[Dimensions of the human temporal bone that are relevant to cochlear implantation surgery in infants and toddlers. ].

Early cochlear implantation enables prelingual deaf individuals to become full members of the hearing society. Although early diagnostics are widely accessible and enable early rehabilitation, implant surgery often may be delayed due to a candidate's young age. The authors' objectives were to determine the anatomical parameters of the pediatric and adult temporal bone that are relevant to cochlear implantation and to ascertain the differences between them in order to assess whether the anatomical differences could influence the surgical technique and the timing of surgery. Along with a survey of the literature, findings from the authors own cochlear implantees were assessed with respect to the most relevant dimensions of the internal electronic package, including the stimulating electrode of the cochlear implant, by measuring the squama of the temporal bone, the mastoid cavity and the facial recess on high resolution computed tomographic images. The skull and the overlying soft tissues proved to be thinner and the mastoid cavity was less developed in children than in adults, while no significant changes were noted in the size of the facial recess. It is recommended to choose modern, thin implants that do not require sinking the implant package into a bone bed. Less bone work in infants and children enables excellent visualization of the round window through the underdeveloped mastoid cavity, which makes the procedure less time-consuming and minimally invasive. Indeed, a young age should alert ear surgeons to be cautious, but no higher risk of injury to important structures is predicted for young subjects than those that might occur in adults. Orv Hetil. 2019; 160(24): 936-943.