison with each corresponding baseline value. The average increase in air density in the small ROI was 64%, while the longest and long ROI boxes showed 44 and 56% increases, respectively. Conclusion: This study describes a method to image the ET and quantify the outcomes of BD of the ET using anatomical landmarks.

Tubomanometry in measurement of velopharyngeal closure: A pilot study

Objective

To investigate the differences in velum closure pattern in people with and without a history of middle ear disease using intranasal pressure curves recorded with the tubomanometer, a Eustachian tube (ET) testing device.

Study Design

Case control study.

Setting

Tertiary referral center.

Subjects and Methods

Tubomanometry nasopharyngeal pressure curves from 20 controls (Group 1) and 20 people with history of otitis media (OM) and possible ongoing ET dysfunction (ETD) (Group 2 or OM/ETD group) were compared. The variables included in the analysis were: (a) ratio of signal amplitude relative to the delivered nasal pressure (C2/delivered pressure x 10); (b) time (s) to achieve maximal signal amplitude (C2-C1); (c) duration of velum closure (s) and (d) plateau decay during the isometric contraction of the velum (C3-C2) and (e) swallow duration (s) (C4-C1). Statistical analysis was conducted using mixed models for the normalized values of individual characteristics.

Results

Age, race and sex distribution in each group was as follows: 24 ± 8 years, 15 whites and 12 females in Group 1; 20 ± 10 years, 19 whites and 15 females in Group 2. Group 2 demonstrated a greater velopharyngeal pressure decay (p = .13), longer swallow duration (p = .10), and longer duration of velum closure (p = .14).

Conclusion

This is the first study using tubomanometry to investigate differences in velopharyngeal closure between controls and individuals with OM/ETD. Although not statistically significant, our results showed that those with OM/ETD demonstrated a longer swallow and velum closure duration, and a higher degree of leakage during velum contraction compared to controls.

The Impact of Lateral Relaxing Incision on Middle Ear Function in Cleft Palate Repair

Children with cleft palate are susceptible to otitis media with effusion. This study aimed to investigate the effect of lateral relaxing incision (RI) on middle ear function in cleft palate patients who underwent palatoplasty using double-opposing Z-plasty (DOZ). This is a retrospective study of patients who underwent bilateral ventilation tube insertion concurrently with DOZ, wherein RI was selectively performed on the right side of the palate (Rt-RI group) or not (No-RI group). The frequency of VTI, duration of the first ventilation tube retention, and hearing outcomes at the last follow-up were reviewed. Outcomes were compared using the χ2 test and t test. A total of 126 treated ears from 63 non-syndromic children (18 male, 45 female) with cleft palate were reviewed. The mean age at surgery was 15.8±6.17 months. There were no significant differences in the frequency of ventilation tube insertion between the right and left ears within the Rt-RI group or between the Rt-RI and no-RI groups in the right ear. Subgroup analysis for ventilation tube retention time, auditory brainstem response thresholds, and air-conduction pure tone averages showed no significant differences. In the DOZ, the use of RI had no significant effects on middle ear outcomes during 3 years of follow-up. Relaxing incision seems to be safe without concern for middle ear function in children with cleft palate.

Cadaveric Study and Micro-Computed Tomography of the Anatomy of Palatine Aponeurosis and its Link to the Soft Palate Muscles and Pharyngeal Muscles

OBJECTIVE

There have been few studies on the anatomy of palatine aponeurosis (PA). Herein, we elucidated the relationship between the PA and soft palate muscles and pharyngeal muscles.

DESIGN

Two cadaveric specimens were dissected to observe the gross anatomy of the PA. Six cadaveric specimens were processed and scanned by micro-computed tomography to determine the elaborate anatomy. Images were exported to Mimics software to reconstruct a three-dimensional model.

RESULTS

The PA covered the anterior (32.1%-38.8%) of the soft palate, extending from the tensor veli palatini (TVP) and connecting to 3 muscles: palatopharyngeus (PP), uvula muscle, and superior pharyngeal constrictor (SC). The SC and PP are attached to the PA on the medial side of the pterygoid hamulus. SC muscle fibers were attached to the hamulus, forming a distinct gap between the hamulus. Some muscle fibers of the PP and uvula originated from the PA. The PA extended from the TVP to the midline and the posterior edge of the hard palate. The PA was not uniformly distributed, which was complementary to the attached muscles in thickness.

