Stapedial Footplate Research Articles

Mutations and altered expression of SERPINF1 in patients with familial otosclerosis.

Otosclerosis is a relatively common heterogenous condition, characterized by abnormal bone remodelling in the otic capsule leading to fixation of the stapedial footplate and an associated conductive hearing loss. Although familial linkage and candidate gene association studies have been performed in recent years, little progress has been made in identifying disease-causing genes. Here, we used whole-exome sequencing in four families exhibiting dominantly inherited otosclerosis to identify 23 candidate variants (reduced to 9 after segregation analysis) for further investigation in a secondary cohort of 84 familial cases. Multiple mutations were found in the SERPINF1 (Serpin Peptidase Inhibitor, Clade F) gene which encodes PEDF (pigment epithelium-derived factor), a potent inhibitor of angiogenesis and known regulator of bone density. Six rare heterozygous SERPINF1 variants were found in seven patients in our familial otosclerosis cohort; three are missense mutations predicted to be deleterious to protein function. The other three variants are all located in the 5′-untranslated region (UTR) of an alternative spliced transcript SERPINF1-012. RNA-seq analysis demonstrated that this is the major SERPINF1 transcript in human stapes bone. Analysis of stapes from two patients with the 5′-UTR mutations showed that they had reduced expression of SERPINF1-012. All three 5′-UTR mutations are predicted to occur within transcription factor binding sites and reporter gene assays confirmed that they affect gene expression levels. Furthermore, RT-qPCR analysis of stapes bone cDNA showed that SERPINF1-012 expression is reduced in otosclerosis patients with and without SERPINF1 mutations, suggesting that it may be a common pathogenic pathway in the disease.

Does the morphology of the ear of the Chinese bamboo rat (Rhizomys sinensis) show "Subterranean" characteristics?

In spite of the growing interest in rodents with subterranean activity in general and the spalacids (Spalacidae) in particular, little is known about the biology of most members of this clade, such as the Chinese bamboo rat (Rhizomys sinensis). Here, we analyzed the ear morphology of R. sinensis with respect to hearing specialization for subterranean or aboveground modes of communication. It is well-known that ecology and style of life of a particular species can be reflected in morphology of its ear, its hearing and vocalization, so we expect that such information could provide us insight into its style of life and its sensory environment. The ratio between the eardrum and stapedial footplate areas, which influences the efficiency of middle ear sound transmission, suggests low hearing sensitivity, as is typical for subterranean species. The cochlea had 3.25 coils and resembled species with good low frequency hearing typical for subterranean mammals. The length of the basilar membrane was 18.9 ± 0.8 mm and its width slowly increased towards the cochlear apex from 60 to 85 μm. The mean density of outer hair cells was 344 ± 22 and of inner hair cells 114 ± 7.3 per 1 mm length of the organ of Corti, and increased apically. These values (except for relatively low hair cell density) usually characterize ears specialized for low frequency hearing. There was no evidence for an acoustic fovea. Apart of low hair cell density which is common in aboveground animals, this species has also relatively large auricles, suggesting the importance of sound localization during surface activity. The ear of the Chinese bamboo rat thus contains features typical for both aboveground and subterranean mammals and suggests that this spalacid has fossorial habits combined with regular aboveground activity.

Congenital ossicular chain malformations with mobile stapes in children: Results in 17 cases.

