Analysis of predictive factors related to long-term hearing and temporal bone development in congenital microtia

Objective: To investigate the predictive factors of long-term hearing threshold and temporal bone development in children with congenital microtia (CM). Methods: 74 patients (92 ears) with CM enrolled, which all had auditory brainstem response (ABR) results during infancy or toddlerhood, pure tone audiometry (PTA) and high-resolution computed tomography (HRCT) results during childhood or adolescence, and had not undergone any surgery. We compared the relationship between ABR, auditory steady-state response (ASSR), the affected side, auricular morphology, presence of external auditory canal stenosis or atresia, PTA average, mastoid pneumatization, Jarhsdoerfer scores, and wether cholesteatoma exists. Results: The average age of ABR in 92 ears was 2.72 +/- 3.52 years old, PTA was 7.26 +/- 2.51 and HRCT was 6.91 +/- 2.76 years old. ABR-AC was related to PTA average, mastoid pneumatization, Jarhsdoerfer scores, and wether cholesteatoma exists in CM. While ABR-ABG was related to all of these factors except Jarhsdoerfer score, and ABR-BC had no relationship with any of them. ASSR only showed correlation with frequencies of 1, 2 kHz and was related to Jarhsdoerfer score, with no other correlations observed. The impaired ear side showed no relevance. However, auricular morphology was related to all of these factors except wether cholesteatoma exist. External auditory canal stenosis or atresia was related to PTA average, but unrelated to mastoid pneumatization. Conclusion: The ABR examination in the infant stage plays a crucial role in predicting the long-term hearing and temporal bone development in patients with CM.