[Temporary shift in auditory threshold for air conduction in an extended range of high frequencies in workers exposed to noise].
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Air↗
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Results for “Bone Conduction”
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Attempt to reconstruct body stature basing on circumferences of long bones in fossil body remains.
Studies were conducted on long bones from Middle Ages row cemetery in Milicz (Wrocław voivodship). Basing on measurements of trunc length in humerus, radius, ulna, femur, tibia and fibula as well as on measurements of circumferences of the truncs, simple correlation coefficients were calculated. The correlation coefficients were used to formulate regression equation permitting to reconstruct bone length from corresponding circumference in cases when epiphysis was destroyed. When applied appropriately, the method may be used to reconstruct length of long bones and the entire stature of extinct population members.
Anthropometry↗
Effects of applied contact force and volume control setting on output force levels of the BAHA Softband.
The BAHA Softband has been developed to provide a transcutaneous anchor for a BAHA until a child is a surgical candidate for the percutaneous BAHA implant. We tested the objective output force level of the BAHA Classic 300 and Compact connected to a Softband on an artificial mastoid to determine: (1) the effects of direct contact force on output force levels (dB); and (2) the required volume control setting to ensure audibility of speech (assuming an average adult reference equivalent threshold force level). Direct contact force was varied from 2 to 5 N in 1 N steps. Output force level increased with increasing contact force. However, the average increase was 3 dB or lower, suggesting that the contact force is of minor importance. Volume control setting appears to be of much greater importance. It is suggested that the volume setting of either device be set to at least 2.5 to ensure audibility of conversational speech. Data from normal-hearing adults with simulated conductive hearing losses are presented to validate this conclusion.
Adult↗
[Clinical significance of preoperative impedance measurements].
On the basis of six particular cases in which the various impairments of the middle ear were verified during the surgical intervention, the authors show how it is possible to obtain by means of the Madsen ZO 70 electroacoustic impedance meter and of the Grason-Stadler Model 1720 otoadmittance meter useful additional information about the preoperative dynamic behavior of the tympano-ossicular system. With regard to the measurement of 'susceptance' and the 'conductance' at 220 and 660 Hz, it permits to establish a better differential diagnostic.
Bone Conduction↗
Diagnosis of cochlear otosclerosis.
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Audiometry↗
Permanent, skin penetrating, bone-anchored titanium implants. A clinical study of host-reaction in bone and soft tissue.
In 12 patients with a skin penetrating retroauricular titanium-implant (Brånemark) the reaction in bone and soft tissue was studied. Observation time was 6 to 36 months. All implants were "osseointegrated", as assessed by repeated manual test, X-ray examination and 99mTC-scintigraphy. Soft tissue reactions appeared to be slight and clinically insignificant. However, all patients produced crusts around the abutment. When the abutment was removed varying degrees of inflammatory reaction in the skin penetration could be observed in most patients. A theory for the development and cause of the soft tissue reactions is proposed and changes in the operative procedure and the design of the abutment to reduce the host reaction are suggested. It is stressed that the clinical significance of this host reaction is uncertain and above all has to be weighed against the important benefits this implant system offers to a severely handicapped group of patients.
Adult↗
The critical size bony defect in a small animal for bone healing studies (II): implant evolution and surgical technique on a rat's femur.
In the preclinical field of orthopaedic and trauma surgery critical size bony defects (CDS) were used to evaluate the biocompatibility and allow to investigate the osteoinductivity and -conductivity of bone substitutes. Concerning the anatomical size the laboratory rat indicates a lower limit in small animals which are appropriate for experiments on bone. The aim of this study was to define a CSD, to develop a suitable fixation system to stabilize bony fragments in CSD and to point out the specialities of the surgical technique. These informations should help for to design and practice studies concerning bone healing on rat's femur. Based on previously acquired anatomical data of rat's femur, the technical challenges and anatomical specialities of different osteosynthesis techniques in rat's femur surgery are demonstrated. Our experiences with different fixation systems and techniques lead to the development of an external fixator, which guarantees for a stable bone fragment fixation, prevents severe soft tissue damage, allows of a roentgenologic evaluation of the defect zone and prevents from undesired direct biomaterial-implant interactions. Neither the proximal nor the distal femoral nailing technique is appropriate for a stable fixation in CSD of rat's femur. To evaluate the reliability of an own developed external fixator 42 nude rats with a 4.0 mm CSD were investigated clinically and roentgenologically over 10 weeks. The external fixator showed only a small implant failure rate. A solid fusion of the bone fragments was not observed within the 10 weeks follow-up period.
