The effect of external auditory canal reconstruction with mastoid obliteration after canal wall down tympanomastoidectomy on hearing function: narrative review and case series.

This study evaluates the impact of mastoid obliteration (MO) on hearing outcomes and ear anatomy following canal wall-down (CWD) tympanoplasty. MO, performed with autologous or homologous materials, aims to restore the external ear canal (EEC) volume and improve postoperative quality of life by reducing heat sensitivity, water exposure, and infection risk. A case series of patients undergoing CWD with simultaneous MO was analyzed, measuring EEC volume (ECV), pure tone audiometry (PTA), and subjective hearing via the Speech, Spatial and Qualities of Hearing Scale (SSQ). Results showed that MO effectively restored ECV within normal ranges, regardless of the obliteration material used, and PTA outcomes indicated good hearing thresholds (≤30 dB). Subjectively, patients reported better hearing experiences, with SSQ scores comparable to or exceeding those of a control population. Literature review corroborates that CWD procedures alter ear acoustics, but MO can reverse these effects, improving sound transmission and perception. Overall, MO with autologous or homologous materials is a safe, effective technique for reconstructing ear anatomy, optimizing hearing outcomes, and enhancing patient-reported hearing quality post-surgery.