The correlation of middle ear aeration with mastoid pneumatization. The mastoid as a pressure buffer

Analysis of growth pattern of temporal bone pneumatization using 3D reconstructed computed tomography

BACKGROUND

Temporal bone pneumatization (TBP) is influenced by age, sex, and race, and it seems to progress rapidly to puberty. However, the extent of TBP in childhood remains unclear.

PURPOSE

To investigate the progression of TBP in children aged 1-18 years via three-dimensional (3D) reconstruction of high-resolution computed tomography (CT) images.

MATERIAL AND METHODS

A total of 432 temporal bones of 216 individuals aged 1-18 years with well-pneumatized mastoid antra on both sides were included in this retrospective work. We created 18 age groups, each with six boys and six girls. Surface rendering of air density was performed using -290 HU to obtain TBP. Statistical analysis employed SPSS version 24.0 software (IBM Corp., Armonk, NY, USA).

RESULTS

The linear regression equations that considered age and volume for all cases (ya), male (ym) and female (yf) were ya = 384.42x + 1790.40, R2 = 0.425; ym = 431.54x + 1440.9, R2 = 0.501; and yf = 337.26 x + 2140.5, R2 = 0.355. Both male and female individuals showed an increase in the average value of pneumatization until the age of 17, and the values ​​of pneumatization at specific ages for boys and girls showed differences. The mean male and female TBP levels differed significantly at 3, 11, and 18 years of age (P < 0.05).

CONCLUSION

TBP in boys was greater than that of girls at adolescence. It was possible to identify the specific periods of significant variation in the degree of pneumatization of temporal bone.

Age-Related Increase in Type C Tympanogram

Background: This study evaluated the relationship between aging and tympanometric changes, specifically the incidence of type C tympanograms, using data from the Korea National Health and Nutrition Examination Survey (KNHANES). Methods: We analyzed data from the 2019-2022 KNHANES, including 26,738 ears from individuals aged 40 and older. Tympanometry at 226 Hz identified type C tympanograms based on peak pressure below -100 daPa. Multiple logistic regression evaluated the association between age and type C tympanograms, adjusting for confounders such as sex, smoking status, allergic rhinitis, chronic sinusitis, and lifestyle disease markers. Results: The incidence of type C tympanograms increased significantly with age (R2 = 0.953, p < 0.001). Age was the most significant factor associated with type C tympanograms (p < 0.001, odds ratio 1.052), while other factors were not statistically significant. Ears with type C tympanograms had significantly poorer hearing thresholds compared to those with type A tympanograms (p < 0.001). Conclusions: Aging is significantly associated with an increased incidence of type C tympanograms, indicating possible middle ear dysfunction in older adults. The correlation between type C tympanograms and poorer hearing thresholds suggests that age-related changes in middle ear function may contribute to hearing impairment. Tympanometric screening in older adults may facilitate early detection and management of middle ear dysfunction, potentially improving hearing outcomes and quality of life.

A Prospective Longitudinal Study to Evaluate the Patency of the Aditus ad Antrum in Chronic Otitis Media Mucosal Type

Chronic otitis media is defined as the chronic inflammation of the mucoperiosteal lining lining of the middle ear cleft which presents with recurrent ear discharge through tympanic membrane perforation. The study was planned to evaluate the patency of the aditus ad antrum in cases of chronic otitis media mucosal type, and its correlation with various direct and indirect indicators of blocked aditus. The prospective longitudinal study was conducted on 100 patients with chronic otitis media mucosal type. The commonest complaint of patients was ear discharge (100%) followed by hearing impairment in 72% patients.Tympanoplasty with antrotomy was performed. The patency and dimensions of the aditus ad antrum were assessed by saline water test. In 41% cases saline test showed blockade, on further drilling patency achieved in 27 cases with minimal drilling and dissection of mucosa with or without fibrotic mucosal bands. In rest 14 cases widening of aditus and atticotomy was required to achieve patency. Out of these nine were having associated tympanosclerosis and five were having edematous mucosa. Ossicular necrosis was seen on 18 cases. Presence of myringosclerosis and polypoidal edematous mucosa increases the probability of an obstructed aditus ad antrum. Mastoid antrostomy and water test for patency can be performed without additional cost and risk to the patient in minimal time and can be considered as the surest indicator of patency of aditus ad antrum.

PNPT1, MYO15A, PTPRQ, and SLC12A2-associated genetic and phenotypic heterogeneity among hearing impaired assortative mating families in Southern India

The study was conducted between 2018 and 2020. From a cohort of 113 hearing impaired (HI), five non-DFNB12 probands identified with heterozygous CDH23 variants were subjected to exome analysis. This resolved the etiology of hearing loss (HL) in four South Indian assortative mating families. Six variants, including three novel ones, were identified in four genes: PNPT1 p.(Ala46Gly) and p.(Asn540Ser), MYO15A p.(Leu1485Pro) and p.(Tyr1891Ter), PTPRQ p.(Gln1336Ter), and SLC12A2 p.(Pro988Ser). Compound heterozygous PNPT1 variants were associated with DFNB70 causing prelingual profound sensorineural hearing loss (SNHL), vestibular dysfunction, and unilateral progressive vision loss in one family. In the second family, MYO15A variants in the myosin motor domain, including a novel variant, causing DFNB3, were found to be associated with prelingual profound SNHL. A novel PTPRQ variant was associated with postlingual progressive sensorineural/mixed HL and vestibular dysfunction in the third family with DFNB84A. In the fourth family, the SLC12A2 novel variant was found to segregate with severe-to-profound HL causing DFNA78, across three generations. Our results suggest a high level of allelic, genotypic, and phenotypic heterogeneity of HL in these families. This study is the first to report the association of PNPT1, PTPRQ, and SLC12A2 variants with HL in the Indian population.

"Benefits of the pedicled osteoplastic flap as a surgical approach of mastoidectomy in cochlear implant surgery"

OBJECTIVE

To evaluate the esthetic and functional results of an osteoplastic flap for mastoid cavity closure in cochlear implant surgery.

STUDY DESIGN

Double-blind, prospective, randomized clinical trial.

SETTING

tertiary referral center.

