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At least 1,063 records · Page 59Linked to original sources
PubMed1999

Diagnosis and management strategies in congenital atresia of the external auditory canal. Study Group on Otological Malformations and Hearing Impairment.

This consensus report represents a distillation of current opinion regarding diagnosis and management of congenital aural atresia. It also takes into account the philosophical differences which exist in Europe. Congenital aural atresia requires prompt diagnosis, genetic counselling and an early assessment of hearing. In bilateral atresia, early amplification with a bone conduction hearing aid is essential for proper speech development. Further rehabilitation in bilateral cases is managed with surgical reconstruction in selected patients or by implantation of a bone-anchored hearing aid. Atresia repair surgery is worthwhile if proper patient selection is made by use of stringent audiological and radiological criteria and state of the art surgery is performed. The divergent views concerning indications, ideal age for surgery and surgical approach to achieve better hearing are discussed. Review of the literature demonstrated that even in the hands of the best surgeons a mean hearing gain of only 20-25 dB is achieved in atresia Type II, with 30-35 dB in Type I. Therefore, surgical reconstruction should only be done in the more favourable cases where post-operative hearing of <25-30 dB is attainable. Less favoured patients should be helped with bone-anchored hearing aids, as this type of surgery does not interfere with the future use of new techniques.

Ear Canal↗
PubMed1998

A new autosomal-dominant locus (DFNA12) is responsible for a nonsyndromic, midfrequency, prelingual and nonprogressive sensorineural hearing loss.

OBJECTIVE: This study aimed to report on the audiologic findings of a nonsyndromic autosomal-dominant hearing loss of which the gene (DFNA 12) recently was found to map to chromosome 11q22-24. The study also aimed to propose and evaluate an algorithm based on the audiometric findings to discriminate between affected and unaffected family members before genetic linkage analysis. STUDY DESIGN: The study design was a retrospective analysis of the audiometric data of genetically affected and unaffected patients. SETTING: The study was conducted at a tertiary referral center. PATIENTS: A total of 17 genetically affected and 54 unaffected family members were studied. INTERVENTIONS: Pure-tone audiometry with air and bone conduction and construction and evaluation of an algorithm were performed. MAIN OUTCOME MEASURES: The type and degree of hearing loss as compared to age and gender-dependent values according to the International Organization for Standardization 7029 standard were measured. For this comparison, the variable "hearing standard deviations" (HSD) is introduced and is defined as the number of standard deviations that a hearing threshold is lying above the age and gender-related median at the given frequency. A description of the algorithm and an evaluation in terms of alpha- and beta-error also were measured. RESULTS: The hearing loss is nonsyndromic, sensorineural, moderate-to-moderately severe (pure-tone average, 51 dB at age 18 years), with an early onset (probably prelingual) and no progression. It affects all frequencies but mainly the midfrequencies (500, 1,000, and 2,000 Hz). The algorithm consists of an analysis of variance to determine the frequency that is most sensitive for the genetic trait under study and on the ranking of the family members according to their hearing loss (HSD) at this frequency. Individual persons are labeled as "affected" or "unaffected" according to this ranking.

Adolescent↗
PubMed2002

Revision tympanomastoid surgery.

We conducted a retrospective study of 50 ears in 48 patients in whom we performed revision tympanomastoid surgery for chronic otitis media. We found that the most common probable causes for the failure of previous surgery were incomplete lowering of the facial ridge (94% of cases), persistent sinodural-angle air-cell disease (92%), persistent tegmental air-cell disease (88%), recurrent or persistent cholesteatoma (66%), persistent mastoid-tip air-cell disease (62%), a small meatus (60%), and persistent hypotympanic air-cell disease (56%). After a mean postoperative follow-up of 26 months, we found no appreciable difference in success rates between patients who had undergone only one previous surgery (93%) and those who had undergone more than one previous surgery (95%) prior to referral to our center. Follow-up hearing data revealed a statistically significant improvement in air and bone conduction and a nonsignificant reduction in the air-bone gap. We conclude that revision mastoid surgery following multiple earlier surgical failures does not carry an appreciably higher risk of failure than does initial revision surgery. Moreover, there appears to have been no change in the causes of failure following mastoid surgery over the past 3 decades.

