To evaluate temporal bone pneumatization with growth using 3D reconstructed computed tomography (CT) images.

Eighty-four temporal bones of 42 patients under the age of 16 years who had undergone head and facial bone CT were included in this retrospective study. The bony growth of the temporal bone and the head size were evaluated with horizontal- and vertical-plane CT images. Pneumatization of the temporal bone was investigated with 3D reconstruction software using axial CT images, dividing them as follows: medially, anterosuperiorly, posterolaterally, and inferiorly. Pneumatization of each individual part was compared with that of other parts and was also evaluated according to the aging process.

The mean pneumatization was measured as 1696.7 mm³ in patients aged under 2 years, 3609.1 mm³ in those aged 2–4 years, 5351.1 mm³ in those aged 5–7 years, 7295.9 mm³ in those aged 8–10 years, 7797.5 mm³ in those aged 11–13 years, and 8526.6 mm³ in those aged 14–16 years. The degree of temporal bone pneumatization of each part was correlated with that of other parts (p < 0.05). The volume of pneumatization increased with growth of the temporal bone and with aging. The degree of pneumatization of specific parts might be related to developmental periods.

The pneumatization of one part might affect the pneumatization of other nearby parts, or all parts might be affected by the same driving force of pneumatization.