INTERVENTION(S)

On hundred and twenty-six patients were randomized in 2 groups for cochlear implant surgery. Cases (n: 63) underwent simple mastoidectomy using an anteriorly pedicled osteoplastic flap for mastoid closure. In controls (n: 63), a traditional periosteal flap was used. Evaluation with the POSAS questionnaire was performed 1 year after surgery to assess surgical wound esthetics. Sixteen patients from each group had postoperative CT-scans and wideband tympanometry to assess mastoid aeration and middle ear absorbance. Gender and time after surgery were correlated.

MAIN OUTCOME MEASURE(S)

Evaluation of the quality of the surgical wound with the application of a questionnaire validated in the medical literature and translated into Portuguese language called POSAS, considering the perception of the blinded patient and doctor regarding the surgical technique proceeded. A lower POSAS score suggests better esthetics of the surgical wound. Secondary outcomes are volumetric measurement of aeration inside mastoid cavity using 3D computer tomography exam, which aims to analyze the influence of fibrocicatricial retraction in the surgical wound into the mastoid and the interference of its aeration volume in the absorption of sound in the middle ear, using the wideband tympanometry exam.

RESULTS

The POSAS questionnaire in the Case group showed a lower level of local pain and itchiness, a skin color and thickness more similar to the surrounding skin and less irregularity and stiffness, with no influence from time after surgery and gender compared to the Control group. The median tomographic volume was 6.37 cc in the cases and 4.60 cc in controls. Wideband tympanometry showed general smaller sound absorbance in the Case group results, specially, at 1000 Hz frequency. No intraoperative or postoperative complications were observed with the osteoplastic flap.

CONCLUSIONS

This technique is an effective and safe alternative to alleviate common problems of mastoid surgery for cochlear implantation. In addition to esthetic benefits, it has less interference in middle ear physiology of sound absorbance and less fibrous tissue into the mastoid cavity during the follow-up of more than 1 year.

The impact of middle ear aeration on surgical outcome after intact canal wall tympanoplasty for cholesteatoma

OBJECTIVE

The aeration status of the middle ear is presumed to be one of the factors affecting the outcome in acquired cholesteatoma. The present study investigated the impact of postoperative middle ear aeration on hearing and recurrence after intact canal wall tympanoplasty.

METHODS

We conducted a retrospective chart review of 127 pars flaccida cholesteatoma patients who underwent primary intact canal wall tympanoplasty at a tertiary academic medical center. We collected data on clinical characteristics, including extent of cholesteatoma, surgical procedure, pre- and postoperative middle ear aeration, hearing level, and recurrence. The aeration was measured before and at one year after operation on two axial computed tomography (CT) planes: at the lateral semicircular canal (mastoid cavity) and at the oval window (tympanic cavity). Based on the postoperative air-bone gap (ABG), patients were categorized into two groups: the successful hearing (ABG ≤15 dB) group and the unsuccessful hearing (ABG >15 dB) group. We used aeration ratio to assess the relationship between postoperative aeration improvement and hearing outcome or recurrence. Multivariate logistic regression analysis was used to identify the factors associated with hearing outcome.

RESULTS

At one year after operation, aeration ratio in both mastoid and tympanic cavities was significantly improved than the preoperative status (p < 0.001, p < 0.001, respectively, Wilcoxon signed-rank test). The positive correlation was found between postoperative aeration ratios of mastoid cavity and tympanic cavity (r = 0.348, p < 0.001, Spearman's rank-correlation coefficient). In mastoid and tympanic cavities, the postoperative aeration ratio in successful hearing group (n = 57) was significantly higher than that in the unsuccessful hearing group (n = 45) at one year after operation (p < 0.001, p = 0.028, respectively, Mann-Whitney U test). Multivariate logistic regression analysis demonstrated that postoperative aeration ratio in mastoid cavity and preoperative ABG were significant independent prognostic factors for successful hearing (odds ratio [95% confidence interval]: 2.630 [0.985 - 7.024], p = 0.045; 0.891[0.840 - 0.944], p < 0.001, respectively). However, postoperative aeration ratios did not significantly differ between with (n = 14) and without recurrence (n = 113) groups in both cavities.

CONCLUSION

Our results suggest that better postoperative aeration in mastoid cavity is independently associated with satisfactory hearing outcome after intact canal wall tympanoplasty in pars flaccida cholesteatoma. However, no significant differences were observed between middle ear aeration at one year after operation and recurrence.

Attic retraction pockets: Classification system

INTRODUCTION

Although attic retractions have previously been classified into Grades 0 through IV, it is often not possible to assign attic retraction pockets into a single specific category. The present study describes an improved classification system based on otoscopic and endoscopic visualization of the retraction pocket fundus, the ossicular status in the attic, degree of scutal erosion, and the presence or absence of cholesteatoma.

MATERIALS AND METHODS

One hundred and fifty-four patients (200 ears) with different grades of attic retraction pockets who were seen by a tertiary referral otology center between August 2015 and July 2018 were selected for this study.

OBSERVATIONS

The new classification system (Grades I, IIa, IIb, IIIa, IIIb, IIIc, IVa, IVb, IVc, and V) was applied to these retraction pockets. Pure tone audiometry was obtained.

RESULTS

All attic retraction pockets could be classified precisely using the new classification system. Forty-four of 200 (22%) of ears showed Grade I Attic retraction, 18 ears showed Grade IIa (9%), 14 showed Grade IIb (7%), 28 showed Grade IIIa (14%), 12 showed IIIb (6%), 20 showed Grade IIIc (10%), 16 showed grade IVa (8%), 12 showed grade IVb (6%), 28 showed grade IVc (14%), and eight showed grade V (4%) attic retraction pockets. Grades I, IIa, IIb, IIIa, and IVa had no significant hearing loss. Average hearing loss was 42 dB and 52 dB in Grades IIIb and IIIc, 44 dB and 58 dB in Grades IVb and IVc, and 61 dB in Grade V.

LEVEL OF EVIDENCE

5 Laryngoscope, 130: 2034-2039, 2020.

The Possible Associations of Nasal Septal Deviation with Mastoid Pneumatization and Chronic Otitis

BACKGROUND:

The nasal septum deviation is the most common deformity of the nasal, and that can be congenital or acquired. Despite many studies exist about the impact of nasal septum deviation on chronic sinusitis and also association between chronic otitis and mastoid pneumatization; few studies exist about the impact of nasal septum deviation on chronic otitis and mastoid pneumatization.

AIM:

The aim of this study was to evaluate the associations of nasal septum deviation and mastoid pneumatization and chronic otitis.