Adolescent↗
PubMed1994

No effect of growth hormone on bone graft incorporation. Titanium chamber study in the normal rat.

A recent series of publications reported greatly improved mechanical properties and increased callus size during the late stages of fracture healing in normal (not hypophysectomized) rats after twice daily injections of growth hormone (GH). We tested whether GH could enhance the incorporation of bone allografts in a new experimental model where we have demonstrated an increase in bone allograft incorporation by local application of basic fibroblast growth factor (bFGF). Cylinders of defatted allogeneic cancellous bone were placed as grafts in titanium Bone Conduction Chambers in the tibiae of female rats. Only one end of this chamber is open for tissue ingrowth. This permits us to measure the distance into the graft that new bone penetrates after entering the chamber. We injected 10 rats with 1.5 IU per rat of subcutaneous human recombinant GH twice daily for 6 weeks and another 10 rats with similar doses of sterile normal saline. GH caused a constant increase in the rate of weight gain and in the serum concentration of insulin-like Growth Factor 1 (IGF 1). Tibiae became longer and the ash weight of the second tail vertebra was increased. We also noted an increased joint cartilage thickness. There was no difference in the amount of new bone that had penetrated and replaced parts of the graft in GH-treated or control rats and this was also the case with TcMDP activity of bone samples from both groups. New bone forms in the grafts by membranous (metaplastic) ossification. It appears that the effects of excessive GH stimulation on endochondral and membranous ossification in this model are markedly different.

Animals↗
PubMedDate not supplied

Advantages of CO2 laser use in surgical management of otosclerosis.

BACKGROUND: Otosclerosis is a progressive osteo-destructive disorder of the bony labyrinth in which the fixation of the stapes causes the hearing loss. The aim of this study was the postoperative determination of parameters of the effect of surgical intervention on hearing and the incidence of complications and, on the basis of the differences in the examined parameters of the study, the estimation of the efficacy of the two mentioned surgical techniques in the treatment of otosclerosis. METHODS: In our research 40 patients with conductive hearing loss caused by otosclerosis underwent surgery with CO2 laser. Functional results were compared postoperatively with the results of 40 patients operated by the classical technique without the use of CO2 laser. The research was accomplished as a prospective comparative study. RESULTS: The air-bone interval (gap) as the difference between the rim of air and bone conductivity for separate frequencies did not significantly differ between the control and the experimental group. Both methods were effective in closing the air-bone gap with the rates of closure to within 10 dB in 82.6% and 75.3% for the laser and drill, respectively. The incidence of tinnitus was significantly lower in patients who underwent surgery with CO2 laser. The frequency of intraoperative and postoperative complications was significantly lower in the laser group. Differences were statistically significant for all parameters (p < 0.05). CONCLUSION: On the basis of the degree of postoperative hearing improvement, tinnitus and the incidence of complications it can be concluded that the use of CO2 laser during inverse stapedoplasty represents an effective and safe method, justifying the promotion of its use in the surgical management of otosclerosis.

Adult↗
PubMed1997

Patterns of hearing loss in non-explosive blast injury of the ear.

A prospective study of hearing loss in 120 cases with non-explosive blast injury of the ear, gathered over a six-year period, is presented. Thirty-three (27.5 per cent) patients had normal hearing, 57 (47.5 per cent) conductive hearing loss, 29 (24.2 per cent) mixed loss and one (0.8 per cent) had pure sensorineural loss. The severity of conductive hearing loss correlated with the size of the eardrum perforation; only a marginal difference was found between water and air pressure injuries, with respect to this type of hearing loss. Of all locations, perforations involving the posterior-inferior quadrant of the eardrum were associated with the largest air-bone gap. Audiometric assessment revealed that none of the patients suffered ossicular chain damage. Three patterns of sensorineural hearing loss were identified: a dip at a single frequency, two separate dips, and abnormality of bone conduction in several adjacent high frequencies. Involvement of several frequencies was associated with a more severe hearing loss than a dip in a single frequency. Healing of the perforation was always accompanied by closure of the air-bone gap, while the recovery of the sensorineural hearing loss was less favourable.

