Bone Conduction Improvement Research Articles

Interest of computer tomography in the study of prognostic factors of otosclerosis.

Otosclerosis is a primary osteodystrophy of the otic capsule that causes stapedo-vestibular ankylosis. Its diagnosis is suspected on the basis of clinical and audiometric elements, basically in the presence of conductive hearing loss with a normal eardrum. The CT-scan is an essential examination for the preoperative evaluation of otosclerosis. The aim of our study was to evaluate the use of CT-scanning in predicting the functional outcome of otosclerosis surgery by correlating postoperative audiometric results and preoperative CT findings. We conducted a retrospective study at the ENT Department in association with the Medical Imaging Department of our hospital, over a period of 8years, from January 2014 to December 2022 and involving 90 patients (104 ears). The average age of our patients was 40years with extremes ranging from 22 to 61years. We noted a sex ratio of 0.38. The preoperative CT-scan showed signs of otosclerosis in 87% of the cases and infra-radiological forms in 13% of the cases. Veillon stage II was the most frequent radiological stage encountered with a percentage of 48%. A good audiometric evolution, defined by a closure of postoperative Air Bone Gap (ABG ≤ 20dB) and by an improvement of Bone Conduction (BC gain ≥ 0), was recorded in 86 cases (82.7%) for ABG and in 84 cases (80.8%) for BC gain. Scanographic predictive factors of poor postoperative outcome for ABG and BC gain were: advanced stages (Veillon stage III and IV), endosteal effraction, and round window involvement. According to multivariate analysis, only the extent of otosclerotic foci was directly and independently associated with the postoperative audiometric outcome. The CT-scan is an essential examination in the preoperative evaluation of otosclerosis. It allows a positive diagnosis to be made and evaluate the extension of otosclerosis. Moreover, thanks to the analysis of the extent of the otosclerosis foci, mainly by the Veillon classification, the CT-scan allows to predict the postoperative audiometric prognosis.

Comparison of Short-Term Hearing Outcome in Stapedotomy Using either Vein or Fat (Adipose Tissue) as Sealing Material.

Introduction Otosclerosis is a common cause of conductive hearing loss in the adult population that is caused by fixation of the stapes footplate. Cochlear otosclerosis may also present with sensorineural or mixed hearing loss. Surgery is the definitive treatment of choice and, during the procedure, sealing of the oval window with autologous tissue graft around the stapes prosthesis has been routinely done to improve hearing outcome and to mitigate postoperative complications. Objective To evaluate the efficacy of two different types of autologous tissue (vein or fat) grafts as oval window sealing materials in stapedotomy in improving short-term hearing outcomes. Methods In our study, 70 patients with otosclerosis who underwent primary stapedotomy were included. They were divided into group 1 (vein graft) and group 2 (fat graft) based on the type of sealing material used. All patients were followed-up at the end of 3 months, undergoing an audiometric examination to assess the hearing outcome. Results A total of 80% ( n = 28) of the patients in group1 had an air-bone gap (ABG) closure < 10dB, and, in group 2, 85.7% had an ABG closure < 10 dB; this difference was found to be statistically insignificant. A total of 42.9% ( n = 15) of the patients in group 1 and of 31.4% ( n = 11) in group 2 had a significant improvement in bone conduction, while 14.3% ( n = 5) of the patients in group 1 and 17.1% ( n = 6) in group 2 had worsening of average bone conduction postoperatively, which was found to be statistically insignificant. Conclusion Both vein and fat grafts had comparable effects on hearing outcomes when used as sealing materials in stapedotomy.

Is the Carhart notch a predictive factor of hearing results after stapedectomy?

SUMMARYThe Carhart notch (CN) is a depression in the bone-conduction audiogram of patients with clinical otosclerosis. The middle frequencies from 0.5 to 2 kHz, which correspond to the resonance frequency of the middle ear, can be substantially improved upon following successful stapes surgery. This retrospective audiometric database and chart review in a tertiary referral centre was performed with the aim of assessing whether the presence of a CN could be predictive of results after stapes surgery in otosclerosis, through improvement in bone conduction (BC) thresholds. Nine hundred and thirty-one cases of stapes surgery over a period of 25 years benefitted from audiological assessment before and 4 months after surgery. A CN was considered present when the BC threshold at the notch frequency (0.5, 1 or 2 kHz) exceeded the mean thresholds at higher and lower adjacent frequencies by at least 7.5 dB. BC threshold improvement was better at 2 kHz (+14.1 ± 12.5 dB vs +12 ± 13.2 dB) and lower at 4 kHz (+3.6 ± 13.5 dB vs +11 ± 14.7 dB) for the CN+ group compared to the CN- group. Moreover, sensorineural hearing loss was more frequent in the CN+ group than in the CN- group. These results indicate that a CN on preoperative audiogram should alert the clinician to lesser postoperative BC improvement at 4 kHz related to a preoperative sensorineural hearing loss or to a higher incidence of postoperative sensorineural hearing loss.

