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!).
Special Senses
Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard in Toxicologic Pathology, 2018
The ear can be divided into three parts: the external ear, middle ear, and inner ear. The external ear consists of the pinna (auricle) and the external ear canal (external auditory meatus), which ends medially at the external surface of the tympanic membrane (ear drum). The structures of the external ear are supported by auricular cartilage, and the secretions from the sebaceous and ceruminous glands contribute to the formation of cerumen. In rodents, Zymbal’s gland is a sebaceous gland located anterior and ventral to the external ear canal. Pathologic changes of the external ear can involve the skin or specific structures of the external ear (Kelemen 1978). Inflammation of the external auditory canal is usually not an issue in toxicologic studies unless clinical signs, such as shaking of the head or ear scratching, are observed. When inflammation does occur, it is characterized by thickening of the wall of the external auditory canal from edema, and the presence of a tan or brown crusty exudate within the canal (Gad 2007). One cause can be ear mites (e.g., Psoroptes cuniculi in rabbits or Otodectes cynotis in dogs). Auricular chondritis is a spontaneous condition reported in several strains of rats that appears as nodular or diffuse thickening of the pinna by granulomatous inflammation of fibrochondrous to chondroosseous tissue (Chiu 1991; Kitagaki et al. 2003). Differential diagnoses include chondrolysis and neoplasms.
Management of facial soft-tissue injuries
John Dudley Langdon, Mohan Francis Patel, Robert Andrew Ord, Peter Brennan in Operative Oral and Maxillofacial Surgery, 2017
Initial evaluation of injuries to the ear should include examination of external and internal structures such as the tympanic membrane and a gross hearing exam to rule out sensorineural hearing loss. The pinna or auricle of the ear is the portion of the external ear most commonly involved in trauma. They consist of a thin central area of relatively avascular cartilage which receives most of its blood supply from the thin overlying layer of skin. This avascular cartilage providing the semirigid configuration of the auricle is a primary concern in the treatment and post-operative management of an ear injury. Meticulous approximation of both skin and cartilage is necessary to assure favourable wound healing and prevent chondritis or tissue necrosis. The cartilage should be covered by skin and a bolster dressing is generally recommended to minimize the risk of haematoma formation which can cause ear deformities such as ‘cauliflower ear’. Leech therapy has also been proposed for haematoma management of the external ear with variable success rates.
Bifurcation of the intratemporal facial nerve: A rare anatomical anomaly
Published in Acta Oto-Laryngologica Case Reports, 2018
Constantina Christou, Johan Wikström, Karin Strömbäck
On the left side, the external ear was normal. On the CT scan, the left middle ear space was evaluated as narrow and the oval window was partially sclerotic. Although the tympanic portion of the facial nerve was covering the oval window and the mastoid portion was slightly anterior positioned, the course of the facial nerve on this side was considered as less aberrant than on the right side. Moreover, the size of the round window was normal and the external auditory ear canal was very narrow. Consequently, the patient was not eligible for surgical reconstruction. At the age of four he was implanted with a fixture applied BAHA. The fitting was limited through severe skin problems and pain and he was therefore planned for an implantation with a semi-implantable BonebridgeR device on the right side. A renewed CT scan at the age of five years showed unchanged anatomical conditions.
Reversible conductive hearing impediments among patients with severe brain injury
Published in Disability and Rehabilitation, 2020
Udi Cinamon, Dov Albukrek, David Dvir, Tal Marom
Each patient underwent a bedside examination by two consulting otolaryngologists, and a rehab nurse. The evaluation included assessment of the gag reflex, tongue and soft palate movements. The external ear canal, the tympanic membrane and middle ear of both ears were assessed by otoscopy. Cerumen impaction was recorded and removed. A fiber-optic evaluation (3.4 mm OD flexible endoscope; Pentax, FNL 10RBS, Japan) of the nasal passages, nasopharynx, both orifices of the ETs, the hypopharynx and palpating the epiglottis with the fiberscope’s tip to evaluate the supraglottic sensation were recorded. Tympanometry studies were performed in both ears in order to retrieve additional information regarding the middle ear (Tympanometer; GSI 38 VERSION 2, Grason-Stadler, Madison WI). In short, tympanomeric reading are designated A, B, C, D. Ttympanogram type A reflects a normal TM and ME, while B and C tympanograms reflect impermanents such as middle ear effusion and tympanic membrane atelectasis [12].
EAS-Combined electric and acoustic stimulation
Published in Acta Oto-Laryngologica, 2021
Anandhan Dhanasingh, Ingeborg Hochmair
In 2005 November, as the world’s first hearing implant company to combine HA with CI audio processor, MED-EL introduced DUET™audio processor in order to overcome all the practical issues with having two separate devices as mentioned above (Figure 14). The DUET™ audio processor featured a single microphone for the TEMPO + audio processor (using the continuous interleaved sampling (CIS+) strategy) and a two-channel HA, allowing 40 dB gain through 1,800Hz in one unit. The ear received the acoustic amplification through the ear mould positioned inside the external ear canal, receives an acoustic amplification from the processor. The processor unit controls both the HA and the CI speech processor, which is powered by a single battery pack. The DUET™ system was designed to amplify acoustic hearing between 125–1,500Hz and between 30–75dB.