LAUSR

BACKGROUND A debate exists on whether the size of temporal bone pneumatization is a cause or consequence of otitis media (a global disease burden). However, a normal middle-ear mucosa is a prerequisite for normal temporal bone pneumatization. This study investigated the size of temporal bone pneumatization with age and the normal distribution of air cell volume in different stages of human growth postnatally. MATERIALS AND METHODS A three-dimensional computer-based volumetric-rendering technique was performed bilaterally on 248 head/brain and internal acoustic meatus CT images of slice thickness ≤ 0.6 mm consisting of 133 males and 115 females with age range 0-35 years. RESULTS The average volume of infant (0-2 years) pneumatization was 1920 mm3, with an expected rapid increase to about 4510 mm³ in childhood (6-9 years). The result also showed a significant increase (p < 0.001) in the volume of air cells up to the young adult stage I (19-25 years), followed by a significant decline in young adult stage II (26-35 years). However, the females were observed to experience an earlier increase than males. Also, population differences were observed as the Black South African population group showed a higher increase in volume with age than the White and Indian South African population groups, though the volumes of the latter increased up to young adult stage II. CONCLUSIONS This study concludes that the pneumatization of a healthy temporal bone is expected to continue a linear increase up until at least adult stage I. Termination of temporal bone pneumatization in an individual before this stage could signify pathologic involvement of the middle ear during childhood.