CONCLUSIONS

PA, as a flexible fibrous membrane, maintains the shape of the soft palate. It extends from the TVP and covers anteriorly about one-third of the soft palate. The PA provides a platform for the soft palate muscles and pharyngeal muscles, connecting to the PP, uvula muscle, and SC. These muscles are important for palatopharyngeal closure and middle-ear function. It is necessary to minimize the damage to the PA during surgical interventions.

Micro-Computed Tomography-Based Three-Dimensional Anatomical Structure of the Region Around the Pterygoid Hamulus

OBJECTIVE

Palatoplasty would involve the structures around the pterygoid hamulus. However, clinicians hold different opinions on the optimal approach for the muscles and palatine aponeurosis around the pterygoid hamulus. The absence of a consensus regarding this point can be attributed to the lack of investigations on the exact anatomy of this region. Therefore, we used micro-computed tomography to examine the anatomical structure of the region surrounding the pterygoid hamulus.

DESIGN

Cadaveric specimens were stained with iodine-potassium iodide and scanned by micro-computed tomography to study the structures of the tissues, particularly the muscle fibers. We imported Digital Imaging and Communications in Medicine images to Mimics to reconstruct a 3-dimensional model and simplified the model.

RESULTS

Three muscles were present around the pterygoid hamulus, namely the palatopharyngeus (PP), superior constrictor (SC), and tensor veli palatini (TVP). The hamulus connects these muscles as a key pivot. The TVP extended to the palatine aponeurosis, which bypassed the pterygoid hamulus, and linked the PP and SC. Some muscle fibers of the SC originated from the hamulus, the aponeurosis of which was wrapped around the hamulus. There was a distinct gap between the pterygoid hamulus and the palatine aponeurosis. This formed a pulley-like structure around the pterygoid hamulus.

CONCLUSIONS

Transection or fracture of the palatine aponeurosis or pterygoid hamulus, respectively, may have detrimental effects on the muscles around the pterygoid hamulus, which play essential roles in the velopharyngeal function and middle ear ventilation. Currently, cleft palate repair has limited treatment options with proven successful outcomes.

Functional aspects of the Eustachian tube by means of 3D-modeling

The extent of dysfunction of the Eustachian tube (ET) is relevant in understanding the pathogenesis of secondary otological diseases such as acute or chronic otitis media. The underlying mechanism of ET dysfunction remains poorly understood except for an apparent genesis such as a nasopharyngeal tumor or cleft palate. To better describe the ET, its functional anatomy, and the biomechanical valve mechanism and subsequent development of diagnostic and interventional tools, a three-dimensional model based on thin-layer histology was created from an ET in this study. Blackface sheep was chosen as a donor. The 3-D model was generated by the coherent alignment of the sections. It was then compared with the cone-beam computed tomography dataset of the complete embedded specimen taken before slicing. The model shows the topographic relation of the individual components, such as the bone and cartilage, the muscles and connective tissue, as well as the lining epithelium with the lumen. It indicates a limited spiraling rotation of the cartilaginous tube over its length and relevant positional relationships of the tensor and levator veli palatine muscles.

[Auditory processing in children and adolescents with cleft palate]

BACKGROUND

Patients with cleft palate often suffer from recurrent otitis media chronica with effusion during infancy. The consecutive binaural conductive hearing loss is seen as a risk factor for developing auditory processing disease. Since there are just a few studies examining auditory processing in this population this study aimed to investigate on an own patient cohort with different cleft manifestations in terms of auditory processing disorders in context to given studies.

MATERIAL AND METHODS

This study included 48 patients (5-16 years): all patients had a non-syndromic cleft palate and normal peripheral hearing at the time of examination. The protocol included otoscopy, pure tone audiogram, speech intelligibility in noise, dichotic speech discrimination, auditory short-term memory and a parental questionnaire.

