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1.
J Craniomaxillofac Surg ; 48(8): 733-740, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32591131

RESUMO

OBJECTIVES: The aim of this study was to assess the microarchitecture and turnover in irradiated cancellous mandibular bone and the relation with radiation dose, to elucidate the effects of radiotherapy on the mandible. PATIENTS AND METHODS: Mandibular cancellous bone biopsies were taken from irradiated patients and controls. Micro-CT scanning was performed to analyze microstructural bone parameters. Bone turnover was assessed by histomorphometry. Local radiation dose at the biopsy site (Dmax) was estimated from radiotherapy plans. RESULTS: Twenty-seven irradiated patients and 35 controls were included. Osteoid volume (Osteoid Volume/Bone Volume, OV/BV) [0.066/0.168 (median/interquartile range (IQR), OV/BV; %), P < 0.001], osteoid surface (Osteoid Surface/Bone Surface, OS/BS) [0.772/2.17 (median/IQR, OS/BS; %), P < 0.001] and osteoclasts number (Osteoclasts per millimetre bone surface, Ocl/mmBS; mm2) [0.026/0.123 (median/IQR, Ocl/mmBS; mm2), P < 0.001] were decreased; trabecular number (Tb.N) was lower [1.63/0.63 (median/IQR, Tb.N; 1/mm-1), P = 0.012] and trabecular separation (Tb.Sp) [0.626/0.24 (median/IQR, Tb.Sp; µm), P = 0.038] was higher in irradiated mandibular bone. With higher Dmax, trabecular number increases (Spearman's correlation R = 0.470, P = 0.018) and trabecular separation decreases (Spearman's correlation R = -0.526, P = 0.007). Bone mineral density (BMD, milligrams hydroxyappetite per cubic centimetre, mgHA/cm3) [1016/99 (median/IQR, BMD; mgHA/cm3), P = 0.03] and trabecular separation [0.739/0.21 (median/IQR, Tb.Sp; µm), P = 0.005] are higher whereas connectivity density (Conn Dens) [3.94/6.71 (median/IQR, Conn Dens), P = 0.047] and trabecular number [1.48/0.44 (median/IQR, Tb.N; 1/mm-1), P = 0.002] are lower in Dmax ≤50 Gy compared to controls. CONCLUSIONS: Radiotherapy dramatically impairs bone turnover in the mandible. Deterioration in microarchitecture only affects bone irradiated with a Dmax of <50 Gy. The 50 Gy value seems to be a critical threshold to where the effects of the radiation is more detrimental.


Assuntos
Densidade Óssea , Mandíbula , Biópsia , Humanos , Microtomografia por Raio-X
2.
Oral Oncol ; 87: 126-130, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30527227

RESUMO

OBJECTIVES: Hypovascularisation is thought to play an important role in the pathogenesis of osteoradionecrosis. The objective of this study was to assess the microvascular system in the irradiated mandibular bone marrow. MATERIALS AND METHODS: Mandibular bone biopsies were taken from 20 irradiated patients and 24 controls. Blood vessels were visualized using CD34 antibody stain to detect endothelial cells. The vascular density (VD) and vascular area fraction (VAF) were measured. Mean vessel lumen area, perimeter and diameter of the vessels were calculated for each vessel. A distinction was made between large and small vessels (cut-off point <400 µm2). RESULTS: Vascular density and vascular area fraction were lower in the irradiated group. The mean vascular perimeter and mean vascular diameter were higher in samples with a local radiation dose of ≥50 Gy, whereas the percentage of small vessels was lower. Larger vessel perimeter is associated with higher radiation dose. A longer interval between biopsy and radiotherapy is associated with a larger mean vessel perimeter and a lower percentage of small vessels. CONCLUSIONS: Radiation dosages higher than 50 Gy mainly affect the smaller vessels. With increased time after irradiation, the share of smaller vessels in the mandibular bone marrow seems to decrease. In search of the exact mechanisms of irradiation damage and osteoradionecrosis of the mandible, the role of the microvascular system in the mandibular bone marrow should be further explored.