The prognostic influence of pre-surgery bone conduction values on the improvement of hearing in patients treated surgically as a result of middle-ear conditions.

Background The influence of the mechanics of the middle ear on the function of the inner ear has been studied for many years. Among surgeries performed in the middle-ear area, those restoring full functionality of the system transmitting sound inside the middle ear may be pointed out as those fully restoring the mechanical influence of the middle ear on the function of the inner ear. Aim: The aim of the performed analysis is to find the prognostic importance of measured pre-surgery values of bone conduction on the improvement of hearing in patients operated as a result of middle-ear disorders. Methods The analysis included 271 patients hospitalised and operated on due to otosclerosis or perforation of the tympanic membrane between 2016 and 2019. Only patients who had not had a surgical operation within the middle ear prior to the study were included. An audiological assessment was performed with the use of pure tone thresholds audiometry. Results A beneficial influence of the performed surgery on the improvement of bone conduction was observed in patients, in which the average threshold value of bone conduction measured before the surgery did not exceed 40 dB. In cases of the perceptive component of hearing impairment being higher than 40 dB, no statistically significant, beneficial influence of a performed stapedotomy or myringoplasty on the change of bone conduction thresholds was observed. Conclusion The perception component of hearing impairment up to 40 dB indicates bone conduction improvement after surgical restoration of the influence of middle-ear mechanics on the inner ear in patients treated as a result of otosclerosis, as well as of eardrum perforation.

The effect of various treatment modalities in idiopathic sudden sensorineural hearing loss: A retrospective evaluation

Objective: In this study, we retrospectively evaluated the effects of treatment modalities on healing in patients diagnosed with idiopathic sudden sensorineural hearing loss.&#x0D; Material and Method: In this study, we retrospectively reviewed the records of 65 patients diagnosed with idiopathic sudden sensorineural hearing loss and treated as inpatients. The treatment modalities applied to the patients were determined randomly. &#x0D; Results: The effect of intra-tympanic steroid and / or hyperbaric oxygen therapy in addition to intravenous steroid on 500, 1000, 2000 and 4000 Hz frequencies and improvement in bone conduction was not statistically significant.&#x0D; Conclusion: Although intra-tympanic steroid or hyperbaric oxygen therapy in addition to intravenous steroid therapy, which is the standard treatment of idiopathic sudden sensorineural hearing loss, does not increase the rate of improvement and speed, it may help to reduce the undesirable effects of the steroid dose.

Evaluation of the safety and effect of the endoscopic stapes surgery: a multi-center study

Objective: To analyze the safety of endoscopic stapes surgery, and to compare the results with stapes surgery under microscopic approach. Methods: This was a retrospective study. One hundred and thirty seven patients from Eye Ear Nose and Throat Hospital of Fudan University and other seven hospitals were enrolled in this study. Eighty eight patients, in whom 29 were male, and 59 were female, aged from 29 to 66 years old, with an average of 40.1±10.7, underwent endoscopic stapedotomy and 49 patients, in whom 17 were male, and 33 were female, aged from 32 to 64 yeas old, with an arerage of 38.7±9.2, underwent microscopic stapedotomy for otosclerosis. Interventions included endoscopic and microscopic stapes surgeries. Main outcome measures consisted of operating time, preoperative and postoperative hearing, intraoperative findings, and postoperative complications. SPSS 16.0 software was used to analyzed the date (t test and χ(2) test) . Results: Patients in the group who underwent endoscopic stapes surgery showed a mean operative time of (74.1±26.0) min. Patients in the group treated by microscopic approach had a mean operative time (66.5±15.9) min. Statistical difference was evident (t=1.279, P<0.05) . The average operative time of endoscopic surgery became shorter as the cases increased. The average duration of the last 10 cases was shorter than that of the first 10 cases in both groups. The differences were significant (t value was 3.028, 3.610, both P<0.05). No statistical difference was found in air conduction threshold improvement (t=1.074, P=0.289) , air-bone gap closure (t=-0.135, P=0.893) and bone conduction improvement (t=1.222, P=0.228) between the two groups. No difference regarding the incidence of the postoperative complications (chorda tympanum damage: 6 cases vs 2 cases, χ(2)=0.08,P>0.05; vertigo:18 cases vs 9 cases,χ(2)=0.09, P>0.05; facial paralysis: 0 case vs 0 case) between the two groups was found. Conclusion: Audiological outcomes achieved by endoscopic surgery are similar to the results obtained through a microscopic approach. Endoscopic stapes surgery is safe.

