Effect of mastoid bone pneumatization on the conformation and depth of the sinus tympani, a high-resolution computed tomography study.

PURPOSE: To investigate the relationship between mastoid pneumatization and the conformation and depth of the sinus tympani (ST) in patients with chronic otitis media (COM), based on the high-resolution computed tomography (HRCT) scans. METHODS: Two hundred and two patients affected by COM were included in the study. The patients were divided into three groups according to the extent of mastoid pneumatization on HRCT scans; pneumatized (group 1), diploic (group 2) or sclerotic (group 3). The variation in the ST area (types A, B, C) was assessed using a radiomorphological classification based on the relationship between the medial boundary of the ST and the third portion of the facial nerve. Depth of the ST was calculated by measuring the distance between the medial boundary of the ST and medial boundary of the third portion of the facial nerve RESULTS: There was a statistically significant difference between the groups in terms of the type of ST (p < 0.001). The mean depths of the ST were 1.59 ± 0.82 mm (0.00-2.80 mm) in group 1, 1.10 ± 0.79 mm (0.00-3.00 mm) in group 2 and 0.53 ± 0.63 mm (0.00-2.60 mm) in group 3. The groups were significantly different in terms of the depth of the ST (p < 0.001). CONCLUSION: A well-pneumatized mastoid is highly associated with a deep and posteriorly positioned ST with respect to the facial nerve. The preoperative HRCT scans of patients with cholesteatoma should be carefully evaluated to determine the conformation and depth of the ST.

Implanting straight into cochlea risks the facial nerve: a Cartesian coordinate study.

PURPOSE: To describe the straight-into-cochlea line that affords the best access for an electrode array to enter via the round window, and how this line relates to the facial nerve, the incus, and mastoid size. The straight-into-cochlea line is important to minimize the cochlear trauma and maximize the likelihood of placement into the scala tympani. METHODS: High-resolution CT scans were obtained for ten craniums with the extremes of large (N = 5) and small (N = 5) mastoid pneumatization; the specimens were from a series of 41 ear normal craniums. Using FIJI, a publicly available software program, the straight-into-cochlea insertion line was determined by defining the x-y-z coordinates of the middle of the round window and a point 6.0 mm into the cochlea on its centrifugal wall. Then, from the extended straight-into-cochlea insertion line, we determined the shortest perpendicular distance to the middle of the fallopian canal, and from that "fallopian point" to the apex of the posterior process of the incus. RESULTS: We found good repeatability of measurements. We found the extended straight-into-cochlea insertion lines routinely close to or in the midst of the fallopian canal (50 % ≤ 1.0 mm). We found the lines 4.7-7.8 mm from the apex of the posterior process of the incus. Line positions relative to "fallopian point" and incus showed no relation to mastoid pneumatization. For the distance "fallopian point" to incus, bilateral symmetry was suggested. CONCLUSIONS: Using landmarks registered in an x-y-z coordinate system, straight-into-cochlea insertion via the round window puts the facial nerve at risk.

Evaluation of the Sigmoid Sinus Morphology by Cone Beam Computed Tomography; Touchstone of the Posterior Cranial Fossa.

OBJECTIVE: In this study, we aimed to analyze the relationship of the sigmoid sinus (SS) with the external auditory canal, facial nerve, and mastoid cells from an anatomic point of view, to define the position of the SS during transmastoid, translabyrinthine, retrosigmoid (lateral suboccipital) approaches, in tympanomastoidectomy and posterior cranial fossa surgery. METHODS: In this study, the morphologic structures associated with the sigmoid sinus were evaluated in cone beam computed tomography images taken between 2015 and 2022. The images of 68 men and 106 women, aged 18-65 years, obtained from the archive of Ankara University Faculty of Dentistry, Department of Oral and Maxillofacial Radiology were analyzed. RESULTS: The most common SS pattern was type II, with a rate of 60.8% (n = 209); the second was type III, with 20.6% (n = 71); and the least common was type I, with 18.6% (n = 64). Although the distance between the horizontal line passing through the external auditory canal and facial nerve and the anterior contour of the SS was highest in type I (right, 7.26 ± 1.62; left, 7.44 ± 0.97), it was lowest in type III (right, 4.40 ± 1.50; left, 4.84 ± 1.16) (P < 0.05). CONCLUSIONS: This study highlights the importance of the SS position in surgery, with special reference to otologic, neurotologic, and posterior cranial fossa surgery. To avoid intraoperative complications, each patient should be evaluated preoperatively by appropriate radiologic methods.