Adolescent↗
PubMed1997

[Surgical treatment of otosclerosis in the aged. Results of retrospective analysis].

Otosclerosis is, per se, a disease which rarely occurs after the age of 50. This is why stapes surgery is seldom performed in advanced age and there are few reports on the topic in the literature. The authors have performed a retrospective analysis of patients over the age of 65 who had undergone surgery for otosclerosis in the last 27 years. Out of a total of 3585 surgical procedures, 106 patients were analyzed. Most of the cases were in the advanced stages. Assessment of the outcome included pre- and post-operative audiometry, one year after surgery. Inner ear performance was established by evaluating air and bone conduction at 0.5, 1, 2, 3 and 4 kHz. The results showed that performing otosclerosis surgery is worthwhile even in the elderly with mixed auditory impairment, as long as the air-bone gap is limited to 20-30 dB and the surgical procedure is through. In this light, stapedotomy appears to be the most adequate technique. When evaluating the results the possibility of adopting a less powerful hearing aid should also be considered a success.

Age Factors↗
PubMed2005

Mechanism of bone incorporation of beta-TCP bone substitute in open wedge tibial osteotomy in patients.

A histological study was performed of bone biopsies from 16 patients (17 biopsies) treated with open wedge high tibial osteotomies for medial knee osteoarthritis. The open wedge osteotomies were filled with a wedge of osteoconductive beta tricalcium phosphate (beta-TCP) ceramic bone replacement. At the time of removal of the fixation material, core biopsies of the area where the beta-TCP was located were taken at different follow-up periods (6-25 months). beta-TCP resorption, bone ingrowth and bone remodelling were studied. We hypothesized that the incorporation and remodelling process occurs similarly as in animals. Histology showed a good resorption of the beta-TCP with complete incorporation and remodelling into new bone. The different phases as described in animal studies were found. A correlation was found between histological findings and radiological assessment. In conclusion, beta-TCP appeared to be a bone replacement material with optimal biocompatibility, resorption characteristics and bone conduction properties for the clinical use.

Adult↗
PubMed1996

A prospective cohort study of the effect of vincristine on audition.

We conducted a prospective cohort study of the possible ototoxic effect of vincristine among patients treated for lymphoproliferative malignancies. No deleterious effect of moderate doses of vincristine on pure tone audiometry for air and bone conduction and on speech audiometry could be found. Nevertheless, the isolated finding of sensorineural hearing loss in the only patient who received a high dose of vincristine raises the issue of ototoxicity as a possible dose-related and dose-limiting side effect of vincristine.

Adult↗
PubMed2004

Effect of phosphophoryn on rhBMP-2-induced bone formation.

In the present study, dentin phosphophoryn (DPP) derived from fresh bovine dentin was evaluated as a co-factor for recombinant human bone morphogenetic protein-2 (rhBMP-2) in rhBMP-2-induced bone formation in rats. A 5 microg amount of Escherichia coli-derived rhBMP-2 variant was combined with DPP cross-linked to type I collagen (2.4 microg DPP/360 microg collagen), acting as carrier. Next, rhBMP-2/DPP/collagen composites were implanted by onlay-grafting beneath the cranial periosteum in 4-week-old Wistar rats. Rats were sacrificed at 2 and 3 weeks after implantation. Throughout the experimental period, rhBMP-2/DPP/collagen composite induced more bone formation than the rhBMP-2/collagen composite. Moreover, the degradation rate of rhBMP-2/DPP/collagen composite in rat was faster than that of rhBMP-2/collagen composite. Neither DPP/collagen composite nor collagen alone conducted bone formation even at 3 weeks postimplantation. These results indicate that the bone-inducing activity of rhBMP-2 is enhanced by DPP as a co-factor of rhBMP-2 in vivo.

Animals↗
PubMed1999

The effect of gamma-irradiation on the temperature dependence of D.C. electrical conductivity of dry bone.

