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(1/308) Pneumocephalus associated with ethmoidal sinus osteoma--case report.

A 35-year-old female suffered sudden onset of severe headache upon blowing her nose. No rhinorrhea or signs of meningeal irritation were noted. Computed tomography (CT) with bone windows clearly delineated a bony mass in the right ethmoid sinus, extending into the orbit and intracranially. Conventional CT demonstrated multiple air bubbles in the cisterns and around the mass in the right frontal skull base, suggesting that the mass was associated with entry of the air bubbles into the cranial cavity. T1- and T2-weighted magnetic resonance (MR) imaging showed a low-signal lesion that appeared to be an osteoma but did not show any air bubbles. Through a wide bilateral frontal craniotomy, the cauliflower-like osteoma was found to be protruding intracranially through the skull base and the overlying dura mater. The osteoma was removed, and the dural defect was covered with a fascia graft. Histological examination confirmed that the lesion was an osteoma. The operative procedure resolved the problem of air entry. CT is superior to MR imaging for diagnosing pneumocephalus, by providing a better assessment of bony destruction and better detection of small amounts of intracranial air.  (+info)

(2/308) CT and MR findings of Michel anomaly: inner ear aplasia.

In 1863, Michel described a condition characterized by a total absence of differentiated inner ear structures associated with other skull base anomalies, including an abnormal course of the facial nerve and jugular veins. Michel aplasia clearly differs from Michel dysplasia, in which arrest of embryologic development occurs later. Recently, the role of otic capsule formation on mesenchymal differentiation was reported as well as the impact of the genetic deletion of the homeobox gene on the development of the ear, cranial nerves, and hindbrain. We report two patients with a total absence of inner ear structures bilaterally, illustrating the characteristic appearance of Michel aplasia and associated skull base anomalies.  (+info)

(3/308) Comparison of cervicovertebral dimensions in Australian Aborigines and Caucasians.

Cervicovertebral dimensions were compared in a group of 30 male and 30 female young adult Australian Aborigines from the Northern Territory, and a control sample consisting of 60 Caucasian dental students from Adelaide, matched for sex and age. Thirty-six variables, 22 cervical and 14 craniofacial, were derived from standardized lateral roentgenograms with the use of a computerized cephalometric system. Vertebral body height and length were significantly greater in Aboriginal males than females for C3 to C7, while dorsal arch height of C1 and C2 displayed the greatest dimensional variability in both sexes. The antero-posterior length of C1, dens height, and body heights of C3 and C4 were significantly shorter in Aborigines than Caucasians for both males and females. Total length of the column from C2 to C6 was approximately 12 per cent shorter in the Aborigines compared with Caucasians. The height of the posterior arch of C1 was significantly correlated with one or both posterior cranial base lengths in Aborigines and Caucasians. Associations were also noted between mandibular lengths and posterior arch heights of the upper two vertebrae. The results confirm and clarify several previous observations on the relative shortness of the cervical spine in Australian Aboriginals. They also indicate some associations between dimensions of the cervical vertebrae and craniofacial lengths, particularly those representing the posterior cranial base and the mandible.  (+info)

(4/308) Effect of low-dose testosterone treatment on craniofacial growth in boys with delayed puberty.

Craniofacial growth was investigated in boys treated with low-dose testosterone for delayed puberty (> 14 years old; testicular volume < 4 ml; n = 7) and compared with controls (12-14 years; n = 37). Cephalometric radiographs, statural height and pubertal stage were recorded at the start of the study and after 1 year. Craniofacial growth was assessed by nine linear measurements. At the beginning of the study, statural height, mandibular ramus length, upper anterior face height, and total cranial base length were significantly shorter in the delayed puberty boys than in the controls. After 1 year, the growth rate of the statural height, total mandibular length, ramus length, and upper and total anterior face height was significantly higher in the treated boys than in the untreated height-matched controls (n = 7). The craniofacial measurements were similar in the treated boys as compared with the controls. These results show that statural height and craniofacial dimensions are low in boys with delayed puberty. Low doses of testosterone accelerate statural and craniofacial growth, particularly in the delayed components, thus leading towards a normalization of facial dimensions.  (+info)

(5/308) Angiographically occult dural arteriovenous malformation in the anterior cranial fossa--case report.

