Child, Preschool ; Cochlear Implantation ; Ear Canal ; surgery ; Female ; Humans ; Otitis Media with Effusion ; surgery ; Reconstructive Surgical Procedures ; methods

OBJECTIVE The objective of this study was to evaluate the effect of crimping of thepiston to the long process of the incus on sound transmission in the middle ear of the temporal bone model, and to use this information to guide stapes surgery and ossicular reconstruction. METHODS Seventeen temporal bone models was analyzed under different electromechanical stimulations. Scanning laser Doppler interferometry was used to measure the differences in sound conductivity due to the piston and the long process of the incus being crimped to a different degree. RESULTS The degree of crimping of the piston to long process of the incus was defined as either tight,loose or none. The classification was done by three physicians using endoscopic and scanning electron microscopic images. There was no significant disagreement among the doctors. Under 500 mV,800 mV,and 1200 mV of electromechanical stimulations,the degree of sound conductivity between the long process of the incus and piston was determined by scanning laser Doppler interferometry. A computer algorithm was developed in order to simulate acoustic stimulation by electromechanical stimulation. It has been found that the sound transmission loss was 2 dB,which was similar to the sound transmission loss of 3 dB within the incudostapedial joint. But the degree of crimping resulted in variabilities in this number. While the greatest loss was 28 dB,the average loss was 10 dB. CONCLUSION The optimal crimping between the long process of the incus and piston is tight,as it results in less sound transmission loss compared to the physiologic transmission loss within the incudostapedial joint.

OBJECTIVETo assess the amount of sound transmission loss in order to deeply understand the mechanism of middle ear sound transmission for ossicular reconstruction and for guidance of crimping between prosthesis and stapes on sound transmission in stapes surgery.

METHODSIn order to get a correcting magnetic field 2 temporal bone models was used first. Temporal bone models was developed using 17 human temporal bones from fresh cadavers. To measure the sound transmission properties in the middle ear, 15 temporal bone models were detected by scanning laser Doppler interferometry with acoustical stimulation and electromechanical stimulation. An algorithm was developed to simulate acoustical stimulation with electromechanical stimulation. A sound transmission loss within the incudostapedial joint was detected by electromechanical stimulation in 10 temporal bone models.

RESULTSThe average transmission loss within the incudostapedial joint remained 3 dB over the frequencies detected.

CONCLUSIONSThere was a sound transmission loss within the incudostapedial joint, which was a physiological and protection way.

Acoustic Stimulation ; Aged ; Aged, 80 and over ; Algorithms ; Ear, Middle ; physiology ; Female ; Humans ; Joints ; physiology ; Male ; Middle Aged ; Models, Biological ; Sound ; Temporal Bone ; physiology

Objective:To compare the effectiveness of primary malleostapedotomy with revision malleostapedotomy for otosclerosis.Methods:From April 2002 to December 2017, 70 consecutive patients with otosclerosis who underwent malleostapedotomy were reviewed. Depending on the primary malleostapedotomy (P-MS) or revision malleostapedotomy (R-MS), the patients were divided into P-MS group or R-MS group.The intraoperative findings and hearing results before and after surgery were compared between the two groups. ALL data were analyzed using SPSS 23.Results:Totally 73 malleostapedotomy were performed in 73 ears of 70 patients, including 38 P-MS and 35 R-MS. There was no significant difference between the two groups in sex ratio, age and operated ears ( P>0.05 for all). The most common finding at P-MS was incus fixation (50.0%, 19/38) versus prosthesis displacement for R-MS (60.0%, 21/35) . Overall, the air-bone gap (ABG) improvement in P-MS were (18.1±8.2) dB in 0.5-3 kHz and (18.3±8.5) dB in 0.5-4 kHz, without significant difference to those in R-MS ( P>0.05) . 31.4% of R-MS in 0.5-3 kHz and 22.9% R-MS in 0.5-4 kHz achieved an ABG<10 dB, significantly lower than those of P-MS (65.8% in 0.5-3 kHz and 57.9% in 0.5-4kHz; P<0.05). Failure (postoperative ABG>30 dB) occurred in 11.4% in R-MS and 0 in P-MS (for 0.5-3 kHz and 0.5-4 kHz). The incidence of postoperative sensorineural hearing loss (>10 dB increase in bone conduct) in R-MS group was 8.6% in 0.5-3 kHz and 0.5-4 kHz, without significant difference to those in P-MS ( P>0.05) . 80.0% (20/25) of first R-MS achieved ABG<20 dB, compared to 37.5% (3/8) of second R-MS with ABG<20 dB. Conclusions:Although both P-MS and R-MS can significantly improve hearing, with similar risk of inner ear damage, R-MS is less effective and poses a higher risk of failure than P-MS. For patients with insufficient hearing improvement after first R-MS, conventional hearing aids or implantable hearing devices may be considered as an alternative.