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1.
Ann Otol Rhinol Laryngol ; 123(8): 584-90, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24642586

RESUMO

OBJECTIVES: This report aimed to describe a novel and efficient method of tracheoesophageal puncture using a hybrid device assembled from 2 commercially available puncture kits; to demonstrate the utility of this technique in the performance of primary and secondary procedures, under general and local anesthesia, with and without flap reconstruction; and to evaluate the efficacy of concurrent puncture and valve placement. METHODS: Thirty-four patients who underwent either primary or secondary tracheoesophageal puncture for voice restoration. Charts were reviewed retrospectively for complications, time to first valve change, operative time, and blood loss. RESULTS: Using this novel hybrid device, simultaneous puncture and valve placement was achieved in 34 consecutive patients. There was 1 major complication; blood loss was negligible; and the procedure could be accomplished in all cases. There were no cases of prosthesis failure as a result of the insertion technique. CONCLUSION: Concurrent tracheoesophageal puncture and voice prosthesis placement is a simple and efficient method of voice restoration in the laryngectomized patient and can be more easily accomplished with a hybrid device assembled from the components of 2 commercially available puncture kits. It can be performed under local as well as general anesthesia. The procedure is adaptable to a variety of clinical situations.


Assuntos
Esôfago/cirurgia , Laringectomia , Laringe Artificial , Implantação de Prótese/métodos , Punções/métodos , Traqueia/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Neoplasias Laríngeas/cirurgia , Masculino , Pessoa de Meia-Idade , Punções/instrumentação , Adulto Jovem
2.
Otolaryngol Head Neck Surg ; 139(2): 301-6, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18656734

RESUMO

OBJECTIVE: We evaluated the effect of malleus presence or absence on middle ear sound transmission after middle ear reconstruction in a temporal bone model. STUDY DESIGN: Human cadaveric temporal bone study. METHODS: The velocity of the stapes footplate was measured using a laser Doppler vibrometer. After baseline measurements in eight intact temporal bones, reconstructed middle ear transmission with and without the malleus was analyzed. Furthermore, to assess the influence of interposed cartilage, cartilage pieces of three different diameters were inserted and the three test conditions compared. RESULTS: Reconstruction without a malleus tended to be slightly worse at 0.6 to 3.0 kHz. However, these differences were not statistically significant. In the cartilage experiments, the large-diameter cartilage was the worst at 0.25 kHz and 0.5 kHz but was better than the medium-diameter cartilages at 3.0 kHz and 4.0 kHz (P < 0.05). CONCLUSION: Absence of the malleus impaired middle ear sound transmission slightly in the mid frequencies compared to reconstruction with the malleus present; the differences were not statistically significant.


Assuntos
Martelo , Substituição Ossicular/métodos , Osso Temporal/anatomia & histologia , Osso Temporal/cirurgia , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Cadáver , Humanos , Bigorna/anatomia & histologia , Bigorna/cirurgia , Masculino , Pessoa de Meia-Idade
3.
Facial Plast Surg Clin North Am ; 16(2): 183-6, vi, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18355702

RESUMO

Some patients are unhappy with the results of facial plastic surgery, even if the surgeon is pleased with the outcome. Dealing with this potential problem begins with the preoperative assessment as to how the patient might handle a result that is less than perfect. "When in doubt, don't" is a good rule but needs refinement. This article, based on some 40 years of experience, attempts to provide that refinement.


Assuntos
Pacientes/psicologia , Cirurgia Plástica , Humanos , Satisfação do Paciente , Seleção de Pacientes , Personalidade , Período Pós-Operatório , Reoperação/economia
4.
Otolaryngol Clin North Am ; 40(4): 891-901, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17606029

RESUMO

A variety of surgical procedures exist to treat obstructive sleep apnea in adults. Some, such as tracheotomy and maxillomandibular advancement, have very high cure rates, over 90%. These procedures have significant disadvantages, however, and there is a need to define the best combination of low morbidity procedures to provide similar success. To do this, better means to diagnose the sites of obstruction must be used and new procedures must be developed. This article reviews where we are in reaching these goals.


