External ear canal exostosis and otitis media in temporal bones of prehistoric and historic chilean populations. A paleopathological and paleoepidemiological study

Abstract

Conclusions: External ear canal exostosis is more prevalent in northern coastal groups than in the highlands, suggesting that ocean activities facilitate the appearance of exostosis. However, southern coastal groups exposed to colder ocean water have a lesser incidence of exostosis, possibly due to less duration of exposure. There was a high incidence of otitis media in all groups of native population in Chile. One coastal group had a higher incidence, presumably due to racial factors.

Background: This is a paleopathological and paleoepidemiological study in temporal bones which assesses external ear canal exostosis and otitis media in prehistoric and historic native populations in Chile.

Materials and methods: A total of 460 temporal bones were evaluated for exostosis (ex) and 542 temporal bones were evaluated for otitis media (om). The study involved four groups: (1) Prehistoric Coastal (400–1000 AD) populations in Northern Chile (Pisagua-Tiwanaku) (22 temporal bones ex; 28 om); (2) Prehistoric Highland (400–1000 AD) populations in Northern Chile (292 temporal bones ex; 334 om); (3) Pisagua-Regional Developments (coastal) in Northern Chile (1000–1450 AD) (66 temporal bones ex; 82 om); and (4) Historic (1500–1800 AD) coastal populations in Southern Chile (80 temporal bones ex: 18 Chonos, 62 Fuegians. 98 om: 22 Chonos, 76 Fuegians). Skulls were evaluated visually and with an operating microscope. In addition, the otitis media group was evaluated with Temporal bone radiology – -lateral XRays-Schuller view – to assess pneumatization as evidence of previous middle ear disease.

Results: Prehistoric northern coastal groups had an incidence of exostosis of 15.91%, the northern highlands group 1.37%, and the southern coastal group 1.25%. There were changes suggestive of otitis media in: Pisagua/Tiwanaku 53.57%; Pisagua/Regional Developments 70.73%; Northern Highlands population 47.90%; Chonos 63.64%; and Fuegian tribes 64.47%.     

Osteochondroma of the mandibular condyle. Case report (author's transl)]

A rare case of osteocartilaginous exostosis, also called osteochondroma, is described. The resection of the tumor through an extra-oral incision is the treatment of choice. The follow-up covers a period of 4 years. No relapse was observed and postoperatively the function of the temporomandibular joint was practically normal.     

Exostosis of the external auditory canal and sensorineural hearing loss in professional divers]

Audiometric survey and endoscopic study of the external auditory canal were performed on a group of 31 professional divers, all of whom had experienced frequent exposure to dysbaric conditions. The results are as follows. 1) Over 40% had exostosis of the external auditory canal. There was no relationship between the incidence of the exostosis and the length of their occupational career as a diver. Many of the divers had hearing loss whether they had exostosis or not. 2) Over 70% had sensorineural hearing loss, taking into account hearing loss due to aging. Most had no experience of inner ear barotrauma on descent, causing sudden a shift in hearing threshold. Deafness was related to the length of their occupational career as a diver. In conclusion, we speculate that repetitive small changes in barometric pressure on the outer ear influences the pressure on the middle ear and further on that of the perilymph, finally damaging the inner ear auditory system.     

Less radical drilling in surgery for exostoses of the external auditory canal

OBJECTIVE: To estimate the anatomical and functional long-term result of surgery for ear canal exostosis. METHODS: Case rapport review with extraction of data concerning pre- and postoperative anatomical conditions, symptoms and audiology and a clinical and audiological re-evaluation. In the 20-year-period from 1 January 1976 to 1 January 1996, 26 patients were operated on primarily for ear canal exostosis. 19 patients with in total 24 ears were re-evaluated. Control-period 7.2 years. Pre-operatively were found occluding ear-canal exostosis in all patients as well as hearing loss, otitis externa and pain. RESULTS: At the re-evaluation all patient were completely free of their symptoms. 19 out of 24 ears still had some remnants of exostosis, but the ear canal was covered with completely normal skin and had normal migration properties. No signs of re-growth were found in this material. Postoperatively one patient had a sensorineural hearing loss of 85 dB at 6 kHz, one had a dehiscence of the temporomandibular joint and one patient had an anterior ear drum perforation. CONCLUSION: To avoid the complications a less radical drilling of exostoses is proposed, in particular along the superior wall and near the short process of the malleus handle and along the anterior tympanomeatal angle. Removal of the bone from the posterior, inferior and anterior walls with preservation of the canal skin, creates enough lumen providing permanent cure.     