METHODS:

In this study review, all CT scans of PNS and Mastoid View in the imaging section from Imam Ali hospital in 2016-2017 years and cases of nasal septum deviation were enrolled. The nasal septum deviation was recorded, and the degree of nasal septum deviation in the coronal plane that showed the maximum deviation of the nasal septum was recorded. The volume of the mastoid cells automatically and directly was calculated using three diameter measurements (2 coronal diameters and 1 axial diameter) by the program. The software of SPSS 22 was used for statistical analysis.

RESULTS:

There was no relationship between nasal septum deviation severity and incidence of mastoid pneumatization in patients with nasal septum deviation (P > 0.05). There was relationship between nasal septum deviation severity and chronic otitis in patients with nasal septum deviation (P < 0.05). In patients with moderate and severe intensity of nasal septum deviation, the volume of mastoid air cells in deviation side was lower than the front side (P < 0.05).

CONCLUSION:

Based on the results of the CT scan, in patients with moderate and severe nasal septum deviation intensity, the volume of mastoid air cells in deviation side was lower than the front side. Also, there was a relationship between nasal septum deviation severity and chronic otitis.

The potential protective effects of temporal bone pneumatization: A shock absorber in temporal bone fracture

Objectives

We hypothesize that when temporal bone fractures occur, the pneumatic cells in the temporal bone are able to absorb most of the impact force during a traumatic event. This study aims to correlate the degree of pneumatization of the temporal bone with the severity of temporal bone fracture (TBF).

Methods

Charts and computed tomography scans representing 54 TBFs, diagnosed from 2012 to 2017 at a single tertiary hospital, were retrospectively reviewed. Temporal bone pneumatization (TBP) in the petrous apex and mastoid region was evaluated using previously published classification systems. TBP classifications and fracture types were correlated with TBF complications such as sensorineural hearing loss (SNHL), facial nerve palsy (FNP), and vestibular dysfunction.

Results

Patients with increased pneumatization of the temporal bone had significantly fewer and less severe SNHL. SNHL more strongly correlated with the degree of pneumatization in the mastoid (P = 0.005) than that in the petrous apex (P = 0.024). On the other hand, the degree of TBP correlated poorly with FNP and vestibular dysfunction. However, the mastoid hypopneumatization demonstrated significant correlation with otic-capsule violations (P = 0.002). Fractures with otic-capsule violation were 4 times more likely to have vestibular dysfunction (P = 0.043) and 3 times more likely to have SNHL (P = 0.006). FNP was not associated with otic-capsule violating fractures but was 3.5 times more common in comminuted fractures (P = 0.025).

Conclusions

The degree of temporal bone pneumatization was negatively correlated to the incidence of otic-capsule violation and the severity of hearing impairment in patients with temporal bone fracture. This study substantiated the potential protective effect of temporal bone pneumatization in TBFs.

Therapeutic Mastoidectomy Does Not Increase Postoperative Complications in the Management of the Chronic Ear

OBJECTIVE

Tympanoplasty with or without concurrent therapeutic mastoidectomy is a controversial topic in the management of chronic ear disease. We sought to describe whether there is a significant difference in postoperative complications.

STUDY DESIGN

Retrospective cohort study.

SETTING

American College of Surgeons National Surgical Quality Improvement Program public files.

PATIENTS

Current procedural terminology codes were used to identify patients with chronic ear disease undergoing tympanoplasty ± concurrent mastoidectomy in the 2011 to 14 American College of Surgeons National Surgical Quality Improvement Program files.

INTERVENTION

Therapeutic.

MAIN OUTCOME MEASURES

Variables were compared with χ, Fischer's exact, and Mann-Whitney U tests, as appropriate to analyze postoperative complications between tympanoplasty with or without concurrent mastoidectomy. To account for confounding factors, presence of a complication was analyzed in binary logistic regression. Analysis considered sex, hypertension, obesity, advanced age, diabetes, smoking status, American Society of Anesthesiologists Physical status, procedure.

RESULTS

There were 4,087 patients identified meeting criteria (tympanoplasty = 2,798, tympanomastoidectomy = 1,289). There was no statistical difference in postoperative complications (tympanoplasty n = 49 [1. 8%], tympanomastoidectomy n = 33 [2. 6%]; p = 0. 087) or return to the operating room (tympanoplasty = 4 [0. 1%], tympanomastoidectomy = 6 [0. 5%]; p = 0. 082). Binary logistic regression demonstrated smoking as a predictor of a postoperative complication (OR: 1. 758, 95% CI: 1. 084-2. 851; p = 0. 022), while concurrent mastoidectomy did not significantly increase the risk of complication (OR: 1. 440, 95% CI: 0. 915-2. 268; p = 0. 115). There was a significant difference in mean operative time between tympanoplasty and tympanomastoidectomy: 85.7 versus 154.23 min, p < 0. 001.

CONCLUSION

In the management of chronic ear disease, tympanoplasty with concurrent mastoidectomy increases time under anesthesia, but it is not associated with any increased postoperative complications compared with tympanoplasty alone.

Doing Mastoidectomy Along with Tympanic Membrane Repair Reduces the Need for Revision Procedures: A Prospective Study

To determine the role of cortical mastoidectomy on the results of tympanoplsty in tubotympanic type of chronic suppurative otitis media. A prospective, observational, interventional study was conducted from a period of October 2006-October 2008. This included 40 patients of either sex in the age group of 15-45 years having tubotympanic type of CSOM. Tympanoplasty with mastoidectomy was done in all the patients and they were followed up for graft acceptance and hearing impairment for 5 years to see the long term results. Per-operatively, the antrum was involved in 17, aditus in 11 and middle ear in 8 patients. Incus was necrosed in 10 cases and malleus and incus were absent in a single case. Mucoid discharge was found in the middle ear in 12 out of 40 patients. Mucoid discharge ears had antral mucosal hypertrophy in 100%, blocked aditus in 75% and middle ear mucosal hypertrophy in 58% cases; ossicular necrosis in 75% cases. 90% of the cases had graft accepted. In dry ears, graft take up rate was 89% and in ears with mucoid discharge it was 92%. Average air-bone-gap reduced to 13.90 dB as compared to average air-bone-gap (Av. AB Gap1) preoperatively of 38.62 dB. After 5 years, 83.5% patients had >10 dB improvement in hearing. We recommend opening of the mastoid if on inspection of middle ear one finds mucoid type of discharge.