RESULTS

The majority of the parents did not indicate problems in the parental questionnaire. 69 % of the participants showed conspicuous results in the speech intelligibility in noise, whereas the dichotic speech discrimination and the auditory short-term memory were suspicious in 16.7 % only. The results in both tests proved mainly a problem in younger children. Noticeable results in speech intelligibility in noise were found in all age groups.

CONCLUSION

Children and adolescents with cleft palate are at risk to develop auditory processing disorders. In this study population speech intelligibility in noise was the most common problem. 90 % of the children had received a speech therapy which could have already compensated problems concerning dichotic speech discrimination and the auditory short-term memory but not problems in speech intelligibility in noise.

The mechanism of balloon Eustachian tuboplasty: a biomechanical study

Obstructive Eustachian tube dysfunction (OETD) is a common condition resulting from inadequate opening of the Eustachian tube (ET). A new surgical treatment involves high-pressure inflation of a balloon within the ET, with the aim of dilating the soft tissue structure. However, the mechanical effects of this intervention have not been established, nor the impact of changing device size or other technical parameters. A novel experimental technique allowed quantification of plastic and elastic tissue deformation in model materials and then human cadaver ETs during balloon dilation, based on the measured balloon inflation pressure-volume relationship. Plastic tissue deformation was found to be greater using larger balloons and deeper device insertion, but increasing the inflation pressure had a more limited effect, with most deformation occurring well below the clinically used pressures. Histological assessment of ET tissue suggested that mucosal tearing and cartilage cracking were in part responsible for the mechanical changes. Balloon dilation of the ET has huge potential if found to be clinically effective, but currently there is a need to understand and develop the technique further. The novel methods employed in this study will be valuable in future laboratory and in vivo studies of ET balloon dilation. Pressures are reported in Bar as this unit is used for medical balloon dilation procedures in clinical practice. 1 Bar = 100,000 Pa.

Graphical abstract caption

Effects of maxillary expansion on hearing and voice function in non-cleft lip palate and cleft lip palate patients with transverse maxillary deficiency: a multicentric randomized controlled trial

INTRODUCTION

The association between the treatment of transverse maxillary deficiency and the recovery of hearing and voice functions has gained attention in recent years.

OBJECTIVE

This prospective controlled trial aimed to evaluate the effects of rapid maxillary expansion on hearing and voice function in children with non-cleft lip palate and bilateral cleft lip palate with transverse maxillary deficiency METHODS: 53 patients (26 non-cleft and 27 bilateral cleft lip palate; mean age, 11.1±1.8 years) requiring rapid maxillary expansion for correction of narrow maxillary arches were recruited for this trial. Eight sub-groups were established based on the degree of hearing loss. Pure-tone audiometric and tympanometric records were taken for each subject at four different time periods. The first records were taken before rapid maxillary expansion (T0), the second after expansion (T1) (mean, 0.8 months), the third after three months (T2) (mean, 3 months) and the fourth at the end of retention period (T3) (mean, 6 months). ANOVA and Tukey HSD post-hoc tests were used for data analysis. Additionally, voice analysis was done using an updated PRAAT software program in a computerized speech lab at T0 and T2. A paired-samplet-test was used for comparisons of mean values of T0 and T2 voice parameters within both groups.

RESULTS

Rapid maxillary expansion treatment produced a significant increase in the hearing levels and middle ear volumes of all non-cleft and bilateral cleft lip palate patients with normal hearing levels and with mild conductive hearing loss, during the T0-T1, T1-T2, T0-T2, and T0-T3 observation periods (p<0.05). The significant increase was observed in right middle ear volumes during the T0-T1, T0-T2 and T0-T3 periods in non-cleft patients with moderate hearing loss. For voice analysis, significant differences were observed only between the T0 and T2 mean fundamental frequency (F0) and jitter percentage (p<0.05) in the non-cleft group. In the cleft group, no significant differences were observed for any voice parameter between the T0 and T2 periods.

CONCLUSION

Correction of the palatal anatomy by rapid maxillary expansion therapy has a beneficial effect on both improvements in hearing and normal function of the middle ear in both non-cleft and bilateral cleft lip palate patients. Similarly, rapid maxillary expansion significantly influences voice quality in non-cleft patients, with no significant effect in BCLP patients.

