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

Acute otitis media and mastoid growth

CONCLUSIONS

This study implies that the hypothesis that acute otitis media (AOM) in infancy inhibits the growth of the mastoid system cannot be accepted.

OBJECTIVE

To establish a relationship between AOM in children and their mastoid pneumatization development.

PATIENTS AND METHODS

Lateral Schüller mastoid radiographs (LMRs) were measured in two groups of children at ages 2-11 years. Group A (n=116) had a history of recurrent AOM; group B (n=108) had no such history. Patients were treated in a private clinic. Data were analysed at Tel Aviv University. The patients had their LMR taken and measured planimetrically. LMR areas on left and right sides were compared in each group and age and were tested for possible differences using the paired Student's t test. When no left/right difference was detected, the values were averaged. Groups A and B were compared at different ages using two-tailed two-sample unequal variance and correlation coefficients.

RESULTS

The analyses show that the LMR area became gradually and significantly larger with age in group A (R2=0.858; p<0.05). It did not develop significantly in group B.

Pneumatization of the temporal bones in a Greenlandic Inuit anthropological material

The degree of pneumatization of the temporal bones correlates with exposure during childhood and adolescence to infectious middle ear diseases (IMED), both acute and chronic. The pneumatized area as seen on cranial X-rays can be measured. This was applied to an anthropological material in order to develop methods for assessing ancient populations' exposure to IMED. Fifty-six Greenlandic Inuit (Eskimo) crania were examined. The crania were sexed and measured. X-rays were taken bilaterally, using the projection of Runström II, and the pneumatized area was measured planimetrically by computer. In blind trials it was found that the inter- and intraobserver variation was non-significant; that the degree of pneumatization of the temporal ossa did not reflect cranial size or sexual dimorphism; and that the pneumatized areas correlated bilaterally. Asymmetry in the size of the pneumatized areas, an indicator of exposure to IMED, was found in 5 crania (9%).

Mastoid pneumatization in otosclerosis

The extent of mastoid pneumatization in 150 otosclerotic ears was compared with that of 150 healthy control ears. The size of mastoid pneumatization was measured by use of the Schüller lateral x-ray projection with the help of computed planimetry. The measurements showed the average pneumatized area in otosclerotic ears to be 17.4 +/- 5 cm2, in contrast to 12.9 +/- 4 cm2 for the healthy control ears. The difference between the two groups was highly significant (p less than .0001). While both groups showed a bell-shaped distribution of the measured pneumatized area, the curve of the otosclerotic ears was shifted significantly to the right. Our findings indicate a link between otosclerosis on the one hand and highly pneumatized mastoids on the other. This link between a hereditary disease and a specific type of pneumatization points to the likelihood that heredity also plays some role in determining the final type of pneumatization.

Acute otitis media. An animal experimental study

This paper describes an investigation performed to study the middle ear events ensuing from Staphylococcus aureus induced infection in the middle ear cavity of the rat. To obtain an evaluation at both the cell and the tissue level, scanning electron microscopy, transmission electron microscopy and histology were used. Staphylococcus aureus infection appears to be characterized by five major events: (i) cellular response, (ii) humoral response, (iii) mucociliary response, (iv) fibroblastic response, (v) bony response. Since these occurrences correspond to the events witnessed in the human middle ear affected by acute otitis media, S. aureus achieved infection might prove a useful tool for the further study of this disease, by means of animal experiments.

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.