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Journal of the Mechanical Behavior of... Mar 2019Onlay graft bone augmentation is a standard practice to restore the loss of height of the alveolar ridge following loss of a tooth. Cranial grafts, lifted from the...
Onlay graft bone augmentation is a standard practice to restore the loss of height of the alveolar ridge following loss of a tooth. Cranial grafts, lifted from the parietal bone, are sandwiched and used to bridge the bony defect in the jaw by means of small screws. During the elevation of the covering gum and subsequent screw placement, care has to be taken in order to preserve underlying nerves. Therefore, to avoid harm to the patient, a solid education of surgeons is essential, which requires training and experience. A simulator for cranial graft-lift training was already developed and shall be expanded to train the augmentation of the lifted implants. Therefore, in this study, synthetic bones for onlay block graft screw placement with realistic haptics for the screw application training were evaluated and compared with human specimens. Six different polyurethane based bone surrogate composites, enriched with varying amounts of calcium-based mineral fillers and blowing agents, were developed. The haptical properties of these synthetic bones were validated for screw placement and compared with human parietal bone specimens. For that, bones were pre-drilled, screws were automatically inserted using a customized testbench and the slope of the screw-insertion torques were analyzed. The slope of the screw insertion torques of the human reference bones was 56.5 ± 14.0 * 10 Nm/deg, Surrogates with lower amounts of mineral fillers and blowing agents showed lower torques than the human bone. Synthetic bones, validated for drilling, milling and sawing in an earlier study, also achieved significantly lower torques, which were only the half of the human parietal bones. Two intermediate stages of the aforementioned material compositions, consisting of 75% mineral filler with 0.75% blowing agent and 100% mineral filler with 1.00% blowing agent revealed results comparable with human bone (57.4 ± 10.2 *10 Nm/deg, p = 0.893 and 54.9 ± 11.1 *10 Nm/deg, p = 0.795, respectively). In conclusion, our findings suggest that, two newly developed polyurethane-based materials mimicking the haptical properties of an onlay bone graft screw fixation, have been identified. Thus, these surrogates are capable of mimicking real bone tissue in our simulator for the education of novice surgeons.
Topics: Aged; Biomimetics; Bone Screws; Bone Transplantation; Feedback; Female; Humans; Torque; Touch Perception
PubMed: 30580158
DOI: 10.1016/j.jmbbm.2018.12.013 -
BMJ Case Reports Jun 2016
Topics: Adult; Encephalocele; Female; Humans; Infant, Newborn; Magnetic Resonance Imaging; Male; Parietal Bone; Prenatal Diagnosis; Treatment Outcome; Ultrasonography, Prenatal
PubMed: 27365020
DOI: 10.1136/bcr-2016-215812 -
World Journal of Surgical Oncology May 2015A benign fibrous histiocytoma with primary site of origin in the parietal bone has not yet been reported in the literature. We report here a case concerning a... (Review)
Review
A benign fibrous histiocytoma with primary site of origin in the parietal bone has not yet been reported in the literature. We report here a case concerning a 12-year-old girl with a 14-month history of an enlarging parietal bone mass. The tumor was excised after removal of the cortical bone and resection of the tumor surrounding the cortical bone erosion using pre-plasticity titanium repair. Both postoperative histopathological examination and immunohistochemical analysis were consistent with a benign fibrous histiocytoma. No clinical or computed tomography (CT) radiological signs of tumor recurrence and/or metastasis were observed at 12 months. Although a primary benign fibrous histiocytoma of the parietal bone is a rare tumor, it should be considered as a potential diagnosis for any cranial tumor. Surgical intervention is the most effective treatment technique for a benign fibrous histiocytoma.
Topics: Child; Female; Histiocytoma, Benign Fibrous; Humans; Parietal Bone; Skull Neoplasms; Tomography, X-Ray Computed; Treatment Outcome
PubMed: 25951848
DOI: 10.1186/s12957-015-0587-5 -
Journal of Biomechanical Engineering Jun 2021Computational models of infant head impact are limited by the paucity of infant cranial bone material property data, particularly with regard to the anisotropic...
Computational models of infant head impact are limited by the paucity of infant cranial bone material property data, particularly with regard to the anisotropic relationships created by the trabecular fibers in infant bone. We previously reported high-rate material property data for human infant cranial bone tested perpendicular to trabeculae fiber orientation. In this study, we measure the anisotropic properties of human infant cranial bone by analyzing bending modulus parallel to the trabeculae fibers. We tested human bone specimens from nine donors ranging in age from 32 weeks gestational age to 10 months at strain rates of 12.3-30.1 s-1. Bending modulus significantly increased with donor age (p=0.008) and was 13.4 times greater along the fiber direction compared to perpendicular to the fibers. Ultimate stress was greater by 5.1 times when tested parallel to the fibers compared to perpendicular (p=0.067). Parietal bone had a higher modulus and ultimate stress compared to occipital bone, but this trend was not significant, as previously shown perpendicular to fiber orientation. Combined, these data suggest that the pediatric skull is highly age-dependent, anisotropic, and regionally dependent. The incorporation of these characteristics in finite element models of infant head impact will be necessary to advance pediatric head injury research and further our understanding of the mechanisms of head injury in children.