Assuntos
Apneia Obstrutiva do Sono/cirurgia , Humanos , Obstrução Nasal/etiologia , Obstrução Nasal/cirurgia , Palato Mole/cirurgia , Faringe/cirurgia , Apneia Obstrutiva do Sono/diagnóstico , Ronco/etiologia , Ronco/cirurgia , Falha de Tratamento , Resultado do Tratamento , Úvula/cirurgia
5.
Arch Otolaryngol Head Neck Surg ; 131(5): 440-5, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15897424

RESUMO

OBJECTIVE: To examine the efficacy of hyoid myotomy and suspension as a treatment of hypopharyngeal obstruction in obstructive sleep apnea. DESIGN: Prospective, observational study. SETTING: Academic medical center. PATIENTS: Twenty-nine consecutive male patients with suspected hypopharyngeal obstruction INTERVENTIONS: Patients underwent hyoid suspension. Uvulopalatopharyngoplasty with or without tonsillectomy was performed at the same time for those patients who had not undergone this procedure previously. Patients underwent clinical examination and sleep study prior to surgery and approximately 1 year postoperatively. MAIN OUTCOME MEASURES: Primary outcome was a successful surgical result, defined as apnea-hypopnea index lower than 20, 50% or greater decline in apnea-hypopnea index, and no oxygen desaturations below 85% on the postoperative sleep study. Secondary outcomes included daytime sleepiness as determined by the Epworth Sleepiness Scale and the severity of snoring. Postoperative complications were also recorded. RESULTS: Only 5 (17%) of 29 patients achieved a successful outcome. The respiratory disturbance index did not change significantly for the group as a whole, although the lowest oxygen saturation did show some improvement. CONCLUSIONS: Hyoid suspension does not provide results equivalent to those reported for genioglossus advancement or multisession tongue radiofrequency. Hyoid suspension alone is not an efficacious treatment for hypopharyngeal airway obstruction in most patients with obstructive sleep apnea.


Assuntos
Osso Hioide/cirurgia , Apneia Obstrutiva do Sono/cirurgia , Adulto , Idoso , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento
6.
Otol Neurotol ; 26(6): 1245-61, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16272952

RESUMO

OBJECTIVE: The fact that vibration of the skull causes a hearing sensation has been known since the 19th century. This mode of hearing was termed hearing by bone conduction. Although there has been more than a century of research on hearing by bone conduction, its physiology is not completely understood. Lately, new insights into the physiology of hearing by bone conduction have been reported. Knowledge of the physiology, clinical aspects, and limitations of bone conduction sound is important for clinicians dealing with hearing loss and is the purpose of this review. DATA SOURCES: The data were compiled from the published literature in the areas of clinical bone conduction hearing, bone conduction hearing aids, basic research on bone conduction physiology, and recent research on bone conduction hearing from our laboratory. CONCLUSION: Five factors contributing to bone conduction hearing have been identified: 1) sound radiated into the external ear canal, 2) middle ear ossicle inertia, 3) inertia of the cochlear fluids, 4) compression of the cochlear walls, and 5) pressure transmission from the cerebrospinal fluid. Of these five, inertia of the cochlear fluid seems most important. Bone conduction sound is believed to reflect the true cochlear function; however, certain conditions such as middle ear diseases can affect bone conduction sensitivity, but less than for air conduction. The bone conduction route can also be used for hearing aids; since the bone conduction route is less efficient than the air conduction route, bone conduction hearing aids are primarily used for hearing losses where air conduction hearing aids are contraindicated.


Assuntos
Condução Óssea/fisiologia , Membrana Basilar/fisiopatologia , Líquido Cefalorraquidiano/fisiologia , Cóclea/fisiopatologia , Otopatias/diagnóstico , Otopatias/fisiopatologia , Ossículos da Orelha/fisiopatologia , Orelha Média/fisiopatologia , Auxiliares de Audição , Humanos , Osso Temporal/fisiopatologia
7.
Acta Otolaryngol ; 125(1): 33-7, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15799571

