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Mastoid Process (mastoid + process)

Distribution by Scientific Domains

Life Sciences	77%
Medical Sciences	22%

Selected Abstracts

Subdural empyema and cerebellar abscess due to chronic otitis media

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2 2004
K.S. Polyzoidis
Summary The infratentorial variety of the subdural empyema, with or without coexisting cerebellar abscess, is a rare clinical entity that carries a high mortality rate. We briefly describe the case of a 49-year-old man presented with severe debility, fever and an obviously neglected chronic otitis media. The patient had refused surgical treatment several months ago. After admission, his level of consciousness began to deteriorate, and the radiological studies showed infratentorial subdural suppuration extending into the right cerebellar hemisphere, along with chronic pyogenic infection of the middle ear and the mastoid process. Radical mastoidectomy was performed first, followed by extensive right posterior fossa craniectomy. The two subdural collections and the cerebellar abscess were successfully evacuated. Subsequently, he received post-operative antibiotic treatment for 6 weeks. At follow-up, 10 months after surgery, his neurological recovery was complete except for a minor residual cerebellar dysfunction on the right. This unusual case highlights that in patients presented with severe intracranial complications of chronic otitis media, early diagnosis and radical surgical intervention may be life saving. [source]

Quantifying temporal bone morphology of great apes and humans: an approach using geometric morphometrics

JOURNAL OF ANATOMY, Issue 6 2002
Charles A. Lockwood
Abstract The hominid temporal bone offers a complex array of morphology that is linked to several different functional systems. Its frequent preservation in the fossil record gives the temporal bone added significance in the study of human evolution, but its morphology has proven difficult to quantify. In this study we use techniques of 3D geometric morphometrics to quantify differences among humans and great apes and discuss the results in a phylogenetic context. Twenty-three landmarks on the ectocranial surface of the temporal bone provide a high level of anatomical detail. Generalized Procrustes analysis (GPA) is used to register (adjust for position, orientation and scale) landmark data from 405 adults representing Homo, Pan, Gorilla and Pongo. Principal components analysis of residuals from the GPA shows that the major source of variation is between humans and apes. Human characteristics such as a coronally orientated petrous axis, a deep mandibular fossa, a projecting mastoid process, and reduced lateral extension of the tympanic element strongly impact the analysis. In phenetic cluster analyses, gorillas and orangutans group together with respect to chimpanzees, and all apes group together with respect to humans. Thus, the analysis contradicts depictions of African apes as a single morphotype. Gorillas and orangutans lack the extensive preglenoid surface of chimpanzees, and their mastoid processes are less medially inflected. These and other characters shared by gorillas and orangutans are probably primitive for the African hominid clade. [source]

Searching for DNA in museum specimens: a comparison of sources in a mammal species

MOLECULAR ECOLOGY RESOURCES, Issue 3 2010
M. CASAS-MARCE
Abstract The number of genetic studies that use preserved specimens as sources of DNA has been steadily increasing during the last few years. Therefore, selecting the sources that are more likely to provide a suitable amount of DNA of enough quality to be amplified and at the minimum cost to the original specimen is an important step for future research. We have compared different types of tissue (hides vs. bones) from museum specimens of Iberian lynx and multiple alternative sources within each type (skin, footpad, footpad powder, claw, diaphysis, maxilloturbinal bone, mastoid process and canine) for DNA yield and probability of amplification of both mitochondrial and nuclear targets. Our results show that bone samples yield more and better DNA than hides, particularly from sources from skull, such as mastoid process and canines. However, claws offer an amplification success as high as bone sources, which makes them the preferred DNA source when no skeletal pieces have been preserved. Most importantly, these recommended sources can be sampled incurring minimal damage to the specimens while amplifying at a high success rate for both mitochondrial and microsatellite markers. [source]

Mastoiditis,Paleopathological evidence of a rarely reported disease

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009
Stefan Flohr
Abstract Since antibiotics have become available, mastoiditis has become a rare disease in modern Western societies. However, it is still common in developing countries. It can be hypothesized that in earlier historical and prehistoric times, mastoiditis must have posed a serious threat to people's lives, and that the prevalence of this disease is probably underrepresented in the paleopathological literature. The present study identifies pathological changes in the pneumatized cells of the mastoid process in human skeletal samples from two early medieval cemeteries from Germany (Dirmstein: n = 152 mastoids, Rhens: n = 71 mastoids), using macroscopic, endoscopic, low-power microscopic, scanning-electron and light microscopic techniques, and draws some epidemiological conclusions as to the frequency of the disease diagnosed in the archaeological samples. Osseous changes because of mastoiditis were diagnosed in 83.4% of the temporal bones. The frequency in the skeletal sample from Dirmstein was higher than in the sample from Rhens. In both populations, males were more often affected than females and older individuals more often than younger individuals. The high frequency of mastoiditis observed was most likely due to an accumulation of osseous changes during individual lifetimes and supports the hypothesis that mastoiditis was a serious health problem in pre-antibiotic times. It may be assumed that subclinical forms of mastoiditis and their osseous manifestations may even nowadays occur more often than was previously thought. It is suggested that the disease should be given more consideration in paleopathological investigations. Am J Phys Anthropol 2009. © 2008 Wiley-Liss, Inc. [source]