To prospectively evaluate surgical findings and hearing results in children undergoing surgery for congenital malformations of the ossicular chain with a mobile stapes footplate (Teunissen and Cremers class III malformations). A nonrandomized, nonblinded, prospective case series. Fifteen consecutive pediatric patients who underwent 17 surgical procedures for congenital ossicular malformations with a mobile stapes at a tertiary referral center were included. In 16 cases, postoperative pure-tone audiometry was available. The surgical technique for repair of the ossicular chain was dictated by the surgical findings at the time of surgery. The majority of the cases underwent ossiculoplasty. A Teflon piston, partial ossicular replacement prosthesis, or total ossicular replacement prosthesis was used in these cases. Associated surgical techniques included malleus relocation, Silastic banding, drilling out of a bony bridge, and a combination of these techniques. Hearing loss was evaluated using preoperative and postoperative four-frequency (0.5, 1, 2, and 4 kHz) audiometry. Air-conduction thresholds, bone-conduction thresholds, and air-bone gaps were measured. Postoperative audiometry was performed at 3, 6, 9, 12, 18, and 24 months after surgery and at a yearly interval thereafter. Overall, a postoperative air-bone gap closure to 10 dB or less was achieved in 63% of the included cases. A postoperative air-bone gap closure to 20 dB or less was achieved in 75%. Postoperative sensorineural hearing loss did not occur in any of the cases. Ossicular reconstruction is a feasible treatment option in children with congenital malformations of the ossicular chain with a mobile stapes footplate. 4. Laryngoscope, 126:682-688, 2016.

Stabilization of total ossicular replacement prosthesis using cartilage “shoe” graft

PurposeWe aimed to determine the effect of a cartilage shoe graft placed between the foot of the TORP and the stapes footplate on hearing improvement and long-term displacement rates. Materials and methodsPatients who underwent TORP ossiculoplasty were divided into two groups. The TORP-alone group consisted of 32 patients who underwent TORP placement without cartilage shoe graft and served as the control group. The study group consisted of 56 patients who underwent placement of cartilage shoe graft together with TORP. Pure-tone audiometry was administered to all patients before and 3, 6 and 12months after surgery. Indications for surgery, surgical technique used, postoperative complications, and air and bone conduction thresholds at 500, 1000, 2000 and 4000Hz were recorded for all patients. ResultsNo significant difference in postoperative air–bone gaps was observed between the groups. The number of patients with air–bone gaps less than 20dB was 14 (25%) in the study group and 8 (25%) in the control group. There was no significant difference in changes in air–bone gaps between the groups. Dislocation of the prosthesis was observed in 3 patients in the study group (5.3%) and 4 in the control group (12.5%). There was less dislocation of the prosthesis in the study group, but the difference was not statistically significant. ConclusionPlacement of a cartilage graft between the footplate of the stapes and the foot of the prosthesis may have positive effects on long-term hearing improvement and rates of prosthesis displacement. Further research with larger patient numbers is needed to identify the advantages of shoe graft.

Electro-Mechanical Stimulation of the Cochlea by Vibrating Cochlear Implant Electrodes.

Electro-acoustic stimulation (EAS) of the cochlea uses the preserved residual low-frequency hearing for acoustic stimulation in combination with electrical stimulation. The acoustic low-frequency component is amplified and high-frequency hearing is enhanced by a cochlear implant (CI). In this work, the feasibility of EAS by the floating mass transducers (FMTs) firmly attached to the implanted electrode was investigated and the achieved stapes displacement was compared with sound stimulation. Experiments were performed in eight fresh human temporal bones compliant to the ASTM standard (F2504-5). Four EAS custom-made prototypes (EAS-CMP) were tested, consisting of standard MED-EL CI electrodes with Vibrant Soundbridge (VSB) FMTs or a Bonebridge (BB) FMT tightly molded to the electrode in different orientations. The stapes footplate (SFP) response to EAS-CMP stimulation and sound stimulation was measured using a Laser Doppler Vibrometer (LDV). The SFP displacement amplitudes achieved by EAS-CMP stimulation were calculated to 1 VRMS FMT input and were pair-wise statistically compared between prototypes yielding no significant differences at frequencies ≤1 kHz. At frequencies ≤1 kHz stimulation by the BB FMT resulted in a flat and potentially highest SFP displacement amplitude of approximately -40 dB re μm at 1 VRMS input voltage. Estimated equivalent sound pressure levels achieved by the BB FMT prototype were approximately 83-90 eq. dB SPL at frequencies ≤1 kHz. The feasibility of cochlear stimulation by vibrating electrodes was shown although the achieved output level at frequencies ≤1 kHz was too low for EAS applications.

Trans-Oval-Window Implants, A New Approach for Drug Delivery to the Inner Ear: Extended Dexamethasone Release From Silicone-based Implants.