Animals↗
Comparison of plasma-sprayed hydroxyapatite coatings and hydroxyapatite/tricalcium phosphate composite coatings: in vivo study.
This study aimed to compare biological properties, including osteoconduction, osseointegration, and shear strength, between plasma-sprayed hydroxyapatite (HA) and HA/tricalcium phosphate (TCP) coatings, using a transcortical implant model in the femora of canines. After 3 and 12 weeks of implantation, the implants with surrounding bone were assessed histologically in undecalcified sections in backscattered electron images (BEIs) under a scanning electron microscope (SEM). After short-term (3 week) follow-up, both coatings conducted new bone formation and revealed direct bone-to-coating contact. The HA/TCP coating could not enhance early host-to-coating responses. At 12 weeks, serious dissolution of the HA/TCP coatings evidently occurred. By the new bone healing index (NBHI) and apposition index (AI), we found no significant difference between HA/TCP-coated implants and HA-coated implants throughout all implant periods. At 12 weeks of implantation, some particles dissociated from the HA/TCP coating were found within the remodeling canal. After push-out measurements, the shear strength and failure mode of HA/TCP-coated implants were similar to those of HA-coated implants, and no statistical differences were found between either coating. Consequently, this study indicates that HA/TCP coatings have excellent biological response and may be considered suitable bioactive ceramic coatings for short-term clinical use.
Animals↗
Fixation of the anterior mallear ligament: diagnosis and consequences for hearing results in stapes surgery.
In the search for possible causes of unfavorable results after stapes surgery, the study reported here focused on the anterior mallear ligament, since it has been previously reported that partial mallear fixation (PMF) leads to functional failure in 38% of cases of stapes revision surgery. The aims of the study were to identify effective methods for the diagnosis of PMF and experimentally assess the conductive hearing loss that results from PMF. The study included vibration amplitude measurements of the ossicles by laser Doppler interferometry (LDI) in 19 patients and 5 fresh human temporal bone (TB) specimens. Analysis of their dynamic behavior was performed by finite element modeling (FEM). Similar, significant changes of manubrium vibration patterns for PMF were found by FEM calculations, in TB experiments, and in patients. We could identify PMF either before operation, using LDI, or during operation, by manual palpation. In the TB experiments and FEM calculations, the attenuation of the stapes displacement due to an isolated PMF was approximately 10 dB and frequency-dependent. Untreated anterior mallear ligament fixation produced a persistent air-bone gap of approximately 10 dB after stapedioplasty.
Acoustic Impedance Tests↗
Cytologic examination and carcinoembryonic antigen assay of fine needle aspirates of bone tumors.
A prospective study of 28 consecutive fine needle aspirates of bone was conducted comparing the sensitivities of cytologic diagnosis with carcinoembryonic antigen (CEA) content to determine if the CEA assay could enhance the sensitivity of cytologic diagnosis of carcinoma metastatic to bone. Aspirates obtained radiologically or at surgery underwent cytologic examination and CEA assay. Cytologic examination was performed on Papanicolaou-stained smears and/or cell blocks. CEA was measured with an enzyme immunoassay; 5 ng/mL was used as the cutoff. Twenty-one were malignant and seven benign. The sensitivities of cytology and CEA were 85% and 47.6%, respectively, and the specificities, 100%. Mean CEA and sensitivity were highest for adenocarcinoma of lung (361.5 ng/mL, 77%), lowest for carcinoma of breast and negative for lymphoma, myeloma and benign aspirates. High CEA was useful in (1) suggesting adenocarcinoma of lung in patients with an unknown primary, (2) suggesting a new primary lung adenocarcinoma in a patient with previous transitional cell carcinoma of bladder, and (3) discriminating lung adenocarcinoma from adenocarcinomas of kidney, thyroid, prostate or endometrium.