The effect of gamma-irradiation with doses from 10 to 500 kGy on the electrical conductivity (g) of dry bone was studied. Temperature measurement of electrical conductivity were made from 393 to 533 K. The dependence obtained indicates the increase in g with temperature. An increase in irradiation dose resulted in a decreased g value for each dose up to temperature 462 K. Temperature 462 K was interpreted as the temperature of collagen melting point in dry bone. Above 462 K, g values were dose independent. A dose of 500 kGy shifted the melting point to lower temperature. In addition, the activation energy for the charge conduction process was calculated. Obtained values for electrical conductivity and activation energy were typical for dielectrics and indicated degradation of the organic component of bone.

Animals↗
PubMed1994

[Comparative speech audiometry examinations with compact disk and cassette tape].

We compared the results of speech audiometry, performed with recorded tape and compact disc recordings (CD), respectively, in 21 subjects with bone-conduction hearing losses CHL and 27 subjects with sensorineural hearing losses. In all cases, speech audiometry was performed by using the 1969 Freiburg speech test material based on the German DIN standard 45626. In subjects with air-bone gaps, the hearing loss for speech was 2.3 dB smaller if tested by use of CD and speech recognition was 10.5 points better. Smaller differences could be found in sensorineural HL. For CD, hearing losses were 1.2 dB smaller and speech recognition scores were increased by only 1 point. These differences were not statistically significant. These findings show that calculations of hearing impairments and individual hearing handicaps from tables commonly used in Germany in medicolegal expert evaluations should not be changed if CD records are used that are based on 1969 DIN 4526 recordings. However, the handling of compact discs has many advantages in relation to the handling of tapes.

Adult↗
PubMed2002

[Hearing disorders among private farmers in Poland].

The studies of the state of hearing were conducted among a selected group of 128 farmers, aged 28-65 years with employment ranging from 11 to 40 years. The study design covered physical laryngologic examinations, detailed otologic medical history and proper audiometric tests (air and bone conduction). The results of the study showed that the highest mean values of hearing loss remained mostly within two high frequencies of 4 and 6 kHz and were 34.9-39.7 d B. These frequencies are typical of acoustic trauma. A highly statistically significant correlation (p < 0.001) was observed between hearing loss and age (r = 0.32-0.53 for 3-8 kHz), while a slightly weaker correlation was noted between hearing loss and employment duration (r = 0.20-0.27 for 3-8 kHz; p < 0.01). The mean values of hearing loss obtained among farmers were considerably enhanced, compared to the control group (42 people aged 29-59 years), the difference being very high statistically (p < 0.001). The studies of the state of private farmers' hearing clearly confirm the hypothesis that an excessive exposure to noise present in the farming equipment, is the major cause of the decreased hearing among farmers.

Adult↗
PubMed2000

Histologic and mechanical evaluation of impacted morcellized cancellous allografts in rabbits: comparison with hydroxyapatite granules.

The bioactivity and mechanical properties of morcellized allografts and hydroxyapatite (HA) granules were evaluated in a rabbit model. Allografts were replaced by viable trabecular structures within 8 weeks. The yield strength and stiffness of allografts were within normal cancellous bone levels by 3 weeks and were maintained afterward. The amount of newly formed bone around HA granules was comparable to that around allografts. The yield strength and stiffness of HA granules were significantly higher than those of allografts at 3 and 12 weeks. Allografts offer the advantage of being replaced by host-bone without significant deterioration in mechanical properties over the course of remodeling. HA granules can also be used for a bone substitute given their bioactivity in bone conduction and superiority in mechanical properties to allografts.

Animals↗
PubMed2006

Resorption of auditory ossicles and hearing loss in mice lacking osteoprotegerin.

