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Objective To determine the ability to detect the presence of epithelial remnants after total ear canal ablation (TECA) and lateral bulla osteotomy (LBO) with endoscopy and to identify the most common locations of epithelial remnants after tympanic curettage. Study design Experimental study. Animals Five fresh canine cadavers with no gross evidence of middle ear disease. Methods Ten TECA-LBO were performed by four surgeons. After tympanic curettage, a 1.9-mm rigid 30° endoscope was inserted into the rostral, caudal, dorsal, ventral, and medial sections of the tympanic cavity. Three observers evaluated otoscopic images for epithelial remnants in each compartment. The median distribution of epithelial remnants was calculated for each section of the tympanic cavity with a three-dimensional tympanic cavity model. Results Epithelial remnants were identified in at least one of the five areas of the tympanic cavity after each TECA-LBO. The rostral section contained the most epithelial remnants (35.6%), while the medial section contained the least amount (1.8%). Conclusion Use of a 1.9-mm rigid endoscope was an effective method to evaluate all sections of the tympanic cavity after curettage in TECA-LBO. Epithelial remnants were consistently found after TECA-LBO, especially in the rostral compartment. Clinical significance Intraoperative endoscopy should be considered to improve removal of epithelium after initial TECA-LBO or revision surgeries.

Small and hyperostotic tympanic bone spicules (STBS and HTBS) extending from the tympanic wall or from the septum bullae into the tympanic cavity have been described in large feline species such as Siberian tigers or African lions and in canids such as dogs, red foxes and wolves. Detailed descriptions of prevalence, location and orientation were performed for dogs and African lions by means of necropsy and conventional computed tomography (cCT). Aims of the current study were to describe same characteristics for domestic cats by means of microcomputed tomography (µCT) and cCT. A total of 15 cats or rather 30 ears were examined. Furthermore, new bone formations extending into the tympanic cavity shaped like small lamellae were found and named "tympanic bone crests" (TBCs). The registered phenomenon of a thickened tympanic wall in some cats was named "tympanic wall thickening" (TWT). STBS appeared in 43% of the ears being bilateral in 44% of the cases, whereas HTBS appeared in one ear. TBC was present in 33% of the ears with a bilateral prevalence of 67%, and TWT could be detected in 13% of the ears. The mentioned structures are just barely or not at all detectable with cCT; therefore, µCT is necessary for an identification and detailed description. The origin and the factors inducing the development of examined phenomena are unknown, and it is hypothesized that the occurrence can be assessed as anatomical norm variations.

Because the vestibulocochlear organs are tiny and complex, and are covered by the petrous part of the temporal bone, they are very difficult for medical students to dissect and visualize during gross anatomy classes. Here, we report a time-saving and fail-safe procedure we have devised, using a hand-held hobby router. Nine en bloc temporal bone samples from donated human cadavers were used as trial materials for devising an appropriate procedure for dissecting the vestibulocochlear organs. A hand-held hobby router was used to cut through the temporal bone. After trials, the most time-saving and fail-safe method was selected. The performance of the selected method was assessed by a survey of 242 sides of 121 cadavers during gross anatomy classes for vestibulocochlear dissection. The assessment was based on the observation ratio. The best procedure appeared to be removal of the external acoustic meatus roof and tympanic cavity roof together with removal of the internal acoustic meatus roof. The whole procedure was completed within two dissection classes, each lasting 4.5 hr. The ratio of surveillance for the chorda tympani and three semicircular canals by students was significantly improved during 2013 through 2016. In our dissection class, "removal of the external acoustic meatus roof and tympanic cavity roof together with removal of the internal acoustic meatus roof" was the best procedure for students in the limited time available. Clin. Anat. 30:703-710, 2017. © 2017Wiley Periodicals, Inc.

Objective To describe a transoral approach for tympanic bulla osteotomy in the dog. Study design Anatomic cadaveric study. Sample population Fifteen canine cadavers (n = 29 tympanic bullae), including mesaticephalic, dolichocephalic, and brachycephalic breeds. Materials and methods The oral surface of the tympanic bulla was identified during an anatomical study (3 canine cadavers) and the ventral approach to the tympanic bulla was described (3 canine cadavers). The safety of the technique was assessed (9 canine cadavers, n = 17 bullae) during further anatomical dissections, where a complete approach and drilling of the tympanic bulla were performed. Results In all cases, tympanic bulla osteotomy was performed without damaging the inner ear, the epitympanic recess contents, and the neurovascular structures. The oral approach to the tympanic bulla was easier in mesaticephalic and dolichocephalic dogs than in brachycephalic breeds. Conclusion This study defines anatomical landmarks for transoral bulla osteotomy, without a high risk of damage to neurovascular and anatomical structures within and/or surrounding the tympanic cavity. This minimally invasive approach to the tympanic bulla is performed via a natural opening, and does not require simultaneous access through the ear canal. In vivo evaluation of this technique is required to verify its safety in clinical cases prior to large scale application.

Prevalence of subclinical middle ear lesions in dogs that undergo computed tomography (CT) and magnetic resonance imaging of the head has been reported up to 41%. A predisposition in brachycephalics has been suggested, however evidence-based studies are lacking. Aims of this retrospective cross-sectional study were to compare CT characteristics of the middle ear in groups of nonbrachycephalic and brachycephalic dogs that underwent CT of the head for conditions unrelated to ear disease, and test associations between thickness of the soft palate and presence of subclinical middle ear lesions. One observer recorded CT findings for each dog without knowledge of group status. A total of 65 dogs met inclusion criteria (25 brachycephalic, 40 nonbrachycephalic). Brachycephalic dogs had a significantly thicker bulla wall (P = 2.38 × 10(-26)) and smaller luminal volume (P = 5.74 × 10(-20)), when compared to nonbrachycephalic dogs. Soft palate thickness was significantly greater in the brachycephalic group (P = 2.76 × 10(-9)). Nine of 25 brachycephalic dogs had material in the lumen of the tympanic cavity, compared to zero of 45 of nonbrachycephalics. Within the brachycephalic group, a significant difference in mean soft palate thickness was identified for dogs with material in the middle ear (12.2 mm) vs. air-filled bullae (9 mm; P = 0.016). Findings from the current study supported previous theories that brachycephalic dogs have a greater prevalence of subclinical middle ear effusion and smaller bulla luminal size than nonbrachycephalic dogs. Authors recommend that the bulla lumen volume formula previously developed for mesaticephalic dogs, (-0.612 + 0.757 [lnBW]) be adjusted to 1/3(-0.612 + 0.757 [lnBW]) for brachycephalic breeds.

In postcontrast computed tomographic (CT) images, feline nasopharyngeal polyps typically demonstrate enhancement of the peripheral rim. Computed tomographic images and histologic specimens of a case series of 22 cats with surgically removed nasopharyngeal polyps were reviewed retrospectively in an attempt to elucidate the origin of rim enhancement. Polyps were present in the tympanic cavity in 15 (68%) cats (three with extension into the nasopharynx), only in the nasopharynx in four (18%) cats, and only in the external ear canal in the remaining three (14%) cats. All polyps had variable degrees of epithelial injury. Hemorrhage and inflammatory infiltration were significantly more marked in the superficial stroma whereas edema was significantly more marked in the core stroma. In noncontrast CT images (n = 22), the tympanic bulla was thickened in all 15 cats with a polyp in the tympanic cavity and enlarged in eight (53%) of these cats. In postcontrast CT images (n = 15), an outer zone of relatively increased attenuation compatible with a rim was observed in 11 (73%) polyps. The magnitude and extent of rim enhancement in CT images was positively correlated with the histologic grade of inflammation in the superficial stroma and negatively correlated with the grade of edema in the superficial stroma. It appears that inflammation is the major determinant of contrast medium accumulation in feline nasopharyngeal polyps, and the tendency for inflammation to affect predominantly the superficial layers explains the frequent observation of a rim in postcontrast CT images.

