Volume and Surface of the Mastoid Cell System in Otitis Media With Effusion in Children: A Case-Control Study by Three-Dimensional Reconstruction of Computed Tomographic Images

Objective: To characterize the pneumatization of the temporal bone in age-matched healthy children and in children with otitis media with effusion (OME). Study Design: Prospective case-control study. Setting: Tertiary hospital center. Patients: This study included 40 healthy children and 56 children with OME, with age ranging from 2 to 18 years. Intervention: Mastoid volume and surface determination by 3-dimensional reconstruction of axial temporal bone computed tomographic images. Main Outcome Measure: Mastoid volume and surface area comparison of healthy children and children with OME. Results: The mastoid cell system (MCS) grows continuously up to the age of 18 years, with different intensities. The mean +/- SD MCS volume and surface of children with OME are significantly lower (2.82 +/- 1.51 ml and 40.45 +/- 18.14 cm(2), respectively) than those of healthy children (10.05 +/- 5.3 ml and 84.47 +/- 37.95 cm(2), respectively). The mastoid volume and surface area of the left and right ears correlate well in healthy children. In children with bilateral OME, the ipsilateral and contralateral ears can be largely different. The ratio of surface and volume is constant in age groups. Conclusion: In children with OME, the functional volume of MCS acting as a pressure buffer and the surface area serving for gas exchange are small. In case of OME, 1 ear could be more seriously affected by the disease. Otitis media with effusion presumably has a negative effect on the mastoid pneumatization process. The surface-to-volume ratio is constant through chronological age and is a good indicator of a normal middle ear function.