Topics: Occipital Bone
PubMed: 33564856
DOI: 10.1115/1.4050127 -
BMJ Case Reports Oct 2017Lipoedematous scalp (LS) is an extremely rare condition characterised by a soft and boggy consistency in the scalp due to an increased layer of subcutaneous tissue.In... (Review)
Review
Lipoedematous scalp (LS) is an extremely rare condition characterised by a soft and boggy consistency in the scalp due to an increased layer of subcutaneous tissue.In this report, we present a case of LS in a 64-year-old Indian woman. Clinical examination revealed only vague boggy lumpiness involving the whole of occipital scalp extending to parietal scalp. MRI scalp showed diffuse fatty infiltration of the scalp, particularly at the posterior parietal and occipital convexity extending to both lateral aspects of the cranium, with homogeneous signal in keeping with fat. Incidentally MRI also found diffuse fatty infiltration of the parotids.The aethiopathogenesis of LS is still unknown, however it is believed that the hormone leptin could be the key hormone in the dysregulation of fat deposition and distribution. This case report highlights the subtle features with which these cases can present and explores the literature on reported cases of LS.
Topics: Female; Humans; Lipedema; Lipomatosis; Middle Aged; Parietal Bone; Parotid Diseases; Parotid Gland; Scalp Dermatoses; Subcutaneous Fat
PubMed: 28993353
DOI: 10.1136/bcr-2017-220808 -
Molecular Genetics and Metabolism... Dec 2023Mucopolysaccharidosis type II (MPS II, OMIM 309900) is an X-linked disorder caused by a deficiency of lysosomal enzyme iduronate-2-sulfatase (IDS). The clinical...
Mucopolysaccharidosis type II (MPS II, OMIM 309900) is an X-linked disorder caused by a deficiency of lysosomal enzyme iduronate-2-sulfatase (IDS). The clinical manifestations of MPS II involve cognitive decline, bone deformity, and visceral disorders. These manifestations are closely associated with IDS enzyme activity, which catalyzes the stepwise degradation of heparan sulfate and dermatan sulfate. In this study, we established a novel -deficient mice and further assessed the enzyme's physiological role. Using DNA sequencing, we found a genomic modification of the Ids genome, which involved the deletion of a 138-bp fragment spanning from intron 2 to exon 3, along with the insertion of an adenine at the 5' end of exon 3 in the mutated allele. Consistent with previous data, our -deficient mice showed an attenuated enzyme activity and an enhanced accumulation of glycosaminoglycans. Interestingly, we noticed a distinct enlargement of the calvarial bone in both neonatal and young adult mice. Our examination revealed that deficiency led to an enhanced osteoblastogenesis in the parietal bone, a posterior part of the calvarial bone originating from the paraxial mesoderm and associated with an enhanced expression of osteoblastic makers, such as and . In sharp contrast, cell proliferation of the parietal bone in these mice appeared similar to that of wild-type controls. These results suggest that the deficiency of could be involved in an augmented differentiation of calvarial bone, which is often noticed as an enlarged head circumference in MPS II-affected individuals.
PubMed: 38053930
DOI: 10.1016/j.ymgmr.2023.101021 -
Cureus Oct 2020Enlarged parietal foramina (PFM) are congenital calvarial defects characterized by bilateral parietal bone defects (>5 mm), occurring on each side of the sagittal suture...
Enlarged parietal foramina (PFM) are congenital calvarial defects characterized by bilateral parietal bone defects (>5 mm), occurring on each side of the sagittal suture along its posterior aspect. While often lacking underlying intracranial malformations, there has been increasing recognition of coexisting brain malformations in certain subtypes. We present a case of a 12-year-old girl presenting with new-onset grand mal seizure with developmental delay and a known family history of epilepsy. Brain MRI revealed large, bilateral parietal bone defects with underlying cortical malformation (polymicrogyria and ulegyria) and vascular abnormalities (persistent falcine sinus), related to PFM. This case report describes the genetic basis for recognized subtypes of PFM and the rare association of brain malformations associated with PFM due to mutations in the ALX4 homeobox gene.
PubMed: 33269135
DOI: 10.7759/cureus.11204 -
Journal of Maxillofacial and Oral... Jul 2022Melioidosis is a potentially fatal, life-threatening infection caused by the gram-negative saprophytic organism Burkholderia. It is a disease endemic to Southeast Asia...