Volume of Mastoid Pneumatization: Three-Dimensional Reconstruction with Ultrahigh-Resolution Computed Tomography

The volume of the mastoid air cell system was measured in 69 patients with normal middle ears. All patients underwent axial ultrahigh-resolution computed tomography. Mastoid pneumatization was marked on each axial slice, and 3-dimensional reconstruction was performed. The volumes were measured with a volumetric algorithm. A polyethylene tubing phantom with a density similar to that of bone on computed tomography was devised. The polyethylene tubing was tied in a particular fashion so as to create interconnecting air spaces with a known volume. The phantom was scanned with the imaging parameters used for scanning the temporal bone. The air in the tubing was marked, and 3-dimensional reconstruction for the marked phantom air was performed. The volume of the interconnecting air spaces was measured and found to be identical to its known volume, thereby verifying the accuracy of the method used. The mean mastoid volume was 6.61 cm3. The smallest volume measured was 1.3 cm3, and the largest was 12.7 cm3. The importance of this technique lies in its high accuracy, ease of use, and ability to directly correlate mastoid size and clinical findings.

Role of tympanometric volume in paediatric tympanoplasty

OBJECTIVE

To determine the prognostic significance of "Tympaometric Volume" for paediatric tympanoplasty type I in a select age-group of 5-8 years.

METHODS

A prospective study was conducted in 30 children with chronic suppurative otitis media-inactive mucosal disease of either sex. Pre-operative tympanometric volume was recorded in all the cases and statistically analysed with the graft uptake results post-operatively. All the patients underwent tympanoplasty type I by underlay technique using temporalis fascia graft. An intact graft at the end of 6 months, and a postoperative hearing improvement of 10 dB or greater in two consecutive frequencies, was regarded as surgical and audiological success, respectively. The statistical analysis was done using Mantel Haenszel χ(2) i.e. Chi square test, and Fisher exact p value test for confirmation.

RESULTS

We recorded an impressive surgical success rate of 87% and an audiological improvement of 70% in this study. On the basis of mean tympanometric volume of 1.6 cm(3) the patients were divided into two groups: in Group A (tympanometric volume<1.6 cm(3)), and group B (tympanometric volume>1.6 cm(3)). A graft uptake of 95% and 77% was recorded in Group A & B, respectively. However, the statistical evaluation of the data revealed no significant effect of this factor.

CONCLUSIONS

In this study no correlation between the tympanometric volume and the surgical success of paediatric tympanoplasty in select age group of 5-8 years was observed.

Patency of the aditus ad antrum in tubotympanic chronic suppurative otitis media

OBJECTIVES

To evaluate the patency of the aditus ad antrum in cases of tubotympanic chronic suppurative otitis media (CSOM) and to measure its dimensions. Also, to examine its mucosa histologically for the presence of granulation tissue or occult cholesteatoma.

STUDY DESIGN

Prospective case series.

SETTING

Main Alexandria University Hospital (tertiary referral center).

SUBJECTS AND METHODS

Fifty adult patients with tubotympanic CSOM without evidence of cholesteatoma, after adequate medical control of otorrhea, presented with mild or moderate conductive hearing loss. In all patients, tympanoplasty with cortical mastoidectomy was performed. The patency and dimensions of the aditus ad antrum were assessed using a 30° endoscope. Biopsies were obtained from unhealthy mucosa to detect the presence of granulation tissue or occult cholesteatoma.

RESULTS

Ten cases (20%) had a blocked aditus ad antrum by unhealthy and edematous mucosa. Biopsies revealed granulation tissue in all cases. No occult cholesteatoma was detected. The results were further analyzed in relation to multiple variables to detect any clinical clues of a blocked aditus.

CONCLUSION

Of the studied cases, 20% had a blocked aditus. The prevalence of an obstructed aditus was higher among older patients with a long history (>1 year) of ear discharge. Marginal and subtotal central perforations and the presence of myringosclerosis increase the probability of an obstructed aditus ad antrum.

Usefulness of cortical mastoidectomy in myringoplasty

OBJECTIVES

The usefulness of cortical mastoidectomy in myringoplasty remains an issue of controversy. We aimed to assess the effectiveness of mastoidectomy on outcomes of tympanoplasty performed in patients with persistent or intermittent discharging chronic suppurative otitis media without cholesteatoma.

STUDY DESIGN

Prospective, randomized, single-blinded study. Level of evidence-1B.

SETTING

Tertiary referral center.

PATIENTS

Three hundred twenty consecutive adult patients presenting persistent or intermittent otorrhea during the preceding 6 months scheduled for myringoplasty were included.

INTERVENTIONS

Patients were randomly assigned to undergo either myringoplasty with cortical mastoidectomy (Group A) or myringoplasty only (Group B).

MAIN OUTCOME MEASURES

Graft success rate and mean postoperative air-bone gap. Auditory outcomes were evaluated at one year postoperatively.

RESULTS

At the end of the follow-up period, there were 24 failures within Group A (success rate, 82.8%) and 34 within Group B (success rate, 76%), statistically not significant. In the univariate analysis, 3 factors were found to be significant in predicting success rate: healthy opposite ear, a long dry period preceding the operation and nonsmoker status. The only factor attaining significance in the multivariate analysis was a dry period longer than 3 months.

CONCLUSION

Cortical mastoidectomy offers no additional benefit in myringoplasty performed on patients with persistent or intermittent discharging CSOM and no evidence of cholesteatoma or mucosal blockage within the antrum.

Mastoid geometry in a cross-section of humans from infancy through early adulthood with a confirmed history of otitis media

OBJECTIVE

This study describes the changes in mastoid air cell system (MACS) geometry with age in ears with a history of otitis media (OM), without (GR-I) or with (GR-II) middle ear fluid on the CT scan.

METHODS

Thirty-seven (74 MACSs) CT scans were selected to approximate 4 MACSs/year between 1 and 18 years. For each MACS, the volume, surface area and surface area/volume ratio were reconstructed using standard procedures. Correlation analysis was used to define the left-right relatedness for the geometric parameters, and regression analysis was used to determine the effect of age on those parameters for each group.

