목적: Common cavity deformity is a rare congenital bony labyrinth malformation associated with profound hearing loss. Cochlear implants are widely used for hearing rehabilitation for common cavity deformities; however, the reported prognosis is poor. As a result of the deformed anatomical structure, it is important to consider the position of the electrodes to maximize the performance of the cochlear implant. The present study aimed to discuss the impact of electrode placement on hearing outcomes 방법:A retrospective medical chart review of 8 common cavity deformity patients (10 cochlear implants) who received cochlear implants was performed in a single university hospital. All implant surgery used single-slit labyrinthotomy methods. Electrodes were manually bent before insertion to prevent misplacement and to reduce physical damage to the neuroepithelium. 결과:Four of 10 electrodes were misplaced with their tips placed in the anterior semicircular canal or internal auditory canal. However, all patients after implant surgery including misplace electrodes gained auditory perception and improved hearing functions. One patient who has electrodes that did not contact the inner wall of the cavity showed limited active electrodes (27%) compared to others (64 – 100%). 결론:Proper contact of the electrode with the inner wall was more likely important for cochlear implant success for common cavity deformity than the appropriate placement of the electrode tip.