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PubMedDate not supplied

Distribution profiles of fluoride in three different kinds of rat bones.

The study was performed to reveal the detailed distribution profiles of fluoride in three different kinds of rat bone--humerus, vertebral arch, and parietal bone--and to compare this with the histological appearance of each bone type. Two groups of Wistar rats were provided water ad libitum containing 0 and 100 ppm fluoride, respectively, for 24 weeks. The fluoride distribution profiles across the bone of the three different bones from the outer to the inner surface were determined by means of an abrasive micro-sampling technique. In control animals, both humerus and parietal bones showed higher concentrations at the periosteal and endosteal surfaces, while the vertebral arch showed additional high levels in the middle (containing trabecular bone) of the tissue. In exposed animals, fluoride levels increased greatly in all three bone types. The vertebral and parietal fluoride distribution profiles were relatively unchanged, although humerus fluoride increased from periosteum to endosteum. The differences in fluoride distribution profiles were apparently related to the histological appearances of these bones. The surface area of bone available and the extent of vascularity appear to affect fluoride uptake.

Animals↗
PubMed1989

[Osteoblastic skull metastasis of lung cancer].

A case of osteoblastic skull metastasis of lung cancer is reported. A 56-year-old female patient was admitted to our hospital with complaints of headache and tumor of the right parietal bone. A plain skull X-ray showed hyperostotic feature of the right parietal bone. CT scan displayed that right parietal bone became thick and osteoblastic. Soft tissue was shown in the hyperostotic bone under MRI. An external carotid angiogram showed that the skull tumor was fed by the middle meningeal artery. The skull tumor and 2 solid intracerebral tumors were extirpated. Histological examination revealed adenocarcinoma in the skull and intracerebral lesions. The present case indicates that osteoblastic stimulating factor may be secreted by lung cancer.

Adenocarcinoma↗
PubMedDate not supplied

Computed tomographic evaluation before cranial bone harvesting to avoid unexpected hazards during aesthetic procedures.

Nowadays, cranium is the preferred bone-graft donor site for facial aesthetic operations. Preoperative information about the quality of cranial bone, such as bone thickness or presence of the diplopic space, can be useful to minimize intracranial complications. This fact is neglected in reconstructive and aesthetic surgery. The aim of this study is to assess the reliability of Computed Tomography (CT) to determine cranial bone quality. Sixty-four cadaver parietal bones, the preferred site for bone-graft harvesting, were used in this study. In the first stage, posterior parietal bone thickness, which is accepted as the thickest part of cranium, was measured at specially determined points using a micrometer and the results were recorded. Bone thickness was then measured again in the same points with CT. The two methods were compared statistically. The measurements were not found to be statistically different. The similar values obtained with CT and micrometers suggest that CT can accurately and reliably determine cranial thickness. Preoperative CT can be a significant guide for the harvest of cranial bone grafts without any intracranial complications in aesthetic surgery.

Bone Transplantation↗
PubMed1985

Bone cells predispose bone surfaces to resorption by exposure of mineral to osteoclastic contact.

The cell-free endocranial surface of young adult rat parietal bones was used as a substrate for osteoclastic bone resorption, either without prior treatment, or after incubation of the parietal bones with collagenase or neonatal rat calvarial cells. Untreated, the endocranial surface consisted of unmineralized organic fibres; incubation with calvarial cells or collagenase caused disruption and removal of these fibres, with extensive exposure of bone mineral on the endocranial surface, without morphologically detectable mineral dissolution. Neonatal rabbit osteoclasts resorbed bone to a greater extent from parietal bones pre-incubated with calvarial cells or collagenase than from untreated bones; mineral exposure and subsequent osteoclastic resorption were both increased if calvarial cells were incubated with parathyroid hormone; removal of bone mineral after incubation with calvarial cells removed the predisposition to osteoclastic resorption. These experiments demonstrate that calvarial cells are capable of osteoid destruction, and indicate that one mechanism by which osteoblasts induce osteoclastic bone resorption may be through digestion of the unmineralized organic material that covers bone surfaces, to expose the underlying resorption-stimulating bone mineral to osteoclastic contact.

Animals↗
PubMed1994

Primary meningioma intimately related to skull: case report and review of the literature.