Multi-scale modeling of an upper respiratory airway: Effect of mucosal adhesion on Eustachian tube function in young children

BACKGROUND

The Eustachian tube is a collapsible upper respiratory airway that is periodically opened to maintain a healthy middle ear. Young children, <10 years old, exhibit reduced Eustachian tube opening efficiency and are at risk for developing middle ear infections. Although these infections increase mucosal adhesion, it is not known how adhesion forces alters the biomechanics of Eustachian tube opening in young children. This study uses computational techniques to investigate how increased mucosal adhesion alters Eustachian tube function in young children.

METHODS

Multi-scale finite element models were used to simulate the muscle-assisted opening of the Eustachian tube in healthy adults and young children. Airflow during opening was quantified as a function of adhesion strength, muscle forces and tissue mechanics.

FINDINGS

Although Eustachian tube function was sensitive to increased mucosal adhesion in both adults and children, young children developed Eustachian tube dysfunction at significantly lower values of mucosal adhesion. Specifically, the critical adhesion value was 2 orders of magnitude lower in young children as compared to healthy adults. Although increased adhesion did not alter the sensitivity of Eustachian tube function to tensor and levator veli palatini muscles forces, increased adhesion in young children did reduced the sensitivity of Eustachian tube function to changes in cartilage and mucosal tissue stiffness.

INTERPRETATIONS

These results indicate that increased mucosal adhesion can significantly alter the biomechanical mechanisms of Eustachian tube function in young children and that clinical assessment of adhesion levels may be important in therapy selection.

Balloon dilation of the Eustachian tube: clinical experience in the management of 126 children

Balloon dilation of the Eustachian tube has been recently introduced as a novel and minimally invasive method for treating chronic obstructive Eustachian tube dysfunction. For the first time worldwide, we assessed the role of this technique in the treatment of children with Eustachian tube dysfunction who did not respond to other treatments. We retrospectively analysed the medical records of 60 children (mean age: 6.3 years, range: 28 months to 12 years) who underwent balloon dilation of the Eustachian tube using the Bielefeld balloon catheter. In addition, the parents of a further 66 children who underwent balloon dilation (mean age: 8 years, range: 4 to 13 years) were asked to complete a standardised written questionnaire and were interviewed by telephone about the postoperative course of their children. There were no complications during surgery. Clinical symptoms improved in more than 80% of patients. No patient reported a deterioration of symptoms. Of the participating parents, 81.3% were very satisfied or satisfied with the outcome of treatment. Balloon dilation is a rapid, simple and safe method for the treatment of both adults and children with Eustachian tube dysfunction that does not respond to other treatments. Further studies, ideally multicentre studies, are required in order to optimise the definition of existing and potential new indications for this treatment approach and to establish this treatment in the management of children with refractory chronic Eustachian tube dysfunction.

Panel 2: Anatomy (Eustachian Tube, Middle Ear, and Mastoid-Anatomy, Physiology, Pathophysiology, and Pathogenesis)

Objective In this report, we review the recent literature (ie, past 4 years) to identify advances in our understanding of the middle ear-mastoid-eustachian tube system. We use this review to determine whether the short-term goals elaborated in the last report were achieved, and we propose updated goals to guide future otitis media research. Data Sources PubMed, Web of Science, Medline. Review Methods The panel topic was subdivided, and each contributor performed a literature search within the given time frame. The keywords searched included middle ear, eustachian tube, and mastoid for their intersection with anatomy, physiology, pathophysiology, and pathology. Preliminary reports from each panel member were consolidated and discussed when the panel met on June 11, 2015. At that meeting, the progress was evaluated and new short-term goals proposed. Conclusions Progress was made on 13 of the 20 short-term goals proposed in 2011. Significant advances were made in the characterization of middle ear gas exchange pathways, modeling eustachian tube function, and preliminary testing of treatments for eustachian tube dysfunction. Implications for Practice In the future, imaging technologies should be developed to noninvasively assess middle ear/eustachian tube structure and physiology with respect to their role in otitis media pathogenesis. The new data derived from these structure/function experiments should be integrated into computational models that can then be used to develop specific hypotheses concerning otitis media pathogenesis and persistence. Finally, rigorous studies on medical or surgical treatments for eustachian tube dysfunction should be undertaken.