A 62-year-old male presented with a dural arteriovenous malformation located in anterior cranial fossa manifesting as acute right frontal intracerebral and subdural hematomas. Cerebral angiography showed only mass sign, but surgical exploration disclosed the dural arteriovenous malformation in the anterior cranial fossa. Anterior cranial fossa dural arteriovenous malformation should be considered if computed tomography reveals intracranial bleeding involving the frontal base, even if cerebral angiography does not demonstrate vascular anomalies.  (+info)

(6/308) Craniofacial morphology in 6-year-old Icelandic children.

The purpose of the study was to describe the craniofacial characteristics of 6-year-old Icelandic children, make a normative standard for children with an Angle Class I molar relationship, and compare them to those with an Angle Class II molar relationship. The material consisted of the radiographs of 363 children, 184 (50.7 per cent) boys and 179 (49.3 per cent) girls with a mean age of 6 years 7 months (range: 5 years 7 months-7 years 8 months). Twenty-two reference points were digitized and processed by standard methods with the Dentofacial Planner computer software program. The 33 variables calculated included both angular and linear. Two sample t-tests were used to study the differences between different groups. Only minimal differences could be noted between sexes in sagittal and vertical angular measurements. Linear measurements, on the other hand, were usually larger for the boys. When compared with Norwegian material of the same age group, similar trends were observed between sexes in both studies, but the Icelandic children showed slightly more mandibular prognathism and a lower mandibular plane angle. When compared with children with an Angle Class I molar relationship, children with an Angle Class II molar relationship did not have a different maxillary prognathism nor a different mandibular length. Cranial base dimensions were all significantly greater and the cranial base flexure was also significantly more obtuse in the distal group.  (+info)

(7/308) Differential responses to parathyroid hormone-related protein (PTHrP) deficiency in the various craniofacial cartilages.

PTHrP null mutant mice exhibit skeletal abnormalities both in the craniofacial region and limbs. In the growth plate cartilage of the null mutant, a diminished number of proliferating chondrocytes and accelerated chondrocytic differentiation are observed. In order to examine the effect of PTHrP deficiency on the craniofacial morphology and highlight the differential feature of the composing cartilages, we examined the various cartilages in the craniofacial region of neonatal PTHrP deficient mice. The major part of the cartilaginous anterior cranial base appeared to be normal in the homozygous PTHrP deficient mice. However, acceleration of chondrocytic differentiation and endochondral bone formation was observed in the posterior part of the anterior cranial base and in the cranial base synchondroses. Ectopic bone formation was observed in the soft tissue-running mid-portion of the Meckel's cartilage, where the cartilage degenerates and converts to ligament in the course of normal development. The zonal structure of the mandibular condylar cartilage was scarcely affected, but the whole condyle was reduced in size. These results suggest the effect of PTHrP deficiency varies widely between the craniofacial cartilages, according to the differential features of each cartilage.  (+info)

(8/308) The mouse bagpipe gene controls development of axial skeleton, skull, and spleen.

The mouse Bapx1 gene is homologous to the Drosophila homeobox containing bagpipe (bap) gene. A shared characteristic of the genes in these two organisms is expression in gut mesoderm. In Drosophila, bap functions to specify the formation of the musculature of the midgut. To determine the function of the mammalian cognate, we targeted a mutation into the Bapx1 locus. Bapx1, similar to Drosophila, does have a conspicuous role in gut mesoderm; however, this appears to be restricted to development of the spleen. In addition, Bapx1 has a major role in the development of the axial skeleton. Loss of Bapx1 affects the distribution of sclerotomal cells, markedly reducing the number that appear ventromedially around the notochord. Subsequently, the structures in the midaxial region, the intervertebral discs, and centra of the vertebral bodies, fail to form. Abnormalities are also found in those bones of the basal skull (basioccipital and basisphenoid bones) associated with the notochord. We postulate that Bapx1 confers the capacity of cells to interact with the notochord, effecting inductive interactions essential for development of the vertebral column and chondrocranium.  (+info)