PubMed · 10699833
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J Y Sichel, R Eliashar, I Dano. 2000. Explaining the Weber test.. https://doi.org/10.1016/s0194-5998(00)70071-4
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The importance of early hearing screening has long been recognized, as the prognosis for the hearing impaired child is improved when the diagnosis is made as early as possible, and the intervention is begun immediately. For clinical screening of hearing impairment, the recording of otoacoustic emissions was recommended. As some risk factors for early brain damage are at the same time also risk factors for dysfunction of auditory system, we presumed that infants at risk for brain damage have hearing impairment more frequently than the rest of the population of the same age. We were interested in the role of otoacoustic emission testing during the assessment of auditory function in these infants. There were 110 infants at risk for brain damage included in the study. After thorough otorhinolaryngological examination, auditory function was estimated by recording of otoacoustic emissions, tympanometry, pure tone audiometry and, when necessary, auditory brainstem responses. Otoacoustic emissions were recorded by Madsen-Electronics Celesta 503 in an acoustically treated sound room. We registered spontaneous as well as transient and distortion product otoacoustic emissions. The neurologist formed two groups with different degrees of neurological risk. The collected results of auditory function were compared with the degree of neurological risk. For the statistical analysis, the procedure chi(2) and Fischer test were used. Spontaneous otoacoustic emission was detected in 38.2% of examinees. Evoked otoacoustic emissions were registered in 87.3% of infants. The testing had to be repeated in 32.7% of infants. We observed evoked otoacoustic emissions to be present also in a child with sensorineural hearing impairment and no auditory brainstem responses. Up to 32.7% of infants at risk for brain damage were hard of hearing. Conductive hearing loss was discovered with 25.4% of infants, and eight (7.3%) had sensorineural hearing impairment. In the group of examinees with only risk factors 3.6% had sensorineural impairment and in a group with abnormal motor development, there were 18.5% with that kind of hearing loss. Fischer test confirmed a statistically significant difference between the groups. Infants at risk for brain damage have more frequently impaired auditory function than their peers. For this reason, it is especially important to focus attention on the hearing condition when dealing with this population. Recording of evoked otoacoustic emissions is very helpful in pediatric audiometry, but any interpretation of the results should consider the possibility of auditory neuropathy.
This study aimed to evaluate the effect of surgically assisted rapid palatal expansion on the skeletal structures of the midface. Ten patients (mean age 28.5 years) were investigated by means of acoustic rhinometry, study model analysis and sonography before and after the procedure of surgically assisted rapid palatal expansion. The measurements revealed that surgically assisted rapid palatal expansion not only resulted in transverse expansion of the maxilla, providing dental arch space for lining up the teeth; the procedure also caused a substantial enlargement of the maxillary apical base and of the palatal vault, providing space for the tongue for correct swallowing and thus preventing relapse. There was a distinct subjective improvement in nasal breathing associated with enlargement of the nasal valve towards normal values and with an increase of nasal volume in all compartments. The measurements showed a marked influence of surgically assisted rapid palatal expansion on the skeletal structures of the midface. The significant widening can be demonstrated by non-invasive examination. Success of the osteotomy procedure can be readily monitored by sonographic examination of the expansion and the subsequent ossification, which allows individually adjusted retention periods and avoids frequent radiation exposure.
The recording of otoacoustic emissions is suitable for the detection of hearing loss in small children. The test meets the following requirements for hearing screening: it is carried out in a few minutes, specialized personnel is not necessary, the results do not depend on the vigilance of the child, and total costs are comparably low. However, the choice of a suitable device is quite essential. A test of the ILO88, ILO92, Echosensor (Otodynamics Ltd.), and Echoscreen (Madsen) devices was performed with 102 children (aged < 1 year). Additionally, a software package (Otoclass) for offline analysis of ILO88 data files was tested. The results indicate that all devices applying OAE as a screening measure was able to detect every ear (n = 25) with a hearing loss indicated by the outcome of a control BERA (stimulus level 35 dB nHL), thus reaching a sensitivity equal to 100%. The specificity of the different OAE devices depends on the underlying detection strategy. The best results were achieved with the automated Echoscreen device (95.9%) followed by the Otoclass analysis software (94.2%). The Echosensor device failed in our study to provide good specificity (77.3%). Reflex audiometry, which is favored by pediatricians in Germany, when used alone is completely inadequate as a screening method, even if conducted by a well-trained investigator. In our study, only 61.5% of the children with hearing loss were detected with reflex audiometry, and 42.7% of the children with normal hearing were misclassified. These results deviated from the results presented in ref. 13 to a large extent, as the Hanover group attested sensitivity and specificity of 100% for reflex audiometry (HNO 43, Reuter et al.). The deviating results are discussed in detail.