Mastoid pneumatization in otosclerosis

Impact of the Angles of the Septal Deviation on the Degree of the Mastoid Pneumatization

Introduction:

The aim was to explore the developmental relationships between the angles of septal deviations and the degree of the mastoid pneumatization.

Materials and Methods:

In total, 143 patients with a diagnosis of septal deviation who underwent septoplasty were included. The patients were divided into three groups in terms of the angles of the septal deviation. The angle of the septal deviations was defined as mild (<9 degrees), moderate (between 9 and 15 degrees) and severe (15 degrees and above). The degree of the mastoid pneumatization of each groups were compared.

Results:

In right-sided septal deviation subjects, the right mastoid air cell volumes of group mild, moderate and severe were 6,31±2,33 cm3, 5,20± 1,51 cm3, and 5,31±1,57 cm3, respectively. The mean right mastoid volumes of each groups did not differ in right-sided deviations subjects (P>0.05). The mean left mastoid volumes of each groups did not differ in right-sided deviations subjects (P>0.05). In right-sided septal deviation subjects, the mean volume of the right and left-sided mastoid air cells of each groups did not differ (P>0.05). In left-sided septal deviation subjects, the mean volume of the right and left-sided mastoid air cells of each groups did not differ (P>0.05).

Conclusions:

No developmental relationships between the angles of septal deviations and the degree of the mastoid pneumatization was observed in the study.

Tympanic Resonance Hypothesis

Seemingly unrelated symptoms in the head and neck region are eliminated when a patch is applied on specific locations on the Tympanic Membrane. Clinically, two distinct patient populations can be distinguished; cervical and masticatory muscle tensions are involved, and mental moods of anxiety or need. Clinical observations lead to the hypothesis of a “Tympanic Resonance Regulating System.” Its controller, the Trigeminocervical complex, integrates external auditory, somatosensory, and central impulses. It modulates auditory attention, and directs it toward unpredictable external or expected domestic and internal sounds: peripherally by shifting the resonance frequencies of the Tympanic Membrane; centrally by influencing the throughput of auditory information to the neural attention networks that toggle between scanning and focusing; and thus altering the perception of auditory information. The hypothesis leads to the assumption that the Trigeminocervical complex is composed of a dorsal component, and a ventral one which may overlap with the concept of “Trigeminovagal complex.” “Tympanic Dissonance” results in a host of local and distant symptoms, most of which can be attributed to activation of the Trigeminocervical complex. Diagnostic and therapeutic measures for this “Tympanic Dissonance Syndrome” are suggested.

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.

Does the Degree of the Mastoid Pneumatization Affect the Side of Bell Palsy?

OBJECTIVE

The aim is to investigate the impact of degree of mastoid pneumatization on the affected side of Bell palsy (BP).

STUDY DESIGN

Retrospective study in tertiary academic hospital.

METHODS

In total, 52 patients who were diagnosed with as BP were included in the study. Each patient was staged using House-Brackmann (HB) staging system. All patients underwent temporal bone computed tomography imaging. House-Brackmann scores, side of the BP, and mastoid pneumatization of all of patients were evaluated in the present study.

RESULTS

Regarding the degree of the mastoid pneumatization, there were no significant differences between the affected side and the unaffected side (P = 0.439). The degree of the mastoid pneumatization of the affected side and the unaffected side did not differ between males and females (P = 0.918 for the affected side, P = 0.765 for the unaffected side, respectively). A negative correlation between the age and mastoid pneumatization of each side was found (P = 0.001, P = 0.025, respectively). There was no significant correlation between HB score and the degree of the mastoid pneumatization of each side (P = 0.789, P = 0.703).

CONCLUSION

As a conclusion, the degree of the mastoid pneumatization is not one of the risk factors for BP. Further randomized studies with larger numbers of patients are needed to confirm these findings.

Impact of the Degree of the Mastoid Pneumatization on Cartilage Type 1 Tympanoplasty Success

OBJECTIVES

To evaluate the effect of the degree of the mastoid pneumatization on the success rate of cartilage type 1 tympanoplasty.

STUDY DESIGN

A retrospective clinical chart review.

METHODS

In total, 90 patients (44 females and 46 males; average age, 38.40 ± 11.12 years; age range: 21-65 years) who underwent cartilage type 1 tympanoplasty were included. Demographics and anatomical outcomes were recorded. The patients were divided into 2 groups in terms of anatomical success. In group A, all patients had intact grafts without perforation, retraction, or lateralization, and a dry ear, at 6 months postoperatively. In group B, reperforation of the tympanic membrane was evident 6 months postoperatively. The mastoid air cell volumes of each groups were compared.