Bones conduct sound in the middle ear. The three ossicles-the malleus, incus, and stapes-form a chain that transmits vibrations from the tympanic membrane to the oval window of the inner ear. Little is known about bone remodeling events in these ossicles and about potential effects of osteoporosis on hearing loss. Osteoclastic bone resorption is enhanced in Opg(-/-) mice lacking osteoprotegerin, which is a soluble decoy receptor for the osteoclastogenic cytokine RANKL. We asked whether auditory ossicles are resorbed in Opg(-/-) mice, and whether these mice suffer from impaired auditory function. All three ossicles in Opg(-/-) mice showed thinning, especially at the malleal manubrium and incus body. Most notably, unlike in the case in wild-type mice, the junction between the stapes and the otic capsule was fixed in Opg(-/-) mice, and the stapedial footplate was thinner and broader. Radiological analyses revealed that malleal cortical thickness was positively correlated with tibial bone mineral density in Opg(-/-) and control littermate mice. Furthermore, progressive hearing loss was detected in Opg(-/-) mice starting at 6 to 15 weeks of age. These data suggest that osteoprotegerin plays a crucial role in hearing by protecting the auditory ossicles and otic capsule from osteoclastic bone resorption.

Acoustic Stimulation↗
PubMed1991

[Reoperations in otosclerosis. Indications, intraoperative findings, and results].

The audiological outcome of 140 stapedectomy revisions done between 1977 and 1987, as well as the pre- and intraoperative findings and the subjective appraisal of the revisions, are presented. The recurrence of the conductive deafness was the most often indication for the surgical revision and the shift of the prosthesis, verified intraoperatively, the most encountered finding. Audiological results showed, as mean value, an important reduction of the transmissive hearing loss whilst the bone conduction remained unaltered. Patients' subjective evaluation of the results were worse than audiometric controls. From the retrospective study of these 140 revisions the AA' experience is that the stapedectomy revision offers no major risk for the inner ear.

Adolescent↗
PubMed2006

Myringoplasty for anterior and subtotal perforations using KTP-532 laser.

A retrospective study was performed on patients who underwent myringoplasty for either anterior or subtotal perforations over an 8-year period (from 1994 till 2004). We used the KTP-laser assisted anterior anchoring technique combining with anterior "pull-back" method. Patients' ages ranged from 6-62 years (median 36.5). The mean follow-up period was 2.8 years (minimum 6 months). The audiological results were analysed with the "Pytel software", which was developed in our department. As for the procedure, the drum remnant was freed from the malleus handle with the use of the laser and elevated out of it's sulcus anterior-superiorly. Large fascia graft was fashioned with a split of 4-5 mm in the middle of one edge. The graft was placed using the underlay technique medial to the handle of the malleus. A pull-back tunnel was created at the border of the anterior quadrants to further facilitate the survival of the graft. In this series the graft taking rate was 100%. Reperforation due to an undersized fascia was observed in one case. Post-operative audiological results indicated no bone conduction threshold elevation in any frequencies. Using the laser, cochlear trauma can be prevented, double fixation of the drum prevents lateralisation and blunting. Wide canalplasty makes both the approach and the follow-up very easy. Thorough soft tissue and bone work is advantageous from the fascia taking rate point of view.

Adolescent↗
PubMed2005

Comparison of titanium and Robinson stainless steel stapes piston prostheses.

OBJECTIVE: Although stainless steel stapes prostheses have generally been considered magnetic resonance imaging safe, there is concern that this may change with the development of more powerful imaging systems. The objective of the study was to determine whether a titanium piston stapes prosthesis would be audiometrically and surgically equivalent to a Robinson stainless steel piston for stapedectomy. STUDY DESIGN: Retrospective chart review. SETTING: Private otology practice. PATIENTS: In all, 50 patients underwent stapedectomy with a Gyrus titanium piston prosthesis. These patients were matched on the basis of age and preoperative bone-conduction scores with patients who underwent stapedectomy with a Robinson stainless steel piston prosthesis. MAIN OUTCOME MEASURES: Audiometric results are analyzed, and surgical complications noted. RESULTS: There was no significant difference between groups in hearing improvement or postoperative air-bone gap. The mean four-frequency hearing improvement was 27.7 dB for the stainless steel group and 27.8 dB for the titanium group. The mean postoperative air-bone gap was 2.65 dB for the stainless steel group and 2.60 for the titanium group. Neither group had a surgical complication. CONCLUSION: The titanium stapes prosthesis is a good alternative to a stainless steel prosthesis.

Adult↗