Fatigue analysis of tympanic membrane after ossiculoplasty

CONCLUSION

A tentative conclusion was made that the finite element method can be used to investigate the fatigue life of the tympanic membrane after ossiculoplasty; the main reason of the extrusion of the tympanic membrane may not be blamed to the fatigue mechanism under normal sound pressure.

OBJECTIVE

This study was to investigate the extrusion of the prosthesis from the tympanic membrane at post-ossiculoplasty by finite element method.

METHODS

A finite element model of the human middle ear has been constructed and used as the model of the constructed middle ear at post-ossiculoplasty. Then the fatigue life of the tympanic membrane was calculated under different sound pressure level using this model.

RESULTS

The tympanic membrane would not be extruded under normal sound pressure level. The sound pressure level which caused the tympanic membrane to crack in less than 3 years was higher than 145.17 dB (362.5 Pa).

Tubotympanic system functioning

The Eustachian (auditory) tube and tympanomastoid cavities form an anatomic and functional whole that cannot easily be divided, and is therefore known as the "tubotympanic system". The system has been the focus of several studies, with complex and sometimes contradictory results, making an overview of its functioning difficult to obtain. The objective of the present article is to review the current state of knowledge, as an indispensable preliminary to understanding tubotympanic system dysfunction, and notably the development of chronic otitis. The system as a whole is covered by mucosa, which provides continuity, although with certain particularities from one area to another, and plays a primordial role. Thus, under physiological conditions, gas diffusion across the tympanomastoid mucosa largely ensures the equilibrium of pressure between the middle ear and outside environment, the tube orifice being very little involved. Under large rapid change in atmospheric pressure, the aeration function of the Eustachian tube comes into play, governed by a reflex mechanism. The system also has other functions that are essential to good middle-ear functioning: protection against nasopharyngeal secretions and pathogens and against certain physiological noises; middle-ear cavity clearance by mucociliary transport of pathogens, partly related to submucosal gland secretion; and immune defense.

Impact of pharyngofixation in cleft palate repair surgery on the development of chronic adhesive otitis media

BACKGROUND

A significant percentage of children with cleft palate suffer from otitis media with effusion and its consequences, such as deafness, chronic adhesive otitis and cholesteatoma. This study aimed to determine whether these effects can be minimised by selecting pharyngofixation as the surgical technique for cleft palate correction.

METHODS

A retrospective study was performed of 155 patients (308 ears) who underwent surgery from age 5 months to 8 years and were followed up for 36-84 months.

RESULTS

In all, 125 ears (41 per cent) had epitympanic retraction, 45 ears (14 per cent) had sinus tympani retraction and 5 patients (3 per cent) had cholesteatoma. Use of the pharyngofixation technique did not significantly correlate with (1) the severity of otological findings or (2) the incidence of retraction pockets in the epitympanum and sinus tympani (p = 0.53).

CONCLUSION

Pharyngofixation did not significantly alter the severity of long-term otological findings.

Hearing sensitivity in adults with a unilateral cleft lip and palate after two-stage palatoplasty

OBJECTIVE

To evaluate long-term hearing and middle ear status in patients treated for a unilateral complete cleft lip and palate (UCLP) by two-stage palatoplasty.

METHODS

Forty-nine UCLP patients aged 17 years and older were included in this retrospective study. Patients were invited for a multidisciplinary long-term follow-up of their treatment at a tertiary center for craniofacial surgery in the Netherlands. ENT assessment included tympanometry and pure-tone audiometry. Medical files were searched for medical and surgical history.

RESULTS

In total, 19.4% of the patients had significant long-term hearing loss (PTA > 20 dB), comprising conductive hearing loss in 21.5% of the patients. In the majority (70%), this hearing loss was more pronounced at higher frequencies. In 25% the high fletcher index showed hearing thresholds above 20 dB. Ventilation tubes were placed at least once in 78.7% of the patients. The frequency of tube insertion was positively correlated with the incidence of reduced tympanic compliance (tympanogram type B) and the need for a pharyngoplasty.

