OBJECTIVE: To evaluate the safety of the circular round window and discus anatomic landmarks of posterior wall of internal auditory canal by investigating the microscopic anatomy of internal auditory canal area of the retrosigmold approach, which can provide the anatomical basis for acoustic neutrinomas surgery. METHOD: Fifteen adult cadaver heads (30 sides) fixed with formalin were used in the study. The retrosigmold approach operations were imitated to dissect the blood vessels and nerves in internal auditory canal area by opening round bony window and removing posterior wall of internal auditory canal. RESULT: Fifteen specimens of 30 sides circular bone window were opened without injury with transverse sinus and sigmoid sinus. The vertical distance between the highest point of bone window margo superior and the lowest point of transverse sinus margo inferior was (4.02 ± 0.32) mm. The vertical distance from the most anterior point of bone window leading edge to the most posterior point of sigmoid sinus trailing edge was (6.31 ± 0.43) mm. The internal auditory canal tubercle located in the anterior superior position of internal auditory canal. The vertical distance from the highest point of internal auditory canal tubercle to the upper margin of internal auditory canal was (2.31 ± 0.32) mm. To expose the whole internal auditory canal, the length and width of the internal auditory canal posterior wall removal was (7.29 ± 0.32) mm, (4.12 ± 0.29) mm. Within this removal range, no case of cochlea, semicircular canal or venous was injured in 30 specimens. CONCLUSION The method of opening round window through retrosigmold approach is simple, practial and convenient. With little variation and easiness of location, the sinternal auditory canal tubercle can be used in the identification of the internal auditory canal. When exposing the whole internal auditory canal, the removal scope of the posterior wall should be paid more attention to, in order to avoid the damage of cochlea, semicircular canal and jugular bulb.
Adult ; Cranial Sinuses ; Ear Canal ; Ear, Inner ; Humans ; Round Window, Ear ; anatomy & histology ; Semicircular Canals ; anatomy & histology ; Temporal Bone

OBJECTIVETo study the bone anatomic structure of the temporal bone region and provide reference in implant surgery in this region.

METHODSManual quantitative measurements of the bone structure were performed in 73 skull specimens (38 from male and 35 from female).

RESULTSIn the area of 8:00-11:00 (right ear) and 16-22 mm from center of the external auditory canal in the temporal bone region, the minimum bone thickness is as follows: 11:00: 6.77 mm in male, 5.18 mm in female; 10:00: 8.60 mm in male, 6.77 mm in female; 9:00: 9.85 mm in male, 7.30 mm in female; 8:00: 14.50 mm in male, 10.80 mm in female.

CONCLUSION(1) In the temporal bone region, the area of 8:00-11:00 (right ear) and 16-22 mm from center of the external auditory canal offers sufficient bone for implants. The length of implants should be as follows: 11:00: 4-5 mm in male, 3-4 mm in female; 10:00: 4-7 mm in male, 4-5 mm in female; 9:00: 4-8 mm in male, 4-6 mm in female; 8:00: 4-12 mm in male, 4-8 mm in female. (2) Towards the external auditory canal and from 12:00 to 11:00, 10:00 to 8:00, the bone became thicker, so, if no ample bone is available in the initial site, the location should be shifted anti-clockwise in right side (clockwise in left side) and closer to the external auditory canal. (3) The differences between male and female are statistically significant in the temporal bone region, so they should be treated distinguishingly during the clinical practices.

Ear Canal ; anatomy & histology ; Female ; Humans ; Male ; Prostheses and Implants ; Temporal Bone ; anatomy & histology

OBJECTIVE: To study a new surgical approach for cochlear implantation. METHOD: We operated on 8 cadaver heads (16 side) use Suprameatal approach for cochlear implantation, describe related anatomic mark. RESULT: The electrode is passed through the suprameatal tunnel, the EAC groove, the space underneath the chorda tympani between the malleal and the long process of the incus, and the cochleostomy. Angle between tunnel and temporal imaginary line is 28.0 degrees +/- 1.3 degrees in adult, 29.0 degrees +/- 1.7 degrees in children, the location of inserting electrode into cochleostomy is (1.31 +/- 0.13) mm to round window in adult, (1.19 +/- 0.12) mm in child. CONCLUSION The SMA approach is a safe technique, maintaining a safe distance to facial nerve and chorda tympani. So We should make right decision in clinic.
Adult ; Child ; Chorda Tympani Nerve ; anatomy & histology ; Cochlear Implantation ; methods ; Ear Canal ; anatomy & histology ; surgery ; Facial Nerve ; anatomy & histology ; Humans ; Round Window, Ear ; anatomy & histology