Providing Insight for Pediatric Ear Surgery: Analysis of Middle Ear Development via HRCT.

OBJECTIVES: Providing insight for pediatric ear surgery via investigations on the development patterns of ossicles, mastoid, and external auditory canal (EAC). METHODS: This retrospective study analyzed high-resolution computed tomography (HRCT) scans of 191 healthy temporal bones ranging from infants to adults. Subjects were grouped by 1-year intervals for developmental regression models and 3-year intervals for stage comparisons using t-tests or Mann-Whitney U tests. RESULTS: The size of auditory ossicles and tympanic cavity (TC) remained stable during development, while the minimum diameter of the tympanic sinus (TS) entrance was reduced. Regarding mastoid pneumatization, the air cells can be observed at birth, became pronounced at 2 years old, and were fully developed around the age of 5, with subsequent growth primarily involving radial expansion. Furthermore, the EAC demonstrated significant growth with age: the width of EAC increased linearly ( y ̂ $$ \hat{y} $$ = 0.12x + 4.01, R2 = 0.85), while the length of EAC followed a polynomial growth pattern ( y ̂ $$ \hat{y} $$ = -0.03x2 + 1.15x + 6.25, R2 = 0.96). CONCLUSIONS: Ossicles and TC remain stable during development. Furthermore, mastoid air cells may have developed in the early stages of life, while their diameter increases synchronously with EAC. All in all, ossicular chain reconstruction surgery and endoscopic ear surgery can be performed in babies. LEVEL OF EVIDENCE: NA Laryngoscope, 2024.

Status and Depth of Mastoid Antrum and the Pattern of Mastoid Pneumatization in Cases of Large, Subtotal Perforations and Posterosuperior Retraction Pockets (PSRP).

The present study aimed to evaluate the pneumatization status of the mastoid air cells in general with the depth and status of mastoid antrum in particular, in patients of chronic otitis media (COM). This is an observational cross-sectional study in sample size of 60 participants with large, subtotal perforation and posterosuperior retraction pocket (PSRP). Mean age with large central and subtotal perforation combined was 35.78 years, compared to 32.13 years in PSRP. Granulations seen in antrum in 71.6% and cholesteatoma observed in 15%. Mean depth of the mastoid antrum was 17.27 mm. A well pneumatized mastoid in 21.6%, diploic 28.3% and sclerotic in 50% was noted in this study. Chronic otitis media affects temporal bone pneumatization, particularly the mastoid antrum. Our findings indicate that the depth of the mastoid antrum is slightly greater in cholesteatoma cases due to bone erosion. As early intervention enhances postoperative quality of life by preserving or restoring auditory function, understanding the mastoid pneumatization and antrum depth is crucial for managing chronic otitis media effectively.

Differences in mastoid pneumatization between Asians and Caucasians.

BACKGROUND: Anatomical differences of the mastoid pneumatization in Asian and Caucasian patients must be considered when performing the retrosigmoid craniotomy since it may have implications to avoid specific complications such as cerebrospinal fluid infections or fistula. METHODS: We selected cranial CT scans of 120 Asian and 120 Caucasian patients, who were treated at the Mitsui Memorial Hospital (Japan) and at the Heidelberg University Hospital (Germany). Mastoid pneumatization was classified according to the relationship of the mastoid air cells (MAC) to the sigmoid sinus (Type I - III). The risk of mastoid air cell opening through craniotomy increases from Type I to III. Comparative analyses between gender and ethnicities were performed using the Chi2 Test and the independent T-Test and considered significant if p < 0.05. RESULT: In Caucasians, Type III pneumatization was significantly overrepresented compared to Type II or I, compared to the Asian cohort (Type III:II:I in Caucasians = 60 %:26 %:14 %; in Asians = 28 %:43 %:29 %). Importantly, we found significant differences in pneumatization types between Caucasians and Asians in both gender subgroups (m: Type III 60 % vs 35 %; Type II 30 % vs 36.7 %; Type I 10 % vs 28.3 %, p = 0.008; f: Type III 60 % vs 23.3 %, Type II 21.7 % vs 48.3 %, Type III 18.3 % vs 28.3 %, p < 0.001; Chi2 Test). CONCLUSION: Caucasian patients are more prone to the opening of the mastoid air cells than Asian patients when performing a retrosigmoid craniotomy due to differences in the degree of mastoid pneumatization. This may help to avoid complications such as postoperative infections or cerebrospinal-fluid fistula.