A Case of Cholesterol Granuloma at the Petrous Apex with Improvement of Bone Conduction after Drainage Surgery

A Case of Cholesterol Granuloma at the Petrous Apex with Improvement of Bone Conduction after Drainage Surgery

Результаты хирургического лечения пациентов с кохлеарной формой отосклероза

Despite the progress in otosurgery, the efficient treatment of patients with the cochlear form of otosclerosis (according to the classification of N.A. Preobrazhensky, 1962) remains an important task. The authors have developed and implemented an advanced stapedoplasty method, providing the improvement of hearing in this category of patients. and described the methods of differential diagnostics for selection of patients according to the developed method. The article describes in details the early and long-term functional results of surgical treatment of 60 patients with cochlear and mixed II forms of otosclerosis, divided into the main and control groups. The main group is represented by 30 patients who underwent a cartilage-on-vein stapedoplasty according to the improved method. The control group included 30 patients, in which 18 people underwent a cartilage-on-vein stapedoplasty according to the method developed by Lenin Prize winner V. F. Nikitina, and 12 people who underwent V. T. Palchun’s piston stapedoplasty. The results demonstrate a statistically significant improvement of bone conduction in the main group in average by 15–20 dB throughout the entire tone scale (except for high frequencies in some patients) and the complete closure of the bone-air interval with subsequent preservation of the results. Based on the obtained data, the authors present the expediency and perspectivity of implementation of the advanced stapedoplasty method.

Factors that have an influence on bone conduction thresholds changes after otosurgery in the patients operated on due to the perforation of the tympanic membrane with the preserved ossicular chain.

The aim of the middle ear surgery is to eliminate abnormalities from the mucous, ensure the due airing of the postoperative cavity and reconstruct the sound-conducting system in the middle ear. Numerous reports can be found in literature on the changes to bone conduction as a consequence of middle ear surgery. The aim of the work is to define the factors that affect bone conduction in the patients operated on due to the perforation of the tympanic membrane with the preserved and normal mobile ossicular chain. A prospective analysis of patients operated on due to diseases of the middle ear in 2009-2012 was carried out. The cases of patients operated on for the first time due to chronic otitis media were taken into consideration. The analysis encompassed the patients who had undergone myringoplasty. The patients were divided into several groups taking into account the abnormalities of the mucous observed during otosurgery. A significant improvement of bone conduction was observed in the patients with dry perforation, without other lesions in the middle ear. The appropriate pharmacological treatment before otosurgery in patients with permanent discharge from the ear resulted in significant bone conduction improvement. The elimination of granulation lesions turned out to be a positive factor for the future improvement of the function of the inner ear. The lack of abnormalities on the mucous of the middle ear (e.g. granulation,) and discharge has a positive impact on improvement of bone conduction after myringoplasty. Adhesions in the tympanic cavity, especially in the niche of the round window, have a negative impact on improvement of bone conduction in patients after myringoplasty.

Postoperative bone conduction threshold changes in patients operated on for chronic otitis media--analysis.

Postoperative hearing improvement is measured as Air-Bone gap changes. Changes in bone conduction threasholds as a results of otosurgery is also discussed. We discuss factors that have influence on bone conduction threasholds changes in individuals operated due to chronic otitis media. The prospective analysis involves the patients operated on middle ear due to chronic infection in the Department of Otolaryngology at the Jagiellonian University of Krakow in the years 2010-2013. 457 otosurgeries were performed in this period of time. 293 first time operated on patients with chronic otitis media were analysed. Statistically significant bone conduction improvement was noticed after myringoplasty and in individuals with intact ossicular chain. No bone conduction threasholds improvement was observed with defects to the ossicles. Unchanged mucous lining middle ear spaces and intact ossicular chain are crucial for bone conduction improvement after otosurgery. Scars, especially in round window, are poor prognostic factor for hearing improvement. Cleaning of the middle ear from granulation has an positive influence for bone conduction threasholds changes.