A report is made of a primary meningioma intimately associated with the left sphenoid ridge and temporal bone of a 41-year-old woman. The lesion produced hyperostosis of the involved bones, ipsilateral proptosis, and reduced vision for 4.5 years. The radiotherapy yielded little improvement of the exophthalmos and vision. Review of 125 reported meningiomas intimately related to the skull and presenting primarily with hyperostosis and minimal soft tissue component, including the current case, disclosed that all but one affected the cranium proper, particularly the middle ear, temporal bone, frontal bone, and parietal bone. The exceptional one was in the mandible. They tended to occur between the fifth and seventh decades of life with the peak occurrence between the fifth and sixth decades. The average age was 46 years for overall. The female-to-male ratio was 2:1. Six of 125 primary meningiomas closely associated with the skull were malignant and two of these spread to the lungs. The pulmonary metastasis was spontaneous in one case.

Adult↗
PubMed2006

A model for the pharmacological treatment of crouzon syndrome.

OBJECTIVE: Crouzon syndrome is caused by mutations in fibroblast growth factor receptor 2 (FGFR2) leading to constitutive activation of receptors in the absence of ligand binding. The syndrome is characterized by premature fusion of the cranial sutures that leads to abnormal cranium shape, restricted brain growth, and increased intracranial pressure. Surgical remodeling of the cranial vault is currently used to treat affected infants. The purpose of this study was to develop a pharmacological strategy using tyrosine kinase inhibition as a novel treatment for craniosynostotic syndromes caused by constitutive FGFR activation. METHODS: Characterization of cranial suture fusion in Fgfr2 mutant mice, which carry the most common Crouzon mutation, was performed using micro-computed tomographic analysis from embryogenesis through maturation. Whole calvarial cultures from wild-type and Fgfr2 mice were established and cultured for 2 weeks in the presence of dimethyl sulfoxide control or PD173074, an FGFR tyrosine kinase inhibitor. Paraffin sections were prepared to show suture morphology and calcium deposition. RESULTS: In untreated Fgfr2 cultures, the coronal suture fused bilaterally with loss of overlap between the frontal bone and parietal bone. Calvaria treated with PD173074 (2 micromol/L) showed patency of the coronal suture and were without evidence of any synostosis. CONCLUSION: We report the successful use of PD173074 to prevent in vitro suture fusion in a model for Crouzon syndrome. Further studies are underway to develop an in vivo treatment protocol as a novel therapeutic modality for FGFR associated craniosynostotic syndromes.

Animals↗
PubMedDate not supplied

[Cephalography in Thalassemic patients].

This article reported a study of cephalography in 60 Thalassemic patients between the age of 11-16 years old. There were 8 beta-thalassemia, 35 beta-thalassemia/Hb E and 17 Hb H diseases. Sixty age-matched controlled patients were used for comparison. It was found that 11 thalassemic patients (18.2%) had showed absence of frontal sinus, only 3 cases had showed absence of maxillary sinus, 38 cases (63.3%) had thickening of frontal bone and parietal bone, mostly in the anterior region. Twenty-two cases (36.6%) had fine granular pattern of bone, five cases (8.3%) had hair on end appearance and 44 cases (73.3%) had thin cortex at posterior and inferior margins of ramus. There were not found in control subjects. There was no significant relationship between the absence of frontal sinus and the thickening of the frontal bone at p less than 0.05.

Adolescent↗
PubMed1978

[Ontogenic development of the surface of craniofacial sagittal angular sectors in man and chimpanzee].

By means of a technique for measuring surfaces by direct reading, six angular sectors have been studied (3 for the face and 3 for the skull) at various ontogenic periods of Man, common chimpanzee and dwarf chimpanzee. The growth curves have been drawn for absolute values and for relative values. They show a certain evolutive parallelism between the frontal bone and the parietal bone, and between the face and the mandible, with a special fate for the occipital bone.

Adult↗
PubMed2000

Cranial vault expansion: a comparison of magnetic coupled distraction to traditional surgical repositioning.

