Mastoid Air Cell System Research Articles

Chronic Middle Ear Inflammation and the Development of Mastoid Air Cell System

Chronic Middle Ear Inflammation and the Development of Mastoid Air Cell System

The causes of asymmetry of the mastoid air cell system.

Starting from age 2 up to 7 years, 79 otherwise healthy children underwent nine tympanometric tests. At the age of 7, mastoid X-rays were obtained and the air cell areas measured by planimetry. The mean area was 8.4 cm2, with a left-right mean difference of 1.57 cm2. The children could be divided into three groups: (1) the ears with the smallest cell system associated with abnormal tympanograms (i.e. 'agreement'); (2) the ears with the largest cell system associated with abnormal tympanograms (i.e. 'disagreement'); (3) children with symmetrical cell systems and tympanograms. Significant majority of children showed 'agreement'. The results indicate that the size of the mastoid air cell system is determined by the degree of pathological involvement of the middle ear during childhood.

Anterior hypotympanic approach for glomus tumor of the infratemporal fossa.

The anterior hypotympanic approach to the infratemporal fossa permits direct exposure of glomus jugulare and glomus tympanicum tumors of the middle ear, hypotympanum and petrous apex with the preservation of normal structures and hearing. Smaller glomus tumors arising in the middle ear extend anteriorly along the paths of least resistance into the hypotympanum and petrous apex to involve the carotid canal and, only later in the course of disease, extensively involve the jugular bulb, neck, or mastoid air cell system. Clinical experience demonstrates that this approach can effectively cure or control small glomus tumors in selected patients. In patients with more extensive disease, the surgical field may be expanded by removing the mastoid tip with facial nerve mobilization to remove the jugular bulb and posterior tumor extensions while preserving middle ear function and hearing.

Mastoid pneumatization. Evidence of the environmental theory.

Forty-one randomized, otherwise healthy children with tympanometry were observed from birth until the age of 6 years. At a total of 13 trials, tympanometry and otoscopy were performed. The tympanometric profile was correlated to the size of the mastoid air cell system, as determined by planimetric measurement of roentgenograms taken at age 6 years. There was a notable correlation between the size of the cell system and the tympanometric profile. Thus, the least affected ears with mostly normal or slightly abnormal tympanometry had considerably larger cell systems than the most affected ears with secretory otitis and tubal dysfunction. The findings support the environmental theory of pneumatization.

Reconstruction of the posterior canal wall with Proplast.

Many ears with prior radical or modified radical mastoidectomy operations can be rehabilitated by reconstruction of the posterior canal wall with the porous biocompatible implant material Proplast. Many techniques have been advanced for reconstruction of the posterior canal wall and/or obliteration of the mastoid bowl. We prefer reconstruction of the posterior canal wall to obliteration of the mastoid bowl on the theoretical grounds that with obliteration you lose the pneumatic buffer of the mastoid air cell system and you might be burying infection and/or cholesteatoma in the depths of the mastoid. In this article we shall present our results with elimination of the open mastoid bowl by reconstruction of the posterior canal wall with Proplast. A retrospective study of 83 consecutive patients who underwent reconstruction of the posterior canal wall with Proplast during the 5-year period 1974 to 1978 was undertaken. The surgical technique consisted of rebuilding the tympanic membrane, when necessary, repairing the ossicular chain, when necessary, and reconstructing the posterior canal wall. The overall success rate for the posterior canal wall reconstructions was 46% (38 of 83). However, after modifications were made in the technique, especially in the use of thicker fascia and/or perichondria and periosteum over the Proplast, the success rate increased dramatically to 68% (19 of 28).

Ear drum mobility and middle ear volume measured with tympanometry.

Tympanometry was evaluated as a measure of the volume of the air-containing space of the middle ear cleft as well as of tympanic membrane displacement in persons with intact tympanic membranes. Static compliance reduced with compliance of ear canal volume at -400 mm H2O, was determined with 0.22 kHz probe tone frequency. Further the difference in compliance obtained at +/- 400 mm H2O was regarded as a measure of ear drum mobility. The volume of the middle ear cleft including the mastoid air cell system was measured indirectly by X-ray of the ear in a lateral projection. No relation was found to exist between static compliance and mastoid air cell area measured on the X-ray film. Nor was there any relation found between ear drum mobility measured with tympanometry and size of the mastoid air cell system.

The unsafeness of 'safe' ears.