RESULTS

The mean mastoid pneumatization in groups A and B was 5.32 ± 1.96  and 5.06 ± 2.12 cm, respectively. The mastoid pneumatization of diseased ears did not differ between the groups (P > 0.05). The mastoid pneumatization of diseased ears did not differ between males and females (P > 0.05). The mastoid pneumatization of normal ears did not differ between the groups (P > 0.05). The mastoid pneumatization of normal ears did not differ between males and females (P > 0.05).

CONCLUSIONS

The degree of mastoid pneumatization did not affect the success rate of cartilage type 1 tympanoplasty. Further studies with larger numbers of patients are needed to evaluate the relationship between the degree of the mastoid pneumatization and anatomical outcomes after placement of various graft types.

The spatial distribution of otosclerosis: a quantitative study using design-based stereology

CONCLUSION

This study documents that otosclerotic bone remodeling is distributed centripetally around the inner ear space whereas normal bone remodeling is distributed centrifugally. We suggest that this inverse relation reflects the unique osteo-dynamic setting of the otic capsule: since perilabyrinthine bone remodeling is extremely low, osteocyte deficiency and microcracks accumulate in excess toward the inner ear space with age. This may disrupt the osseus functional network, impede propagation of anti-resorptive signals, and precipitate otosclerotic bone remodeling with a spatial preference for older bone.

OBJECTIVE

To quantify the spatial distribution of otosclerotic bone around the inner ear space in order to explore a possible spatial relation with normal capsular bone remodeling.

METHODS

Otosclerotic lesions in 53 undecalcified human temporal bones were identified and volume data were measured with the CAST-grid system and processed by dedicated software for advanced design-based stereology.

RESULTS

The maximum volume fraction of otosclerotic bone was observed in the innermost perilabyrinthine zones of the otic capsule. The volume fraction of otosclerotic bone declined gradually but significantly from the inner ear space towards the capsular periphery with a general perilabyrinthine centripetal distribution.

Temporal bone Pneumatization in Otosclerosis

Objectives

To determine whether there is a difference in the pneumatization of temporal bones with otosclerosis versus normal temporal bones.

Methods

A retrospective study of 46 ears from 24 adult patients with otosclerosis and 64 ears from 47 adult patients in a control group. The study group included temporal bone CT scans available from patients with otosclerosis. The control group consisted of patients who had temporal bone CTs for reasons likely unrelated to a history of middle ear disease. Data were obtained with a virtual reality system that allows three-dimensional manipulation and analysis.

Results

The temporal bone pneumatization for the otosclerosis group was 4.82 ± 2.27 cm3 vs 6.06 ± 2.71 cm3 for the control group. Two-sample t test analysis revealed no statistical significance ( P = 0.059) between pneumatization in the control vs otosclerosis groups.

Conclusion

There is no difference in temporal bone pneumatization between patients with otosclerosis and a control population. Therefore, temporal bone pneumatization by itself is not an adequate explanation for the apparent protective effect of otosclerosis against otitis media. © 2008 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Cranial base morphology and temporal bone pneumatization in Asian Homo erectus

The external morphological features of the temporal bone are used frequently to determine taxonomic affinities of fossils of the genus Homo. Temporal bone pneumatization has been widely studied in great apes and in early hominids. However, this feature is rarely examined in the later hominids, particularly in Asian Homo erectus. We provide a comparative morphological and quantitative analysis of Asian Homo erectus from the sites of Ngandong, Sambungmacan, and Zhoukoudian, and of Neandertals and anatomically modern Homo sapiens in order to discuss causes and modalities of temporal bone pneumatization during hominid evolution. The evolution of temporal bone pneumatization in the genus Homo is more complex than previously described. Indeed, the Zhoukoudian fossils have a unique pattern of temporal bone pneumatization, whereas Ngandong and Sambungmacan fossils, as well as the Neandertals, more closely resemble the modern human pattern. Moreover, these Chinese fossils are characterized by a wide midvault and a relatively narrow occipital bone. Our results support the point of view that cell development does not play an active role in determining cranial base morphology. Instead, pneumatization is related to available space and to temporal bone morphology, and its development is related to correlated morphology and the relative disposition of the bones and cerebral lobes. Because variation in pneumatization is extensive within the same species, the phyletic implications of pneumatization are limited in the taxa considered here.

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.

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 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.

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.