The purpose of this study was to develop a new strategy to deliver drugs to the inner ear from dexamethasone (DXM)-loaded silicone implants and to evaluate the distribution of the drug in the cochlea with confocal microscopy. Systemic drug administration for the treatment of inner ear disorders is tricky because of the blood-cochlear barrier, a difficult anatomical access, the small size of the cochlea, and can cause significant adverse effects. An effective way to overcome these obstacles is to administer drugs locally. In vitro, the drug release from DXM-loaded silicone-based thin films and tiny implants into artificial perilymph was thoroughly analyzed by high-performance liquid chromatography. In vivo, a silicone implant loaded with 10% DXM and 5% polyethylene glycol 400 was implanted next to the stapes's footplate of gerbils. Delivery of DXM into the inner ear was proved by confocal microscopy imaging of the whole cochlea and the organ of Corti. The study showed a continuous and prolonged release during 90 days in vitro. This was confirmed by confocal microscopy that allowed detection of DXM by fluorescence labeling in the cell body of the hair cells for at least 30 days. Interestingly, fluorescence was already observed after 20 minutes of implantation, reached a climax at day 7, and could still be detected 30 days after implantation. Thus, we developed a new device for local corticosteroids delivery into the oval window with an extended drug release of DXM to the inner ear.

Comparing human middle-ear motion and pressure gain across idealized and progressively more realistic three-dimensional finite-element models

The mammalian tympanic membrane (TM) is linked to the cochlea via a flexible and circuitous three-bone ossicular chain for which much of the mass is concentrated away from the entry axis to the cochlea. As the TM area (ATM) is much larger than that of the stapes footplate (AFP) and the length of the malleus (LM) is somewhat longer than the incus (LI), the middle ear is considered to function as a pressure transformer to optimize the flow of vibrations from low-density air to high-density cochlear fluid, with an ideal pressure gain defined as (ATM/AFP)*(LM/LI). Even so, the reasons for this complex ossicular arrangement, as opposed to the more straightforward case of a columella directly connecting the TM to the cochlea, are not entirely clear. We explore the effects of middle-ear anatomy and material properties on ossicular motion and pressure gain by comparing the behavior of a series of 3D finite-element models ranging from idealized simple axisymmetric cases of a flat-circular or conic TM connected to a columella, all the way to an anatomically accurate three-ossicle human middle-ear model based on a micro-CT scan of a temporal bone. In doing this, we will test whether the complex 3D anatomy of the human middle ear can be shown to offer any concrete advantages in terms of pressure gain over a simpler columella design, or whether other possible reasons for this complex design are more likely. [Work supported by R01 DC05960 from the NIDCD of the NIH.]

The Codacs™ direct acoustic cochlear implant actuator: exploring alternative stimulation sites and their stimulation efficiency.

This work assesses the efficiency of the Codacs system actuator (Cochlear Ltd., Sydney Australia) in different inner ear stimulation modalities. Originally the actuator was intended for direct perilymph stimulation after stapedotomy using a piston prosthesis. A possible alternative application is the stimulation of middle ear structures or the round window (RW). Here the perilymph stimulation with a K-piston through a stapes footplate (SFP) fenestration (N = 10) as well as stimulation of the stapes head (SH) with a Bell prosthesis (N = 9), SFP stimulation with an Omega/Aerial prosthesis (N = 8) and reverse RW stimulation (N = 10) were performed in cadaveric human temporal bones (TBs). Codacs actuator output is expressed as equivalent sound pressure level (eq. SPL) using RW and SFP displacement responses, measured by Laser Doppler velocimetry as reference. The axial actuator coupling force in stimulation of stapes and RW was adjusted to ~ 5 mN. The Bell prosthesis and Omega/Aerial prosthesis stimulation generated similar mean eq. SPLs (Bell: 127.5–141.8 eq. dB SPL; Omega/Aerial: 123.6–143.9 eq. dB SPL), being significantly more efficient than K-piston perilymph stimulation (108.6–131.6 eq. dB SPL) and RW stimulation (108.3–128.2 eq. dB SPL). Our results demonstrate that SH, SFP and RW are adequate alternative stimulation sites for the Codacs actuator using coupling prostheses and an axial coupling force of ~ 5 mN. Based on the eq. SPLs, all investigated methods were adequate for in vivo hearing aid applications, provided that experimental conditions including constant coupling force will be implemented.