Identification of perpetuating factors, such as otitis media (OM), is important for the successful management of canine chronic otitis externa (OE).Occult OM can occur in cases of chronic OE; a focused magnetic resonance imaging (MRI) examination is a useful tool in their management.One hundred twenty one client-owned dogs presented for investigation and treatment of chronic OE between 2009 and 2018.Mixed retrospective (74 dogs) and prospective (47 dogs) study of chronic OE cases without neurological signs, describing the MRI, otoscopic and cytological findings; comparing cases with and without MRI evidence of OM.A total of 123 MRI studies were analysed (two dogs scanned twice). A short, focused MRI scan allowed detection of inflammation of the mucosal bulla lining as well as excellent discrimination between avascular material and vascularised soft tissue in the tympanic cavity. OM was found in 41 of 197 (21%) ears with chronic otitis externa. On otoscopy, the tympanic membrane was intact in six of 41 ears (15%), ruptured in 16 of 41 (39%) and not visible in 14 of 41 (34%) [no data in five of 41 (12%)]. Analysis of cytological findings showed that the presence of rods was only associated with an increased likelihood of OM when found together with inflammatory cells.Occult OM is a not uncommon finding on MRI of dogs with chronic OE. A targeted MRI study ("bulla mini-scan") may be useful as part of the clinical investigations.L'identification de facteurs perpétuant, tels que l'otite moyenne (OM), est important pour la gestion efficace d'otite chronique externe (OE). HYPOTHÈSES/OBJECTIFS: Une OM occulte peut se développer dans les cas d’OE chroniques; un examen d'imagerie par résonance magnétique (MRI) est un outil utile pour la gestion.Cent-vingt-et-un chiens de propriétaires présentés pour investigation et traitement d’OE chronique entre 2009 et 2018. MATÉRIEL ET MÉTHODE: Une étude mixte rétrospective (74 chiens) et prospective (47 chiens) de cas d’OE chroniques sans signe neurologique, décrivant les IRM, les données otoscopiques et cytologiques; comparaison de cas avec et sans preuve d’OM par IRM. RÉSULTATS: Un total de 123 études d’IRM a été analysé (deux chiens scannés deux fois). Un IRM court et ciblé permet la détection de l'inflammation de la muqueuse tapissant la bulle ainsi qu'une excellente discrimination entre le matériel avasculaire et les tissus mous vascularisés de la cavité tympanique. L’OM a été trouvée pour 41 des 197 (21%) oreilles avec otite externe chronique. A l'otoscopie, la membrane tympanique était intacte pour six des 41 oreilles (15%), rompue dans 16 des 41 (39%) et non visible dans 14 des 41 cas (34%) [pas de donnée pour cinq des 41 (12%)]. Les analyses des données cytologiques ont montré que la présence de bacilles était seulement associée avec une augmentation marquée de l’OM quand trouvée associée avec des cellules inflammatoires.Une OM occulte n'est pas rare à l’IRM pour les chiens atteints d’OE chronique. Une étude ciblée sur les IRM (“bulla mini-scan”) peut être utile en tant que part des investigations cliniques.INTRODUCCIÓN: la identificación de factores perpetuantes, como la otitis media (OM), es importante para el manejo adecuado de la otitis externa crónica (OE) canina. HIPÓTESIS/OBJETIVOS: La OM oculta puede ocurrir en casos de OE crónica; un examen por resonancia magnética focalizada (MRI) es una herramienta útil en su manejo. ANIMALES: ciento veintiún perros de propietarios particulares se presentaron para investigación y tratamiento de OE crónica entre 2009 y 2018. MÉTODOS Y MATERIALES: estudio mixto retrospectivo (74 perros) y prospectivo (47 perros) de casos crónicos de OE sin signos neurológicos, que describe la MRI, los hallazgos otoscópicos y citológicos; comparando casos con y sin evidencia de OM en la resonancia magnética. RESULTADOS: se analizaron un total de 123 estudios de resonancia magnética (dos perros escaneados dos veces). Una resonancia magnética corta y focalizada permitió detectar la inflamación del revestimiento de la mucosa de la bulla, así como una excelente discriminación entre el material avascular y el tejido blando vascularizado en la cavidad timpánica. Se encontró OM en 41 de 197 (21%) oídos con otitis externa crónica. En la otoscopia, la membrana timpánica estaba intacta en seis de 41 oídos (15%), se rompió en 16 de 41 (39%) y no era visible en 14 de 41 (34%) [sin datos en cinco de 41 (12%)] . El análisis de los hallazgos citológicos mostró que la presencia de bacilos solo se asoció con una mayor probabilidad de OM cuando se encontraron junto con células inflamatorias. CONCLUSIONES E IMPORTANCIA CLÍNICA: la OM oculta es un hallazgo relativamente frecuente en MRI de perros con OE crónica. Un estudio de resonancia magnética dirigido (“mini-scan de la bulla”) puede ser útil como parte de las investigaciones clínicas.Die Identifizierung von perpetuierenden Faktoren, wie eine Otitis media (OM), sind wichtig für ein erfolgreiches Management einer chronischen Otitis externa des Hundes (OE).Eine okkulte OM kann in Fällen chronischer OE auftreten; für ein erfolgreiches Management ist eine fokusierte Magnetresonanzuntersuchung (MRI) ein nützliches Werkzeug.Einhunderteinundzwanzig Hunde in Privatbesitz wurden zur Untersuchung und Behandlung einer chronischen OE zwischen 2009 und 2018 vorgestellt.Eine gemischte retrospektive (74 Hunde) und prospektive (47 Hunde) Studie von Fällen mit chronischer OE ohne neurologische Zeichen; eine Beschreibung des MRI, otoskopischer und zytologischer Befunde; sowie ein Vergleich der Fälle mit und ohne MRI Evidenz einer OM.Insgesamt wurden 123 MRI Studien analysiert (zwei Hunde wurden zweimal gescannt). Ein kurzer, fokusierter MRI Scan ermöglichte das Erkennen einer Entzündung der Mucosa der Bulla sowie eine ausgezeichnete Unterscheidung zwischen avaskulärem Material und vaskularisiertem Weichteilgewebe in der Paukenhöhle. Eine OM wurde bei 41 der 197 (21%) Ohren mit chronischer Otitis externa festgestellt. Otoskopisch war das Trommelfell bei sechs der 41 Ohren (15%) intakt, bei 16 der 41 (39%) rupturiert und bei 14 der 41 (34%) unsichtbar [es gibt bei fünf von 41 (12%) keine Daten]. Eine Analyse der zytologischen Daten zeigte, dass das Vorkommen von Stäbchen nur mit einer erhöhten Wahrscheinlichkeit einer OM assoziiert werden konnte, wenn sie zusammen mit Entzündungszellen gefunden wurden.Eine okkulte OM ist kein seltener Befund am MRI von Hunden mit chronischer OE. Eine gezielte MRI Studie („Bulla Mini-Scan“) könnte als Teil der klinischen Untersuchungen nützlich sein.背景: 犬の慢性外耳炎(OE)の管理を成功させるためには中耳炎(OM)のような永続的要因の特定が重要である。 仮説/目的: オカルトOMは慢性OEの場合に発生する可能性がある。集中磁気共鳴画像法(MRI)検査は、その管理に役立つツールである。 被験動物: 2009年から2018年の間に慢性OEの調査および治療のために来院した飼育犬121頭。 材料と方法: 本研究は神経学的徴候のない慢性OE症例の回顧的(74頭)および前向き(47頭)混合研究で、MRI検査、耳鏡検査および細胞学的所見について説明する。 また、MRI検査により確定したOMの有無による症例の比較を説明する。 結果: 計123件のMRI研究を解析した(2頭の犬に関しては2回スキャンした)。短焦点MRIスキャン法により、粘膜鼓室胞の炎症の検出および鼓膜腔内の無血管物質および血管化軟組織との優れた識別が可能になった。 OMは、慢性外耳炎を伴う197耳中41耳(21%)で検出された。耳鏡検査では、鼓膜は41耳のうち6耳(15%)で無傷で、41耳のうち16耳(39%)で破裂し、41耳のうち14耳(34%)で可視化できなかった[データなし41耳5耳(12%)] 。細胞学的所見解析により、桿菌が炎症細胞と一緒に発見された場合のみ、OMの可能性の増加と関連することが示された。 結論と臨床的重要性: オカルトOMは、慢性OE犬のMRI検査においては珍しい所見ではない。対象を絞ったMRI研究(「bulla mini-scan」)は、臨床調査の一環として役立つ可能性がある。.背景: 确定是否存在像中耳炎(OM)这样的持久病因,对犬慢性外耳炎(OE)的成功治疗很重要。 假设/目标: 慢性OE患犬可出现隐性OM; 在对其管理上,磁共振成像(MRI) 聚焦检查是一种有用的工具。 动物: 在2009年至2018年间,121只家养犬因慢性OE接受调查和治疗。 方法和材料: 对无神经症状的慢性OE病例进行回顾性(74只犬)和前瞻性(47只犬)混合研究,报告MRI、耳镜和细胞学检查结果;比较有和没有MRI证明的OM病例。 结果: 共分析了123例MRI研究(2只犬扫描两次)。MRI短的聚焦扫描可以检测到鼓泡内膜的黏膜炎症,并能很好分辨鼓室内的无血管物质和血管化软组织。在197只慢性外耳炎患犬中,有41只(21%)发现OM。在耳镜检查中,41只耳道中有6只(15%)鼓膜完整,16只(39%)鼓膜破裂,14只(34%)鼓膜不可见[有5只(12%)没有数据]。细胞学分析结果显示,当杆菌与炎症细胞一起出现时,OM的可能性增加。 结论和临床意义: 在慢性OE犬身上,MRI发现隐性OM的情况并不少见,靶向MRI研究(“鼓泡微扫描”)对部分临床检查可能有意义。.A identificação de fatores perpetuadores, como a otite média (OM), é importante para o manejo bem-sucedido da otite externa (OE) crônica canina. HIPÓTESE/OBJETIVOS: A OM oculta pode ocorrer em casos de OE crônica; um exame de ressonância magnética (RM) focalizada é uma ferramenta útil em seu manejo.Cento e vinte e um cães pertencentes a clientes apresentados para investigação e tratamento de OE crônica entre 2009 e 2018. MÉTODOS E MATERIAIS: Estudo retrospectivo (74 cães) e prospectivo (47 cães) de casos crônicos de OE sem sinais neurológicos, descrevendo os achados de ressonância magnética, achados citológicos e otoscópicos; comparando casos com e sem evidência de OM na RM.Foram analisados ​​123 estudos de ressonância magnética (dois cães examinados duas vezes). Ressonância magnética curta e focada permitiu a detecção de inflamação do revestimento mucoso da bula, além de uma excelente discriminação entre material avascular e tecido mole vascularizado na cavidade timpânica. Encontrou-se OM em 41 de 197 (21%) ouvidos com otite externa crônica. À otoscopia, a membrana timpânica estava intacta em seis das 41 orelhas (15%), rompida em 16 das 41 (39%) e não visível em 14 das 41 (34%) [não há dados em cinco das 41 (12%)]. A análise dos achados citológicos mostrou que a presença de bastonetes estava apenas associada a uma maior probabilidade de OM quando encontrada junto com células inflamatórias. CONCLUSÕES E IMPORTÂNCIA CLÍNICA: A OM oculta é um achado incomum na RM de cães com OE crônica. Um estudo de ressonância magnética direcionado (“mini-scan bulla”) pode ser útil como parte das investigações clínicas.