Exostosis of the zygoma. Apropos a case

Exostosis is a benign bony process arising from cortical bone. It is generally localized at the fertile metaphysis of long and some flat bones. Localization to the zygoma and/or the coronoid process is exceptional (5 cases in the world literature). We report an original case of exostosis with isolated zygomatic localization in a 14-year-old girl and review the literature. We emphasize the clinical features and the diagnostic and therapeutic approach in this condition.     

Exostosis of the internal auditory canal in a patient with myotonic dystrophy

A 53-year-old patient with myotonic dystrophy presented to our clinic with progressive bilateral hearing loss. The ENT status and particularly the otological examination were without pathological signs. Pure tone audiograms showed a bilateral moderate to severe sensorineural hearing loss. Routinely performed computed tomography of the temporal bones revealed the rare picture of exostosis of the internal auditory canals and the medial surface of the petrous bones. To our knowledge, this is the first report describing exostosis of the internal auditory canal in a patient with myotonic dystrophy, although at present it remains unclear in how far there is a causal connection between these two pathologies.     

Incidence of "recurrences" following surgical removal of ear canal exostoses]

A clinical review of 55 patients, who underwent an operative removal of exostosis of the external ear canal during the last 10 years, brought us to two main conclusions. While there are no true recurrences, it is possible in cases of continuous exposure to cold water that in regions which were not touched by the first operations new exostosis will occur. The drilling and sucking noise during the operative procedure might cause an inner ear damage, as the sound transmission is unimpeded. Intraoperative protective measures are recommended.     

Canalplasty for severe external auditory meatus exostoses

Exostoses of the external auditory meatus is a well known condition which infrequently requires surgical correction. However, the stenosis caused by severe exostosis can affect quality of life considerably and may require surgical intervention. Canalplasty, in such a situation, is a valid and effective management option. In our series the commonest indication for surgery was recurrent otitis externa. The detailed surgical technique is described and a retrospective analysis of 65 such procedures is presented. There were only two significant complications, both post-operative stenosis, requiring further corrective surgery. In conclusion, canalplasty for the exostosis of the external auditory meatus is a safe surgical option.     

Exostoses and Cavernous Venous Formation in the External Auditory Canal of the Hooded Seal as a Functional Physiological Organ

Exostoses of the external auditory canal (EAC) develop after protracted mechanical, chemical or thermal irritation in particular. This is a common disorder among aquatic sportsmen and has been considered unique to Man. We dissected and photodocumented the EACs of 5 newborn and 3 adult Hooded Seals (Cystophora cristata). Serial sections of the EACs were prepared for light microscopic evaluation after staining with haematoxylin-eosin or toluidine blue. All EACs exhibited a firm, broad-based, mountain peak-shaped exostosis on the floor of the meatus, lateral to the eardrum. In addition, the meatal skin of the bony EAC harboured large venous sinuses. The exostosis and venous sinuses of the seal EAC participate in the protection of the sensitive hearing apparatus, particularly the pars tensa portion of the drum, during diving.     

Exostoses and cavernous venous formation in the external auditory canal of the hooded seal as a functional physiological organ

Exostoses of the external auditory canal (EAC) develop after protracted mechanical, chemical or thermal irritation in particular. This is a common disorder among aquatic sportsmen and has been considered unique to Man. We dissected and photodocumented the EACs of 5 newborn and 3 adult Hooded Seals (Cystophora cristata). Serial sections of the EACs were prepared for light microscopic evaluation after staining with haematoxylin-eosin or toluidine blue. All EACs exhibited a firm, broad-based. mountain peak-shaped exostosis on the floor of the meatus, lateral to the eardrum. In addition, the meatal skin of the bony EAC harboured large venous sinuses. The exostosis and venous sinuses of the seal EAC participate in the protection of the sensitive hearing apparatus, particularly the pars tensa portion of the drum, during divine.     