Bony landmarks as an aid for intraoperative facial nerve identification

CLINICAL ANATOMY, Issue 7 2007
L.M. Greyling
Abstract Identification of the facial nerve trunk is essential during surgery of the parotid gland. Numerous landmarks have been researched and used. The relation between the facial nerve to two constant bony landmarks, the tip of the mastoid process and the central point of the transverse process of the atlas was investigated. Forty cadavers were dissected. A preauricular incision exposed the nerve trunk. Bony landmarks were identified and marked. The distance from the nerve trunk to the mastoid process and the atlas was measured. The mean distance between the mastoid process and nerve for the left was 9.18 ± 2.05 mm and for the right, 9.35 ± 1.67 mm. The mean distance between the atlas and the nerve for the left was 14.31 ± 3.59 mm and for the right, 13.76 ± 4.65 mm. Confidence intervals were determined. The importance of the aforementioned data revolves around minimizing the chance of injury to the facial nerve during surgery. The applicability of these landmarks needs to be studied in the clinical setting. Clin. Anat. 20:739,744, 2007. © 2007 Wiley-Liss, Inc. [source]

Quantifying temporal bone morphology of great apes and humans: an approach using geometric morphometrics

Electrical stimulation of the vestibular system prevents postoperative nausea and vomiting

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2000
F. Pusch
Background: Electrical stimulation of the vestibular system may prevent nausea and vomiting. We studied the influence of transcutaneous impulse stimulation in prevention of postoperative nausea and vomiting (PONV) following gynaecological surgery. Methods: In this randomised study 70 women undergoing elective gynaecological surgery under general anaesthesia were assigned to receive either the activated (stimulation group) or the inactivated (non-stimulation group) impulse stimulator. The stimulator comprises the stimulator itself, two negative electrodes on a headset applied over both mastoid processes and a nuchal positive electrode. The device yielded a pulse frequency of 5 Hz direct current, individually adjustable between 0.5 and 4 mA. A trapezoid stimulation of 50 ms was applied. Nausea, vomiting, dizziness and the amount of antiemetic drugs used were assessed during the first 4 h postoperatively. Results: Lower postoperative nausea scores with a lower incidence of vomiting and postoperative dizziness were found in the stimulation group. A lower amount of antiemetic drugs was needed in the stimulation group when compared to the non-stimulation group (P<0.01 between groups). Conclusion: This study suggests that electrical stimulation of the vestibular system may be useful in prevention of PONV. [source]

Differential diagnosis of mastoid hypocellularity in human skeletal remains

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009
Stefan Flohr
Abstract Mastoid hypocellularity is frequently used as an indicator of chronic otits media in paleopathological investigations. The condition can be caused by a poor development of air cells during infancy and early childhood (primary hypocellularity) or by obliteration of air cells with bone during later life (secondary hypocellularity). We performed a macroscopic, radiographic, and microscopic study of pneumatization patterns in 151 mastoid processes of individuals from an early-medieval cemetery in Germany, with emphasis on the architecture of the nonpneumatized portion of hypocellular mastoid processes. Two types of primary mastoid hypocellularity were distinguished. The first was characterized by a poorly defined boundary between the pneumatized portion and the nonpneumatized portion and a trabecular thickening in the spongy bone of the latter. The second showed a well-defined boundary between the pneumatized portion and the nonpneumatized portion and normal spongy bone architecture in the latter. The key feature for the diagnosis of secondary hypocellularity was the recognition of the walls of former air cells. Our observations closely match the histopathological findings by Wittmaack (Wittmaack: Über die normale und die pathologische Pneumatisation des Schläfenbeins. Jena: Gustav Fischer [1918]), who developed a concept of the normal pneumatization process of the temporal bone and the pathogenesis of aberrant pneumatization. We agree with Wittmaack's view that two types of primary mastoid hypocellularity can be distinguished morphologically. Regarding the pathogenesis of these types, we, however, conclude that Wittmaack's concept needs to be revised and updated. Further studies are required to establish the relationship between morphological findings in cases of mastoid hypocellularity and the health status of individuals. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source]