The distance between stapedial footplate and incus in otosclerosis surgery

BackgroundThe measurement of the piston length during stapedotomy is important and it may have significant effects on the surgical outcome. ObjectiveTo determine the piston length in a group of otosclerosis patients who underwent primary stapedotomy. Material and methodsBetween Sep 2013 and Sep 2014, 85 patients with diagnosed otosclerosis underwent primary stapedotomy. Teflon prosthesis of 0.6 mm of diameter was used in all patients. The distance between medial surface of the long process of incus and center point of the stapedial footplate measured. The piston length calculated by adding 0.25 mm for the thickness of footplate and 0.50 mm for placement of the prosthesis into the vestibule. ResultsThe distance between stapedial foot plate and incus ranged from 3.50 to 4.50 mm. The mean distance was 3.95 ± 0.16 mm. In majority of cases (74.1%) piston length was 4.75 mm followed by 4.50 mm in 15.3% and 5.00 mm in 5.9%. Piston length was 4.25 mm in 3.5% and 5.25 mm in only 1.2% of patients. There was no significant post-operative complication and air bone gap closure obtained in all patients. ConclusionThe most common distance between foot plate and incus is 4.00 mm. No case needed a piston longer than 5.25 mm or shorter than 4.25 mm.

中頭蓋窩硬膜まで進展した二次性真珠腫例

Secondary cholesteatoma is relatively rare, but can develop by extension of the tympanic epithelium into the tympanic cavity through perforation of the marginal membrane. The subject reported herein was a 68-year-old male patient with a history of persistent bilateral otorrhea since childhood. Examination revealed a large perforation in the tympanic membrane on both sides, with debris observed on the promontory of the right tympanic cavity. The hearing level was 66.7 dB in the right ear, and 65 dB in the left ear. Subsequently, a secondary cholesteatoma, with the cholesteatoma matrix extending continuously from the upper edge of the tympanic membrane perforation was observed, a tympanoplasty was attempted under general anesthesia on the right side. Among the ossicles, only the stapedial footplate and the handle of the malleus were found to remain, and the horizontal portion of the facial nerve canal was also broadly destroyed. While the antrum mastoideum was filled by the cholesteatoma extending from the tympanic cavity, the cholesteatoma matrix and the dura mater of the middle cranial fossa were tightly adherent and very difficult to separate. Therefore, the plasty method, referred to as the “open method tympanoplasty”, was employed, allowing the cholesteatoma matrix in the mastoid antrum to remain. Until now, five years after the surgery, no recurrence has been observed. Thus, in patients with chronic otitis media associated with tympanic perforation and pesistent otorrhea in whom the perforation is found to extend to the handle of the malleus, the possibility of a secondary cholesteatoma should be borne in mind. In such cases, rather than continuing with conservative treatment, it is important to examine the patient carefully, bearing in mind the possibility of secondary cholesteatoma.

TORP Ossiculoplasty Outcomes with and without a Stapes Footplate Prosthesis

The titanium stapes footplate prosthesis (FPP) was designed to ensure a stable connection of a total ossicular replacement prosthesis (TORP) to the stapes footplate and maximize acoustic coupling by centering the footplate on the oval window. Our goal was to assess the impact of the FPP on TORP ossiculoplasty outcomes. Case series with chart review. Tertiary care center. Adult patients undergoing TORP ossiculoplasty with (n=53) or without (n=108) a stapes FPP. Rate of prosthesis displacement and audiologic outcomes were tabulated for statistical analysis. A lower rate of prosthesis displacement and statistically better audiologic outcomes were seen in FPP patients. The pure-tone average air-bone gap (PTA-ABG) was closed to <20 dB in 69.8% (37/53) of patients in the study arm and 44.4% (48/108) of patients in the control arm (P=.003). The PTA-ABG was decreased by a mean±SD of 19.3±11.7 dB and 12.6±11.0 dB in the study and control groups, respectively (P=.0012). Use of the titanium stapes FPP during TORP ossiculoplasty provides a statistically significant advantage in short-term PTA-ABG closure and a higher rate of successful rehabilitation of conductive hearing loss. Further studies are necessary to assess any long-term advantages a FPP may offer.