Assuntos
Medula Óssea/irrigação sanguínea , Neoplasias de Cabeça e Pescoço/radioterapia , Mandíbula/irrigação sanguínea , Osteorradionecrose/patologia , Radioterapia de Intensidade Modulada/efeitos adversos , Adulto , Idoso , Biópsia , Medula Óssea/patologia , Medula Óssea/efeitos da radiação , Estudos de Casos e Controles , Relação Dose-Resposta à Radiação , Feminino , Humanos , Masculino , Mandíbula/patologia , Mandíbula/efeitos da radiação , Osteotomia Mandibular , Pessoa de Meia-Idade , Osteorradionecrose/etiologia , Osteorradionecrose/cirurgia , Doses de Radiação , Fatores de Tempo
4.
Ned Tijdschr Tandheelkd ; 125(3): 169-171, 2018 Mar.
Artigo em Holandês | MEDLINE | ID: mdl-29525814

RESUMO

The treatment of oral cancer usually consists of surgical removal of the tumour, possibly followed by radiotherapy. The purpose of this dissertation research was to investigate the effects of radiotherapy on the oral tissues, in particular the superficially positioned epithelial cells in the oral mucosa. Earlier studies with electron microscopy revealed that unradiated oral mucosa cells, when observed at high magnification, contain microplicae (ridges or folds). Together with various saliva components, these microplicae form a protective layer that offers defence against, for instance, microorganisms. Radiotherapy damages these microplicae and may even destroy them altogether. Studies have shown that this effect of radiation can be observed in animals as well as in humans. As the radiation dose increased (50 Gy or more) the destruction of the microplicae was more severe. With a dose of 60 Gy or more the microplicae completely disappeared. This process may play an important role in the occurrence of osteoradionecrosis in the jaw and failure of dental implants placed after radiotherapy.


Assuntos
Mucosa Bucal/efeitos da radiação , Radioterapia/efeitos adversos , Relação Dose-Resposta à Radiação , Humanos , Mucosa Bucal/citologia , Neoplasias Bucais/radioterapia
5.
Ned Tijdschr Geneeskd ; 162: D2119, 2018.
Artigo em Holandês | MEDLINE | ID: mdl-29328013

RESUMO

A 53-year-old woman presented with painful macroglossia and periorbital papules. Based on this clinical features and biopsies the diagnosis of nodular amyloidosis was established. Further analysis revealed that multiple myeloma was the underlying hematological disorder.


Assuntos
Amiloidose , Macroglossia , Mieloma Múltiplo , Língua/patologia , Amiloidose/etiologia , Amiloidose/patologia , Biópsia/métodos , Diagnóstico Diferencial , Feminino , Humanos , Macroglossia/diagnóstico , Macroglossia/patologia , Macroglossia/fisiopatologia , Pessoa de Meia-Idade , Mieloma Múltiplo/complicações , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/patologia
6.
J Oral Rehabil ; 45(4): 334-343, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29314144

RESUMO

Long-standing loss of natural teeth in the mandible can lead to severe jaw atrophy and even mandibular fracture. There is no consensus on the best pre-prosthetic surgical treatment to reconstruct the atrophic edentulous mandible. The purpose of this review was to provide an overview of the existing literature and to give an evidence-based recommendation for bone grafting and future research. This systematic review was conducted according to the PRISMA statement. A literature search was performed in online databases Pubmed and Cochrane library for articles published between January 1980 and September 2017. The search was conducted using Medical Subject Heading terms: alveolar ridge augmentation; mouth, edentulous and mandible. Eligible articles were included according to in- and exclusion criteria and assessed on quality. Dental implant survival and bone stability were the primary outcomes. Secondary outcomes were complications. Twenty-four text articles matched the criteria and were included. Eleven articles were assessed to be of adequate quality for analysis. Graft stability seems to be higher in vertical distraction and tent-pole grafting, but as the dental implant survival is high (91.7% or higher) regardless of the procedure used for bone augmentation, this is of no clinical relevance. The survival rate of dental implants is high, regardless of the bone augmentation procedure used. High-quality clinical trials are needed to support the current evidence and guidelines on pre-implant bone grafting. Reporting of future research should include proper baseline characteristics and treatment description, as well as uniform outcome rendering.


Assuntos
Aumento do Rebordo Alveolar/métodos , Implantação Dentária Endóssea/métodos , Prótese Dentária Fixada por Implante , Mandíbula/cirurgia , Boca Edêntula/cirurgia , Perda do Osso Alveolar , Implantes Dentários , Humanos , Boca Edêntula/fisiopatologia
7.
Int J Implant Dent ; 3(1): 34, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28741276