Adolescent↗
High parity is associated with increased bone size and strength.
Some, but not all, studies report an association between decreased hip fracture risk and high parity despite similar bone mineral density (BMD). Our hypothesis was that bone size, a major determinant of bone strength, is greater in women with high parity compared with low parity or nulliparous women. A cross-sectional study of 168 Hutterite women aged 40-80 years was conducted. BMD, bone mineral content (BMC) and bone area of the total body (TB), hip, femoral neck (FN), and lumbar spine (LS) were measured, as well as bone geometry at the 4% and 20% distal radius and bending strength at 20% radius. Diet and activity recall and strength measurements were obtained. Of the 168 women, 42 (25%) were nulliparous while the remaining women reported 1 to 16 births (median=6). Of the 126 parous women, 122 (97%) breast-fed their infants (range 1.5-24 months). Hip, FN and LS BMD were not associated with either parity or months of breast-feeding. TB BMC and bone area (both, p<0.05) and FN bone area (p<0.01) were associated with parity. FN bone area was 4% greater in women with 7+ vs 1-4 children. Torsional bending strength, which includes structural and material bone properties, at the 20% distal radius was greater with higher parity (p=0.01). No bone measure was associated with average months of breast-feeding. High parity is associated with increased radial torsional bending strength and femoral neck size. The greater femoral neck size, without higher BMD, may explain the reduced hip fracture risk among women with high parity previously reported in some studies.
Adult↗
Transplantation of culture expanded bone marrow cells and platelet rich plasma in distraction osteogenesis of the long bones.
Longer treatment period in distraction osteogenesis (DO) leads to more frequent complications. We developed a new technique of transplantation of culture expanded bone marrow cells (BMC) and platelet rich plasma (PRP) in DO of the long bones. Retrospective comparative study was conducted between the bones treated with and without BMC and PRP in DO to assess the efficacy of this new technique of transplantation. Ninety-two bones (46 patients) that were lengthened in our hospital and followed up until removal of the pins were divided into two groups according to the cell (BMC+PRP) treatment. The BMC-PRP(+) group consisted of 32 bones (14 femora, 18 tibiae) in 17 patients (10 boys and 7 girls), while the BMC-PRP(-) group consisted of 60 bones (25 femora, 35 tibiae) in 29 patients (13 boys and 16 girls). The clinical outcome including the age at operation, amount of length gained, the healing index, the delay in consolidation, and complications were compared between the two groups. The healing between the femoral and the tibial lengthening was also assessed. The average age at operation was 15.8 years in the BMC-PRP(+) group and 15.5 years in the BMC-PRP(-) group. Although there were no significant differences in the age at operation and the length gained between the two groups, the average healing indices of the BMC-PRP(+) group in short stature and in limb length discrepancy were significantly lower than those of the BMC-PRP(-) group (P=0.0019 and P=0.0031, respectively). A delay in consolidation was seen in 45% of the BMC-PRP(-) group but never observed in the BMC-PRP(+) group (P<0.0001). The rate of complications was 23% of the BMC-PRP(-) group and only 6% of the BMC-PRP(+) group (P=0.0406). The femoral lengthening showed significantly faster healing than the tibial lengthening by the BMC and PRP transplantation (P=0.0004) In conclusion, transplantation of BMC and PRP shortened the treatment period and reduced associated complications by accelerating new bone formation in DO.
Adolescent↗
Incidence and characteristics of otosclerosis in the Japanese population.