Determinants of Change in Air-Bone Gap and Bone Conduction in Patients Operated on for Chronic Otitis Media.

BackgroundMiddle ear surgery aims to eliminate pathology from the middle ear, improve drainage and ventilation of the postoperative cavity, and reconstruct the tympanic membrane and ossicles.The aim of this work is to define the factors that affect ABG (air-bone gap) and bone conduction in the patients operated on due to chronic otitis media.Material/MethodsA prospective analysis of patients operated on due to diseases of the middle ear during 2009–2012 was carried out. The cases of patients operated on for the first time due to chronic otitis media were analyzed.The analysis encompassed patients who had undergone middle ear surgery. The patients were divided into several groups taking into account the abnormalities of the middle ear mucous and damage of the ossicular chain observed during otosurgery.ResultsA significant hearing improvement was observed in patients with type 2 tympanoplasty in the course of chronic cholesteatoma otitis media and in patients with simple chronic inflammatory process in whom a PORP was used in the reconstruction. Granulation tissue was an unfavorable factor of hearing improvement following tympanoplasty.A significant improvement of bone conduction was observed in the patients with dry perforation without other lesions in the middle ear.The elimination of granulation lesions was a positive factor for the future improvement of the function of the inner ear.ConclusionsThe presence of granuloma-related lesions in the middle ear spaces is likely to impede hearing improvement.Damage to the ossicular chain rules out the possibility of bone conduction improvement after surgery.The prognosis on tube-related simple chronic otitis media after myringoplasty, with the preserved continuity of the ossicular chain, consists of closing the ABG and leads to significant improvement of bone conduction.

Tympanotomy with sealing of the round window as surgical salvage option in sudden idiopathic sensorineural hearing loss

Conclusion: Tympanotomy with sealing of the round window is a promising surgical alternative as a salvage strategy in younger patients with acute idiopathic sensorineural hearing loss (SNHL) and may be considered as an alternative drug delivery method to the round window. Objectives: To analyze the potential benefit of the sealing of the round window with special emphasis on the age of treated patients and the influence of time elapsed between symptom onset and surgery. Methods: This was a retrospective cohort study of 25 patients (13 males,12 females) with an average age of 55 years (range 31–75 years) with sudden SNHL, who underwent an enaural tympanotomy with sealing of the round niche using triamcinolone-soaked fascia. Pre- and postoperative bone conduction thresholds were compared for each frequency and for the pure-tone average (PTA) measured at 500 Hz, 1 kHz, 2 kHz, and 3 kHZ. The time (days) between primary symptom onset and surgery as well as age was scrutinized. Hearing improvement was described as ‘no improvement' (0–9 dB), ‘moderate recovery' (10–29 dB), or ‘marked recovery' (≥30 dB). The difference in age of patients who improved was compared to those who did not. Results: A statistically significant improvement in PTA values (mean change 20.4 dB) was noted (p = 0.0002). In all, 13/25 (52%) patients exhibited improved bone conduction postoperatively regardless of age and time of treatment. A marked recovery (≥30 dB) could be seen in eight patients (median time to surgery, 9 days; average age, 48.5 years); recovery between 10 and 30 dB in five patients (median time to surgery, 10 days; average age, 46.6 years). Twelve significantly older patients showed no improvement (average time to surgery, 19 days; average age, 61.8 years; p = 0.004). No patient over the age of 65 years showed improvement in bone conduction.

Mixed Hearing Loss in Iatrogenic Tympanic Membrane Perforations over the Round Window Niche and the Immediate Effect of Paper Patch Myringoplasty

Objectives: Report the immediate audiologic effect of paper patch myringoplasty to repair iatrogenic tympanic membrane perforations directly over the round window. Methods: Retrospective case-control study of 15 patients treated for inner ear disease with a MicroWick and dexamethasone for 1 month, resulting in 2-mm perforations over the round window. Paper patch myringoplasties were performed to repair the perforations. Audiograms were performed before and immediately after the paper patch myringoplasty. Results: After paper patch placement, there was a significant improvement in air-bone gap at 250 (p < 0.001), 500 (p = 0.003), and 1000 Hz (p = 0.004) and a significant improvement in bone conduction (BC) threshold at 250 (p = 0.002), 500 (p < 0.001), 1000 (p = 0.002), 2000 (p = 0.003), and 3000 Hz (p = 0.02). Conclusions: Paper patch myringoplasty improves both air conduction and BC hearing from small perforations over the round window. The decrease in BC hearing is a result of middle ear mechanics and is not a true sensorineural hearing loss.