Summary An 8-year-old Warmblood gelding was referred for evaluation of headshaking to the Clinic for Horses, University of Veterinary Medicine Hannover. Based on clinical signs and computed tomography – as well as magnetic resonance imaging – findings, otitis media was diagnosed. Medical treatment including trimethoprim potentiated sulfadimethoxine and meloxicam for 3 weeks did not result in cessation of clinical signs. Therefore, the tympanic cavity was opened transendoscopically using an Nd:YAG-laser via the guttural pouch according to surgical procedures in human and small animal medicine, leading to a considerable improvement of clinical signs.

Rounded, sessile, hyperattenuating structures detected in computed tomography (CT) studies of canine tympanic bullae have been termed “otoliths.” These have been proposed to represent dystrophic mineralizations or heterotopic bone formations in the middle ear that are potentially related to chronic otitis media. Aims of the current study were to describe the prevalence, macroscopic, and histological features of structures consistent with “otoliths” in the canine tympanic cavity. Tympanic bullae from 50 routinely necropsied dogs and 139 retrospectively retrieved CT scans of canine clinical cases were examined. Small tympanic bone spicules with pointed or clubbed tips essentially arising from the free margin of the septum bullae were bilaterally present in the tympanic cavities of all 50 of the necropsied dogs. In 48% of the dogs, “otolith”-like CT-detectable bone spicules carrying drumstick-like hyperostoses that were 1–6 mm in diameter were also present. In the retrospective survey of bulla CT scans of 139 cases, the prevalence of hyperostotic tympanic bone spicules (HTBS) was 20%. Findings from the current study indicated that the presence of small tympanic bone spicules in adult dogs is most likely due to physiological bone growth in the septum bullae and that HTBS represent osseous proliferations of small tympanic bone spicules. However, the factors inducing formation of hyperostotic spicules from small tympanic bone spicules remain unknown. The high prevalence of HTBS displaying a similar appearance in bulla CT scans in dogs suggests that these spicules should be included in a differential diagnosis list for “otoliths.”

Objective To use cross-sectional imaging (helical computed tomography (CT)) combined with conventional anatomical dissection to define the normal anatomy of the nasal cavity and bony cavitations of the koala skull. Methods Helical CT scans of the heads of nine adult animals were obtained using a multislice scanner acquiring thin slices reconstructed in the transverse, sagittal and dorsal planes. Subsequent anatomical dissection permitted confirmation of correct identification and further delineation of bony and air-filled structures visible in axial and multiplanar reformatted CT images. Results The nasal cavity was relatively simple, with little scrolling of nasal conchae, but bony cavitations were complex and extensive. A rostral maxillary recess and ventral conchal, caudal maxillary, frontal and sphenoidal paranasal sinuses were identified and characterised. Extensive temporal bone cavitation was shown to be related to a large epitympanic recess. Conclusions The detailed anatomical data provided are applicable to future functional and comparative anatomical studies, as well as providing a preliminary atlas for clinical investigation of conditions such as cryptococcal rhinosinusitis, a condition more common in the koala than in many other species.

We have developed a new finite element (FE) model of human right ear, including the accurate geometry of middle ear ossicles, external ear canal, tympanic cavity, and mastoid cavity. The FE model would be suitable to study the dynamic behaviors of pathological middle ear conditions, including changes of stapedial ligament stiffness, tensor tympani ligament (TTL), and tympanic membrane (TM) stiffness and thickness. Increasing stiffness of stapedial ligament has substantial effect on stapes footplate movement, especially at low frequencies, but less effect on umbo movement. Softer TTL will result in increasing umbo and stapes footplate displacement, especially at low frequencies (f1500 Hz. As (TM) thickness was increased, the umbo displacement was reduced, especially at very low frequencies (f

We describe the computed tomography (CT) findings in 11 dogs with middle ear cholesteatoma. The cholesteatoma appeared as an expansile tympanic cavity mass with a mean attenuation value of 55.8 +/- 4.2 Hounsfield units. There was no appreciable contrast enhancement of the tympanic bulla contense but ring enhancement was seen in four dogs. Due to the slow progressive growth, the lesion causes severe bone changes at the contour of the tympanic bulla, including osteolysis, osteoproliferation and osteosclerosis, expansion of the tympanic cavity, and sclerosis or osteoproliferation of the ipsilateral temporomandibular joint and paracondylar process. Cholesteatoma can cause lysis of the petrosal part of the temporal bone, leading to intracranial complications. Although not definitive, CT provides useful information for distinguishing a middle ear cholesteatoma from otitis media and neoplasia. In otitis media, enlargement of the tympanic cavity is not routinely observed. In tumors that primarily affect the middle or inner ear, the predominant signs are lysis of the contour of the tympanic bulla or the petrosal part of the temporal bone, soft tissue swelling around the middle ear and marked contrast enhancement. In tumors that arise from the external ear, a soft tissue mass is visible within the external acusticus meatus, and the middle ear is only involved secondarily.