Active chronic otitis media affects 0.5 per cent of adults and has two main variants. The first is when there is a squamous epithelial retraction pocket or cholesteatoma. The second variant is when the disease is primarily of the mucosa of the middle ear and mastoid air-cell system. Classically a cholesteatoma is considered 'unsafe' because of the risk of complications, particularly intracranial infection. Mucosal disease, on the other hand, is considered 'safe' because complications are thought to be rare. Surgery in the form of a modified radical mastoidectomy is considered to make active chronic otitis media 'safe'. A retrospective review of 26 consecutive brain abscesses considered secondary to active chronic otitis media revealed that a cholesteatoma was present in 12 (46 per cent), mucosal disease in 10 (38 per cent) and a modified radical mastoidectomy had been performed in four (15 per cent). Mucosal disease and a modified radical mastoidectomy should no longer be considered 'safe'. However, the risk of developing an intracranial abscess from any type of active chronic otitis media is low, in the region of one in 3,500.

Mastoid pneumatization in secretory otitis. Further support for the environmental theory.

A cohort of 222 randomized healthy children was followed with 7 repetitive tympanometries from the age of 4 to the age of 7 years. At the age of 8, the size of the mastoid air cell system in 17 children with normal tympanometric profiles and in 27 children with pathological tympanometric profiles, indicating secretory otitis, was examined by planimetry. The air cell system was significantly larger in the normal group than in the abnormal group, strongly indicating the validity of the environmental theory of pneumatization.

The petromastoid canal.

The embryology and anatomy of the petromastoid canal is reviewed. This structure may be responsible for the passage of some infections of the middle ear cleft into the posterior fossa. It also transmits important blood vessels to a portion of the bony labyrinth, to the facial canal, and to the mucosa of the mastoid air cell system.

Late post-operative hearing results correlated with the severity of tissue changes in ears with chronic otitis media.

Late hearing results in 627 ears (574 patients) operated on radically for chronic otitis media are presented. Clinically, the ears were followed-up annually for 5-14 years. The results are correlated with the severity of histopathological changes in the tympanic cavity and in the mastoid air-cell system and also with the management of the tympanic mucosa and ossicular chain at operation. The mean post-operative air-bone gap was significantly better in ears with mild histopathological changes than in ears with severe histopathological changes in the middle ear (17.0 db./33.1 db.; p less than 0.001) or mastoid (29.0 db./34.2 db.; p less than 0.01) at operation. The difference in hearing results in favour of the former group was more significant in ears in which the tympanic mucosa had been saved at operation (p less than 0.01/p less than 0.001) than in ears in which the mucosa had been removed (p less than 0.05).

The temporal bone in patients with Meniere's disease.

Sixty-three patients with Meniere's disease were compared with a group of healthy individuals with respect to findings at tomography and plain radiography. The temporal bone in patients differed in many respects from that in the healthy controls. Characteristic features in patients were a lack of periaqueductal pneumatization, a lack of pneumatization medial to the arcuate eminence, a short vestibular aqueduct, a narrow external aperture of the vestibular aqueduct, and a reduction in size of the mastoid air cell system. The mean mastoid area in the diseased ear in patients was 7.93 cm2 and in controls 11.59 cm2. The vestibular aqueduct was visible in its full length on tomograms in 81% of the healthy controls and in 65% of the diseased ears in patients. The mean volume of the mastoid air cell system in Meniere patients, determined at operation, was 5.3 ml.

Acute otitis media and radiographic findings in the mastoid air cell system

The area of the mastoid pneumatization was measured planimetrically on lateral X-ray pictures of the ears of 232 patients with acute otitis media. In the present otitis media patients the mean size of the air cell system as a function of the age was similar to the values given in earlier investigations of “normal” populations. The size of the air cell system was classified as small, medium-sized or large as a function of the age based upon the mean ± 1 S.D. There were 61 patiens who had no previous history of otitis media. However, 10% of these patients had a small air cell system and only 15% a large cell system, which indicated that many had suffered from otitis media which had not been recognized. The size and clouding of the air cell system had a significant prognostic value with regard to healing and eventual outcome of the disease.

Volume Measurement of Middle Ear and Mastoid Air Cell System with Impedance Audiometry on Patients with Eardrum Perforations

(1982). Volume Measurement of Middle Ear and Mastoid Air Cell System with Impedance Audiometry on Patients with Eardrum Perforations. Acta Oto-Laryngologica: Vol. 93, No. sup386, pp. 70-73.

The size of the mastoid air cell system among black and white children with middle ear effusion

The incidence of middle ear disease among black American children is lower than among white children. Many factors may contribute to this difference. The possibility of an anatomical variation regarding the cellularity of the mastoid process was investigated. The size of the mastoid air cell system was measured in black and white children with and without middle ear effusion. A significantly smaller mastoid air cell system was found in the groups with middle ear disease compared to those without disease. No difference between white and black children in diseased as well as non-diseased ears could be demonstrated.

Ear surgery and mastoid air cell system.

