Hearing Loss Profiles in Sporadic and Familial Microtia: Clinical Insights From an Ecuadorian Cohort

Background

Microtia is a congenital anomaly of the external ear that often leads to hearing loss due to associated auditory canal and middle ear malformations. While right-ear predominance and conductive hearing loss are well-documented, few studies have compared anatomical and audiological differences between sporadic and familial cases, especially in underrepresented populations.

Objective

To compare the clinical, anatomical, and auditory characteristics of patients with sporadic versus familial microtia in an Ecuadorian cohort.

Methods

A cross-sectional study was conducted on 146 patients with microtia, classified as either sporadic or familial. Demographic, clinical, and risk factor data were collected through structured interviews. Audiological evaluations included auditory evoked potentials, otoacoustic emissions, tympanometry, pure-tone audiometry, and speech audiometry, based on patient age and canal patency. Statistical analysis included Mann–Whitney U and Chi-square tests (p < 0.05).

Results

Right-ear involvement was most common (45.45%). Grade 3 microtia was the most prevalent, while Grade 4 was observed exclusively in familial cases. Conductive hearing loss predominated (74.67% left ear, 83.33% right ear). Although no significant differences in hearing loss type or severity were found between groups, familial cases showed a trend toward more severe impairment. Otoacoustic emissions and stapedial reflexes were more frequently absent in right ears. Pure tone perception and speech recognition were also more impaired on the right side.

Conclusion

Microtia is most commonly right-sided and associated with significant conductive hearing loss. Familial cases may present with more severe features. Early diagnosis and intervention are essential to mitigate developmental consequences, particularly in resource-limited settings.