OBJECTIVE: In order to provide help for preoperative assessment of cochlear implantation, related dissection of temporal bone was conducted guided by high resolution computerized tomography (HRCT) in accordance to the main steps of cochlear implantation, and was compared to HRCT measurements on a viewing workstation. METHOD: Six temporal bones were dissected according to the main steps of cochlear implantation and scanned in axial and semilongitudal planes by HRCT to observe the relationship between anatomy and HRCT. RESULT: The width of facial recess in dissection was (3.13 +/- 0.34) mm at the level of round window, and (4.12 +/- 0.44) mm at the level of oval window. The width of facial recess in HRCT was (3.20 +/- 0.38) mm at the level of round window, and (4.14 +/- 0.47) mm at the level of oval window. The whole course of facial nerve was visualized clearly in semilongitudal plane. No statistically significant differences were found between the results of dissection and HRCT. CONCLUSION The distance in axial between facial nerve and posterior wall of external auditory canal and the distance from facial nerve to round window in semilongitudal plane are the most important parameters which reflect the position of facial nerve. The vertical portion of facial nerve, posterior wall of external auditory canal, round window are important measurement landmarks. Related preoperative measurements of cochlear implantation by HRCT can help to guide clinic surgery.
Child, Preschool ; Cochlear Implantation ; methods ; Cochlear Implants ; Ear Canal ; anatomy & histology ; Facial Nerve ; anatomy & histology ; Humans ; Infant ; Round Window, Ear ; anatomy & histology

OBJECTIVETo evaluate the feasibility of localizing the internal auditory canal (IAC) and the facial nerve through the root of the zygoma, foramen spinosum and the head of the malleus in middle fossa approach with the assistance of high resolution computerized tomography (HRCT).

METHODSEighteen human cadaveric temporal bones were scanned and measured by HRCT. Cadaver specimen were divided into two groups. Group A was studied first through a middle fossa approach to find out the relationship between the HRCT measurements and the anatomic measurements. Then 4 whole human cadaveric heads (8 temporal bones) of group B were dissected using a HRCT oriented middle fossa approach to localize IAC with the root of the zygoma, foramen spinosum and the head of the malleus as landmarks. The two measurement methods were analysed with the Paired-Sample T test, and the difference was thought to be statistical significant when P < 0.05.

RESULTSIn Group A, there were no statistical significant differences between the CT measurements and the anatomic measurements from the head of the malleus to other important anatomic structures. In group B, the operation was guided with CT measurements: the distance between the head of the malleus and the root of the zygoma, and the distance between the head of the malleus and foramen spinosum. Within the range 1.5 mm to 3.7 mm, the head of malleus was correctly localized. In seven out of the eight cases, the root of the zygoma, the head of the malleus and the internal auditory canal were in a straight line, whereas, in one case, there was an angle of 15 degrees between the root of zygoma -head of malleus line and head of malleus -internal auditory canal line.

CONCLUSIONSHRCT would provide more information on the distance relationship between the head of malleus and the root of the zygoma, foramen spinosum and the internal auditory canal. The head of the malleus could be localized through the root of the zygoma and foramen spinosum with HRCT and therefore the IAC could be exposed with the head of the malleus as a landmark in middle fossa approach when other landmarks were not recognizable.

Adult ; Ear Canal ; anatomy & histology ; diagnostic imaging ; Ear, Inner ; anatomy & histology ; diagnostic imaging ; Humans ; Malleus ; anatomy & histology ; diagnostic imaging ; Petrous Bone ; anatomy & histology ; diagnostic imaging ; Temporal Bone ; anatomy & histology ; diagnostic imaging ; Tomography, X-Ray Computed ; methods ; Zygoma ; anatomy & histology ; diagnostic imaging