The canine ear consists of the pinna, external ear canal, middle ear and inner ear. The external ear is composed of auricular and annular cartilage. The auricular cartilage of the pinna becomes funnel shaped at the opening of the external ear canal. The vertical ear canal runs for about 1 inch, then forms the horizontal ear canal, which is composed of auricular and annular cartilage. The middle ear consists of an air-filled tympanic cavity, three auditory ossicles, and tympanic membrane. The tympanic membrane is a semitransparent membrane divided into the pars flaccida and pars tensa. The tympanic cavity consists of a small epitympanic recess, a large ventral bulla and the tympanic bulla proper. On the medial wall of the tympanic cavity is the promontory, which houses the cochlea. The cochlear (round) window is located in the caudolateral portion of the promontory, covered by a thin membrane. The vestibular (oval) window is located on the dorsolateral surface of the promontory, covered by a thin diaphragm over which the footplate of the stapes is attached. The auditory tube is a short canal that extends from the nasopharynx to the rostral portion of the tympanic cavity proper. The auditory ossicles are the bones that transmit and amplify air vibrations from the tympanic membrane to the inner ear. The inner ear is housed in a bony labyrinth in the petrous portion of the temporal bone. The bony labyrinth contains the membranous labyrinth with its sensory organs responsible for hearing and balance.

Objectives/Hypothesis: We present the case of a 21-year-old woman who underwent endoscopy-assisted surgery with topical mitomycin for a large cholesterol granuloma in the petrous apex that involved the eustachian tube. Study Design: Case report. Methods: Minimally invasive surgery was performed on the cholesterol granuloma with endoscopic assistance, and topical mitomycin (0.4 mg/mL) was administered to prevent scarring of the newly created drainage/ventilation route. With the endoscopic approach, the drainage/ventilation route was secured not only from the tympanic cavity, but also using a guidewire inserted from the pharyngeal orifice of the eustachian tube. Results: The drainage/ventilation route between the nasopharynx and middle ear cavity involving the cholesterol granuloma has been preserved more than for 9 months postoperatively. Her hearing has recovered. Conclusions: This less invasive technique is a surgical option for patients with a large cholesterol granuloma in the petrous apex involving the eustachian tube. Laryngoscope, 2009

The aim of the study was to systematize the key developmental phases of the stapedius muscle and the pyramidal eminence to clarify their formation, as well as to understand the variations and anomalies that can affect these structures. Sixty human embryos and fetuses between 38 days and 17 weeks of development were studied. The stapedius muscle is formed by two anlagen, one for the tendon, which derives from the internal segment of the interhyale, and another for the belly, located in the second pharyngeal arch medial to the facial nerve and near the interhyale but forming a completely independent anlage. In the interhyale, two segments were differentiated, these forming an angle; at the vertex, the belly of the stapedius muscle is attached. The internal segment is located from the attachment of the belly of the stapedius muscle to the anlage of the stapes, forming the anlage of the tendon of the stapedius muscle. The external segment completely disappears at the beginning of the fetal period. The pyramidal eminence is formed by an anlage independent of Reichert's cartilage, from the mesenchymal tissue of the tympanic cavity, which condenses around the belly of the stapedius muscle from 12 weeks of post-conception development. The length of the tendon of the stapedius muscle in adults varies, depending on the attachment site of the belly of the stapedius muscle in the interhyale, which would determine the length of the internal segment (anlage of the tendon) and consequently the tendon length. This variation depends on the greater or lesser persistence of the angulation observed during development, between the tendon and the belly of the stapedius muscle.

ANATOMY AND PHYSIOLOGY OF THE MIDDLE EAR The ear is composed of structures at three levels the outer, middle and inner ear. The middle ear comprises the tympanic membranes, tympanic cavity, ossicles and the auditory tube, and transmits sound to the inner ear. The major difference between the cat and dog lies in the structure of the middle ear. Whereas the mesotympanic cavity and epitympanic recess of the middle ear of the dog are partially separated by a bony shelf from the larger ventromedial hypotympanic cavity, the cat’s tympanic chamber is separated into two almost distinct cavities communicating through a small slit-like opening in the bony separation, which widens into a distinct foramen caudally (Fig. 1).This separation gives rise to the characteristic ‘double shell’ profile of the tympanic structures visible on anteroposterior radiographic views (Fig. 2). The lining of the cat’s tympanic chambers is reported to contain more abundant ciliated and secretory cells than the dog. A number of nerves pass through the tympanic chamber and their distribution within the middle ear is similar to that of the dog; the facial nerve and the vestibulocochlear nerve reach the internal auditory meatus in close association. The facial nerve lies exposed in the dorsal aspect of the tympanic cavity. On entering the middle ear, the tympanic plexus (facial nerve mixed with vagal branches) distributes widely across the bony promontory. Sympathetic postganglionic fibres (from the first cervical nerve) pass through the bulla. In the cat, the tympanic plexus is reported to be more exposed, or possibly more sensitive to, iatrogenic trauma.

SUMMARY. That Grandala is a true Thrush there can be no doubt, though in the matter of the form of the wing—that is to say of the length of the primaries in relation to the secondaries— it differs from all other Turdidae. This, however, is an adaptive character. Its cranial characters must determine its systematic position, which is among the lower, less specialised members of the group in which Merula and Turdus seem to hold the highest place. That the form of the tympanic cavity will afford an important aid in determining the systematic position of this group in relation to allied groups seems certain from the results which have come to light during this brief investigation. It will probably prove no less valuable as a taxonomic factor within the group. It will probably be found that the several genera can be divided into two sections—A with a temporal fossa, and B with no temporal fossa. Section A will be further divided into (a) with a large bullate tympanic wing and circumaural groove associated with the superior tympanic recess, and (b) with the tympanic recess lacking a circumaural groove. Much material, however, will have to be collected before this suggestion can be put to the test, while a great deal of investigation needs to be done in regard to the nestling skull, since the relative contribution made to the formation of the “tympanic wing” by the squamosal and exoccipital respectively are by no means yet determinable. This point can only be settled by the examination of young skulls before the closure of the sutures.

Tympanoplasty operations to improve hearing impairment require a wide middle ear cavity and reconstruction of columellar formations. There is no specific material for use in the reconstruction of columellar formations. Tissue response to BMP has been employed as regenerative material. To our knowledge, however, there are no reports of the reconstruction of columellar formations using recombinant human bone morphogenetic protein-2/bovine collagen composites in the middle ear. The purpose of this study is to investigate whether recombinant human bone morphogenetic protein-2/bovine collagen composites (rhBMP-2 composites) are appropriate for use as regenerative material for tympanoplasty. In the form of pellets, rhBMP-2 composites were implanted as columellae into the tympanic cavity. At 2, 4, 6, 8, and 12 weeks after surgery, the middle ear of the animals (n = 4 at each week) was stained with hematoxylin-eosin for light microscopic observation. All composites were in the process of ossification or had ossified according to their developmental stages and were covered with a single layer of squamous or cuboidal epithelium. The new bone formed in these composites was persistently stable and displayed some columellar conditions assessed by histological examination. This study led to the conclusion that rhBMP-2 composites make excellent regenerative material for auditory ossicles.