External ear canal exostosis and aquatic sports

Many reports suppose that the development of aural exostosis depends on the action of an irritative stimulus like frequent and repeated cold water contact. This survey studies the incidence of this lesion in a group of 433 athletes practicing aquatic sports on a highly competitive level. Among these, water activities like sailing and deep-sea diving, which up to now were never considered, were also studied. 32 exostoses were found to affect 12 subjects monolaterally and 20 subjects bilaterally. Not one of a control group of 476 athletes was found to be affected by aural exostosis. For each athlete in this study the following parameters are considered: age and sex, type of sport, total amount of hours spent in water contact, aural pathology history and otoscopic findings. The authors suggest the existence of facilitating factors other than total water contact time, as shown by the absence of a precise correlation between this parameter and the presence of the aural hyperostotic lesion.     

A case of external auditory canal chondroma

The differential diagnosis for an external auditory canal mass is relatively broad, with exostosis, osteoma, fibroma, keratoma, and congenital cholesteatoma among the more common diagnoses. However, an additional diagnosis, external auditory canal chondroma, should also be considered in the differential. These rare lesions are most often found in individuals of Asian ancestry. However, this is not always the case as demonstrated by this case report of an external auditory canal chondroma in a Caucasian teenager.     

Specific features of mineral and protein metabolism in patients with paranasal osteoma

A comparative analysis of biochemical blood picture was made in 20 patients with osteoma of the paranasal sinuses before and after surgical treatment. A total of 17 tests characterizing metabolism and 680 biochemical examinations were made. Investigation of mineral and other kinds of metabolism may be important in diagnosis of osteomas, hyperostosis, exostosis and malignant tumors, determination of activity and tumor growth rate.     

Osseous tumors of the jaw

The osseous tumors of the jaw bones are relatively rare but very oft malignant. This work analyses the different epidemiological, clinical, radiological, histological and therapeutic features of the benign and malignant osseous tumors of the jaw bones, with regard to the most recent literature. The described benign tumors are the osteoma and osteomatosis, the osteoblastoma and osteoid osteoma, the desmo-osteoblastoma and the exostosis. The osteosarcoma is the unique malignant osseous tumor encountered.     

Surgery of the external ear canal

Diseases of the external ear canal are a frequent reason for consulting the otolaryngologist. Conservative treatment is sufficient in most cases. Chronic problems of the external ear canal, however, sometimes require surgical treatment. Enlargement of the external ear canal as well as the entrance of the external ear canal are often simultaneously performed together with tympanoplasties, in order to obtain good access to the middle ear and to facilitate postoperative care. In this review, we focus on surgical techniques for different pathologies such as exostosis, stenosis, fibrosis, and tumors of the external ear canal.     

Exostoses of the paranasal sinuses

While bony exostoses of the external auditory canal have long been recognized as a complication of cold-water swimming, bony exostoses of the paranasal sinuses have not been previously reported. We present an unusual case of multiple exostoses of the paranasal sinuses, which began coincident with nasal irrigation with cold gentamicin solution. The patient had had prior endoscopic sinus surgery. Topical antibiotic gentamicin irrigation lessened recurrence of bacterial sinus episodes. He admitted to using the irrigation directly from the refrigerator daily for two years. A biopsy was consistent with exostosis. Patients should be counseled to avoid irrigating their paranasal sinuses with cold irrigants. Laryngoscope, 2010.     