CONCLUSION

The present study reports long-term hearing outcomes in UCLP patients with hard palate closure at 3 years of age. Persistent hearing loss was observed in 19.4% of our patients (PTA > 20 dB), mainly at the higher frequencies. Ventilation tube placement was associated with reduced tympanic compliance and higher risk on hearing loss (PTA air conduction). Our high incidence of velopharyngeal incompetence during early childhood, which is likely associated with Eustachian tube dysfunction, might have contributed to these results.

Quantitative representation of Eustachian tube component movements during swallowing

OBJECTIVE

Describes a method of dynamic video-endoscopy of the Eustachian tube (ET) orifice at the nasopharynx to quantitatively represent ET component movements during swallowing using a graphic function and analyze their importance to its opening mechanics.

METHODS

This was a pilot study of relational event capture using a polar coordinate system applied to trans-nasal video-endoscopic recordings of the ET during 3 swallows in 5 adults. After topical anesthesia of the nose, a 45° telescope was introduced unilaterally and focused on the ipsilateral ET orifice. For each recording, consecutive still-frame images were analyzed by identifying 4 fixed-point locators; the luminal apex, lateral and medial walls and the torus. A frame-normal, horizontal line was constructed through the apex and, then, the medial angles defined at the intersection of the horizontal line and the lines from apex to each point locator were measured. The magnitudes of these angles were plotted as a function of time (i.e. successive frames) for each swallow.

RESULTS

The resulting graphs captured the "in plane" relational movements for the locator points during a swallow. Complex interactions among the ET components were resolvable and the patterns were reproducible across swallows. Individual peculiarities observable on review of the corresponding "movies" such as double-swallows, delayed swallows and ET luminal constriction were easily identified in the graphic representation.

CONCLUSION

This methodology is potentially useful for summary presentations of the ET mechanics of individual patients and for quantifying differences in those mechanics between groups defined by their history of middle-ear disease.

Multi-scale finite element modeling of Eustachian tube function: influence of mucosal adhesion

The inability to open the collapsible Eustachian tube (ET) leads to the development of chronic Otitis Media (OM). Although mucosal inflammation during OM leads to increased mucin gene expression and elevated adhesion forces within the ET lumen, it is not known how changes in mucosal adhesion alter the biomechanical mechanisms of ET function. In this study, we developed a novel multi-scale finite element model of ET function in adults that utilizes adhesion spring elements to simulate changes in mucosal adhesion. Models were created for six adult subjects, and dynamic patterns in muscle contraction were used to simulate the wave-like opening of the ET that occurs during swallowing. Results indicate that ET opening is highly sensitive to the level of mucosal adhesion and that exceeding a critical value of adhesion leads to rapid ET dysfunction. Parameter variation studies and sensitivity analysis indicate that increased mucosal adhesion alters the relative importance of several tissue biomechanical properties. For example, increases in mucosal adhesion reduced the sensitivity of ET function to tensor veli palatini muscle forces but did not alter the insensitivity of ET function to levator veli palatini muscle forces. Interestingly, although changes in cartilage stiffness did not significantly influence ET opening under low adhesion conditions, ET opening was highly sensitive to changes in cartilage stiffness under high adhesion conditions. Therefore, our multi-scale computational models indicate that changes in mucosal adhesion as would occur during inflammatory OM alter the biomechanical mechanisms of ET function. Copyright © 2016 John Wiley & Sons, Ltd.

Electrophysiological assessment of auditory processing disorder in children with non-syndromic cleft lip and/or palate

Objectives

Cleft lip and/or palate is a common congenital craniofacial malformation found worldwide. A frequently associated disorder is conductive hearing loss, and this disorder has been thoroughly investigated in children with non-syndromic cleft lip and/or palate (NSCL/P). However, analysis of auditory processing function is rarely reported for this population, although this issue should not be ignored since abnormal auditory cortical structures have been found in populations with cleft disorders. The present study utilized electrophysiological tests to assess the auditory status of a large group of children with NSCL/P, and investigated whether this group had less robust central auditory processing abilities compared to craniofacially normal children.

