The relationship between traumatic tympanic membrane perforations and pneumatization of the mastoid

We evaluated the possible relationship between tympanic membrane perforatio ns resulting from blast trauma or slap and pneumatization of the mastoid ce lls. A total of 25 male patients with tympanic mem bra ne perforations resu lting from blast injury (n = 7), slap (n = 17), and football hit (n = 1) an d 20 healthy male volunteers without any ear problem had temporal bone comp uted tomographic scans in the axial plane, parallel to the infraorbitomeata l line, with 2 mm slice thickness and 2-mm intervals using bone algorithm w ith a ProSpeed Spiral tomography machine. The area of air cells in each sli ce was measured using trace and area measurement functions of the tomograph y machine, and by multiplying the resulting area by slice thickness, the vo lume of each slice was calculated. For each ear, the total of volumes of ai r cells was calculated by adding the volumes of each slice containing air c ells. The calculated volumes of mastoid cells were evaluated by comparing m icroscopic findings. Both patient and control groups consisted of males, an d their ages ranged from 17 to 32 (mean 24.5) years. Microscopic examinatio ns revealed that perforations were frequently located in the lower quadrant s and that most of them were less than 3 mm. There were no pars flaccida an d marginal perforations. Ossicular chain destruction was noted neither in t emporal bone tomographic nor during intraoperative examinations. The mean ( +/- SD) volumes of right and left ear mastoid air cells in patient and cont rol groups were 6.92 +/- 2.45 vs. 7.00 +/- 2.59 cm(3) and 9.04 +/- 4.55 vs. 8.95 +/- 4.53 cm(3), respectively, and the differences were not statistica lly significant. It was found th at the level of mastoid pneumatization has no statistically significant effect on tympanic membrane pathologies due t o blast or other injuries. Copyright (C) 2000 S. Karger AG, Basel.