Objective: Evaluation of the deafness etiology, ear examination findings and hearing levels of deaf children in a large series.
Patients and methods: We studied 840 deaf primary school children (486 male, 354 female, mean age 12.69+/-3.52, range 5-22). A questionaire investigating the prenatal, perinatal and postnatal etiological causes was prepared and pedigree analysis was performed. After ENT examination, odyologic tests were performed.
Results: The etiological features of deafness were found for genetic causes as 429 cases (51.1%), 127 children (15.1%) for acquired group and 284 children (33.8%) for unknown group. We confirmed 136 (15.5%) syndromic deaf children and 19 of them (13.9%) were autosomal recessive (AR), 105 of them (77.2%) were autosomal dominant (AD), six (4.4%) of them were X-linked. Two hundred and ninety-three deaf (33.4%) children were in the familial nonsyndromic group. In this group, the inheritance of 255 (87%) were AR, 23 (7.8%) were AD and 15 (5.2%) were X-linked recessive. Febrile convulsion was identified as the most common etiology in 36 (4.3%) cases in the acquired group. Three hundred and twenty-two (67.7%) children had profound HL (above 91 dB), 111 (23.3%) had severe HL and 43 (9%) had moderately severe HL. Sensorineural HL was found in 439 (92.2%) and mixed type hearing loss was seen 37 (7.8%) of 476 cases. We found many major and minor abnormalities and ocular, ear and dental pathologies. The prevalence of ear diseases was found in 203 (24.2%) of children. Impacted wax was found in 80 (9.5%) of 840 children with otoscopic examination and was the most common pathology, retraction in 70 (8.3%) and perforation in 15 (1.8%) followed it.
Conclusion: Preventable ear disease are important health problems among school children for the deaf because these diseases can affect the real level and type of deafness, so determining early diagnostic criteria, ear diseases and minor abnormalities is important for early rehabilitation. Syndromes can be prevented in pregnancy, infections can be prevented in prenatal or postnatal period but unknown group cannot be prevented although the unknown etiology can be reduced by multidiciplinary approach.