The association between high jugular bulb and mastoid pneumatization in adults.

Purpose: The purpose of this study was to analyze the relationship between the degree of high jugular bulb (HJB) and mastoid pneumatization using high-resolution computed tomography (HRCT). Methods: Between April 2019 and June 2022, HRCT of the temporal bone was retrospectively analyzed in 1,025 patients. By excluding the other coexistent pathologies, 113 patients with HJBs were recruited for the study. The degree of the HJBs were defined as follows: Grade I, JB situated between inferior annulus of tympanic membrane and cochlear basal turn (CBT). Grade II, JB situated between CBT and lateral semicircular canal (LSC). Grade III, JB situated above LSC. The volume of mastoid pneumatization was based on HRCT images using a 3D reconstruction. Results: There were 32 male and 81 female subjects (mean age, 41.2 ± 14.0 years; age range, 18-80 years). The male group included 16 Grade I, 28 Grade II and 6 Group III HJB subjects. The female group included 38 Grade I, 62 Grade II and 31 Group III HJB cases. In the different groups of HJB, the mastoid cell volume differences were also not statistically significant (p = 0.165). In the classification, Grade II was most common (90/181, 49.7%). Conclusion: This study found no correlation between mastoid air cell volume and HJB, suggesting that HJB may not affect the mastoid air cell development and disease occurrence. These data must be considered exploratory, requiring more extensive cross-sectional studies.

Effect of pre-operative mastoid pneumatisation on tympanoplasty success.

OBJECTIVE: This study aimed to compare the effect of pneumatised and non-pneumatised mastoid on the success of tympanoplasty in terms of rate of graft uptake and air-bone gap improvement. METHOD: A comprehensive electronic search of PubMed Medline, Scopus, Web of Science and Cochrane Library was conducted in August 2020 for articles from 1990 to 2020. Selected studies were published in the English language, were conducted on human patients, were concerned with evaluating pre-operative mastoid pneumatisation on tympanoplasty success, were not laboratory studies and were not opinion studies. Five studies were included with 178 patients in the pneumatised group and 97 patients were included in the non-pneumatised group. Comparison between both groups was performed in terms of graft uptake rate and air-bone gap improvement. RESULTS: Although the pneumatised group showed better graft uptake rate than the non-pneumatised group, there was no statistically significant difference between the two groups in the success rate of tympanoplasty. CONCLUSION: Pneumatisation of the mastoid does not significantly affect the success rate of tympanoplasty.

Investigating the significance of vestibular aqueduct pneumatization and pediatric hearing loss.

INTRODUCTION: Vestibular aqueduct enlargement on imaging is associated with pediatric hearing loss, though the mechanism is not well understood. After reviewing temporal bone imaging in pediatric patients from our institution with no obvious cause of hearing loss, we postulate that pneumatization of bone surrounding the vestibular aqueduct may also be associated with hearing loss. METHODS: 342 temporal bone CT scans performed at Children's Hospital of Michigan between January 2018 and December 2020 were reviewed. Scans were assessed for the presence, laterality, and degree of vestibular aqueduct pneumatization (PVA). Electronic medical record data was collected on age, gender, hearing status, medical comorbidities, and otologic comorbidities. Cases were secondarily reviewed to ensure validity. 159 patients were included in the final analysis; excluded scans included duplicates, patients with unknown hearing status, patients older than 21 years old, and patients with another known cause of hearing loss including inner ear malformations. RESULTS: 17.6% of patients demonstrated vestibular aqueduct pneumatization. Hearing loss percentage was comparable between the PVA and non-pneumatized group (42.9% vs 42.0%), but hearing loss was more likely to be sensorineural in the PVA group (91.7% vs 80.0%). When patients with only newborn hearing data available were excluded from the PVA group, hearing loss percentage was higher in the PVA group (50% vs 42.0%). Patients with hearing loss in the PVA group were older than those without hearing loss (14.92 years old vs 10.67 years old). CONCLUSION: Hearing loss in enlarged vestibular aqueduct syndrome is typically progressive, bilateral, and sensorineural. Our preliminary findings suggest that vestibular aqueduct pneumatization may be another anomaly associated with a primarily sensorineural hearing loss. Further studies are needed to strengthen this postulated link.

The Effect of Anteriorly Located Sigmoid Sinus on Postoperative Hearing Gains: A Case-Control Study.