RESUMO

CONCLUSIONS: This prosthesis has the advantage of rapid adjustment at the time of insertion in order to achieve optimal tension and, as a result, optimal sound transmission. OBJECTIVE: To test the acoustic performance of a new, adjustable incus replacement prosthesis in a human temporal bone model. MATERIAL AND METHODS: Experiments were performed in seven human temporal bones, before and after removal of the incus and insertion of the prosthesis. The input comprised 406 pure tones ranging in frequency between 0.1 and 10 kHz at an intensity of 80 dB SPL at the tympanic membrane. The output measurement was stapes footplate displacement, determined by means of a laser Doppler vibrometer. Three lengths of the prosthesis were investigated: optimal, optimal +0.2 mm and optimal +0.4 mm. RESULTS: The optimal-length prosthesis produced similar results to those of an intact middle ear. The slightly longer prostheses decreased middle ear sound transmission at all test frequencies, except those near 1.5 kHz.


Assuntos
Prótese Ossicular , Osso Temporal/anatomia & histologia , Titânio/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Audiometria de Tons Puros , Materiais Biocompatíveis , Humanos , Bigorna/anatomia & histologia , Masculino , Ajuste de Prótese/instrumentação , Som , Estribo/anatomia & histologia , Membrana Timpânica/anatomia & histologia , Vibração
8.
Hear Res ; 198(1-2): 10-24, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15567598

RESUMO

The vibration patterns of the round window (RW) membrane in human cadaver temporal bone specimens were assessed by measurements of the velocity of reflective targets placed on the RW membrane with an approximate spacing of 0.2 mm. The velocity was measured in the frequency range 0.1-10 kHz by a laser Doppler vibrometer in four specimens with air conduction (AC) stimulation and in four specimens with bone conduction (BC) stimulation. The response pattern was investigated by analyzing the velocity response of all targets on the RW membrane, by making iso-amplitude and iso-phase contour plots of the membrane surface, and by creating animations of the surface vibration at several frequencies. Similar response pattern was found with AC and BC stimulations. At frequencies below 1.5 kHz, the RW membrane vibrates nearly as a whole in an in-and-out motion and above 1.5 kHz, the membrane moves primarily in two sections that vibrate with approximately 180 degrees difference. Indication of some traveling wave motion of the RW membrane at those frequencies was also found. At higher frequencies, above 3 kHz, the membrane motion is complex with a mixture of modal and traveling wave motion. An increase of the stimulation level did not alter the vibration pattern; it only gave an increase of the RW membrane vibration amplitude corresponding to the increase in stimulation. When the mode of stimulation at the oval window was altered, by the insertion of a 0.6 mm piston, the vibration pattern of the RW membrane changed.


Assuntos
Condução Óssea/fisiologia , Movimento/fisiologia , Janela da Cóclea/fisiologia , Vibração , Estimulação Acústica , Idoso , Cadáver , Feminino , Humanos , Fluxometria por Laser-Doppler , Masculino , Microesferas , Pessoa de Meia-Idade
9.
Hear Res ; 181(1-2): 131-43, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12855371

RESUMO

It is generally accepted that bone conduction (BC) stimuli yield a traveling wave on the basilar membrane (BM) and hence stimulate the cochlea by the same mechanisms as normal air conduction (AC). The basis for this is the ability to cancel or mask a BC tone with an AC tone and the ability to generate two tone distortion products with a BC tone and an AC tone. The hypothesis is proposed that BC stimulates the BM not only through the hydrodynamics of the scala vestibuli and scala tympani, but also through osseous spiral lamina (OSL) vibrations. To test this hypothesis the BM and OSL response with AC as well as BC stimulation was measured with a laser Doppler vibrometer. Human temporal bones mounted on a shaker were used to record the velocities of the bone per se, the BM and the OSL. The measurements were then converted to relative BM and OSL velocities. The results from the basal turn of the cochlea show similar behavior with AC and BC stimulation. The motion of the OSL at the edge where it connects to the BM is in phase and is typically 6 dB lower than the BM motion. With BC stimulation, there is less phase accumulation in the OSL after the cochlea is drained; the OSL moves due to inertial forces and resonates at approximately 7 kHz. Inertial vibration of the OSL may partially contribute to the total response of BC sound, especially at the high frequencies, although current models of the cochlea assume a rigid OSL. The measurements reported here can be used to include a flexible OSL in cochlear models.