RESULTS

Twenty scans were from female and 17 from males. Fluid was observed in 12 left, 4 right and 10 bilateral MACSs. The MACS volume and surface area of GR-I increased with age, were significantly greater than those for age-matched MACSs in GR-II, but show large variability. Those measures in GR-II were independent of age and a large percentage of these MACS volumes was <5 ml. The surface-area/volume ratio for MACSs in both groups was independent of age and group assignment. The left-right correlations for the three geometric parameters of the MACS were significant for all MACS in the two groups, and for bilateral MACS concordant for group assignment. The left-right correlations for surface area and volume were not significant for bilateral MACSs discordant for group assignment.

CONCLUSIONS

These results suggest that: the growth of MACS volume and surface area is genetically programmed but that this is disrupted by long-lasting OM; the effect of OM on MACS growth may depend on the duration and timing of the disease, and the MACS surface area/volume ratio does not explain the effect of MACS volume on the rate of gas exchange between middle ear and blood.

Myringosclerosis: an indication of a blocked aditus

Tympanoplasty has been the mainstay of treatment in chronic otitis media. In a non cholesteatomatous chronic otitis media, there has been much debate whether a cortical mastoidectomy is required or not. Creating an aerating mastoidectomy in cases of blocked aditus ad antrum helps in reducing the recurrence. However, the status of aditus is not always known unless a mastoidectomy is performed. In this study we try to find out if there is any clinical clue regarding a blocked aditus ad antrum by looking at the tympanic membrane. Fourty-three cases of cortical mastoidectomies were retrospectively studied in this series. Patency of aditus ad antrum was analyzed with respect to presence of myringosclerosis and the status of middle ear mucosa. In this study myringosclerosis was found to be significantly associated with a blocked aditus while no such association was found with the status of middle ear mucosa. The presence of myringosclerosis may indicate a blocked aditus ad antrum and performing a cortical mastoidectomy in such cases may help in creating an aerated mastoid, thereby possibly reducing the recurrence rate.

Do patients with sclerotic mastoids require aeration to improve success of tympanoplasty?

CONCLUSION

We could not find any significant difference in the results for graft success rate and functional hearing results between the myringoplasty and tympano-mastoidectomy groups. So mastoidectomy may not be necessary for successful tympanic membrane reconstruction and hearing improvement.

OBJECTIVE

To investigate the effect of aerating mastoidectomy on the surgical success rate of myringoplasty.

METHODS

This was a retrospective study. Data were analyzed from 92 patients who underwent surgical repair of tympanic membrane perforations due to chronic suppurative otitis media (CSOM) without cholesteatoma. Tympano-mastoidectomy was performed in 46 patients with a small sclerotic mastoid. The other 46 patients underwent myringoplasty without mastoidectomy. Patients were evaluated for success in tympanic membrane reconstruction and hearing levels after a minimum follow-up duration of 1 year.

RESULTS

Tympanic membrane perforation closure was successful in 76.1% (n = 35) of the 46 patients undergoing myringoplasty and in 78.3% (n = 36) of the 46 patients undergoing myringoplasty with mastoidectomy. The difference between the closure rates of the two groups was not statistically significant (p > 0.05). The difference between the two groups for hearing gain was also not statistically significant (p > 0.05).

Pressure equilibration in the penguin middle ear

CONCLUSIONS

King penguins have a venous structure in the form of a corpus cavernosum (CC) in their middle ear (ME) submucosa. The CC may be viewed as a special organelle that can change ME volume for pressure equilibration during deep-sea diving it is a pressure regulating organelle (PRO). A similar CC and muscles also surround the external ear (EE) and may constrict it, isolating the tympanic membrane from the outside. A CC was previously found also in the ME of marine diving mammals and can be expected to exist in other deep diving animals, such as marine turtles.

OBJECTIVES

Marine animals require equalization of middle ear (ME) pressure when diving hundreds or thousands of meters to catch prey. We investigated what mechanism enables king penguins to protect their ME when they dive to great depths.

MATERIALS AND METHODS

Biopsies and serial sections of the ME and the EE of the deep diving king penguin (Aptenodytes patagonicus) were examined microscopically.

RESULTS

It was demonstrated that the penguin ME has an extensive network of small and large submucosal venous sinuses. This venous formation, a corpus cavernosum, can expand and potentially 'flood' the ME almost completely on diving, thus elevating ME pressure and reducing the ME space. The EE has a similar protective mechanism.

Impact of Jacobson's (Tympanic) Nerve Sectioning on Middle Ear Functions

OBJECTIVE

The purpose of this study was to evaluate the influence of sectioning of the Jacobson's (tympanic) nerve on middle ear functions.

METHOD

Twenty-five adult New Zealand rabbits were included in this study. The Jacobson's nerve was cut in the left ear of the rabbits (study group), whereas only a small mucosal incision was performed while keeping the Jacobson's nerve intact in their right ear (control group). After the operation, the ears were assessed both otomicroscopically and histopathologically on Days 30, 60, and 90.

RESULTS

On otomicroscopy, retraction pockets were observed in 48 and 4% of the ears in the study and control groups, respectively (p < 0.001). Middle ear effusion was observed in 56 and 12%, respectively (p < 0.01). Histopathologically, an inflammation in the middle ear mucosa was present in all ears in the study group, whereas it was present only in 20% of the control ears (p < 0.001). Goblet cells were observed in 48 and 20% in the study and control groups, respectively (p < 0.04). In the study group, the otomicroscopic and histopathologic findings were more prominent on Day 60 compared to Day 90 (p < 0.05).

CONCLUSION

Tympanic glomus cells seem to act as middle ear chemosensory organs and are involved in the regulation of middle ear aeration. Disruption of these neural elements such as Jacobson's nerve negatively impacts on middle ear functions and may result in atelectasis.

The mastoid as a functional rate-limiter of middle ear pressure change

INTRODUCTION

The physiological function of the mastoid air cell system (MACS) with respect to middle ear (ME) pressure-regulation remains controversial because predictive mathematical models and experimental data to formulate and test hypotheses are lacking.

OBJECTIVE

A mathematical description of MACS volume effects on the rate of ME pressure change is presented; the agreement between published data and model prediction is examined for consistency with the hypothesis that the MACS acts as a functional rate-limiter of ME pressure change, and an explanation for the relationship between MACS volume and otitis media is discussed.