There are many studies on the effects of temporal bone anatomical variations on a mastoid pneumatization. Considering the effects of the anatomic variations on mastoid pneumatization, it is considered that many anatomic variations may affect graft success rates and postoperative hearing threshold gains. We aimed to evaluate the effects of various anatomic variations on postoperative hearing gains among patients undergoing tympanoplasty. This retrospective cohort study conducted in a tertiary-care university hospital. This study enrolled 57 patients who underwent primary type 1 tympanoplasty operation using the temporal muscle fascia. The patients were divided into two groups as those with an anteriorly located sigmoid sinus (group 1), and no anatomic variation (group 2). Airway gain values at the frequency range of 250 Hz-8000 Hz and pure tone average (PTA) value were calculated preoperatively and at postoperative sixth month. The gains attained by the patient groups with anatomic variations were compared with group 2. There were significant differences between Group 1 and Group 2 in terms of the airway frequencies of 250, 500, 2000, 4000 Hz, and PTA value. We detected a lesser postoperative hearing gain in patients with an anteriorly located SS. We believe that anatomic variations that may affect middle ear and mastoid cavity may also affect postoperative hearing gain.

Congenital cholesteatoma: Clinical features and surgical outcomes.

OBJECTIVES: A typical presentation of congenital cholesteatoma (CC) is asymmetric conductive hearing loss (CHL). As CHL is usually associated with middle ear effusion, diagnosis of CC is frequently delayed. This study aimed to describe the clinical characteristics, treatment and outcomes of children with CC. METHODS: The medical files of children diagnosed with CC at a large tertiary pediatric medical center during 2000-2019 were reviewed. The primary outcome measures were: presenting symptoms, surgical findings, stage of disease, recurrence rate and hearing outcome. Imaging findings and the size of mastoid air cells were assessed in CT scans. RESULTS: Thirty-nine children were diagnosed with CC. The presenting symptom was unilateral CHL in 85%, with an average speech reception threshold of 41.5 ± 13.7 dB in the affected ear. The mean time from first symptoms to diagnosis was 1.3 years. The surgical approach was exploratory tympanotomy in 25% and canal wall up mastoidectomy in 69%. Seventy percent of the children presented with Potsic stage III-IV. The mean postoperative speech reception threshold was 26.4 ± 12.2 dB (P = 0.002). Recurrence of cholesteatoma occurred in 38% of the patients, mostly in stage III-IV. Mastoid air cell size was significantly smaller on the affected than the unaffected side. CONCLUSIONS: In children with persistent unilateral or asymmetric conductive hearing loss, CC should be suspected. Late diagnosis of CC is associated with a high recurrence rate. This highlights the need to promote awareness to the disease among primary physicians in the community health care system.

Can MDCT Scan of the Temporal Bone Looking at Pneumatization Predict Surgical Vulnerability of the Facial Nerve?

OBJECTIVES: The aim of this study is to investigate the scutum-cochleariform process (CP) and scutum-promontorium distances according to the mastoid pneumatization condition. METHODS: Two hundred temporal multidetector computed tomography scans (90 males and 110 females) were evaluated retrospectively. The scutum-CP and scutum-promontorium distances were measured. Facial canal dehiscence (FCD) in the tympanic segment and mastoid pneumatization were also evaluated. RESULTS: The distances between scutum-CP and scutum-promontorium were not different between males and females and between right and left sides. Facial canal dehiscence in the tympanic segment was detected: 5.6% (right) and 7.8% (left) in males and 5.5% (right) and 10.0% (left) in females. Grade 4 (100%) pneumatization was detected mainly in 55.6% to 57.8% of the patients in both genders. Grade 0 (0%) pneumatization (sclerosis) was detected in 22.2% to 28.2% of both males and females. In more pneumatized mastoids, the scutum-CP and scutum-promontorium distances increased. In sclerotic mastoids, the scutum-CP and scutum-promontorium distances decreased. Facial canal dehiscence rates were not related to the mastoid pneumatization levels. CONCLUSION: Cochleariform process is an important landmark to localize the tympanic segment of the facial canal. In sclerosed mastoids, scutum-CP and scutum-promontorium distances decreased. There was no relationship between FCD rates and mastoid pneumatization levels. It may be due to the development of FCD that occurs during the intrauterine period. In endoscopic and classic ear surgeries, mastoid pneumatization must be evaluated preoperatively to avoid facial nerve injuries.

