Temporal bone trauma effects on auditory anatomical structures in mastoid obliteration.

PURPOSE: The risk of temporal bone fractures in head trauma is not negligible, as injuries also depend on the resistance and integrity of head structures. The capacity of mastoid cells to absorb part of the impact kinetic energy of the temporal bone is diminished after open cavity mastoidectomy, even if the surgical procedure is followed by mastoid obliteration. The aim of our study was to evaluate the severity of lesions in auditory anatomical structures after a lateral impact on cadaveric temporal bones in which open cavity mastoidectomy followed by mastoid obliteration was performed, compared to cadaveric temporal bones with preserved mastoids.

METHODS

The study was carried out on 20 cadaveric temporal bones, which were randomly assigned to two groups. In the study group, open cavity mastoidectomy followed by mastoid obliteration with heterologous materials was performed. All temporal bones were impacted laterally under the same conditions. Temporal bone fractures were evaluated by CT scan.

RESULTS

External auditory canal fractures were six times more seen in the study group. Tympanic bone fractures were present in 80% of the samples in the study group and 10% in the control group (p = .005). Middle ear fractures were found in 70% of the samples in the study group and 10% in the control group (p = .02). Otic capsule violating fractures of the temporal bone were present only in the study group.

CONCLUSIONS

Mastoid obliteration with heterologous materials after open cavity mastoidectomy increases the risk of fracture, with the involvement of auditory anatomical structures.