Resultate und außer- gewöhnliche Komplikationen der Chirurgie der Gehörgangexostosen

We present a retrospective study on 22 operations of exostosis of the external auditory canal in 20 patients. 8 patients were passionated by water sports. The most frequent indication for surgery (13 operations) was recurrent external otitis or ceruminal obstruction. In 7 cases the need for a wider access to the middle ear indicated surgery. Surgery was usually performed as an outpatient procedure, maximum hospitalization was 3 days. The mean healing period was 6 (3-10) weeks. Mean follow up was 43 (3-110) months. There were no severe intraoperative complications such as facial paresis, lesions of the ossicles or of the inner ear. As intraoperative complications we found 2 perforations of the tympanic membrane, 2 expositions of the capsule of the mandibular joint, one of which was followed by chronic pain. As postoperative complications we found an early soft tissue stenosis of the external auditory canal and one late soft tissue stenosis which recurred after revision surgery. No recurrence of exostosis was seen. We describe an up to now unknown complication: the appearance of bilateral petrositis caused by staphylococcus epidermidis after bilateral surgery in an otherwise healthy patient. This study confirms that severe complications are rare, minor ones however relatively common. And that also minor complications may have a troublesome follow. Therefore and because of the potential of severe complications indication for surgery must be made cautiously and risks of the operation must not be underestimated.     

A survey of otologic training in US residency programs

Otologic cases are dwindling in numbers, jeopardizing the clinical training of our residents. A survey was performed to determine the magnitude of the problem facing our training programs. Seventy-three of 79 questionnaires distributed were returned. Results of the survey indicate that facial nerve decompression, exostosis repair, and stapedectomy were, on the average, infrequently performed by residents. Training for these seldom-performed procedures consists of temporal bone laboratory experience, close operative supervision, and the use of private patients for resident training. The majority (84%) of respondents did not feel that fellowship training was required to perform otologic surgery on graduation or that it should be required for obtaining hospital privileges in seldom-performed cases. Approximately three quarters (76%) of the program directors consider the training of seldom-performed procedures to be a moderate-to-serious problem facing otologic training today.     

26例外耳道骨瘤患者临床特征分析

目的:总结外耳道骨瘤的诊治经验。方法:回顾性分析行手术治疗的26例外耳道骨瘤患者的临床资料。结果:患者均行手术切除肿物,病理学诊断均为骨瘤。22例术前传导性听力下降者听力恢复正常,2例术前混合性听力下降者气导听力分别平均提高15、20dB。随访1年以上未见复发及并发症发生。结论:外耳道骨瘤是一种少见的良性肿瘤,诊断可以借助颞骨CT扫描;需与外耳道骨疣鉴别,确诊依靠病理检查;手术是外耳道骨瘤的惟一治疗方法。     

How can the hooded seal dive to a depth of 1000 m without rupturing its tympanic membrane? A morphological and functional study.

Recent studies using a satellite-linked dive recorder have shown that the hooded seal (Cystophora cristata), a common Arctic pinniped, can dive to a depth of > 1000 m and stay submerged for close to 1 h. At these depths the water pressure reaches 100 atm, entailing obvious risk of serious damage to the hearing apparatus, mainly the tympanic membrane (TM) and middle ear (ME). We dissected and photodocumented the temporal bones of five newborn and three adult hooded seals in order to study the temporal bone structure and reveal its protective mechanisms for extreme pressure changes. Specimens were sectioned and stained for light microscopy. The thicknesses of the pars tensa and pars flaccida were found to average 60 and 180 microm, respectively. The ME cavity hosts a cavernous tissue of thin-walled vessels beneath the modified respiratory epithelium. The ME and external ear canal (EAC) volumes can be altered appreciably by filling/emptying the cavernous tissue with blood. The ossicles were fixed by contracting the tensor tympani and stapedius muscles simultaneously with complete occlusion of the EAC. According to Boyle's law, the volume of the gas-filled ME cavity at a depth of 1000 m is only 1% of its volume at the surface of the sea. Ascent from such a depth allows the gas in the ME cavity to expand, causing the TM to bulge laterally. This movement is counteracted by a reduction in the blood volume inside the cavernous sinuses, action in the tensor tympani and stapedius muscles and discharge of gas through the Eustachian tube. The presence of a firm, broad-based exostosis in the floor of the EAC lateral to the TM helps to obstruct the EAC.