Assuntos
Ar , Membrana Basilar , Condução Óssea , Som , Lâmina Espiral , Vibração , Estimulação Acústica/métodos , Idoso , Idoso de 80 Anos ou mais , Cadáver , Feminino , Humanos , Lasers , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Fatores de Tempo , Ultrassonografia Doppler
10.
Laryngoscope ; 113(6): 929-32, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12782798

RESUMO

OBJECTIVES/HYPOTHESIS: There is a paucity of data to guide the optimal management of the airway in patients after maxillectomy. The decision on whether a concomitant tracheostomy is needed is often dictated by the surgeon's training and experience. We reviewed our experience with maxillectomy to assess the need for tracheostomy in postoperative airway management. STUDY DESIGN: Retrospective analysis at a university hospital. METHODS: We identified 121 patients who underwent 130 maxillectomies between October 1990 and September 2001. Twenty-four of these were total (all six walls removed), 45 were subtotal (two or more walls removed), and 61 were limited (only one wall removed). Reconstruction ranged from none to microvascular free flap, with split-thickness skin graft being the most common reconstructive option. RESULTS: Only 10 tracheostomies (7.7%) were performed at the time of maxillectomy. These included four tracheostomies in patients who underwent bulky flap reconstruction, two tracheostomies in patients who underwent both flap reconstruction and mandibulectomy, one tracheostomy in a patient who underwent mandibulectomy, one tracheostomy in a patient with mucormycosis in anticipation of prolonged ventilatory support postoperatively, and two tracheostomies at the surgeons' discretion because of concern for upper airway edema. Among the 111 patients who underwent 120 maxillectomies without concomitant tracheostomy, 1 patient (0.9%), a 74 year-old man with oxygen-dependent chronic obstructive pulmonary disease, required repeat intubation on day 3 and again on day 10 after the surgery, because of respiratory failure; fiberoptic examination confirmed the absence of upper airway compromise. CONCLUSIONS: The routine performance of tracheostomy in patients undergoing maxillectomy is unnecessary. Selective use of tracheostomy may be indicated in situations in which mandibulectomy or bulky flap reconstruction is performed or a concern for postoperative oropharyngeal airway obstruction because of edema or packing exists.


Assuntos
Obstrução das Vias Respiratórias/cirurgia , Maxila/cirurgia , Seio Maxilar/cirurgia , Neoplasias Otorrinolaringológicas/cirurgia , Doenças dos Seios Paranasais/cirurgia , Neoplasias dos Seios Paranasais/cirurgia , Cuidados Pós-Operatórios , Complicações Pós-Operatórias/cirurgia , Traqueostomia , Procedimentos Desnecessários , Adulto , Idoso , Idoso de 80 Anos ou mais , Obstrução das Vias Respiratórias/diagnóstico , Terapia Combinada , Feminino , Humanos , Masculino , Mandíbula/cirurgia , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico , Reoperação , Estudos Retrospectivos
11.
Facial Plast Surg Clin North Am ; 21(4): 579-84, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24200376

RESUMO

This article reviews some basic principles of patient selection for facial plastic surgery. There are patients who are not good candidates, independent of the deformity and the ability of the surgeon. Reasons include subtle and not so subtle psychiatric disorders, unrealistic expectations, lack of communication despite multiple visits, and litigious patients. Complications or suboptimal results are not well handled in these patients and often produce an uncomfortable experience for the surgeon and staff in the postoperative period. These patients are best avoided or should be provided a much longer evaluation period prior to any surgery.


Assuntos
Satisfação do Paciente , Seleção de Pacientes , Relações Médico-Paciente , Procedimentos de Cirurgia Plástica/psicologia , Complicações Pós-Operatórias/psicologia , Recusa em Tratar , Humanos , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/terapia , Cuidados Pré-Operatórios/métodos , Encaminhamento e Consulta
12.
Otol Neurotol ; 32(1): 98-103, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20930654