Vitamin C Deficiency Impairs Mineralization of Ossicle in Mice

Objectives: Vitamin C-deficient (VCD) mice develop spontaneous bone fractures and exhibit hearing loss. However, the effects on the micro-architecture of the ossicles and the underlying mechanisms have not been fully understood. In this study, we test the hypothesis that vitamin deficiency impairs osteoblast differentiation and function of the ossicles. Methods: The morphologic characteristics of the ossicles in VCD and wild-type mice were evaluated with a stereoscopic microscope. Micro-structure of the ossicles was analyzed by micro computed tomography (µCT). Osteoblast differentiation was determined by immunostaining of the bone marker gene, osteocalcin. Sound transmission along the ossicular chain was evaluated with laser Doppler vibrometer. Results: The ossicles in VCD mice demonstrated thinner bone in the manubrium of malleus and stapes footplate. µCT analyses further verified that the bone volume/total volume fraction (BV/TV) was significantly reduced in the stapes footplate (51.5 ± 3.9% vs 61.2 ± 1.5%; P &lt; .05) and the manubrium of malleus (24.9 ± 5.3% vs 39.0 ± 5.0%; P &lt; .05) in VCD mice. The expression of osteocalcin was significantly decreased in the ossicles of VCD mice (17.8 ± 3.3 vs 32.4 ± 4.7; P &lt; .05). However, the preliminary data revealed a modest change in sound transmission along the ossicular chain. Conclusions: These findings suggest that VCD decreased expression of osteoblast differentiation marker, osteocalcin, and reduced bone volume and of the ossicles without significantly altering sound transmission. These results may indicate that the pathogenesis of VCD-induced hearing loss might be due to a deficiency at the inner ear or auditory neuron level. Further studies are warranted.

Total Ossiculoplasty Outcomes with and without a Stapes Footplate Prosthesis

Objectives: Compare audiologic outcomes of total ossicular replacement prosthesis (TORP) ossiculoplasty performed with and without the placement of a stapes footplate prosthesis (FPP). Methods: A retrospective chart review was performed to identify adult patients undergoing TORP ossiculoplasty by the same surgeon at a tertiary care center between 1998 and 2012. Indications for surgery included cholesteatoma, atelectasis/perforation, chronic otitis media, and glomus tumor. Patients with a history of stapes surgery on the ear of interest were excluded from the study. Results: A lower rate of prosthesis displacement and statistically better audiologic outcomes were seen in FPP patients. The pure-tone average air-bone gap (PTA-ABG) was closed to &lt;20 dB in 69.8% (37/53) of patients in the study arm and 44.4% (48/108) of patients in the control arm ( P &lt; .001). The PTA-ABG was decreased by an average of 19.3 dB ± 11.7 dB (standard deviation, SD) and 12.6 dB ± 11.0 dB (SD) in the study and control groups, respectively ( P = .0014). Conclusions: Use of the titanium stapes FPP during TORP ossiculoplasty was associated with a statistically significant advantage in short-term PTA-ABG closure and a higher rate of successful rehabilitation of conductive hearing loss in this study. A lower rate of prosthesis displacement was seen in the FPP group, but further studies and longer follow-up periods are needed to validate this observation.

Extratympanic observation of middle ear structure using a refractive index matching material (glycerol) and an infrared camera

High-resolution computed tomography has been used mainly in the diagnosis of middle ear disease, such as high-jugular bulb, congenital cholesteatoma, and ossicular disruption. However, certain diagnoses are confirmed through exploratory tympanotomy. There are few noninvasive methods available to observe the middle ear. The purpose of this study was to investigate the effect of glycerol as a refractive index matching material and an infrared (IR) camera system for extratympanic observation. 30% glycerol was used as a refractive index matching material in five fresh cadavers. Each material was divided into four subgroups; GN (glycerol no) group, GO (glycerol out) group, GI (glycerol in) group, and GB (glycerol both) group. A printed letter and middle ear structures on the inside tympanic membrane were observed using a visible and IR ray camera system. In the GB group, there were marked a transilluminated letter or an ossicle on the inside tympanic membrane. In particular, a footplate of stapes was even transilluminated using the IR camera system in the GB group. This method can be useful in the diagnosis of diseases of the middle ear if it is clinically applied through further studies.