Objectives/Hypothesis: In conductive hearing loss (HL), even though preoperative examinations including audiometry, tympanometry, and computed tomography (CT) scan are applied, exploratory tympanotomy is necessary to make an exact diagnosis of ossicular interruption and stapes fixation. Precise preoperative diagnosis would be useful for patient counseling, surgical indications, and planning. The advantages of office-based OtoScan laser-assisted myringotomy (LAM), which makes a circular and non-hemorrhagic perforation, prompted us to investigate other uses of LAM in addition to ventilation and drainage of the tympanic cavity. To make presurgical diagnosis in conductive HL, endoscopes with an outer diameter of 1.7 or 1.9 mm were used to inspect the middle ear pathology through perforations with a diameter of 2 mm made by LAM. Methods: In the outpatient clinic, a circular perforation with a diameter of 2 mm was made in the tympanic membrane with LAM. An endoscopic view of the ossicular chain through a 70° angled tip endoscope held immediately to the outer side of the perforation was obtained to diagnose conduction disturbance loci in conductive HL cases. Results: Ossicular chain abnormalities were easily and safely detected by clean endoscopic views obtained through a nonhemorrhagic circular perforation. When necessary, insertion of the tip of the endoscope into the tympanic cavity provided additional views of epitympanum. Conclusion: We suggest that transtympanic endoscopy through the perforation made by LAM is an effective and safe office-based procedure for diagnosis in conductive HL cases and could be an alternative procedure to replace exploratory tympanotomy.

Objective: The aim of this study was to investigate the transtympanic ventilation time, the healing course of the tympanic membrane, the early and late complications, and the recurrence rate of otitis media with effusion (OME) within 6 months after CO 2 laser myringotomy with the CO 2 laser otoscope Otoscan. Study Design: Prospective clinical study. Materials and Methods: In this study, laser myringotomy was performed with the CO 2 laser otoscope Otoscan in a patient population comprising 81 children (159 ears) with a history of otitis media with effusion (OME) associated with adenoidal and sometimes tonsillar hyperplasia. The procedure on the tympanic membrane was accordingly combined with an adenoidectomy, a CO 2 laser tonsillotomy, or a tonsillectomy and therefore performed under insufflation anesthesia. In all ears, approximately 2 mm circular perforations were created in the lower anterior quadrants with a power of 12 to 15 W, a pulse duration of 180 msec, and a scanned area of 2.2 mm in diameter. Results: None of the children showed postoperative impairment of cochleovestibular function such as sensorineural hearing loss or nystagmus. Otomicroscopic and videoendoscopic monitoring documented the closure time and healing pattern of tympanic membrane perforations. The mean closure time was found to be 16.35 days (minimum, 8 days; maximum, 34 days). As a rule, an onion-skin-like membrane of keratinized material was seen in the former myringotomy perforations at the time of closure. At the follow-up 6 months later, the condition of the tympanic membrane of 129 ears (81.1%) could be checked by otomicroscopy and videoendoscopy and the hearing ability by audiometry and tympanometry. The CO 2 laser myringotomy sites appeared normal and irritation-free. Two of the tympanic membranes examined (1.6%) showed atrophic scar formation, and 1 (0.8%) had a perforation with a diameter of 0.3 mm. The perforation was seen closed in a control otoscopy 15 months postoperatively. OME recurred in 26.3% of the ears seen intraoperatively with mucous secretion (n = 38) and in 13.5% of the ears with serous secretion (n = 37; P

Local lesions observed in otitis, create favourable conditions for the growth of fungi and development of mycoses both in the external and middle ear, as well as in post-operative cavities, especially in cases of open-type surgery. The objective of this study was: (1) to determine the prevalence of mycotic infections in inflammatory conditions of the ear; (2) to evaluate the relationship between the presence of fungi and clinical symptoms of inflammation; and (3) to construct a model of therapeutic procedure. The study concerned 345 individuals, including 295 patients (381 ears) who presented with symptoms of otitis. The mycological examinations revealed presence of fungi in 30.4% cases (116 ears). Positive culture results were obtained predominantly in patients with post-operative suppuration (52.8%). Otomycosis was more often associated with fungi of the genus Candida (3/5) than with fungi of the genus Aspergillus (2/5). The analysis of symptoms in otomycoses showed that in bacteria-induced otitis, pruritus, discharge, post-operative defective hearing and headaches are most common; the analysis of signs showed that reddened epidermis and lining of the tympanic cavity are statistically more frequent. The therapeutic protocol adopted in otomycoses yields good results: 89%--complete cure.

The purpose of this report is to contribute to the knowledge of the morphogenesis of the human stapedius muscle. We have studied the stapedius structure development in 17 temporal bones from human fetuses. Chronological ages were from 48 days (21 mm) to 29 weeks (270 mm). Samples were fixed in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in sequence of 7 microns and were stained with haematoxylin & eosin and Martins' trichrome. Four maturation stages were observed in the development of the stapedius muscle structure. First, the formation of the 'primordium muscularis' in the mesenchyme of the tympanic cavity (promyoblasts) was observed in a 36-mm embryo. Second, its differentiation into myoblasts, and its next cellular fusion to form muscle tubes, was seen in a 99-mm foetus. In the third stage, myofibrogenesis phenomena were developed, to synthesize, the myotube myoblasts, myofilaments, phenomena we observed that took place during the 14th to 17th weeks of development. The last stage was characterized by the presence of striated muscle fibres, at first intermingled with myotubes (18th to 26th weeks), until in the 29th week fetuses (270 mm) the skeletal muscle fibre was completely differentiated. We conclude that in the 29th week of development (270 mm) the stapedius muscle structure is completely differentiated, although the functional development is not complete until birth.

To guide surgery of nerves that traverse and surround the tympanic cavity in the rat, anatomical illustrations are required that are topographically correct. In this study, maps of this area are presented, extending from the superior cervical ganglion to the otic ganglion. They were derived from observations that were made during dissections using a ventral approach. Major blood vessels, bones, transected muscles of the tongue and neck and supra and infrahyoid muscles serve as landmarks in the illustrations. The course of the mandibular, facial, glossopharyngeal, vagus, accessory and hypoglossal nerves with their branches, and components of the sympathetic system, are shown and discussed with reference to data available in the literature. Discrepancies in this literature can be clarified and new data are presented on the trajectories of several nerves. The course of the tympanic nerve was established. This nerve originates from the glossopharyngeal nerve, enters the tympanic cavity, crosses the promontory, passes the tensor tympani muscle dorsally, and continues its route intracranially to the otic ganglion as the lesser petrosal nerve after intersecting with the greater petrosal nerve. Auricular branches of the glossopharyngeal and of the vagus nerve were noted. We also observed a pterygopalatine branch of the internal carotid nerve, that penetrates the tympanic cavity and courses across the promontory.