RESUMO

HYPOTHESIS: The Vibrant Soundbridge floating mass transducer (FMT) is part of a commercially available implantable hearing device in which the FMT can be placed in the round window (RW) niche or attached to a partial (V-PORP) or total ossicular replacement prosthesis (V-TORP) contacting the stapes head or footplate. The goal is to provide efficient transfer of sound vibration into the cochlea. The hypothesis is that the FMT location on the prosthesis is superior to the RW location. BACKGROUND: No direct comparisons of the 3 FMT sites have been performed using the same measurement location. METHODS: A new measurement method called the third window method was used in eleven fresh human temporal bones to compare the sites. A small hole was made into the scala tympani of the temporal bones preserving the endosteum. A reflective target was placed on the third window endosteum and displacement of the cochlear fluid was measured using a Polytec HLV-1000 laser Doppler vibrometer. The input to the FMT at all locations was a constant 316 millivolts (mV); the frequency range was 0.5 to 8.0 kHz. RESULTS: The V-PORP and V-TORP FMT locations both provided statistically significant better performance above 1.0 kHz than the RW site but not below that frequency. The V-PORP and V-TORP responses were similar at all test frequencies. CONCLUSION: In this temporal bone model, the FMT provided better higher frequency performance when attached to a PORP or TORP than in the RW niche.


Assuntos
Prótese Ossicular , Janela da Cóclea/cirurgia , Osso Temporal/cirurgia , Humanos , Implantação de Prótese/métodos , Transdutores
13.
Otol Neurotol ; 31(9): 1404-8, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21113980

RESUMO

HYPOTHESIS: Middle ear ossicular replacement prostheses whose length can adjust in vivo to changes in middle ear dimensions following insertion may have acoustic advantages. BACKGROUND: Optimal tension is an important factor in the acoustic performance of incus-stapes replacement prostheses. Length is the primary determinant of postinsertion tension with conventional prostheses. Postoperative changes in prosthesis tension may occur leading to a worsening of postoperative hearing. METHODS: Testing of a self-adjusting prosthesis (SAP) containing a polyurethane sponge attached to the head of a titanium partial ossicular replacement prosthesis (PORP) was performed in 5 fresh temporal bones. This SAP was compared with optimal length PORPs at different tensions. Sound input was 80 dB sound pressure level at 0.1 to 10 kHz. Stapes footplate displacement was measured using a laser Doppler vibrometer before and after incus removal and after PORP and SAP insertion between the malleus and stapes. One to 3 glass shims were then inserted between the malleus and optimal length PORP and SAP to change prosthesis tension. Measurement of stapes displacement was repeated with increased prosthesis lengths of 0.15, 0.30, and 0.45 mm. RESULTS: There was a clear tendency in the optimal length PORPs for a decrease in footplate displacement below 1.0 kHz, in general proportional to the increasing length. The SAP provided equivalent transmission as the optimal length PORP below 4.0 kHz and better transmission below 1.0 kHz at the varying increased lengths. CONCLUSION: An SAP seems to decrease the effect of changes in prosthesis length between the malleus and stapes at lower frequencies.


Assuntos
Prótese Ossicular , Idoso , Idoso de 80 Anos ou mais , Ossículos da Orelha/fisiologia , Humanos , Masculino , Martelo/cirurgia , Pessoa de Meia-Idade , Poliuretanos , Desenho de Prótese , Ajuste de Prótese , Procedimentos de Cirurgia Plástica , Estribo/fisiologia , Osso Temporal/fisiologia , Titânio
15.
Arch Facial Plast Surg ; 11(1): 34-9, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19153291

RESUMO

OBJECTIVE: To introduce a novel quantitative method measuring preoperative and postoperative brow position and apply it to a cohort of patients undergoing endoscopic brow suspension. DESIGN: Retrospective review of patients who underwent endoscopic brow- and forehead-lift using a consistent operative technique and method of fixation. Changes in brow position were measured using standardized digital photographs of patients taken before and after surgery. Brow elevation was determined using a novel measurement system based on the ratio of the vertical height of the brow to the distance between the lateral corneal limbus and the medial canthus. RESULTS: Sixteen consecutive patients (32 eyebrows) underwent surgery between January 7, 2003, and January 15, 2006, without any major complications. With follow-up ranging from 6 to 31 months (mean follow-up, 18 months), a statistically significant elevation of brow position was found. Mean brow ratio measurements increased by 18.0% on the right side and 16.1% on the left side, for an overall mean increase in brow position of 17.1%. The brow elevation ratio remained increased by a mean of 16.8% for patients who were followed up for almost 2 years and beyond. CONCLUSIONS: The brow elevation ratio can be applied to patients undergoing brow suspension procedures with standard office photography. The ratios provide the surgeon with a quantitative dimension for assessing outcomes of brow elevation and can be used in comparative analysis of each patient's baseline brow position.