Preserving bone conduction in patients with labyrinthine fistula

The management of labyrinthine fistula is a controversial issue. Hearing preservation represents a major challenge. Retrospective study of 31 patients with labyrinthine fistula confirmed intra-operatively during cholesteatoma surgery. In all cases, total matrix removal was performed, and the fistula covered with bone dust, periostium and/or cartilage. Twenty-five patients received a high intra-operative dosage (500 mg) of intravenously applied steroids at least 15 min before handling the fistula. Outcome measurements included comparison of the pre-operative and post-operative bone conduction to assess inner ear function. The results were, the fistula was located in the lateral semicircular canal (LSC) in 22 patients (71.8%) and in the oval window in eight. One patient had a double localization in the superior and lateral semicircular canals. Out of the LSC fistulas, five patients (16.12%) had a fistula type I, 8 had type IIa (25.8%), four (12.9%) type IIb, and six patients type III (19.35%). Three out of eight patients with fistula located in the oval window had a total absence of the footplate, other four presented a partial anterior resorption at the level of the fissula antefenestram and the remaining one had a fractured platina. Pre-operatively, the bone conduction displayed a mean threshold of 35 dB. Twenty-two (85%) out of 26 patients treated intra-operatively with steroids showed preservation or improvement of bone conduction. Patients with fistulas of the oval window, type I, IIa and III fistulas in the LSC treated with cortisone presented good sensorineural hearing outcome (preservation or significant improvement of inner ear function in the majority of cases-91%); the auditory results for group IIb were inconclusive. Five patients did not receive steroids, four of them developed partial sensorineural hearing loss and one went deaf. To conclude, cholesteatoma surgery with a single-staged matrix removal on perilymphatic fistulas, after intra-operative intravenous administration of a high dosage of steroids followed by a multilayer closure of the fistula achieved a hearing preservation or improvement in 85% of our patients.

Bone conduction improvement after surgery for conductive hearing loss.

The objective is to evaluate change in post-operative bone conduction in patients who underwent surgery for conductive/mixed hearing loss due to various reasons. The study design is of retrospective case review and tertiary referral center setting. Five-hundred patients with unilateral conductive/mixed hearing loss were divided into five equal groups (each representing different causes for pre-operative hearing loss), who underwent appropriate surgical correction and had a follow-up audiogram available. The intervention comprises surgery (like myringoplasty and ossiculoplasty with closed or open cavity mastoidectomy for chronic otitis media, stapes mobilization for tympanosclerosis and stapedotomy for otosclerosis) for conductive/mixed hearing loss. Significant improvement or worsening in bone conduction was defined as 15dB or more improvement or worsening of bone conduction threshold at least in two frequencies between 500 and 4000Hz. All the other groups also showed a consistent pre-operative bone conduction reduction with an equally consistent improvement in post-operative bone conduction improvement to a varying degree with otosclerosis group having maximum percentage of patients with post-operative bone conduction improvement (60%). The measurement of bone conduction is not necessarily a true reflection of the function of the inner ear. Middle ear makes a contribution to bone conduction and correction of a middle ear conductive lesion causes an apparent improvement in inner ear function. The apparent inner ear hearing loss caused in this way may be reversible to some extent.

Tympanic membrane perforation: Size, site and hearing evaluation

ObjectiveTo assess different clinical scales of TM perforation size; to evaluate the effect of the size and the site of a perforation on the hearing level and frequencies. MethodsProspective study. Observers had subjectively estimated the size in millimeter and in percentage of a particular perforation; objectively computerized measures of TM perforations area were analyzed. Agreement between different measures was studied. Cases with postoperative intact TM and an air-bone gap (ABG) of 10dB or less were studied. ResultsGlobal mean preoperative ABG was 21.8±17dB. Preoperative ABG was different between small-large and small-total perforations (p=0.001). Difference of the preoperative ABG was statistically significant between perforations filling up the four quadrants and perforation limited to one quadrant in the postero-inferior, antero-superior and antero-inferior site. No statistically difference between perforation sites was identified for each affected frequency. Difference is statistically significant (p=0.001) between the 250Hz and the other frequencies for the medium, large and total perforations. After myringoplasty bone conduction improvement was statistically significant for the frequencies 500 (p=0.04), 1000 (p=0.04) and 2000Hz (p=0.011). Agreement was large enough when TM perforation size was expressed in percentage and absent when expressed in millimeter. ConclusionTM perforation can be clinically estimated quite precisely as a percentage of the TM area. Conductive hearing loss is frequency dependent; with the greatest loss occurring at the lowest sound frequencies. Hearing loss does not depend on the perforation's location.