Background and Objective: Application of laser irradiation targeting the inner ear has to be investigated for therapeutic effectiveness in cochlear injury and dysfunction. In vitro data demonstrate low-level laser-induced photochemical and photobiologic cell response, depending on cell type and irradiation parameters such as light dose. The aim of the presented study was to determine the light dose received by the cochlear hair cells by using different irradiation modalities for the human petrous bone. Study Design/Materials and Methods: Lightdosimetric assessment was performed in human cadaver temporal bones (n = 13) after removing the cochlear membranous labyrinth. The external auditory meatus, the tympanic membrane (quadrants), and the mastoid bone were illuminated by a helium-neon laser (λ = 593 nm) and diode lasers of different wavelengths (λ = 635, 690, 780, and 830 nm). The spatial distribution of transmitted light in the cochlear windings was measured by means of a retro-cochlearly positioned endoscopic CCD camera for image processing and was assigned to acoustic frequencies according to the tonotopic organization of the cochlea. For an estimation of the corresponding space irradiance in an intact cochlea, correction factors have been calculated by a Monte Carlo procedure on the basis of experimentally determined optical properties of skull bone. Results: The transmission of light across the tympanic cavity and the promontory depends strongly on wavelength of the laser and the position of the radiator. Trans-tympanal irradiation results in spatial intensity variations of a factor 4 to 10 within the cochlear windings. The space irradiance in an intact cochlea is 10 to 20 times the measured irradiance. For an irradiation of the mastoid, the light transmission within the cochlea is 10 3 to 10 5 times smaller compared with an irradiation of the tympanic membrane and is extremely variable for different specimens. Conclusion: The strong dependence of the cochlear light distribution on various irradiation parameters demonstrates the impact of preclinical lightdosimetric investigations for effective individual laser irradiation of the human cochlea. Because of the observed spatial intensity variations, the optimal external light dose has to be chosen with regard to the tonotopy of the human cochlea. The obtained results are enabling us to apply defined laser light doses to different cochlear winding areas. Mastoidal irradiation leads to therapeutically insufficient light doses within reasonable treatment times, whereas transmeatal irradiation is recommendable. Further studies are mandatory for development of clinical devices for transmeatal irradiation of the cochlea. Lasers Surg. Med. 28:18-26, 2001.

Summary We have performed a study on 11 human embryos regarding the development of the tympanic ossicles and their relationship with the first pharyngeal arch. After performing measurements to date the embryos and foetuses chronologically, we performed a meticulous dissection of the temporal bones. Subsequently, they were fixed in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in 7-mm sequences and stained with Martin’s trichrome technique. In the 21- and 24-mm cranium-raquis (CR) length human embryos, we have observed the head of the malleus and the body of the incus close to Meckel’s cartilage, in addition to the handle of the malleus, the long limb of the incus and the stapes. Between them there was a mesenchymal band inside the primordium of the tympanic cavity. In the 27-mm CR embryo, the various components of the malleus and incus were fusing, and in the 30-mm CR embryo the union was complete. From our observations, we can conclude that the malleus and the incus are derived from the first and second pharyngeal arches.

Artificial distortion of the skull alters not only the shape, the size and the proportion of the neurocranium, but it deforms each part of the skull. Deformation itself causes damage, and several diseases also become more frequent (Jozsa, L. and Pap, I. (1992) Pathological alterations on artificially distorted skulls. Annles Historico-Naturales Musei Nationalis Hungarici, 84: 189–194). Marked prognathy, temporo-mandibular arthrosis, deformed and narrowed auditory canal and tympanic cavity, and developmental disturbances of the paranasal sinuses can often be recognized. Bone structure is different from the normal structure, and radiological markers of chronic hypertension of the cranial cavity can be observed. As a result of the artificial deformation of the neurocranium, the bones of the facial skeleton are modified in both shape and position. The practice of artificial cranial deformation was common among certain tribes during the 4–5th century in Hungary. The deformed shape of the skull is outlined clearly on the facial reconstruction of a woman from the Migration Period from the site of Mozs. The longer than normal facial bones and marked prognathy determine the direction and mass of facial muscles giving a characteristic feature to the face. Copyright © 1999 John Wiley & Sons, Ltd.

This study was undertaken to develop a functional model of otitis media with effusion (OME) in the pig (Sus scrofa), with the purpose of investigating the origin of lymphocytes populating the middle ear during the course of an inflammatory process. The relevance of the model to the human condition of OME is to a large extent dependent on the anatomical and physiological similarities between the middle ear cavity and the pharyngeal lymphoid tissue of the pig and man. Anatomical specimens were collected from 7 young Large White pigs to determine the gross anatomy of the middle ear cavity and the histological characteristics of the middle ear mucosa. It was found that the anatomy of the 3 parts of the middle ear cavity in man and in the pig is broadly similar, although some minor differences were observed. The porcine eustachian tube was seen to be cartilaginous throughout its length in contrast to the part osseous, part cartilaginous structure found in man; the porcine ossicles were slightly different in shape to those of man and the air cell system was situated inferior to the tympanic cavity in the pig as opposed to posteriorly in man. This paper describes the structure and morphology of the pig middle ear cavity and compares and contrasts it with that of man. The minor differences observed are of anatomical importance but do not diminish the usefulness of the pig middle ear cleft as a potential model for human middle ear disorders.

The paratympanic organ is a specialized sensory organ of birds located in the medial wall of the tympanic cavity. It possesses a sensory epithelium formed by type II hair cells and supporting cells. The supporting cells are tall, narrow units that extend from the basement membrane to the free epithelial surface. They show a fine structure characterized by numerous mitochondria, a conspicuous Golgi complex and a well-developed RER. Moreover, some uncommon structures, probably formed by heaped RER cisternae, are frequently present in the cytoplasm. Adjacent supporting cells are connected by numerous and extensive gap junctions; moreover, small gap junctions between hair cell and supporting cells are to be found. The possible mechanical and metabolical functions of the paratympanic organ supporting cells are discussed. J. Morphol. 236:65–73, 1998. © 1998 Wiley-Liss, Inc.

The fimt detailed description of the braincase of the Triassic early archosaurian reptile Elythrosuchus is presented. Features plesiomorphic for archosaurs that are described include an ossified laterosphenoid, a ‘semilunar depression’, posteroventrally positioned internal carotid foramina, a basisphenoid ‘intertuberal plate’, an un- or incompletely ossified medial wall of the otic capsule and channel for the perilymphatic duct, a metotic foramen undivided by bone, and a short lagenar recess. Among the earliest archosaurs, the braincase of Erythrosuchus is considered to share more derived similarities with the erythrosuchid Shansisuchus than with other taxa, although further study is required to ascertain whether these similarities are homologous. An understanding of non crown-group archosaur morphology is important for resolving controversial questions of homology concerning braincase features in extant archosaurs, as well as for improving estimates of archosaur phylogeny. The most recent common ancestor of crocodiles and birds is hypothesized to have lacked a ‘semilunar depression’ and basisphenoid ‘intertuberal plate’, and to have had laterally positioned internal carotid foramina, a short lagena, an undivided metotic foramen, an unossified eustachian system, and elements of the tympanic cavity that were not pneumatized.

Golden moles (Chrysochloridae) are fossorial mammals known to have unusual mallei. The aim of this study was to describe and quantify aspects of the auditory morphology of golden moles in order to determine their systematic and functional implications. Observations were made on skeletal material as well as histological sections. The results of this study do not support the separation of the genus Calcochloris from Amblysomus. It was found that the morphology shared by all the studied genera is indicative of specialization for hearing low frequency sound. The tympanic membrane to stapes footplate ratios, ossicular lever arm ratios and incudomallear joint morphology suggest low frequency specializations in genera with small mallear heads and high frequency specializations in genera with large mallear heads. However, the size and degree of trabeculation of the tympanic cavity are not consistent with this result. It is proposed that all golden moles are low frequency hearers with differences in their range of sensitivity according to how much time they spend foraging above ground.

Objective: Establish new treatment for patients with MRSA infected ears without using anti-MRSA antibiotics, in order to not produce new resistant bacteria to the anti-MRSA antibio-tics. Japanese herbal medicines have never produced any new resistant bacteria, and some agents have anti-MRSA function.Method: Three concurrent therapies using 2 local treatments, ear irrigation with normal saline and nasal povidone iodine gel treatment, and Japanese herbal medicine administration were applied 3 times a week to 14 patients with MRSA-infected ears. In this study, we first selected Hocchuekikitou as Japanese herbal medicine.Results: In 11 patients, MRSA successfully disappeared after several weeks and the infection was also controlled. However, 3 patients were cured after changing Japanese herbal medicine from Hocchuekikitou to Jyuzentaihotou. The mucous membrane of the tympanic cavity which can be observed through tympanic perforation was normal. Therefore, tympanoplasty was easily performed under the normal no...

