Air spaces of the temporal bone: a morphometric analysis with clinical implications

Background: The main objective of the present study was to analyze the morphological variations of the air spaces of the temporal bone, that is, the pneumatized and air-filled spaces of the temporal bone cavities. Materials and methods: A total of 99 sides were analyzed. Temporal bone pneumatic spaces (TBPS) were defined as the free spaces inside the cavities of the temporal bone filled with air, excluding the volume of the structures present in the investigated region. Total volumes of TBPS were calculated as the sum of total volumes of mastoid air cells (MAC), tympanic cavity (TC), and external auditory canal (EAC). Analyses were performed considering the general population and the female and male subgroups. Results: The overall results obtained on Polish popublation were set as follows: the median total volume of TBPS was demonstrated at 7882.58 mm3 (LQ: 6200.56 mm3 ; HQ: 10393.16 mm3). The median volume of MAC was set at 5813.05 mm3 (LQ: 4224.94 mm3 ; HQ: 8181.81 mm3). The median of the total volume of the EAC was demonstrated at 1294.36 mm3 (LQ: 1099.68 mm3 HQ: 1627.84 mm3). Conclusions: In the present study, the morphometric properties of the temporal bone cavities were analyzed. The results showed that the total volume of the MAC was, on average, lower in women than in men. This should be taken into account when performing procedures on the mastoid, such as mastoidectomies. It is hoped that the results of this study can help reduce potential surgical complications associated with otological procedures