Opinion differ whether simple myringoplasty should be combined with mastoidectomy, which is claimed to provide a large air reservoir for the middle ear. Data are reported on 61 ears, 55 of which had reasonably normal tympanic mucosa but distinct chronic mastoid or epitympanic ear disease. Obliteration of the cavity was performed, combined with tympanoplasty, and the patients were followed up for an average of three years. Normal aeration of the middle ear was seen in all cases with normal middle ear mucosa regardless of whether the posterior canal wall was saved or reconstructed in connection with obliteration. It is concluded that there is no reason for mastoidectomies in small mastoid cell systems in simple myringoplasties.

Totale und basale Ver�dung der pneumatisierten Bulla tympanica (Hypotympanon) des Schweines mit por�ser Tricalciumphosphat-Keramik

The application of tricalciumphosphate ceramic to obliterate the mastoid air cell system is studied in this paper. For this purpose the bulla tympanica of four 2–3 months old pigs was totally excuterated with a drill and consequently filled with adjacent layers of porous tricalciumphosphate ceramic. In six additional animals only the basal cell tract was removed and obliterated with ceramic, leaving intact the apical part of the bulla. The histologic findings at survival times of 1, 3, and 6 months are demonstrated and discussed.

Secretory otitis media and mastoid pneumatization.

The objective of this study is to correlate in children with chronic secretory otitis media the extent of pneumatization with morphological and functional end results after therapy. For this purpose we examined 82 children and adolescents (147 ears), who 5 to 8 years previously were treated with insertion of ventilating tubes for chronic secretory otitis media. We evaluated the morphological and functional end results with otomicroscopy, pure tone audiometry, tympanometry and stapedial reflex testing. Roentgenograms of the temporal bones in a lateral projection were taken initially in 96 ears and at time of control in 145 ears. We judged the size of the mastoid air cell system by visual estimation and classified the mastoids according to the extent of pneumatization into three groups: large, middle-sized and small (sclerotic). Twenty-five percent of the ears had sclerotic mastoids at time of control. Statistically significant correlations exist between arrested pneumatization (sclerotic mastoids), major morphological changes in the tympanic membranes and unfavorable functional results. Also the correlation between sclerotic mastoids and the number of tube insertions required in the course of the disease is statistically significant. But no correlation can be established between the physical properties of secretions and the extent of pneumatization. Arrest of pneumatization leading to a small mastoid air cell system constitutes an unfavorable prognostic factor for the final outcome of chronic secretory otitis media.

Surgery of the mastoid in ears with middle ear effusion.

It has been demonstrated that in most ears with middle ear effusion the mastoid air cells may be involved as well. The mucosal changes and the secretion extends into all cavities of the ear including the mastoid air cells. In most ears insertin of a ventilating tube through the tympanic membrane is adequate for proper aeration of the middle ear as well as of the mastoid air cell system. The draining usually stops and the mucosa gradually changes into its normal condition. In a small percentage of these, the ear will continue to drain and the mastoid will not clear up. Antibiotics and decongestants fail to cure the ear. Surgical intervention of the mastoid may be indicated in the rare cases where conventional treatment fails to control the condition. The aim of this report is to 1) focus attention to the fact that the mastoid is an integral part of the middle ear cavity; 2) discuss the pathogenesis in stubborn ears with middle ear effusion; and 3) demonstrate the surgical procedure commonly used in our department in order to reestablish aeration of the mastoid air cell system. Early recognition and proper treatment of ears with middle ear effusion will hopefully reduce the incidence of stubborn cases and also decrease the number of those cases which end up with chronic otitis media and cholesteatoma. It is hoped that the screening programs involving school and even preschool children, as well as new preventative programs, will diminish the frequency of cases which need extensive surgery as discussed in this paper.

Eustachian tube function and retraction of the tympanic membrane.

The medial displacement of the tympanic membrane or the retracted tympanic membrane is a common clinical finding. Also, retractions are looked upon as the precursor of middle ear cholesteatoma. In current otologic literature there seems to be some dispute whether the retractions of the tympanic membrane are caused by negative intratympanic air pressure or by shrinkage of middle ear adhesions pulling the tympanic membrane or part of it medially. In this study only ears with posterior/superior retractions of the tympanic membrane were investigated. Tympanometry revealed that only 33% of the ears did have middle ear pressure within +/- 100 mm H2O. After insertion of a polyethylene tube through the tympanic membrane, the eustachian tube function was tested using the air pressure equalization technique. None of the ears could change the negative air pressure upon swallowing. Planometric measurements on the x-ray of the mastoid air cell system of the present material deviate from those of a normal material, indicating a significantly smaller air volume in the present material. It may be concluded that dysfunction of the eustachian tube and a small air volume of the mastoid are characteristic features of an ear with posterior/superior retraction of the tympanic membrane.

Pneumatization of Mastoid Air Cell System in Cleft Lip and Plate Cases

Summary27 cases of cleft cases have undertaken in this study. Pneumatization of the mastoid air cell system has been studied in a case of cleft lip & palate. The area of pneumatization is less in cleft lip and palate populations as compared Lo control subject.