Three-dimensional temporal bone reconstruction from histological sections.

To produce a high-resolution, three-dimensional temporal bone model from serial sections, using a personal computer. Digital images were acquired from histological sections of the temporal bone. Image registration, segmentation and three-dimensional volumetric reconstruction were performed using a personal computer. The model was assessed for anatomical accuracy and interactivity by otologists. An accurate, high-resolution, three-dimensional model of the temporal bone was produced, containing structures relevant to otological surgery. The facial nerve, labyrinth, internal carotid artery, jugular bulb and all of the ossicles were seen (including the stapes footplate), together with the internal and external auditory meati. Some projections also showed the chorda tympani nerve. A high-resolution, three-dimensional computer model of the complete temporal bone was produced using a personal computer. Because of the increasing difficulty in procuring cadaveric bones, this model could be a useful adjunct for training.

Diagnosis of stapedial footplate fixation in archaeological human remains

This study analyses changes in the region of the oval window suggestive of stapedial footplate fixation in archaeological human skeletal remains. We endoscopically investigated 621 temporal bones of 385 individuals from five medieval sites in Germany to identify fixations of the stapedial footplate. For differential diagnosis, four cases suspicious of representing stapes fixation or remnants of the fixed footplate were further investigated using microscopic techniques (brightfield and darkfield imaging, phase-contrast microscopy, fluorescence microscopy, CLSM, SEM-BSE imaging), and EDX-analysis, either alone or in combination. Our findings suggest that only two of the four cases represented an intravital fixation of the stapedial footplate. The first case was diagnosed as caused by sclerosis of the annular ligament, the second cases as representing an example of congenital footplate fixation. In a third case, structures that were initially diagnosed as remnants of the footplate were shown to be soil particles. In the fourth case the structures attached to the oval window were identified as apatitic deposits formed by diagenetic agents. Our findings highlight the need for microscopic analyses to distinguish intravital from postmortem changes in the region of the oval window and the differential diagnosis of intravital footplate fixations.

Comparison of Hearing Results of Malleovestibulopexy and Total Ossicular Replacement Prosthesis for Chronic Otitis Media Patients With a Mobile Stapes Footplate

This study aimed to assess differences in hearing outcomes using the malleostapedotomy or malleovestibulopexy (MVP) and total ossicular replacement prosthesis (TORP) techniques in chronic otitis media patients with a mobile stapes footplate. Case series with planned data collection. A university medical center. In total, 27 patients with chronic otitis media at the Sixth Hospital affiliated with Shanghai Jiao Tong University, between January and October 2010, were included. All patients had destruction of incus and stapes superstructures and a mobile stapes footplate. In all patients, surgery was performed under general anesthesia by a retroauricular approach. After the lesions were removed completely, ossicular reconstruction was performed using 1 of the techniques. In all patients, pure-tone audiograms were assessed before and 12 months after surgery. Thirteen patients underwent MVP surgery, whereas the other 14 cases received traditional TORP surgery. All patients showed improvements in functional hearing after surgery. Although the numbers of ears that had closure of the air-bone gap within 20 dB in the MVP group were not statistically significantly higher than those in the TORP group (Fisher's exact test, P > .05), the average postoperative gain of the MVP group was significantly higher than that of the TORP group (t test, P < .05). Functional hearing in chronic otitis media patients with a mobile stapes footplate was better in those who underwent MVP surgery than in those who underwent TORP surgery.