Objective: Illustrate preoperative (to assess radiological landmarks useful for diagnosis and surgery) and postoperative (to visualize complications and evaluate the correct positioning of the FMT) imaging features in patients with congenital aural atresia (CAA) treated with the floating mass transducer (FMT) of the Vibrant Soundbridge on round window (RW).Method: Fifteen patients, aged from 2 months to 54 years, treated with FMT on the RW for bilateral (11 patients) and monolateral (4 patients) CAA, underwent high resolution computed tomography (HRCT) scans and/or cone-beam CT scans (CBCT) preoperatively and postoperatively at 12-to-60-month follow-up times. The first 4 patients had plain-film X-rays.Results: The tympanic cavity was reduced in size in 20 out of 26 ears (76.9%). Ossicular chain abnormalities were present in all ears. These consisted most frequently of a fusion of the malleus to the incus, as observed in 15 ears (61.5%). The RW area was normal in all patients, while the oval window (OW) wa...

Objective: Cholesteatoma is still one of the most challenging ear diseases, its evolution leading sometimes to serious complications (facial palsy, vestibular disorders, meningitis, intracranial abscesses, sigmoid sinus thrombosis, etc). Surgical treatment is always required to heal the disease.Method: We reviewed the surgical reports of 534 patients treated in the ENT Clinic from Cluj between 2003 to 2010. Patients’ ages ranged from 3 to 81 years, with a mean age of 30 years. The surgical procedure was to follow the cholesteatoma extension from the tympanic cavity to the mastoid cavity.Results: Most of the cases were operated in closed technique. We have used for ossicular reconstruction incus body without osteitis, the head of the malleus, and cortical of temporal bone. For tympanic membrane and canal wall reconstruction we have used perichondrium cartilage with or without perichondrium. Patients with complications underwent open technique. Recurrence of suppuration was noticed in 28% of cases, requirin...

Jugular bulb anatomy is variable. A "high-riding" bulb extending into the tympanic cavity is a well-described anomaly. Petrous jugular malposition (diverticulum) (PJMD), however, is rare. The relationship between PJMD and clinical symptoms is questionable because the differentiation between PJMD as an anatomic variant and pathologic process is unproved. A literature review reveals 14 previously documented cases. We report an additional four cases. Diagnostic and management dilemmas are discussed, with the importance of high-resolution CT stressed.

Objective: To describe a simple approach to the rat middle ear because there are few clear descriptions of this technique with minimal morbidity and mortality. Study Design and Setting: Six male Long-Evans rats were used in this study. We designed a cervical approach to the middle ear with the purpose of creating an experimental model of ossiculoplasty that permits the postoperative survival of the animal. Results: It was possible in all cases to visualize the majority of structures of the tympanic cavity: promontory, round window, stapedial artery, stapes, incus, and tympanic membrane. There were no cases of postoperative infection or facial paralysis. Conclusions and Significance: The ventral approach to the rat middle ear is a rapid and simple technique that makes the rat the animal of choice for many otologic investigations. (Otolaryngol Head Neck Surg 2001;124:515-7.)

The discomallear ligament (DML) runs through a narrow space of bony petrotympanic fissure, which joins the articular disc of temporomandibular joint (TMJ) and the malleus in the tympanic cavity. We...

Following the application of a topical anesthetic agent to the tympanic membrane, a number of patients described a sensation of numbness in the mouth. On examination these patients were found to have a significant area of anesthesia on the inferior surface of the ipsilateral soft palate. As a result of auditory tube dysfunction many of the tympanic membranes were atrophic and retracted. In these cases the pars tensa was closely related to the medial wall of the tympanic cavity, and local anesthetic agents applied to the tympanic membrane could easily diffuse through to the promontory and related structures. If the bone over the tympanic plexus or that over the facial nerve were dehiscent these nerves would be exposed to the effect of the anesthetic. We feel that our observation suggests that in some individuals at least, the pathway of sensory innervation of the soft palate may involve either the facial nerve or the tympanic branch of the glossopharyngeal nerve.

Experimental otitis media with effusion was induced in chinchillas by middle ear effusion, which was induced by an injection of immune complex into the tympanic cavity. To elucidate the pathogenesis of otitis media with effusion, cytologic and biochemical findings of the effusion and histopathology of the middle ear mucosa of effusion-induced chinchillas were compared with those of experimental otitis media with effusion induced by different procedures; eustachian tube obstruction, intratympanic inoculation of endotoxin, and immune reaction. No significant differences were seen in cytology, biochemistry, and histopathology among OMEs induced by these procedures. However, middle ear effusions, when compared with the corresponding sera, were proven to contain higher amounts of histamine and prostaglandin E2. These findings seem to demonstrate that middle ear effusion containing a large number of inflammatory mediators is essential for induction and prolongation of inflammatory reaction in the middle ear.

New crania of the Oligocene anthropoidean Aegyptopithecus provide a test of the hypothesized tarsier-anthropoidean clade. Three cranial characters shared by Tarsius and some modern anthropoideans (apical interorbital septum, postorbital septum, "perbullar" carotid pathway) were examined. 1) An apical interorbital septum is absent in Aegyptopithecus. A septum does occur in Galago senegalensis (Lorisidae) and Microcebus murinus (Cheirogaleidae), so the presence of a septum is not strong evidence favoring a tarsiiform-anthropoidean clade. 2) In Aegyptopithecus and other anthropoideans, the postorbital septum is formed mainly by a periorbital flange of the zygomatic that extends medially from the lateral orbital margin onto or near the braincase. The postorbital plate of Tarsius is formed by frontal and alisphenoid flanges that extend laterally from the braincase to the zygomatic's frontal process, which is not broader than the postorbital bars of other prosimians. Periorbital flanges evolved in Tarsius for support or protection of the enormous eyes, as suggested by the occurrence of maxillary and frontal flanges that cup portions of the eye but do not separate it from temporal muscles. 3) The internal carotid artery of Aegyptopithecus enters the bulla posteriorly and crosses the anteroventral part of the promontorium. The tympanic cavity was probably separated from the anteromedial cavity by a septum stretching from the carotid channel to the ventrolateral bullar wall. In Tarsius, the carotid pathway is prepromontorial, and a septum stretches from the carotid channel to the posteromedial bullar wall. Quantitative analyses indicate that anterior carotid position has evolved because of erect head posture. The cranium of Oligocene anthropoideans thus provides no support for the hypothesized tarsier-anthropoidean clade.

Reconstruction of old radical cavities The methods as well as the primary and late results of 74 partial and 93 total reconstructions of old radical cavities were described. In partial reconstructions the tympanic cavity was reconstructed, but the cavity was not eliminated, as it was dry or could be kept dry. In total reconstructions the tympanic cavity and auditory canal were reconstructed, and in most cases the cavity was obliterated, either by muscle or by combined grafts of muscle, tragal cartilage, and homologous septal cartilage. On the basis of the late results, functionally 10–20% poorer than the primary ones, the indications for reconstruction of old radical cavities were discussed. If there is chronic aural discharge, and if the cavity is lined with granulations, the ear can be rendered dry by total reconstruction in 90% of the cases.

The otic region in the skull of archeocetes and odontocetes is compared and interpreted with special emphasis on the morphology and suspension of the ear bones. In archeocetes, the periotic was obviously separate from the mastoid but still integrated within the skull via a long anterior and posterior process. The rotation of the cochlear part of the periotic was already obvious. The tympanic bone was attached to a decreasing number of neighboring elements, with the periotic becoming more and more important in the later archeocetes. The accessory air sacs of the tympanic cavity had invaded some of the adjacent skeletal elements and attained a moderate-to-remarkable extension. In the evolution of the odontocetes, the periotic and tympanic were successively uncoupled from the skull and combined to a new morphological and functional unit (tympanoperiotic complex). This uncoupling was mainly achieved by shortening the periotical processes and simultaneously extending the tympanic air sacs. For functional reasons, however, the periotic (posterior process) stayed in immediate contact with the mastoid, the latter remaining in the lateral wall of the skull. In advanced marine dolphins, the bony sheaths of the accessory air sacs are largely reduced, presumably because of volume fluctuations in the tympanic cavity during diving. The perfect uncoupling of the ear bones from the skull obviously was an essential prerequisite for directional hearing, for effective ultrasound orientation and communication, and finally, for the striking development of the dolphin brain.