Improvement of bone conduction after stapes surgery in otosclerosis patients with mixed hearing loss depending from surgical technique

This study investigate the effect of stapes surgery on bone conduction (BC) improvement in otosclerotic patients with mixed hearing loss and also compare the effect of three different types of surgery (complete stapedectomy, partial stapedectomy and microfenestration stapedotomy) on this improvement. We retrospectively reviewed surgical database of 84 otosclerotic patients with mixed hearing loss. Sixty-two patients (75%) had significant improvement in BC after surgery (P = 0.03). In 85% of patients with follow-up time longer than 1 year, this improvement had remained. Improvement in BC after surgery was better in partial stapedectomy group (82.6%) and complete stapedectomy group (80.8%) in comparison with microfenestration stapedotomy group (63%) (P = 0.052).

Bone conduction variation poststapedotomy

We evaluated the variation in bone conduction auditory thresholds in patients undergoing surgical intervention for otosclerosis as part of our report on the use of surgery in patients with a small air-bone gap. Of the 110 patients who underwent stapedotomy, 45 were treated by traditional surgery and 65 with carbon dioxide laser, with a follow-up of 3 years at 500-, 1000-, 2000-, and 3000-Hz frequencies. Both surgical techniques resulted in improvements in air conduction in more than 95% of cases; bone conduction improved more in patients treated with carbon dioxide laser (7.1 dB) compared to those treated with traditional surgery (4 dB) ( P < .01). Furthermore, improvement in bone conduction was greater and more frequent in younger subjects (below 45 years) ( P < .05). In conclusion, this study allows us to express a positive prognosis when considering otosclerotic patients with sensorineural hearing loss and small air-bone gap.

Preservation of labyrinth and facial function in extensive cholesteatoma

Surgery for cholesteatoma is a challenge, especially in extensive cholesteatomas with invasion around the facial nerve and the labyrinth. Presence of facial weakness, vertigo and deafness together with chronic discharge from the ear usually indicates a more advanced disease. One hundred and twenty ears with cholesteatoma were reevaluated; in seventy-two patients an open technique was used and in forty-eight a closed technique. In two patients there was a preoperative facial paresis and one suffered from facial tics preoperatively. The facial function was more frequently deranged in patients with labyrinth erosion than in patients without. In the group of patients where the labyrinth was involved the bone conduction remained unchanged postoperatively, except for a few patients where a slight improvement was noted at frequencies of 500 and 2000 Hz. The improvement of bone conduction in some of the patients is probably dependent on recovery of the inner ear mechanism. A rather high proportion of fistulae patients had an exposed facial nerve and or a preoperative facial dysfunction, which, however, returned to normal postoperatively. As a conclusion, ears with cholesteatoma combined with labyrinthine symptoms are more frequently associated with a dehiscent facial nerve than other ears and disturbed facial function is then more common. During surgery it is important to be aware of the risk of an uncovered facial nerve.

Promontory drilling in stapedectomy.

Evaluate in stapedectomy the clinical outcome and audiometric results (particularly bone conduction) of drilling the promontory because of a narrow oval window niche. Retrospective. Tertiary referral center, private otology practice. Twenty-five stapedectomy patients requiring promontory drilling who had surgery between 1995 and 2000. A total of 25 patients were evaluated with a minimum 6-month follow-up. Only patients who required promontory drilling and who had complete preoperative and postoperative audiometric testing including bone conduction were included. Promontory drilling was performed with a skeeter drill to thin the promontory. Twenty-five stapedectomy patients who did not undergo promontory drilling were randomly selected from this same period as a comparison group. In addition to the narrow oval window niche, associated anatomical findings were facial nerve overhang in five patients and an obliterated footplate in three patients. Ninety-six percent of cases were successful (<10 dB postoperative air-bone gap). The one unsuccessful case was a strut over the mobile footplate that was later successfully revised. No patients suffered from intraoperative or postoperative tinnitus or vertigo. The mean 4-frequency (500-4,000 Hz) pure-tone average revealed slight improvement in bone conduction postoperatively. Drilling of the promontory in stapedectomy is required in only a small percentage of cases. Although audiometric results indicated the possibility of a slight amount of acoustic trauma from the drilling, the effect on hearing was minimal and not considered a contraindication to this procedure.