METHODS

The mathematical description shows that the value of a single, free parameter, termed the "MACS buffering efficiency" (M) determines if MACS volume affects the rate of ME pressure change caused by diffusive gas exchange. The MACS serves no rate-limiting function for M=0, acts as a gas sink for M>1 and acts as a gas reserve (rate-limiter) for M<1.

RESULTS

Fitting the model equation to published adult human data yielded an estimate for M of 0.2. This implies that larger MACS volumes are associated with lesser rates of change in ME pressure caused by diffusive gas exchange and lesser required frequencies of effective Eustachian tube openings to maintain near ambient ME pressures.

CONCLUSION

If well-controlled studies confirm M<1 for children and adults, larger MACS volumes will increase the time required to develop sufficient ME underpressures to cause otitis media by hydrops ex vacuo during transient or prolonged periods of Eustachian tube dysfunction.

Directional asymmetry in the measured nitrous oxide time constant for middle ear transmucosal gas exchange

OBJECTIVES

Simple, 2-compartment mathematical models of middle ear (ME) transmucosal gas exchange reproduce observed ME pressure behavior. These models require input of an experimentally determined, lumped-parameter exchange constant for each represented gas species. Previous model applications assumed directional asymmetry for those parameters, which has not been experimentally validated.

METHODS

As a surrogate for the inert gas nitrogen (N2), for which exchange is too slow to be measurable, the nitrous oxide (N2O) transmucosal exchange constant for 16 ears of 8 monkeys was measured for positive and negative ME blood N20 gradients.

RESULTS

The paired exchange constants for each ear were highly correlated, but the ME-blood/blood-ME exchange constant ratio was approximately 13. Modeling shows this asymmetry to depend on the value of the arterial-venous/arterialME ratio, a variable in the exchange constant for perfusion-limited gases.

CONCLUSIONS

These results support an asymmetric rate of transmucosal N20 and, by extension, N2 exchange for the ME. Because the primary controlling parameter for ME pressure behavior in the absence of eustachian tube opening is the rate of transmucosal N2 exchange, this effect needs to be incorporated into the simple 2-compartment exchange models for predictive accuracy. The gradient ratio dependence suggests that parameter-free modeling may require treating the ME mucosa as having a distributed gradient for certain gas species.

Volume variation of mastoid pneumatization in different age groups: a study by three-dimensional reconstruction based on computed tomography images

Although there have been some reports that measured the size of mastoid pneumatization, only a few studies have reported the age-related variations in the mastoid air cell system using three-dimensional (3D) reconstruction techniques of computed tomography (CT) images. We performed a retrospective, cross-sectional study. A 3D reconstruction based on CT images was performed on 199 ears of 102 patients (age range 6-84 years) without otologic disease by a surface-rendering algorithm. The results showed that mastoid pneumatization continued to grow until the third decade. Thereafter, it declined slowly, and then rapidly after the seventh decade. No statistically significant difference was found between male and female or between right and left sides. There was a significant difference between the larger and smaller sides of individuals. The volume measurement technique based on the 3D reconstruction technique reported here is widely available, highly accurate and easy to perform.

Rate of Nitrous Oxide Exchange Across the Middle Ear Mucosa in Monkeys Before and After Blockage of the Mastoid Antrum

OBJECTIVES: We tested the hypothesis that mastoid volume buffers the rate of change in middle ear pressure caused by transmucosal, inert gas exchange.

STUDYDESIGN: Twelve monkeys were randomly assigned to group 1 or group 2. Right ears of group 1 had sham surgery and of group 2 had obstruction of the mastoid antrum. Before and after surgery, the time constant for transmucosal N2O exchange was estimated from N2O breathing experiments. The hypothesis predicts that the postoperative time constant measured for right ears of group 2 but not group 1 is greater than that measured before surgery.

RESULTS: Mastoid antrum block significantly decreased right middle ear volume but did not affect the time constant for transmucosal N2O exchange.

CONCLUSION: A mastoid gas-reserve function is not supported by the experimental data.

SIGNIFICANCE: These results for monkeys and the theory developed to explain the effect of mastoid volume on transmucosal inert gas exchange suggest that the results for previous experiments in humans interpreted as evidencing a mastoid gas-reserve function are consistent with alternative explanations.

Cartilage tympanoplasty for posterosuperior retraction pockets of the pars tensa in children

OBJECTIVE

To assess the functional and anatomic results of cartilage grafting in children with a severe retraction pocket of the posterosuperior part of the pars tensa and operated on by pocket excision and cartilage grafting.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Fifty six children (60 ears) with severe posterosuperior retraction pockets.

INTERVENTION

Excision of the pocket and tympanic reinforcement with a tragal or conchal cartilaginous graft.

MAIN OUTCOME MEASURES

Postoperative anatomic (otoscopy, computed tomography) and functional (pure tone audiometry thresholds) outcome. The follow-up time was 27 +/- 18 months (mean +/- SD).

RESULTS

Retraction recurrences requiring additional surgery occurred in 5 cases (8%). The risk of recurrence was lower in children older than 10 years and when the whole surface of the pars tensa was reinforced (chi(2) test, p< 0.05 for both factors). Functionally, hearing was improved even when the ossicular chain was intact. In case of disrupted ossicular chain, direct contact between the graft and eroded incudostapedial joint gave good hearing results.

CONCLUSIONS

Cartilage reinforcement of the whole surface of the pars tensa is probably the best treatment of a severe posterosuperior retraction pocket. The flexibility and thinness of cartilage from the cymba conchae makes it particularly suitable in this indication.

Barotrauma vis-a-vis the "chronic otitis media syndrome": two conditions with middle ear gas deficiency Is secretory otitis media a contraindication to air travel?

We compared 17 patients (29 ears) with barotrauma with 171 patients suffering from "chronic ears" (secretory otitis media, atelectasis, or previously operated cholesteatoma). The patients with "chronic ears" were followed up prospectively, and none were found to suffer from barotrauma after flying on a commercial airplane. The mastoid pneumatization (seen on lateral mastoid radiographs) was significantly larger in ears with barotrauma, averaging 16.85 cm2, versus 12.9 cm2 in normal controls, whereas in "chronic ears" it was only 3.6 cm2. During flight on a commercial airplane, the middle ear has to equalize about 20% of its gas volume with the ambient pressure. This equalization must happen within 15 to 20 minutes of ascent and descent in order to avoid barotrauma. This 20% is a fivefold greater task for ears with a large mastoid pneumatization than for ears with an undeveloped pneumatization; "chronic ears" usually have an undeveloped mastoid pneumatization. The smaller the middle ear (mastoid) volume, the smaller the volume of gas needed to pass through the eustachian tube in order to equalize pressure changes during flying. This factor may explain why "chronic ears" rarely suffer from barotrauma. It also implies that eustachian tubes of secretory otitis, atelectatic, and cholesteatomatous ears have little problem in equalizing large pressure differences (over 2,000 mm H2O) within 15 to 20 minutes of landing, in contrast to what has been traditionally believed. Individuals with "chronic ears" can be advised that they can fly safely.

