Abstract

Background: Approximately 5% of the general population have some sort of ear defect. There is limited knowledge on congenital external ear abnormalities among deaf pupils in Northern Nigeria and the country at large.

Patients and Methods: A cross-sectional study with a control population which assessed the prevalence of congenital external ear abnormalities among deaf pupils in Kaduna metropolis. Deaf pupils from two schools for the deaf were recruited for this study from November 2016 to August 2017. The pupils had screening audiometry done to ascertain their hearing thresholds. Data was collected using questionnaires in a multi-staged sampling fashion. The generated data was analysed using Statistical product and service solutions (SPSS) for windows version 20.

Results: A total of 430 subjects with equal number of controls participated in this study. The mean age for the subjects and controls were 13.48 ± 2.36 and 13.08 ± 1.81 respectively. The male:female ratio for the subjects was 1.29:1. Ninety three out of the 430 subjects had ear abnormality, giving a prevalence of 21.6%. The most common major anomaly in the subjects were external auditory canal atresia 3 (0.7%) and congenital absence of the tragus 3 (0.7%) while microtia 7 (1.6%) was the most common major abnormality in the controls. There was a slight preponderance of left sided abnormalities in both groups. Thirty four subjects (7.9%) had major abnormalities. The most common minor abnormality was pre-auricular sinus in 37 (8.6%) of 63 subjects, Overall, sixty two subjects (14.4%) had minor abnormalities, (p=0.001).

Conclusion: Prevalence of congenital external ear abnormality was higher among the deaf compared to the general population. Pre-auricular sinus was the most frequent congenital external ear abnormality among the participants and there was a slight left sided preponderance.

Keywords: External ear abnormalities; Congenital; Deaf pupils; Kaduna