The relationships among mastoid air cell development, tympanic sinus depth, and residual disease after surgery in children with congenital cholesteatoma.

Background: Mastoid development, tympanic sinus depth, and residual disease after surgery for congenital cholesteatoma are probably related, but these relationships have not been examined in detail.Aims/objectives: This study aimed to clarify the relationships between the abovementioned factors. Materials and Methods: The subjects were 31 patients with congenital cholesteatoma (stage III or IV in Potsic's staging system) that underwent mastoidectomy. The cross-sectional area of the mastoid air cells was measured as described previously. Tympanic sinus depth was classified into A-C using Marchioni et al.'s system.Results: Patients with deep tympanic sinuses or residual disease exhibited significantly greater mastoid air cell development. However, little residual disease was found in the mastoid air cells. Conversely, residual disease was observed more frequently in the patients with deep tympanic sinuses.Conclusions and significance: After surgery for congenital cholesteatoma, residual disease is more likely to occur in patients with marked mastoid growth, possibly because they have deep tympanic sinuses. Cases in which congenital cholesteatoma spreads to the mastoid air cells are classified as stage IV in Potsic's system, but our findings indicate that invasion into a deep tympanic sinus is more important than invasion into the mastoid air cells.

A quantitative study of the suppression of the development of the mastoid air cells by the presence of congenital cholesteatoma.

Background: The mastoid air cells are considered to develop better in children with congenital cholesteatoma but only a few quantitative studies have examined. Aims/objectives: The present study was undertaken in order to clarify the relationships between the development of the mastoid air cells in children with congenital cholesteatoma and clinical factors. Materials and methods: Mastoid air cell development was evaluated in 53 children with congenital cholesteatoma. The sizes of the mastoid air cells were measured on computed tomography scans of the temporal bone, and clinical factors, including age, the extent of invasion, and whether it was located close to the eustachian tube were evaluated. Results: The cross-sectional area of the mastoid air cells was significantly smaller on the affected side than on the unaffected side, especially in the older patients. The cases involving invasion into the mastoid portion also had smaller mastoid cells. Whether the cholesteatoma was located close to the eustachian tube had no effect. Conclusions and significance: The mastoid air cells on the affected side were less well developed. Our findings indicate that a high age and the presence of cholesteatoma in the mastoid region might be associated with suppressed mastoid pneumatization.

Is there a relationship between mastoid pneumatisation and facial canal dimensions?

OBJECTIVE: To evaluate mastoid pneumatisation and facial canal dimensions. METHOD: In this retrospective study, 169 multidetector computed tomography scans of temporal bone were reviewed. Facial canal dimensions were evaluated at the labyrinthine, tympanic and mastoid segments using axial and coronal multidetector computed tomography scans of temporal bone. Mastoid pneumatisation and facial canal dehiscence were evaluated. Facial canal dehiscence was measured if it was found to be present. RESULTS: This study showed that facial canal dimensions decreased in pneumatised mastoids. Facial canal dimensions in females were smaller than in males. Facial canal dehiscence was detected in 5.9 per cent and 6.5 per cent of the patients on the right and left sides, respectively. No correlations were found between facial canal dehiscence and mastoid pneumatisation. The length of dehiscence was 1.92 ± 0.44 mm (range, 0.86-2.51 mm) on the left side. In older subjects, left facial canal dehiscence was detected more, and the length of the dehiscence increased. CONCLUSION: This study concluded that during surgery, facial canal dehiscence should be kept in mind in order to avoid complications.

Relationship between the degree of mastoid pneumatization and the presence of persistent foramen of Huschke.

The aim of this study was to determine the relationship between the degree of mastoid pneumatization and the presence of persistent foramen of Huschke (FH). Temporal computed tomography images of 714 patients (1428 ears) who applied to the Otorhinolaryngology Department of Karabuk University Training and Research Hospital between January 2016 and June 2018 were retrospectively analysed. We compared the mastoid pnomatization levels of 95 patients (74 females, 21 males, mean age 53.18±15.09years) who had persistent FH and 135 patients (103 females, 32 males, mean age 54.29±15.82years) with no FH who had similar age and gender. FH was found to be unilateral (right: 23, left: 45) in 68 (71.5%) out of 95 patients with FH, and FH was bilateral in 27 (28.4%) patients. The degree of mastoid pnomatization of the patients with FH was significantly higher than the patients without FH (p=0.015). The degree of pneumatization of the mastoid bone may lead to persistent FH by affecting the ossification process of the tympanic segment, which has a close anatomical relationship with it.