We compared the effectiveness of transcutaneously activated magnetic distraction of an osteotomized cranial bone flap to surgical repositioning of the flap with immediate, rigid internal fixation. Thirty immature rabbits were studied. All 30 rabbits underwent complete circumferential osteotomies of both parietal bones and postoperatively all were fitted with head frames. The rabbits were divided into 4 groups. The experimental magnetic distraction group consisted of 10 animals (group 1). In these rabbits magnets were secured to both parietal bones and magnets of opposite polarity were placed in the headframes. Each morning, the magnets in the head-frames were moved 0.25 mm farther away from the skull; this continued for 20 days for a total setback of 5 mm. Five animals served as the magnetic distraction controls; in these animals magnets were placed on the parietal bones but none were attached to the headframes (group 2). The experimental surgical repositioning group consisted of 10 rabbits (group 3). In each the parietal bones were elevated and fixed 5 mm above the rest of the skull using vitallium mesh and screws. Five rabbits made up the surgical respositioning control group (group 4). In these animals, parietal osteotomies were performed but the bones were secured to the skull in their original positions using hardware identical to that used in the experimental group. Six weeks later all of the animals were sacrificed. Two significant differences were identified between the experimental groups: (1) the cranial contours of the animals in the magnetic distraction group were rounded while those of the surgically repositioned group were acutely angled; (2) the osteotomies in rabbits in the magnetic distraction group were essentially completely ossified while in rabbits in the surgically repositioned group there were obvious gaps at the osteotomy sites that were filled with fibrous tissue. These conclusions support the potential utility of magnetically activated distraction as an alternative to current methods of cranial vault remodeling.

Animals↗
PubMed1997

Regional differences of dura osteoinduction: squamous dura induces osteogenesis, sutural dura induces chondrogenesis and osteogenesis.

Dura plays an important role in calvarial morphogenesis. However, precisely what that role is remains unclear. We present here in vivo evidence that dura without other central nervous system components induces both chondrogenesis and osteogenesis. The mechanism is, at least in part, by proximate tissue interaction. The objectives of this experiment were to answer the following: (1) Can dura actually induce osteogenesis without the influence of the underlying brain? (2) What are the requirements of this dura-induced heterotopic osteogenesis? (3) What are the differences between dura underlying sutures and dura underlying the squamous portions of the cranial bones? Dura underlying the metopic, sagittal, and lambdoidal sutures and dura underlying the flat portions of frontal and parietal bones were obtained from neonatal Lewis rats and transplanted into the posterior thoraces of adult Lewis recipients. In group I, dura underlying the metopic, sagittal, and lambdoidal sutures (n = 20) and dura underlying the flat portions of frontal and parietal bones (n = 20) were transplanted individually into separate epitheliomesenchymal pockets. Group II animals had dura underlying the metopic, sagittal, and lambdoidal sutures (n = 10) and dura underlying the flat portions of frontal and parietal bones (n = 10) transplanted individually into surgically created mesenchymal pockets by placing the dura grafts between panniculus carnosus and latissimus dorsi muscles. The animals were sacrificed at 2-week intervals. Light microscopy, special histochemical analysis, immunohistochemistry, and electron microscopy were performed. Bone formation was seen in 15 of the 18 animals (83 percent) in group I. No bone or cartilage formation was seen in group II. Chondrogenesis was seen in 4 animals receiving dura underlying the metopic, sagittal, and lambdoidal sutures in group I. Cellular hyperproliferation was seen at 2 weeks when dura was transplanted close to the hair follicles. These cells had a high nucleus-to-cytoplasm ratio and were positive for transforming growth factor beta. This hyperproliferation was followed by production and accumulation of Alcian blue-positive extracellular matrix that resisted digestion by hyaluronidase. Cellularly active cartilage was seen at 6 weeks. There was no chondrogenesis in animals receiving dura underlying the flat portions of frontal and parietal bones in group I. Electron microscopy demonstrated the presence of proteoglycan-like ground substance and type II collagen in the inner layer of sutural dura and the predominance of dense type I collagen in the squamous dura and the external layer of the sutural dura. The important findings of this experiment are that (1) heterotopically transplanted neonatal dura can induce osteogenesis, (2) this heterotopic osteoinduction by dura requires epitheliomesenchymal interaction, and (3) separating dura into sutural dura and squamous dura, chondrogenesis occasionally occurred in addition to osteogenesis with the former, while only membranous ossification occurred with the latter, indicating intrinsic differences within the dura mater. This dural heterogeneity is supported by direct ultrastructural data.

Animals↗
PubMed2003

In vivo administration of recombinant TNF-alpha promotes bone resorption in mice.