Cochlear implantation in healthy and otitis-prone children: a prospective study

OBJECTIVE

To evaluate and compare the timing of surgery, intraoperative findings, and otitis media-related outcome of cochlear implantation in children who are otitis-prone with their counterparts who are not otitis-prone.

STUDY DESIGN

Prospective.

METHODS

Children referred for cochlear implantation were assigned to a non-otitis-prone group (group A: normal otoscopy on their first visit after referral) or an otitis-prone group (group B: current or a recent history of otitis media at referral). Group B patients were managed using a structured protocol aimed at preimplantation otitis media control. The study reviewed pre-, intra-, and postoperative data.

RESULTS

Of the 18 children studied, 8 were assigned to group A (mean age at referral, 40.6 mo) and 10 to group B (mean age at referral, 31.6 mo). For otitis media control, all otitis-prone children underwent ventilating tube insertion (various numbers of procedures before implantation). Only one otitis-prone child required cortical mastoidectomy also. Time from referral to implantation was similar in the two groups (mean, 6.6 mo). High-resolution computed tomography data showed mastoid pneumatization to be significantly smaller in the otitis-prone group, but the facial recess was not smaller in this group. During implantation, 10 children had inflamed middle ear mucosa. Seven of these belonged to group B. All of these seven children had a round window niche obliterated by the inflamed mucosa, which had to be removed for round window membrane identification. After implantation, only one child had drainage through the ventilating tube for more than 1 week. Two children in group B developed otitis media (1 year postimplantation) that was overcome within 1 week. There were no otitis media-related complications.

CONCLUSIONS

If a structured protocol is used for the control of otitis media before cochlear implantation, otitis media should not require a delay in implantation. In otitis media-prone children, the round window niche is often obscured by inflamed mucosa. Its removal is mandatory for identification of the round window membrane. After cochlear implantation, otitis media is not a frequent occurrence.

Organic change of effusion in the mastoid in otitis media with effusion and its relation to attic retraction

To try to solve the pathogenesis of severe attic retraction viewed from mastoid condition, we examined the residual soft tissue density (RSTD) in the mastoid by computed tomography (CT) in 85 patients (107 ears) with otitis media with effusion (OME) 3 months after tympanostomy tube insertion or later. The incidence of RSTD in the mastoid was significantly higher in OME of adults (52.6%) than in children (24.1%). Ears with severe attic retraction had RSTD significantly more frequently (80%) than those with no or mild attic retraction, and many of the mastoids with severe attic retraction were occupied totally by RSTD. The area of the mastoid (mastoid pneumatization) was significantly smaller, and CT density of the mastoid (sclerotic tendency) was significantly higher in ears with RSTD than in those without. RSTD after tympanostomy tube insertion in the mastoid indicating organic change of effusion was considered one of the important factors relating to the pathogenesis of severe attic retraction.

Experimental results do not support a gas reserve function for the mastoid

The mastoid is an aerated extension of the middle ear gas pocket whose state of development was shown to be an indicator of past and future otitis media experience. While the function(s) of the mastoid is not known, a number of hypotheses has been advanced to explain the reported association between mastoid size and middle ear disease. These include the hypotheses that, with respect to the middle ear, the mastoid functions as a pressure buffer, a gas reserve, and/or a pressure regulator. In this paper, a physical model of the mastoid is presented that makes specific predictions against which the validity of the hypothesized gas reserve function could be tested. Data from three published clinical experiments were evaluated for consistency with the predictions of the model, and the hypothesis was rejected. Also, when reinterpreted within the context of the model, the published data do not support a pressure-regulating function for the mastoid.

Mucosal surface area determines the middle ear pressure response following establishment of sniff-induced underpressures

INTRODUCTION

Miura and colleagues presented data that they interpreted as evidencing a pressure-regulating function of the mastoid mucosa. Specifically, they reported different responses after sniff-induced middle ear (ME) underpressure for ears with and without a history of otitis media with effusion (OME). To understand the mechanism underlying that effect, a previously developed mathematical model was adapted to their experiment and used to simulate the expected pressure-time functions under different conditions.

METHODS

A simple, two-compartment model of passive, gradient-driven, trans-mucosal gas exchange was used to simulate ME pressure behaviour. Initial conditions for the free parameters of the model were taken from published data for humans and monkeys. Functions relating surface area to volume for geometric representations of the ME were constructed and used as model parameters. The effect of sniffing on ME gas partial pressure was modelled as a fractional reduction proportional to gas representation in the ME.

RESULTS

The model accurately simulated the time course and magnitude of the post-sniffing pressure change reported for both normal and abnormal MEs. The post-sniffing pressure increase is driven by sniff-induced blood-ME partial pressure gradients for CO2, O2, and H2O, which cause passive counter-diffusion of those gases. The effect of disease on the rate of pressure increase is attributable to the reduced surface area for exchange caused by underdevelopment of the mastoid in ears with a history of OME.

CONCLUSIONS

These results do not support a pressure-regulating role for the mastoid mucosa. Contrary to currently held beliefs, the model simulation suggests that small, not large mastoid volumes buffer ME pressure from rapid change due to trans-mucosal gas transfers.

Role of aerating mastoidectomy in noncholesteatomatous chronic otitis media

OBJECTIVE

To assess the success rate of revision tympanoplasty with aerating mastoidectomy in patients with noncholesteatomatous chronic otitis media who had failed at least one prior tympanoplasty.

STUDY DESIGN

Retrospective chart review.