Evaluation of Role of Mastoid Surgery in the Management of Safe Chronic Suppurative Otitis Media.

This study evaluates the outcome of type 1 tympanoplasty with and with out mastoidectomy. The comparative study comprises of 40 patients with CSOM safe type in dry ear. All cases were operated during a period of one and a half years. 20 of these cases were selected for tympanoplasty alone (Group A) and 20 cases were selected for Tympanoplasty with cortical mastoidectomy (Group B). Patients were reviewed after 3 weeks for inspection of the operated ear. The second and third postoperative reviews were done 6 and 12 weeks respectively for clinical assessment of the operated ear with respect to graft status, ear discharge and hearing improvement. The postoperative audiograms were recorded after 3 months. Type I tympanoplasty with cortical mastoidectomy has better graft uptake (100 %) as compared to without mastoidectomy (95 %). Post-operative A-B gap closure is better in tympano-mastoidectomy (20.48 dB) than tympanoplasty (15.75 dB) with p value <0.05. Post-operative hearing gain and graft uptake were both better with tympano-mastoidectomy and tympanoplasty.

Mastoid antral ventilation tube; new treatment modality for reccurent otitis media with effusion and its long term results.

OBJECTIVES: To evaluate the efficiency of mastoid antral ventilation tube (MAVT) treatment in recurrent/chronic otitis media with effusion (OME). METHODS: 20 OME patients who were unsuccessfully treated with ventilation tube (VT) at least twice, who consented to MAVT and who were followed up at least three years were included in the study group. Control group comprised 10 patients who had the same characteristics and refused to undergo MAVT and underwent VT placement again. Pre-operative and post-operative otomicroscopic, hearing tests, and CT findings were compared between the groups statistically. RESULTS: MAVT was placed into 24 ears of 20 patients. In the control group, VT was placed in 13 ears of 10 patients. Postoperatively, in the study group, one tympanic membrane with adhesion and nine membranes with retraction returned to their anatomic positions after MAVT. In the control group, 2 retracted tympanic membranes returned to normal position. There was significant difference between groups in terms of mastoid aeration (P = 0.006). Post-operative pure tone threshold values and mastoid aeration findings were statistically different from preoperative conditions. CONCLUSION: This preliminary study demonstrates that MAVT may be effective in the surgical treatment of recurrent/chronic OME. However, further studies with larger patient series should be carried out.

Relationship between CT findings and sensorineural hearing loss in chronic otitis media.

OBJECTIVE: To investigate the relationships between the temporal bone CT findings and sensorineural hearing loss in ears with non-cholesteatomatous chronic otitis media (COM). METHODS: Preoperative bone conduction (BC) hearing thresholds of 266 patients (304 ears) with COM were compared with those of 342 normal individuals (440 ears) by audiometry. The incidence of abnormal BC threshold at lower frequencies (250-1000 Hz) and at higher frequencies (2000-4000 Hz) were examined and the differences between control and COM groups were compared by using χ2 test. In the COM group, the cross-sectional area of the mastoid air cells based on the axial CT image (n=255) were correlated with the results of BC threshold. RESULTS: The percentage in the COM group exceeds 15% in their 50s at lower frequencies while in their 40s at higher frequencies. The BC thresholds were significantly better in the group with normal mastoid area than in those with smaller mastoid area at each decadal age group. The BC impairment from COM becomes worse as the course of the disease progresses and deteriorated from 40s rapidly, especially at higher frequencies and in the group with smaller mastoid area. CONCLUSION: These results recommend that early treatment, including surgery, should be considered as early as possible before BC impairment occurs, especially for COM cases with smaller mastoid area, which may indicate the existence of more severe otitis media since earlier childhood.

Pneumatization correlated to myringoplasty and tubal function.

The prognostic significance of the size of mastoid air cell system in the results of myringoplasty has been a matter of debate. Fifty ears with dry central perforation following C.S.O.M. were investigated. The size of mastoid air cell system was determined with planimetry of the X-ray picture and eustachian tube function was assessed using flourescein dye and nasal endoscopy. Myringoplasty was performed in all the 50 ears and postoperative results in terms of graft take up and hearing gain were assessed. The correlation between the size of mastoid air cell system, results of myringoplasty and tubal function has been discussed. The results show no correlation between the size of mastoid air cell system, postoperative results of myringoplasty and eustachian tube function.