BACKGROUND: In vitro studies demonstrated that proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha) modulates bone metabolism. OBJECTIVE: The aim of our study was to confirm the ability of TNF-alpha to induce osteoclastogenesis and bone resorption in an in vivo experiment, with the use of calvarial model in mice. MATERIALS AND METHODS: Twenty C57-Black mice were divided into four groups with five animals in each. The first group was infused subcutaneously on their back with recombinant mouse (rm) TNF-alpha via osmotic minipumps for 3 d, the second group was similarly infused with phosphate-buffered saline (PBS), the third group was infused with rmTNF-alpha to the region above the parietal bone and the fourth group with PBS in the same manner. Number of osteoclasts on parietal bone was determined morphometrically. Serum calcium and phosphates were monitored colorimetrically. RESULTS: Serum calcium level and number of osteoclasts on parietal bone were significantly greater after infusion of rmTNF-alpha above the parietal bone, whereas after subcutaneous delivery these parameters were similar to the control group. CONCLUSION: We are concluding that TNF-alpha has the ability to change the bone metabolism in a paracrine manner only.

Animals↗
PubMed2005

Occipitoparietal benign osteoblastoma: should entire lesion be resected when magnetic resonance images reveal wide abnormal signal intensity in surrounding bone marrow?

BACKGROUND: Benign osteoblastoma is an uncommon primary bone tumor that usually affects long bones and the vertebral column. Its occurrence in the calvarium is rare. Despite the characteristically benign nomenclature of osteoblastoma, it sometimes recurs with the possibility of transforming into a malignant form after an incomplete resection. Therefore, radical resection is recommended whenever possible. However, it has not been clarified whether the adjacent bones should also be completely resected when magnetic resonance (MR) images reveal abnormal signal intensity in the bone marrow. CASE DESCRIPTION: Presented in this case report is a 12-year-old boy with occipital tenderness associated with occipitoparietal bone tumor. Neuroradiological studies demonstrated a solid tumor located in the occipital bone extending over the right parietal bone. Magnetic resonance images further revealed abnormal signal intensity in the bone marrow of the entire occipital and bilateral parietal bones. Macroscopically, the calvarial bone adjacent to the solid tumor appeared to be reddish, but it was not covering the entire area, contradicting the abnormal intensity found on the preoperative MR images. The resected area was determined according to macroscopic findings, and bones with normal color tone were preserved. Because histological examination did not clearly indicate tumor invasion at the margin of the resection site, no additional therapy was given. Although MR images revealed abnormal intensity in the bone marrow of the surgical margin immediately after the operation, the intensity had been normalized by degrees and there was no evidence of recurrence during a follow-up period of 34 months. This may suggest that bone marrow lesion showing abnormal intensity was edema rather than tumor invasion. CONCLUSIONS: The authors conclude that total resection, including a bone marrow lesion, is not always necessary for benign osteoblastoma. Macroscopic findings that show an abnormal color tone of the cortex could be a good indicator in revealing tumor activity invading bone marrow.

Bone Marrow Neoplasms↗
PubMed1990

Parathyroid hormone, but not prostaglandin E2, changes the shape of osteoblasts maintained on bone in vitro.

Parietal bones from 2-week-old rats were dissected free from the sutural regions, dura mater, and periosteum, leaving the surface covered with osteoblasts and some osteoclasts. Prostaglandin (PG) production by these "stripped" bones under basal conditions and after exposure to parathyroid hormone (PTH) was measured by radioimmunoassay of the culture medium (minimum essential medium with or without added 10% heat-inactivated fetal calf serum). Cultured specimens were examined by scanning electron microscopy for changes in osteoblast length, orientation, ruffling, and overlap. As demonstrated previously, PTH caused the osteoblasts to elongate, align, and show fewer ruffles compared to controls. PTH increased PG synthesis by the stripped bones. Indomethacin inhibited PG formation but did not affect the osteoblast shape change. PGE2, indomethacin, or both drugs together had no discernible effect on any morphologic features. These findings indicate that PGE2 does not change osteoblast shape and that the cell shape change with PTH is not mediated by endogenous prostanoids.

Animals↗
PubMed1999

[The use of calvarial bone in nasal reconstruction].

Twenty-seven nasal reconstructions with parietal bone graft performed between January 1989 and January 1995 were analyzed retrospectively. No complications involving parietal bone were observed. After a 2-year follow-up there have been no cases of shifting, extrusion or resorption of the rhinoplasty. Our experience shows that calvarial bone is an ideal material for nasal reconstruction bone grafts.

Adolescent↗
PubMed1991

In vitro studies on bone resorption in neonatal mouse calvariae using a modified dissection technique giving four samples of bone from each calvaria.