Comparison of different computed tomography post-processing modalities in assessment of various middle ear disorders

Several anatomic structures of the middle ear are not optimally depicted in the standard axial and coronal planes. Several 2D and 3D image-processing modalities are currently available for CT examinations in clinical radiology departments. Till now 3D reconstructions of the temporal bone have not been widely used yet, and attracted only academic interest. The aim of this study was to compare axial (source images), 2D and 3DCT post-processing modalities, and to evaluate the value of 3D reconstructed images/virtual endoscopy (VE) in assessment of various middle ear disorders for identification of the best modality/view for assessment of a particular middle ear structure or pathology. 40 patients with various middle ear disorders, planned for surgical intervention were included in prospective study. Multi-slice CT was performed for all patients. Scans were acquired in the axial plane. The axial source datasets were utilized for generation of 2D reformations and 3D reconstructed images. All studied images were divided into three categories: axial (source images), 2D reformations (MPR and sliding-thin-slab MIP) and 3D reconstruction (virtual endoscopy). The visibility of middle ear structures and pathologies with each modality were scored qualitatively using three-point scoring system in reference to operative findings. Stapes superstructure and footplate, incudostapedial joint, oval and round windows, tympanic segment of the facial nerve and tegmen were not optimally depicted in the axial plane. Sinus tympani and facial recess were best visualized with axial images or VE. 3D reconstruction/VE allowed good visualization of all parts of ossicular chain except stapes superstructure. Regarding pathologic changes, 2D reformations and 3D reconstructed images allowed better visualization of erosion of ossicles and tegmen. 3D reconstruction/VE did not allow detection of foci of otospongiosis. 2D reformations can be considered the mainstay in assessment of most middle ear structures and pathologies. 3D reconstruction/VE seems to provide a useful method for a preoperative general overview of the middle ear anatomy, particularly for the ossicular chain, round window and retrotympanum.

Osteometric Dimension of Stapes

Background: In the present study an attempt is made to study the morphometric analysis of ear ossicles to compare and evaluate the various morphometric parameters for designing the prosthesis used by Otologist in people of Gujarat. Aim: To study normal values of stapes this helps in making of stapes prostheses for otologists. Material and Method: Present study was carried out on 60 stapes in anatomy department at 3 medical colleges namely Shri M.P. Shah Govt. Medical College, Jamnagar, Govt. Medical College, Bhavnagar and P.D.U Medical College, Rajkot. The present study was conducted after approval from the institutional ethics committee. Results: the mean total height of stapes was 3.33 ± 0.25 mm, ranging from a minimum of 2.86mm to maximum of 3.9mm. The mean length of footplate of stapes was 2.78 ± 0.15 mm, ranging from a minimum of 2.41mm to maximum of 3.11mm. The mean width of footplate of stapes was 1.34 ± 0.13 mm, ranging from a minimum of 1.05 mm to maximum of 1.73 mm. Conclusion: The results of parameters of the ear ossicles are very helpful in making ear ossicles prosthesis in ossicular chain pathology in Guajarati population. Variation in the dimension of the ear ossicles might be due to racial difference or regional population difference in India. Variation in the dimension of ear ossicles might be due to various types of instruments used for measurement; methods used for measurement of ossicles or inter observer error by other workers.

Minor ossicular anomalies in the middle ear: role of submillimeter multislice computed tomography.

The objective was to elucidate clinical effectiveness of submillimeter multislice 2- and 3-dimensional computed tomography (CT) for diagnosis of congenital middle ear anomaly. Preoperative CT and operative findings were retrospectively analyzed in 36 ears of 33 patients. The distance between the malleal handle (MH) and the incus long process (ILP) was measured in 28 normal ears. Mean ± SD MH-ILP distance in normal ears was 1.8 ± 0.3 mm. In patients with middle ear anomaly, overall specificity, accuracy, and positive and negative predictive values were 99.7%, 98.7%, 91.7%, and 99.1%, respectively. Overall sensitivity was 82.1%, with relatively low sensitivities for detecting fused incudomalleolar joint, lenticular process defect, stapedial footplate defect, and oval window atresia and high sensitivities (80%-100%) for stapedial crural anomaly and certain fibrous connections. Submillimeter CT improved detectability of anomalies of the stapedial superstructure; however, it is still difficult to identify abnormalities of the footplate.