OBJECTIVE: Otosclerosis is thought to be quite an uncommon disease in Japan. However, in recent years the incidence of this disease seems to have increased. Here we report about the characteristics and incidence of this disease in the Japanese population who underwent stapes surgery in our department. METHODS: A total of 80 patients (115 ears), who underwent stapes surgery by a single surgeon in 21 years and 8 months were included in this study. RESULTS: The incidence of clinical otosclerosis was found to be 0.22% among the outpatients with ear disease. During the first half of the period, the ratio of stapes surgery/tympanoplasty was less than 0.05. While, during the second half of this period, this ratio had increased to 0.08. The average number of stapes surgery performed in the first half period was 3.7 ears/year, and that in the second half was 6.8 ears/year. In contrast to otosclerosis in Caucasians, pure tone threshold in lower frequencies was much higher than that of higher frequencies (except for 8000 Hz). However, the improvement of the threshold after surgery was not so different from that reported in Caucasians. CONCLUSIONS: Taken together, the present results clearly demonstrate that the incidence of otosclerosis in Japan has been increasing. Moreover the rise in the slope of the conduction curve at higher frequencies may be a reflection of the pathological characteristics of otosclerosis in Japanese population, which is less invasive and has limited otosclerotic foci in the temporal bone.
Adult↗
Prosthetic reconstructions for external hearing aids and facial epistheses.
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Bone Conduction↗
Fractures of the temporal bone. Diagnosis and surgical considerations.
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Adult↗
Lack of reliability of the SISI procedure for determining inner ear threshold.
Ten normally hearing subjects were tested using the conductive short increment sensitivity index procedure to evaluate the 60-dB constant as used in the test described by Byers (1974). Also investigated were the effects of frequency and order of presentation on the short increment sensitivity index at high sensation levels. Test frequencies included 1, 2, 4, and 6 kHz in random order. Means of all frequencies exceeded the 60-dB constant implemented by Byers (1974). Intersubject variability was large. Frequency and order of presentation were not statistically significant factors. It was recommended that the conductive short increment sensitivity index be used with caution.
Acoustic Stimulation↗
Passive and active intracranial translocation of osteosynthesis plates in adolescent minipigs.
On the basis of the clinical and experimental proof that intracranial translocation of osteosynthesis plates occurs in infants after fixation on frontal bone, we conducted an animal study on four adolescent Göttingen minipigs. Our aim was to study the effects on intracranial translocation of two different types of osteosynthesis plates by comparing the plate-bone interface on the intact frontal bone treated with a multiple-point contact plate versus a conventional smooth one, paying special emphasis to the periosteum. Within a few weeks of implantation, osseous regeneration products surrounded the plate. Total invagination of plates with initial intracranial translocation occurred 12 to 16 weeks postimplantation, regardless of plate design. In epiperiosteal fixation, intracranial translocation was delayed. The results revealed two mechanisms at play here: cranial growth-related passive intracranial translocation, which occurs regardless of plate design, and plate-dependent active intracranial translocation. In conclusion, we recommend that all metal osteosynthesis materials implanted in the infant cranium be removed as early as possible (within 3 months).
Animals↗
Hearing loss in the nonocular Stickler syndrome caused by a COL11A2 mutation.
OBJECTIVE: Evaluation of hearing impairment as a feature of the nonocular Stickler syndrome (type II) linked to COL11A2. STUDY DESIGN: Family study. METHODS: General, orthopaedic, ophthalmologic, and otorhinolaryngologic examinations were performed on 15 affected persons in a Dutch family. Audiograms were obtained and/or retrieved from elsewhere. Cross-sectional and longitudinal analyses were conducted on the hearing threshold (sensorineural component) in relation to the patient's age to evaluate whether hearing impairment was progressive. RESULTS: Mixed hearing loss, i.e., including a substantial air-bone gap of up to 20 to 60 dB, was present in six cases, concomitantly with a submucous or overt cleft palate in five of them. The audiograms in 14 evaluable cases showed the following types of threshold: U-shaped (n = 3), flat (n = 2), flat or gently (downward) sloping (n = 3), gently sloping (n = 3), or steeply sloping (n = 3). Cross-sectional analysis did not reveal any significant effect of age on sensorineural hearing impairment. CONCLUSION: In contrast to the classic Stickler syndrome (type I) with high myopia, this nonocular type shows a high prevalence of sensorineural hearing impairment. The mean sensorineural hearing threshold in our patients was about 40 dB HL (95% CI, 15-65 dB) and was liable to increase (presumably by presbycusis) by several tens of decibels at the highest frequencies. Given the tendency for otitis media to develop in many of these patients, appropriate otologic care is of major importance.
Adult↗