Ears
Marie Lyons, Arvind Singh in Your First ENT Job, 2018
The external ear consists of the pinna and the outer ear canal (seeFigure 1.1). The outer third of the ear canal is cartilaginous, hair-bearing and wax-producing. It is also not particularly sensitive, which makes it relatively easy to inspect with an auroscope. The inner third is bony and exquisitely sensitive. Push too deep into the bony ear canal and the patient will certainly protest! The outer ear canal ends at the eardrum, which in a healthy ear is a pale grey structure (seeFigure 1.2). The most obvious features are the handle of the malleus and antero-inferiorly the cone of light (see below). When you are shown a picture of the eardrum you can always identify which side it is on by the direction in which the malleus is pointing. If the eardrum is on the right side, the malleus will point upwards and superiorly to the right from the middle of the eardrum. If it is on the left side, the malleus will point to the left (amaze your boss at quizzes!).
Growth of the Ear Capsule
D. Dixon Andrew, A.N. Hoyte David, Ronning Olli in Fundamentals of Craniofacial Growth, 2017
The present findings indicated a substantial centrifugal growth of the lateral parts of the temporal bone. All structures situated lateral to the middle ear, the facial canal and the tympanic membrane, showed significant outward growth resulting in a relative inward shift of the inner and middle ear structures. The lateralization of the surface is most obvious in the development of the external auditory canal. A small incomplete ring at term, it develops into a clearly formed canal of more than 8 mm in depth. This growth is most pronounced during the first 2 years of life, but is found to continue through to young adulthood. The mastoid part of the temporal bone was found to undergo the same amount of lateral growth as the external auditory canal. An increase of approximately 10 mm in the thickness of the mastoid bone overlying the fossa incudis, lateral semicircular canal and the facial canal was observed between the newborn and the adult.
Sinus and Ear Infections in the Elderly
Thomas T. Yoshikawa, Shobita Rajagopalan in Antibiotic Therapy for Geriatric Patients, 2005
Otitis externa (OE) represents an inflammatory process of the external auditory canal (EAC). It may be characterized as acute otitis externa, chronic otitis externa, and fungal otitis externa. The external auditory canal is usually lined by squamous epithelium and contains ceruminous glands that provide a natural lipid layer and an acid environment. Normal EAC bacteria include the nonpathogenic bacteria Staphylococcus epidermidis and Staphylococcus capitis, as well as Mycobacterium (11,12). In the geriatric patient, there is a decrease in the ceruminous glands that leads to a decrease in the lipid layer, with scant and dry cerumen as the outcome. This often leads to pruritus and subsequent digital manipulation with the use of cotton-tipped applicators, fingernails, hairpins, etc. This repetititve instrumentation often leads to a break in the integrity of the skin that allows bacteria to penetrate and grow, especially if there is a warm, humid milieu.
Signal processing & audio processors
Published in Acta Oto-Laryngologica, 2021
Anandhan Dhanasingh, Ingeborg Hochmair
Travelling wave latency is a function of the inner ear which the MED-EL CI system models in the filtering process of the sound coding strategy (stage 2, as shown in Figure 5). With natural acoustic stimulation, there is a certain time needed for the acoustic wave to travel from the external ear canal to reach the auditory cortex. All the steps in between result in certain latency/time delay, which can be measured from the wave V of electrically evoked auditory brainstem response (eABR). In contrast, with electric stimulation, all delays in the transmission of a sound wave in the external ear canal are missing. A further complication is that interaural stimulation timing in bilateral CI, SSD, or bimodal stimulation varies with the frequency/pitch of the sound signal. If this interaural stimulation timing is not adjusted during the sound processing stage, then this could create an imbalance or mismatch in the interaural stimulation timing in the SSD patients with CI on their deaf ear in bimodal setting, thus resulting in a much-degraded hearing on the deaf ear and compromising spatial hearing [41].
Outcomes of the Baha Attract System combined with auricle reconstruction in mandarin speaking patients with bilateral microtia-atresia
Published in Acta Oto-Laryngologica, 2019
Xinmiao Fan, Yu Chen, Xiaomin Niu, Yibei Wang, Yue Fan, Xiaowei Chen
In this study, seven patients with bilateral microtia-atresia underwent Baha Attract System implantation and auricle reconstruction simultaneously, whereas the other four underwent Baha Attract System implantation before the auricle reconstruction. In treating patients undergoing implantation before auricle reconstruction, sufficient space should be left for possible future auricle reconstruction. In treating patients undergoing implantation at the same time as the second stage of auricle reconstruction, the implant site should be designed to ensure that the magnet is not placed over the edge of the transplanted flap. In this study, all of the site in all patients was marked at a distance of approximately 7 cm from the external auditory canal, whereas, in normal patients, it can be at 5–7 cm. Both surgical procedures showed positive surgical and audiological results.
Outcomes of transcanal endoscopic middle ear surgery for congenital cholesteatoma
Published in Acta Oto-Laryngologica, 2023
Lianrong Guo, Yongjin Su, Zhi Cai, Yuanyuan Yang
Of the 11 patients, 7 were males, and 4 were females. The patients’ ages ranged from 4 to 32 years, with an average age of 8.63 years, and the course of disease ranged from 1 to 20 years. According to the Potsic classification, 4 of the 11 study patients had stage-1 CC, 3 patients had stage-2 CC, and 4 patients had stage-3 CC. All stage-1 lesions involved the anterior-superior quadrant, while all stage-2 and stage-3 lesions involved the posterior quadrants, either the posterior-superior or posterior-inferior quadrant or both. Kojima et al. [5] classified CC into the closed type (encapsulated cholesteatoma) and the open type (cholesteatoma stroma in direct contact with the middle ear mucosa). In our study, eight CCs were of the closed type, while three CCs were of the open type. The preoperative air-bone gap (ABG) on PTA (defined as the average air-bone conduction difference at 500 Hz, 1 KHz, 2 KHz, and 4 KHz) among patients with Stage 2 CCs was 10, 8, and 9 dB, respectively, while the corresponding postoperative PTA-ABG values were 5, 5, and 6 dB. The hearing test results of the four patients with stage-3 CC are shown in Table 3. All patients were followed up for more than 24 months. No recurrence or complications occurred, except in one patient with stage-3 CC who developed a recurrence probably because the original lesion was extensive. This patient underwent a second operation, but developed external auditory canal stenosis postoperatively. A dilation tube was placed through the external auditory canal, which eventually returned to its normal dimensions.