The aerobic bacterial flora of the middle and external ears was elucidated in 30 normal dogs (60 ears). Bacterial swab samples were obtained by rubbing the surface of the tympanic cavity and external ear canal. In the middle ear, bacteria were cultured from 48 per cent of the total ears and mainly included Escherichia coli (8 per cent), yeasts (8 per cent), staphylococci (7 per cent) and branhamella (7 per cent). In the external ear, bacteria were found in 46 per cent of the total ears and staphylococci (19 per cent) and yeasts (7 per cent) were the main isolates. Mycoplasma was found in one external ear sample, but in no middle ear samples in an examination of 20 ears. The same type of bacterium was hardly ever found in both the middle and external parts of each ear.

The vascular supply of the rat tympanic membrane (TM) was studied by means of otomicroscopy, angiography, acrylic casts, and light microscopy. The branches of the external carotid artery in the external auditory meatus were found to vascularize (1) the pars flaccida, (2) the manubrial part of the pars tensa, and (3) the junction between the fibrocartilaginous ring of the TM and the tympanic sulcus of the temporal bone. The TM vessels of areas 1 and 2 were found beneath the squamous epithelium, close to mast cells and nerve bundles. Vessels originating from the tympanic cavity (also probably emanating from the external carotid artery) supplied the periphery of the pars tensa with minute branches, localized immediately beneath the tympanal epithelium. The portion of the pars tensa between the manubrial part and the periphery lacked a vascular system. Upon mechanical stimulation (gentle pressure on the handle of the malleus), the normally visible vessels dilated and minute branches appeared. This dilation may be caused, at least partly, by a release of vasoactive substances from mast cells and/or nerves in its vicinity. Even under mechanical stimulation, a large portion of the pars tensa seemed to be devoid of vessels. The nutrition of this part may be served by diffusion, with nutrients originating from the vessels in the tympanal rim and along the handle of the malleus. The architecture of the attachment of the fibrocartilaginous ring to the bony sulcus of the temporal bone is quite unique. Thus, the flow in the dense vascular network between these structures may be affected by an altered tension in the pars tensa.

The successful surgical treatment of chronic otitis media or its sequela is frequently related to a ventilated tympanic cavity. Tubes at tympanoplasty have been recommended to assure ventilation until eustachian tube and middle ear mucosal functions have been restored and to prevent the complications of graft loss, atelectasis, cholesteatoma and ossicular destruction. This presentation reviews the literature on the subject and documents our results in 40 patients treated by tympanomastoid surgery with ventilating tubes. The types of tubes used, the surgical technique involved, and the selection of cases suitable for this method are described. Cholesteatoma was the primary disease in 32 patients, 6 had chronic otitis media, 1 cholesterol granuloma, and 1 eosinophilic granuloma. Complete healing of grafts following extrusion or removal of the tubes occurred in 34 patients, 2 tubes remain in place, 3 patients had persistent tube site perforations, and 1 was lost to follow-up. None of the patients had graft breakdown as a result of tube placement, and there has been no recurrence of cholesteatoma. In all cases, the follow-up period is a minimum of 18 months and extends to 92 months.

Summary. 1 Some features of the cranial anatomy, including the chondrocranium, of the burrowing lizard Anniella pulchra are described, mainly from serial sections. 2 The skull shows marked elongation of the temporal region, reduction of the orbits, loss of the temporal arcades and obliteration of the parieto-occipital angle, so that the skull contours are streamlined. 3 The cranial kinesis is thought to be mainly of the mesokinetic type. 4 Basitrabecular processes, menisci and small epipterygoids are present. The parietal bones possess extensive downgrowths which partly enclose the cranial cavity on either side. 5 The chondrocranium shows great reduction in the orbito-temporal region. A low interorbital septum, narrow planum supraseptale and taeniae marginales are present. There are no pila metoptica or pila accessoria and the taeniae mediales are represented only by embryonic rudiments. There are no discrete optic foramina, the optic nerves passing back to the chiasma above the trabecula communis. 6 The eyes are small but can hardly be regarded as degenerate; eyelids, nictitating membrane, lachrymal canaliculi and retractor bulbi muscles are present. 7 The tympanic membrane, tympanic cavity and Eustachian tubes are absent. The columella is massive with a small extra-columella. 8 Conditions in Anniella are compared with those in other burrowing lizards, especially with Anguis fragilis, the skinks Nessia sp., and Acontias meleagris, and amphisbaenids. The main structural features associated with burrowing adaptation in lizards are described. 9 In spite of marked burrowing specialization, the cranial anatomy of Anniella resembles that of more typical Sauria in many important respects, and lacks aberrant features such as are present in amphisbaenids.

The tetrapod middle ear originated by modification of parts of the jaw mechanism of fishes, and its subsequent history is closely associated with the history of the jaw apparatus. Its early evolution is a complex of changes induced by two different influences. On one hand there were modifications of j'aw structure that forced changes upon the middle ear, and on the other there was a tendency for modificatiton of middle ear structure toward refinement of hearing, or for maintenance of hearing in the face of alterations induced by structural changes of the jaw. All of these changes were adaptive in nature. The chorda tympani is a small branch of the facial nerve that passes through the tympanic cavity on its way to the lingual side of the lower jaw. Its relationships to the various parts of the middle ear are remarkably consistent among living tetrapods. Position of the nerve has nothing to do with function of either the middle ear or the jaw mechanism and so is unlikely to have been affected by functional adjustments of the middle ear. Therefore the consistency of its relationships is generally thought to be a conservative feature, one that may be of value in determining patterns of phylogeny, and its position has been extensively studied in living forms. Unfortunately the nerve has left little trace of its position in fossil forms, which have therefore been largely ignored in such studies. Also because of its poor record chorda tympani has seldom been considered in studies of relationships among fossil tetrapods, even though the controversy over the origin and radiation of reptiles currently centers on the nature of the middle ear. A reinterpretation of the pelycosaur stapes (Hotton, 1959) has led to recognition of features that mark the route of the chorda tympani in very primitive reptiles. The present paper is an attempt to correlate this information with the abundant material on the chorda tympani in modern forms, in order to demonstrate that the position of the nerve in the pelycosaurs represents a logical intermediate between the condition of fish and amphibians on one hand and all amniotes on the other, and to show that changes of the middle ear from fish to modern amniotes can reasonably be documented by known fossil forms.

Cells which may be tentatively described as myofibroblasts have been identified by transmission electron microscopy from samples of inflammatory tissue present in the tympanic cavity of ears demonstrating clinical chronic otitis media. These cells possess the ultra-structural characteristics of a markedly indented nucleus, well organized bundles of cytoplasmic microfilaments, and plasmalemma specializations resembling desmosomes. Myofibroblasts are contractile cells which are present in a number of pathological conditions characterized by tissue contraction or distortion such as hepatic cirrhosis, Dupuytren's contracture, and hypertrophic scars. It is possible to hypothesize that myofibroblasts in chronic otitis media may exert synchronized contractile forces which distort the tympanic membrane or ossicular chain and thus lead to conductive hearing loss.

The results of tympanoplasty operations in 55 ears with chronic adhesive otitis media were analysed. In 34% of the ears, the tympanic cavity was found to be aerated on follow-up examination. Hearing improved significantly in only 13 ears (24%). There were severe complications of surgery in two ears (3.6%): one ear became totally deaf and an iatrogenic cholesteatoma developed in the other. Because of these poor results, tympanoplasty is not recommended in the treatment of chronic adhesive otitis media.