ObjectivesThe primary objective was to examine duration of daily cochlear implant (CI) usage at 12 and 24 months post-operatively in single sided deafness (SSD). The secondary objective was to examine factors that could affect CI usage.MethodsRetrospective cohort of patients with SSD who received CI from January 2015 to March 2020. CI usage was evaluated at 12 and 24 months. Hearing loss duration, tinnitus scores and signal-to-noise ratio (SNR) were correlated with CI usage at 12 months.ResultsUsage data was available for 54 patients at 12 months and 38 patients at 24 months. The mean usage was 8.2 h/day (SD 4.2) at 12 months, 7.0 h/day (SD 5.1) at 24 months. 5 out of 54 (9.3%) and 7 out of 38 patients (18.4%) were non-users at 12 and 24 months post-operatively. An improved mean SNR score from pre-operative 4.4 dB (SD 2.8) to - 0.70 dB (SD 4.2) at 12 months post-operative was positively correlated with CI usage at 12 and 24 months. Hearing loss duration and tinnitus scores were not associated with CI usage.Conclusions18.4% of our patients were non-users at 24 months. Mean usage at 24 months was 7.0 h/day. Improved hearing in noise at 12 months was correlated with better usage.

Introduction: 3D-printed temporal bone models enable the training and rehearsal of complex otological procedures. To date, there has been no consolidation of the literature regarding the developmental process of 3D-printed temporal bone models. A brief review of the current literature shows that many of the key surgical landmarks of the temporal bone are poorly represented in models. This study aims to propose a novel design and production workflow to produce high-fidelity 3D-printed temporal bone models for surgical simulation. Methods: Developmental phases for data extraction, 3D segmentation and Computer Aided Design (CAD), and fabrication are outlined. The design and fabrication considerations for key anatomical regions, such as the mastoid air cells and course of the facial nerve, are expounded on with the associated strategy and design methods employed. To validate the model, radiological measurements were compared and a senior otolaryngologist performed various surgical procedures on the model. Results: Measurements between the original scans and scans of the model demonstrate sub-millimetre accuracy of the model. Assessment by the senior otologist found that the model was satisfactory in simulating multiple surgical procedures. Conclusion: This study offers a systematic method for creating accurate 3D-printed temporal bone models for surgical training. Results show high accuracy and effectiveness in simulating surgical procedures, promising improved training and patient outcomes.

Vanessa Yee Jueen Tan MBBS (S’pore), MRCS (Glasgow), MMed (ORL) Department of Otorhinolaryngology – Head and Neck Surgery Singapore General HospitalEdward Zhiyong Zhang MBBS (S’pore), MRCS (Glasgow), MMed (ORL), MCI, FAMS (ORL) Department of Otolaryngology – Head and Neck Surgery Sengkang General HospitalDan Daniel PhD Institute of Materials Research and EngineeringAnton Sadovoy PhD Institute of Materials Research and EngineeringNeville Wei Yang Teo MBBS (S’pore), MRCS (Glasglow), MMed (ORL) Department of Otorhinolaryngology – Head and Neck Surgery Singapore General HospitalKimberley Liqin Kiong MBBS (S’pore), MRCS (Edinburgh), MMed (ORL), FAMS (ORL) Department of Otorhinolaryngology – Head and Neck Surgery Singapore General HospitalSong Tar Toh MBBS (S’pore), MRCS (Edin), MMed (ORL), MMed (Sleep Med), FAMS (ORL) Department of Otorhinolaryngology – Head and Neck Surgery Singapore General HospitalHeng Wai Yuen MBBS (S’pore), MRCS (Edinburgh), MMed (ORL), DOHNS (England), GDFM Ear Nose Throat, Head and Neck Surgery Changi General HospitalCorresponding author: Vanessa Yee Jueen Tan vanessa.tan.y.j@singhealth.com.sg