We report the application of optical coherence tomography (OCT) to the diagnosis and evaluation of otitis media (OM). Whereas conventional diagnostic modalities for OM, including standard and pneumatic otoscopy, are limited to visualizing the surface of the tympanic membrane (TM), OCT effectively reveals the depth-resolved microstructure below the TM with very high spatial resolution, with the potential advantage of its use for diagnosing different types of OM. We examined the use of 840-nm spectral domain-OCT (SD-OCT) clinically, using normal ears and ears with the adhesive and effusion types of OM. Specific features were identified in two-dimensional OCT images of abnormal TMs, compared to images of healthy TMs. Analysis of the A-scan (axial depth scan) identified unique patterns of constituents within the effusions. The OCT images could not only be used to construct a database for the diagnosis and classification of OM but OCT might also represent an upgrade over current otoscopy techniques.
Adult ; Ear Canal/anatomy & histology ; Eustachian Tube/physiology ; Female ; Humans ; Male ; Middle Aged ; Otitis Media/classification/*diagnosis ; Tomography, Optical Coherence/instrumentation/*methods ; Tympanic Membrane/*physiology

We report the application of optical coherence tomography (OCT) to the diagnosis and evaluation of otitis media (OM). Whereas conventional diagnostic modalities for OM, including standard and pneumatic otoscopy, are limited to visualizing the surface of the tympanic membrane (TM), OCT effectively reveals the depth-resolved microstructure below the TM with very high spatial resolution, with the potential advantage of its use for diagnosing different types of OM. We examined the use of 840-nm spectral domain-OCT (SD-OCT) clinically, using normal ears and ears with the adhesive and effusion types of OM. Specific features were identified in two-dimensional OCT images of abnormal TMs, compared to images of healthy TMs. Analysis of the A-scan (axial depth scan) identified unique patterns of constituents within the effusions. The OCT images could not only be used to construct a database for the diagnosis and classification of OM but OCT might also represent an upgrade over current otoscopy techniques.
Adult ; Ear Canal/anatomy & histology ; Eustachian Tube/physiology ; Female ; Humans ; Male ; Middle Aged ; Otitis Media/classification/*diagnosis ; Tomography, Optical Coherence/instrumentation/*methods ; Tympanic Membrane/*physiology

OBJECTIVE: To investigate on the Indication and quality of life of the canal wall up and canal wall down surgery in chronic suppurative otitis media, to provide reference for surgical options. METHOD: The clinical data of patients underwent canal wall up or canal wall down surgery are analyzed. Follow up on 312 patients are accomplished with pure tone audiometry, acoustic impedance for surgical cavity volume, ear endoscopy and the Chinese chronic ear survey (CCES). RESULT: (1) The dry ear rate of canal wall up and canal wall down surgery are 98.7% and 98.6% respectively (P > 0.05). (2) The average cavity epithelization and dry ear time are 40.1 +/- 21.2 days for canal wall up surgery and 53.5 +/- 15.0 days for canal wall down surgery (P < 0.05). The postoperative ear volume to the contralateral normal ear volume ratio are 1.16 +/- 0.10 for canal wall up surgery and 2.05 +/- 1.19 for canal wall down surgery (P < 0.05). (4) Score of the CCES: 91.2 +/- 6.8 points for canal wall up surgery and 72.0 +/- 7.7 for canal wall down surgery (P < 0.05). (5) The proportion of patients feeling change of ear appearance is 5.7% for canal wall up surgery and 80.8% for canal wall down surgery (P < 0.05). (6) Hearing after surgery: objective hearing improvement rate is 58.9% for canal wall up surgery and 24.2% for canal wall down surgery (P < 0.05) according to the questionnaire, while the pure tone audiometry shows no significant difference in hearing thresh hold and air-bone gap. (7) The satisfactory score after surgery is 9.55 points for canal wall up surgery and 8.11 points for canal wall down surgery (P < 0.05). CONCLUSION (1) Patients underwent canal wall up surgery have near-normal external ear morphology, shorter dry ear time and much higher quality of life compared to canal wall down surgery. (2) For experienced ear surgeon, the indication for canal wall up surgery can be extended to cases with diploetic or sclerotic type of mastoid and part of the cases with anatomical variation and intracranial or extracranial complications.
Acoustic Impedance Tests ; Audiometry, Pure-Tone ; Chronic Disease ; Ear Canal ; anatomy & histology ; surgery ; Follow-Up Studies ; Hearing ; physiology ; Hearing Tests ; Humans ; Otitis Media, Suppurative ; surgery ; Otologic Surgical Procedures ; methods ; Quality of Life ; Treatment Outcome