Melioidosis is a potentially fatal, life-threatening infection caused by the gram-negative saprophytic organism Burkholderia. It is a disease endemic to Southeast Asia and Northern Australia. This infection transmits through direct contact, cutaneous inoculation, inhalation, or ingestion, and patients clinically exhibit abscesses in single or multiple organs. It is clinically under-reported due to a low index of suspicion, lack of diagnostic facilities, and misdiagnosis as tuberculosis. Infections of the musculoskeletal system are exceedingly rare, and clinical presentation may vary from the involvement of femoral bone, palmar tenosynovitis, and parietal bone osteomyelitis secondary to central nervous system involvement. The rarity of the melioidosis to secondarily infect a developmental odontogenic cyst leading to focal osteomyelitis of mandible prompts the clinician toward thorough evaluation for early diagnosis and treatment.
PubMed: 35891942
DOI: 10.1007/s12663-022-01763-w -
BMC Veterinary Research Apr 2021The authors report a case of keratinized squamous cell carcinoma (SCC) in a 14-year-old dog with extensive cranial bone invasion. To our knowledge, this is the first...
BACKGROUND
The authors report a case of keratinized squamous cell carcinoma (SCC) in a 14-year-old dog with extensive cranial bone invasion. To our knowledge, this is the first description of such a case of cranial keratinized SCC with aggressive generalized osteolysis described in a dog.
CASE PRESENTATION
The 14-year-old dog was referred for radiological examination with suspicion of head trauma with clinical signs of head deformation, exophthalmos and nasal discharge. The skull radiographs showed a large osteolytic defect of the frontal bone and parietal bone in the region of the external sagittal crest. Findings from the skull CT scan included generalized osteolysis in the region of parietal bone, frontal bones, maxilla on the right side and the nasal bone including the dorsal nasal concha. In the area of bone loss, new soft tissue formation with multifocal foci of mineralization was visible. The ultrasound examination revealed hypoechogenic changes with hyperechoic foci consistent with mineralization and poor vascularization. The brain and ocular structures were without visible changes. Fine needle aspiration cytology (FNAC) was performed, and squamous cell carcinoma was suspected. After 3 months, the re-presented to the clinic. The dog became progressively listless, his appetite was decreased, and he became acutely blind. Follow-up skull CT scan revealed significant osteolysis, which affected a significant aspect of the cranium. All bone defects had been replaced by new 3.5 cm-thick soft tissue formations with multifocal small 1-2 mm areas of mineralization. There was no evidence of metastasis. Histological examination confirmed the suspicion of squamous cell carcinoma.
CONCLUSIONS
This paper is the first report of cranial SCC in a dog causing extensive bone osteolysis. The lesions in this dog originated from the frontal and parietal bones including frontal sinuses. There are variants of tumors that arise from squamous epithelium or resemble SCC in the skull. These examples include adenosquamous carcinoma and proliferating trichilemmal tumours. In addition, there is possible malignant transformation caused by papilloma viruses. In the veterinary literature, there is only one similar description of adenosquamous carcinoma in a cat with similar clinical manifestations. It is justified to suspect a process of neoplastic epithelial origin in all cases of aggressive and extensive skull bone lysis. This issue should be subject to further investigation.
Topics: Animals; Bone Neoplasms; Carcinoma, Squamous Cell; Dog Diseases; Dogs; Male; Skull
PubMed: 33823849
DOI: 10.1186/s12917-021-02843-8 -
Acta Cirurgica Brasileira 2021This study assessed the regeneration potential of mesenchymal stem cells (MSC) from adipose tissue associated with platelet-rich plasma (PRP) in bone regeneration.
PURPOSE
This study assessed the regeneration potential of mesenchymal stem cells (MSC) from adipose tissue associated with platelet-rich plasma (PRP) in bone regeneration.
METHODS
Thirty Wistar rats (Rattus norvegicus albinos) were divided into five groups (according to the grafting material and time to euthanasia): (1) autograft - 14 days (control), (2) autograft - 28 days (control), (3) MSC + PRP - 14 days, (4) MSC + PRP + papaverine - 14 days and (5) MSC + PRP + papaverine - 28 days. After euthanasia, the graft was removed and histological slides were prepared. They were assessed by a blinded pathologist using a previously published histological scale as parameter.
RESULTS
There was some degree of neoformed bone trabeculae (NBT) in 93.3% of the samples, as well as osteoblastic activity (OA). The autograft groups (14 and 28 days) had higher levels in the formation of bone trabeculae. Nonparametric data were analyzed using the Wilcoxon-Mann-Whitney test and proved not to be statistically significant at p < 0.05.
CONCLUSIONS
Experimental parietal bone reconstruction, combining MSC, PRP and papaverine presented regeneration in all groups with no significant difference among them.
Topics: Animals; Bone Regeneration; Mesenchymal Stem Cells; Parietal Bone; Platelet-Rich Plasma; Rats; Rats, Wistar
PubMed: 33503214
DOI: 10.1590/ACB351201