The pars flaccida middle ear pressure and mastoid pneumatization index

The degree of pars flaccida retraction and the levels of mastoid pneumatization were assessed and correlated in 388 adults with intact pars tensa. Poorly pneumatized mastoids were found to be associated with retraction of pars flaccida; the poorer the pneumatization, the deeper the retraction. Well pneumatized mastoids were usually associated with normal position of the pars flaccida. The pars flaccida was previously also shown to retract in face of ME negative pressure--and its degree can be seen to be an index of ME negative pressure. Thus, the correlation of deeper degrees of pars flaccida retractions with mastoid hypopneumatization (and vice versa) lends strength to the studies which show the mastoid pneumatic system to have a function of a passive ME pressure buffer. This observation lends further evidence as to why ears with poorly pneumatized mastoids are a priori at risk to develop complications such as SOM in adults, tympanic membrane retractions and perforations, incus necrosis or retraction pocket cholesteatoma. Ears with a large pneumatic system are hardly at such risk.

Middle ear gas composition and middle ear aeration

Partial pressures of the gases in the middle ears of 14 guinea pigs were measured continuously on-line with a specially designed mass spectrometer. The average values were carbon dioxide 67.55 mm Hg, oxygen 48.91 mm Hg, and nitrogen 596.54 mm Hg. These values confirm earlier measurements and show that the gas composition of the middle ear differs basically from that of air and resembles that of venous blood. These findings are indicative of bilateral diffusion between the middle ear cavity and the blood. We propose that under physiologic as well as under pathologic (ie, atelectatic) conditions, the gas content of the middle ear is also controlled by diffusion. This mechanism fits well with the fluctuating character of atelectatic ears. Thus, a negative middle ear pressure could be secondary to excessive loss of gases through increased and excessive diffusion, although additional mechanisms are probably also involved. A likely contributing factor is poor pneumatization of the mastoid, with consequent absence of a physiologic pressure regulation mechanism by its pneumatic system.

A comparison of mastoid pneumatization in adults and children with cholesteatoma

The records of 190 adults who presented over a 10-year period with previously untreated aural cholesteatomas were analyzed with respect to age, mode of presentation at the level of the tympanic membrane, and pneumatization of the mastoid. The findings were compared with those obtained in an earlier study of 109 children (aged 13 years and younger) seen over the same period of time. Two main types of cholesteatomas were found in both adults and children, most of them (82.3%) associated with sclerotic or diploic mastoids (i.e., poorly pneumatized mastoids) and the rest (17.3%) with pneumatized mastoids. The former type was found more often in adults (96.3%) than in children (57.8%), while the latter was more frequent in children (42.2% as compared to 3.7% in adults). In both adults and children, cholesteatomas associated with poorly pneumatized mastoids showed mainly an attic and mastoid distribution communicating with a pars tensa or pars flaccida retraction or marginal perforation. Cholesteatomas associated with pneumatized mastoids appeared most often behind an intact drug (the so-called congenital cholesteatomas) and were distributed mainly in the tympanic cavity.

Mastoid pneumatization in patients with unilateral aural atresia

Debate continues regarding theories of the control of temporal bone pneumatization. The "hereditary theory" holds that mastoid size is independent of status of the mesotympanum. The "environmental theory" holds that the size of the mastoid air cell system is determined by the degree of pathological involvement of the middle ear during childhood: that is, an abnormal middle ear prompts a small mastoid. This report concerns the volume of temporal bone pneumatization in patients with unilateral aural atresias, involving a malformed mesotympanum and absence of the external ear canal. Computed tomograms of the temporal bones were available for 16 patients. The mastoid pneumatization volumes of the atretic/non-atretic sides were approximately equal (Spearman's r = 0.80, P < 0.01) but not symmetrical. In 12 patients, the atretic side had less pneumatization than did the non-atretic side; in 3, the atretic side had more pneumatization; and, in 1 patient, neither mastoid had any pneumatization. Such a non-symmetrical pattern is unlikely by chance (P < 0.04). These data can be interpreted to endorse both the hereditary and environmental theories of temporal bone pneumatization.

Correlation between mastoid pneumatization and position of the lateral sinus

The distance between the lateral sinus and the external ear canal was measured in 148 patients (150 ears) with completely sclerotic (nonpneumatized) mastoids and in 75 healthy random control subjects (150 ears), with pneumatized mastoids. A highly significant difference (p less than .0001) was found between the two groups, the mean distance (+/- SD) among patients being 7.8 +/- 1.7 mm, while among controls it was 13.5 +/- 2.8 mm. Moreover, a significant positive correlation (p less than .001) was found within the pneumatized control group itself, between the sinus' distance and the degree of mastoid pneumatization. The results of this study may be interpreted by those who espouse environmental theories as denoting that infantile otitis media will determine the position of the lateral sinus. However, those who favor the genetic explanation may maintain that since the position of the sinus is established prenatally and involves organogenetically the shape of the skull, the final position is unlikely to be influenced by postnatal otitis media.