Evaluation of an Infant Temporal-Bone Model as Training Tool.

OBJECTIVE: Evaluation of the face validity of a new artificial model of an infant temporal bone (TB) suitable for surgical training, including cochlear implantation. SUBJECT: Micro-computer-tomography images were obtained from a TB specimen of a 1-year-old normal infant available in an anatomical collection. The TB model was designed and constructed using these images and techniques known from similar models of adult TB. INTERVENTION: Fifteen otology departments in Austria, Germany, and Switzerland rated the infant TB model and compared it with the established adult TB model manufactured commercially by the same company. MAIN OUTCOME MEASURE: The otologists responded to a semi-quantitative questionnaire with a rating scale ranging from 1 (strongly disagree) to 5 (strongly agree). Macroscopic and microscopic anatomic details, drilling experience, and surgical landmarks were rated. The surgical procedures included mastoidectomy, posterior tympanotomy, cochleostomy, and insertion of a cochlear electrode. RESULTS: Overall ratings were similar (3.9) for both the infant and the adult TB models, with ranges of 3.47 to 4.47 (infant model) and 3.5 to 4.33 (adult model). Ratings of specific anatomical details differed as a function of type of model, but without preference of one model over the other. CONCLUSIONS: Infant TB models can be used similarly as adult TB models for surgical training, including cochlear implantation. They may deserve a more important role in surgical training because cadaveric human temporal bones of infants are not available.

An artificial temporal bone as a training tool for cochlear implantation.

OBJECTIVE: Description and evaluation of a newly developed artificial temporal bone (TB) model suitable for surgical training for cochlear implantation. SUBJECT: Based on micro-computed tomographic images, a TB model was designed with material properties as similar to bone as possible. The bony anatomic details were rebuilt as closely as possible with preservation of the endocochlear lumen. INTERVENTION: The TB model was compared with a human cadaveric TB by 8 otologists experienced in cochlear implantation. MAIN OUTCOME MEASURE: The otologists were asked to respond to a semiquantitative questionnaire with scales from 1 (strongly disagree) to 5 (strongly agree). Anatomic details were compared macroscopically and microscopically. The surgical steps of mastoidectomy, posterior tympanotomy, cochleostomy, and insertion of a cochlear electrode were assessed. RESULTS: The material properties and anatomic details of the TB model were generally comparable to the human TB. One exception was the round window membrane, which was not modeled appropriately. The surgical steps, including the insertion of the electrode, were rated as comparable. CONCLUSION: The TB model is suitable for surgical training for interventions such as cochlear implantation. It cannot replace cadaveric human temporal bones completely, but it provides an easily available alternative to train and develop surgical skills. A wider variety of anatomic models, such as an infant's TB or malformations, will increase the value of TB models.