Bone resorption in a modified bone culture system, based on incubation of small fragments from neonatal mouse calvarial bones, has been studied. Four bone fragments were dissected out from each mouse calvaria and were thereafter cultured in CMRL 1066 medium in plastic multiwell dishes. Bone resorption was assessed by 45Ca release from prelabeled bones. The rate of bone resorption in response to parathyroid hormone (PTH) was less in the anterior part of the calvaria compared to the posterior part. After removing the anterior region, four parietal bone fragments that showed identical basal and PTH-stimulated release of 45Ca could be dissected out from each mouse. Excretion of lactate dehydrogenase and beta-glucuronidase was the same in bones cultured submerged or on grids. Uptake of [3H]thymidine in bones cultured submerged was 54% of [3H]thymidine uptake in bones cultured on grids. Dose-response curves, established by using parietal bone fragments, showed that the sensitivity and the magnitude of the increase in 45Ca release seen after stimulation with PTH, prostaglandin E2, and 1 alpha-hydroxyvitamin D3 were the same for bones cultured submerged or on grids. The 45Ca release in response to stimulation with PTH, prostaglandin E2, and 1 alpha-OHD3 was the same in calvarial fragments cultured submerged and those previously obtained with calvarial halves cultured on grids. Thus, even though the rate of DNA synthesis was slower in bones cultured submerged, the rate and the magnitude of resorption were the same in bones cultured on grids or submerged. These data show that it is possible to perform studies on bone resorption with small fragments of neonatal mouse parietal bones.

Animals↗
PubMed1987

Familial incidence of foramina parietalia permagna.

The author presents three cases of congenital parietal bone defects in two generations of one family. Two of them present paired, symmetrically located perforations of the parietal bones and case No. 3 presents a single, 6 X 7 cm defect of the parietal bones, located in the midline. In the presented cases the diagnosis was confirmed by skull radiograph, however, in case 1 angiography was also performed. These congenital skull defects are considered, so far, of no clinical significance, and no associated abnormalities among affected individuals have been found. The problems involved with the formation and assessment of treatment of these defects are discussed.

Adult↗
PubMed2003

Tissue response to a newly developed calcium phosphate cement containing succinic acid and carboxymethyl-chitin.

We developed a new calcium phosphate cement containing succinic acid and carboxymethyl-chitin in the liquid component. In this study, the biocompatibility and osteoconductivity of this new cement were investigated. After mixing, cement in putty form was implanted immediately between the periosteum and parietal bone and in the subcutaneous tissues of rats. In control cement, distilled water was used instead of the liquid component. In addition to histological evaluations, analyses with X-ray diffraction and Fourier transform infrared were performed for the subcutaneously implanted cements. Histological examination showed slight inflammation around the new cement on the bone and in the subcutaneous tissue at 1 week after surgery. At 2 weeks, the cement was partially bound to the parietal bone. The extent of the surface of the new cement directly in contact with the bone increased with time, and most of the undersurface of the new cement bound to the host parietal bone by 8 weeks. Analysis by X-ray diffraction showed that the new cement in the subcutaneous tissue was transformed into hydroxyapatite by 8 weeks. These results indicate that this new calcium phosphate cement is useful as a bone substitute material.

Absorbable Implants↗
PubMedDate not supplied

Premature fusion and excessive calcification of coronal sutures in patients with Klinefelter syndrome.

OBJECTIVE: The purpose of this paper is to report on radiographic features of the cranial vault abnormalities frequently seen but not yet described in detail in patients with Klinefelter syndrome. SUBJECTS: Our studies comprised 72 patients with Klinefelter syndrome and 47,XXY karyotype. The majority of the patients were young between the ages of 16 to 28 years. METHODS: Plain skull radiographs were taken in the frontal and lateral projections. RESULTS: Several abnormalities were observed on skull radiographs of the Klinefelter patients. The most frequent was a premature fusion of the coronal sutures that occurred in 54 of 62 younger patients. In 42 cases extensive calcifications of these sutures were observed. The calcified sutures were dense and widened. In 24 patients the inner table in the anterior part or the parietal bone displayed a marked disruption with thinning of the calvaria at this place. In the posterior part of the parietal bone in 21 patients the inner table was thickened and excessively dense. On frontal radiographs, in 30 patients, there was a flattening of the squamous part of the temporal bones. CONCLUSIONS: Skull radiographs in Klinefelter patients frequently display abnormalities: premature fusion and excessive calcifications of the coronal sutures, irregularities of the inner table of the parietal bone, and flattening of the temporal bones. These radiographic features, when present, may draw attention to the XXY syndrome as the underlying cause of the abnormalities.

Adolescent↗