METHODS

Data were analyzed from 135 patients available for clinical and audiometric studies with a minimum of 18 months' follow-up. All patients had failed at least one prior tympanoplasty and presented with: 1) a persistent tympanic membrane perforation with intermittent drainage, or 2) a wet draining ear, unresponsive to systemic antibiotic and topical management. All patients underwent 1.5-mm, high-density, bone window computed tomography (CT) scanning to assess middle ear, epitympanic, and mastoid air cell pneumatization. All patients underwent revision tympanoplasty with aerating mastoidectomy via a postauricular approach. Patient charts were reviewed for information regarding preoperative radiographic findings, mucosal and ossicular findings at the time of surgery, and success or failure of revision tympanomastoidectomy.

RESULTS

The tympanic membrane graft take rate for the entire group of 135 patients was 90.4% (13 grafts failed). A majority of the patients were found to have radiographic and intraoperative evidence of middle ear/mastoid disease.

CONCLUSION

For patients with noncholesteatomatous chronic otitis media who have failed prior tympanoplastic reconstruction, an aerating mastoidectomy may be indicated and may improve the success rate of the surgery.

Pneumatization in otosclerosis

In this study, degrees of mastoid pneumatization in otosclerotic and normal patients were compared on CT scan and plain X-rays. This study was prospective, conducted on inpatients and outpatients at a large community hospital. Patients were consecutively evaluated with no sex or age predilection. Each patient had a CT scan and a Schuller graph. Temporal bone volumetric and planimetric measurements were done respectively on CT scans and Schuller graphs. Statistically no significant variations were observed between groups. No correlation could be established between the degree of pneumatization and otosclerosis. Neither imaging technique is superior to the other when they are compared.

Mastoid buffering properties: I. Gas partial pressures

Differences in the gas partial pressures between the middle ear (ME) cavity and the blood are an important factor in ME gas economy. Differences in gas partial pressures between various regions of the ME-mastoid air cell system (ME-MACS) could play a role as well. To determine whether gas partial pressure differences do occur between various compartments in the ME, we measured the rate of gas diffusion from one compartment to another in both an artificial model and in the ME-MACS of human temporal bones. The rate of gas diffusion between various areas of the ME and the mastoid tip was found to be rapid, with a half-life on the order of 2 minutes (range 0.8 to 5.3 minutes). We suggest that this high diffusion rate prevents the buildup of significant differences in gas composition in the ME-MACS system, which can therefore be regarded as a homogeneous gas pocket.

Mastoid pneumatization and otosderosis-is there a correlation

The environment versus the genetic influence on the size of the mastoid pneumatization has been debated for years. A concrete evidence of the influence of environmental factors (e.g. inflammation) or heredity on pneumatization is still lacking. In this study the extent to mastoid peumatization in thirty otosclerotic ears was compared with control ears. The size of mastoid pneumatization was measured by the use of Law lateral x-ray projection with the help of planimetry. It was found that the average pneumatized area in otosclerotic ears was 14.73+ -3.55 cm2 compared to 10.60+3.62 cm2 in control ears which was statistically significant. In addition the mean area of mastoid air system was found to be more in the operated ears compared to the contralateral ears, the difference being statistically significant. However there was no correlation of mastoid pneumatization with degree and duration of hearing loss and type of otosclerotic focus. Our findings therefore show a link between otosclerosis and highly pneumatized mastoids thus indicating a likelihood of heredity playing a role in determining final type ot pneumatization.

Influence of the gas exchange function through the middle ear mucosa on the development of sniff-induced middle ear diseases

To investigate the influence of gas exchange function through the middle ear mucosa on the development of sniff-induced middle ear diseases, the authors examined the mastoid pneumatization among patients with sniffing habit using computed tomography, and also examined the change of negative middle ear pressure induced by sniffing using tympanogram. In 20 ears with cholesteatoma or adhesive otitis media, the areas of mastoid cavity measured at the level of the lateral semicircular canal were significantly smaller than those in 26 ears with otitis media with effusion (OME) or attic retraction and in eight normal ears with sniffing habit (P < .01 and P < .0001, respectively). In 26 ears with OME or attic retraction, the areas of mastoid cavity were significantly smaller than those in eight normal ears with sniffing habit (P < .0001). By contrast, in the four ears with sniff-induced middle ear disease, the recovery of negative middle ear pressure in 5 minutes without swallowing was less than 10 mm H2O, whereas in all seven ears with normal eardrum, negative middle ear pressure recovered by more than 20 mm H2O in 5 minutes. These findings suggested that impairment of gas exchange function through the middle ear mucosa, as well as eustachian tube dysfunction, might be closely related to the development of sniff-induced middle ear diseases.

Secretory otitis media in adults: II. The role of mastoid pneumatization as a prognostic factor

The sequelae of secretory otitis media (SOM) were monitored in 72 adult patients with SOM who were followed up for an average of 33 months. It was found that SOM became chronic and retraction of the tympanic membrane appeared as a function of the pneumatization of the mastoid. Ears with poor pneumatization (less than 6 cm2) developed chronic SOM in 52.2% of cases, as compared with 20% in cases with well-pneumatized ears (6 cm2 and above). Atelectasis developed in 37.3% of poorly pneumatized ears, and in only 5.7% of well-pneumatized ears. These sequelae may therefore be linked pathogenetically to the extent of pneumatization, as both the SOM and the sequelae appeared many years after formation and maturation of the pneumatic system. This study supports other studies that view the mastoid pneumatic system as an organ, as a middle ear pressure buffer. Well-pneumatized ears rarely develop a negative pressure and are seldom associated with chronic sequelae. Ears with poorly pneumatized mastoids lack the physiological function of such a pressure buffer. Ears with a tendency to develop a negative gas balance, whether as a result of deficient ventilation or excessive diffusion, will therefore develop a negative pressure more readily when their pneumatic system is underdeveloped, and consequently will be more prone to develop chronic sequelae.

Secretory otitis media in adults: I. The role of mastoid pneumatizationas a risk factor

We analyzed clinically 102 ears with secretory otitis media (SOM) belonging to 72 adult patients who during their adult life had not suffered previously from ear disease. As in children, most of the cases (63%) could be traced directly to an upper respiratory tract infection. The most striking finding was the preponderance of poorly pneumatized mastoids-which were measured planimetrically-among our SOM cohort. This was found in adult SOM ears compared to contralateral healthy ears (4.59 versus 7.88 cm2), as well as when all 102 SOM ears were compared with values of the normal population (5.41 versus 12.9 cm2). This study showed that poorly pneumatized mastoids are a significant risk factor as far as adult SOM is concerned.