Assuntos
Sobrancelhas/anatomia & histologia , Testa/cirurgia , Ritidoplastia/métodos , Adulto , Pesos e Medidas Corporais , Endoscopia , Feminino , Humanos , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Estudos Retrospectivos , Resultado do Tratamento
17.
J Acoust Soc Am ; 118(4): 2373-91, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16266160

RESUMO

In the past, only a few investigations have measured vibration at the cochlea with bone conduction stimulation: dry skulls were used in those investigations. In this paper, the transmission properties of bone conducted sound in human head are presented, measured as the three-dimensional vibration at the cochlear promontory in six intact cadaver heads. The stimulation was provided at 27 positions on the skull surface and two close to the cochlea; mechanical point impedance was measured at all positions. Cochlear promontory vibration levels in the three perpendicular directions were normally within 5 dB. With the stimulation applied on the ipsilateral side, the response decreased, and the accumulated phase increased, with distance between the cochlea and the excitation position. No significant changes were obtained when the excitations were on the contralateral side. In terms of vibration level, the best stimulation position is on the mastoid close to the cochlea; the worst is at the midline of the skull. The transcranial transmission was close to 0 dB for frequencies up to 700 Hz; above it decreased at 12 dB/decade. Wave transmission at the skull-base was found to be nondispersive at frequencies above 2 kHz whereas it altered with frequency at the cranial vault.


Assuntos
Condução Óssea/fisiologia , Cóclea/fisiologia , Crânio/fisiologia , Som , Vibração , Estimulação Acústica , Idoso , Cadáver , Simulação por Computador , Impedância Elétrica , Humanos , Fluxometria por Laser-Doppler , Masculino , Pessoa de Meia-Idade , Modelos Biológicos
19.
20.
J Acoust Soc Am ; 113(2): 902-13, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12597184

RESUMO

The ear canal sound pressure and the malleus umbo velocity with bone conduction (BC) stimulation were measured in nine ears from five cadaver heads in the frequency range 0.1 to 10 kHz. The measurements were conducted with both open and occluded ear canals, before and after resection of the lower jaw, in a canal with the cartilage and soft tissues removed, and with the tympanic membrane (TM) removed. The sound pressure was about 10 dB greater in an intact ear canal than when the cartilage part of the canal had been removed. The occlusion effect was close to 20 dB for the low frequencies in an intact ear canal; this effect diminished with sectioning of the canal. At higher frequencies, the resonance properties of the ear canal determined the effect of occluding the ear canal. Sectioning of the lower jaw did not significantly alter the sound pressure in the ear canal. The sound radiated from the TM into the ear canal was investigated in four temporal bone specimens; this sound is significantly lower than the sound pressure in an intact ear canal with BC stimulation. The malleus umbo velocity with air conduction stimulation was investigated in nine temporal bone specimens and compared with the umbo velocity obtained with BC stimulation in the cadaver heads. The results show that for a normal open ear canal, the sound pressure in the ear canal with BC stimulation is not significant for BC hearing. At threshold levels and for frequencies below 2 kHz, the sound in the ear canal caused by BC stimulation is about 10 dB lower than air conduction hearing thresholds; this difference increases at higher frequencies. However, with the ear canal occluded, BC hearing is dominated by the sound pressure in the outer ear canal for frequencies between 0.4 and 1.2 kHz.


Assuntos
Condução Óssea/fisiologia , Orelha Externa/fisiologia , Limiar Auditivo/fisiologia , Meato Acústico Externo/fisiologia , Humanos , Percepção Sonora/fisiologia , Martelo/fisiologia , Percepção da Altura Sonora/fisiologia , Valores de Referência , Privação Sensorial/fisiologia , Membrana Timpânica/fisiologia , Vibração
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