Methods

146 children with NSCL/P who had normal peripheral hearing thresholds, and 60 craniofacially normal children aged from 6 to 15 years, were recruited. Electrophysiological tests, including auditory brainstem response (ABR), P1-N1-P2 complex, and P300 component recording, were conducted.

Results

ABR and N1 wave latencies were significantly prolonged in children with NSCL/P. An atypical developmental trend was found for long latency potentials in children with cleft compared to control group children. Children with unilateral cleft lip and palate showed a greater level of abnormal results compared with other cleft subgroups, whereas the cleft lip subgroup had the most robust responses for all tests.

Conclusion

Children with NSCL/P may have slower than normal neural transmission times between the peripheral auditory nerve and brainstem. Possible delayed development of myelination and synaptogenesis may also influence auditory processing function in this population. Present research outcomes were consistent with previous, smaller sample size, electrophysiological studies on infants and children with cleft lip/palate disorders. In view of the these findings, and reports of educational disadvantage associated with cleft disorders, further research that focuses on the auditory processing abilities of children with cleft lip/palate disorder is warranted.

The evaluation of eustachian tube paratubal structures using magnetic resonance imaging in patients with chronic suppurative otitis media

Conclusion Eustachian tube (ET) dysfunction, which plays a role in the pathogenesis chronic suppurative otitis media (CSOM), does not seem to be due to differences in paratubal structures. Objective The aim of this study was to compare the magnetic resonance imaging (MRI) findings of the paratubal structures of the ET between normal ears and ears in patients with CSOM. Methods The MRI records of 40 patients who underwent tympanomastoidectomy for a diagnosis of CSOM were reviewed retrospectively. The healthy ears served as the control group. The length, diameter, surface area and volume of the tensor veli palatini muscle (TVPM) and levator veli palatini muscle (LVPM) were measured, in addition to the diameter of the pharyngeal orifice of the ET, volume of the Ostmann fat pad, bimucosal thickness of the lumen of the ET, and mucosal thickness. Results In the pathological ears, the mean length of the TVPM and LVPM was 22.6 mm and 19.3 mm, the mean diameter was 3.2 and 5.3 mm, and the mean volume was 1.75 and 3.2 cm(3), respectively. In addition, the mean diameter of the pharyngeal orifice of the ET was 1.9 mm. There were no significant between-group differences in the paratubal structures (p > 0.05).

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.

Computational analysis of microbubble flows in bifurcating airways: role of gravity, inertia, and surface tension

Although mechanical ventilation is a life-saving therapy for patients with severe lung disorders, the microbubble flows generated during ventilation generate hydrodynamic stresses, including pressure and shear stress gradients, which damage the pulmonary epithelium. In this study, we used computational fluid dynamics to investigate how gravity, inertia, and surface tension influence both microbubble flow patterns in bifurcating airways and the magnitude/distribution of hydrodynamic stresses on the airway wall. Direct interface tracking and finite element techniques were used to simulate bubble propagation in a two-dimensional (2D) liquid-filled bifurcating airway. Computational solutions of the full incompressible Navier-Stokes equation were used to investigate how inertia, gravity, and surface tension forces as characterized by the Reynolds (Re), Bond (Bo), and Capillary (Ca) numbers influence pressure and shear stress gradients at the airway wall. Gravity had a significant impact on flow patterns and hydrodynamic stress magnitudes where Bo > 1 led to dramatic changes in bubble shape and increased pressure and shear stress gradients in the upper daughter airway. Interestingly, increased pressure gradients near the bifurcation point (i.e., carina) were only elevated during asymmetric bubble splitting. Although changes in pressure gradient magnitudes were generally more sensitive to Ca, under large Re conditions, both Re and Ca significantly altered the pressure gradient magnitude. We conclude that inertia, gravity, and surface tension can all have a significant impact on microbubble flow patterns and hydrodynamic stresses in bifurcating airways.