Predicting the Magnet Strength Using a Tablet-Based Tool for Patients Undergoing Cochlear Implantation

Objectives Preoperative image analysis of skin flap thickness and determining the required magnet strength are important in the management of CI surgery. The primary aim of this study is to analyze the application of OTOPLAN®, a tablet-based otological preplanning tool, in assessing skin flap thickness. The secondary aim was to determine if there is any correlation between the skin flap thickness and the selected magnet strength. Methods Fifty-seven computer tomography (CT) image datasets of temporal bones of cochlear implant (CI) patients were collected. CE marked OTOPLAN(®) planning otology software was used to load the patient’s preoperative images for measuring the skin flap thickness in both axial and coronal views. To standardize the skin flap thickness measurement, the top of the pinna on the side of implantation was taken as the measurement point. Results The mean age of the patients was 7.98 ± 1.54 years. The body mass index (BMI) was not considered in this study. The average skin flap thickness was 4.5 ± 1.2 mm (range: 2-7 mm). The inter-rater reliability test revealed strong agreement between the two reviewers (Cronbach’s alpha = 0.90). The majority of the patients were fitted with a magnet strength of 3. A statistically significant positive correlation was observed between the skin flap thickness and the age of the patients (r = 0.69, p = 0.002). Also, between the skin flap thickness and the magnet strength, a strong positive correlation was observed (r = 0.82, p < 0.0001). Conclusions OTOPLAN® is a reliable tool in the measurement of skin flap thickness with little effort. The age and the magnet strength were positively correlated with the skin flap thickness.