RESUMO

BACKGROUND: This study evaluates the clinical, radiological, histological, and histomorphometric aspects of a fully synthetic biphasic calcium phosphate (BCP) (60% hydroxyapatite and 40% ß-tricalcium phosphate), used in a human maxillary sinus floor elevation (MSFE) procedure with 9- and 12-month healing time. METHODS: A unilateral MSFE procedure, using 100% BCP, was performed in two series of five patients with healing times of 9 and 12 months respectively. Clinical and radiological parameters were measured up to 5 years postoperatively. Biopsy retrieval was carried out during dental implants placement. Histology and histomorphometry were performed on 5-µm sections of undecalcified bone biopsies. RESULTS: The MSFE procedure with BCP showed uneventful healing in all cases. All dental implants appeared to be well osseointegrated after 3 months. Radiological evaluation showed less than 1 mm tissue height loss from MSFE to the 5-year follow-up examination. No signs of inflammation were detected on histological examination. Newly formed mineralized tissue was found cranially from the native bone. The BCP particles were surrounded by connective tissue, osteoid islands, and newly formed bone. Mineralized bone tissue was in intimate contact with the BCP particles. After 12 months, remnants of BCP were still present. The newly formed bone had a trabecular structure. Bone maturation was demonstrated by the presence of lamellar bone. Histomorphometric analysis showed at 9 and 12 months respectively an average vital bone volume/total volume of 35.2 and 28.2%, bone surface/total volume of 4.2 mm2/mm3 and 8.3 mm2/mm3, trabecular thickness of 224.7 and 66.7 µm, osteoid volume/bone volume of 8.8 and 3.4%, osteoid surface/bone surface (OS/BS) of 42.4 and 8.2%, and osteoid thickness of 93.9 and 13.6 µm. CONCLUSIONS: MFSE with BCP resulted in new bone formation within the augmented sinus floor and allowed the osseointegration of dental implants in both groups. From a histological and histomorphometric perspective, a 9-month healing time for this type of BCP may be the optimal time for placement of dental implants.

9.
Calcif Tissue Int ; 99(2): 164-73, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27016371

RESUMO

The enzyme 1α-hydroxylase (gene CYP27B1) catalyzes the synthesis of 1,25(OH)2D in both renal and bone cells. While renal 1α-hydroxylase is tightly regulated by hormones and 1,25(OH)2D itself, the regulation of 1α-hydroxylase in bone cells is poorly understood. The aim of this study was to investigate in a primary human osteoblast culture whether parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), calcitonin, calcium, phosphate, or MEPE affect mRNA levels of CYP27B1. Our results show that primary human osteoblasts in the presence of high calcium concentrations increase their CYP27B1 mRNA levels by 1.3-fold. CYP27B1 mRNA levels were not affected by PTH1-34, rhFGF23, calcitonin, phosphate, and rhMEPE. Our results suggest that the regulation of bone 1α-hydroxylase is different from renal 1α-hydroxylase. High calcium concentrations in bone may result in an increased local synthesis of 1,25(OH)2D leading to an enhanced matrix mineralization. In this way, the local synthesis of 1,25(OH)2D may contribute to the stimulatory effect of calcium on matrix mineralization.


Assuntos
25-Hidroxivitamina D3 1-alfa-Hidroxilase/genética , Cálcio/metabolismo , Regulação Enzimológica da Expressão Gênica/genética , Osteoblastos/metabolismo , RNA Mensageiro/metabolismo , Calcitonina/metabolismo , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/metabolismo , Humanos , Rim/metabolismo , Hormônio Paratireóideo/metabolismo
10.
J Reconstr Microsurg ; 32(6): 455-63, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26848563

RESUMO

Background We retrospectively analyzed the incidence and types of postoperative complications after mandibular continuity reconstructions with fibular free flaps (FFF) in patients with oral squamous cell carcinoma (OSCC) and identified potential risk factors for postoperative complications. Methods Data were retrieved from the medical records in the Department of Oral and Maxillofacial Surgery/Oral Pathology, VU University Medical Center/Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands from April 1995 to September 2013, and were statistically analyzed. Results In this study, 85 patients were included in whom 86 FFFs were used for mandibular reconstruction. Thirty-seven patients (43%) developed ≥ 1 surgical complication and 9 patients (10.5%) developed ≥ 1 systemic complication. Three patients (3.5%) developed total flap failure and six patients (7.0%) developed partial flap failure. Surgical complications were correlated with tobacco use, partial glossectomy, type of mandibular defect, and anatomic staging. Systemic complications were associated with age > 60 years and Charlson comorbidity index > 2. Hospitalization > 30 days was associated with type of mandibular defect. Conclusions The use of the FFF for reconstructing mandibular continuity defects in OSCC patients may be associated with postoperative complications. Patients with coexisting medical conditions and anterior mandibular defects have an increased risk for developing complications. Patients who undergo segmental mandibular resection including a partial glossectomy could have a reduced risk for complications.


Assuntos
Fíbula/transplante , Retalhos de Tecido Biológico/irrigação sanguínea , Neoplasias Mandibulares/cirurgia , Reconstrução Mandibular , Complicações Pós-Operatórias/cirurgia , Uso de Tabaco/efeitos adversos , Transplante Ósseo/métodos , Carcinoma de Células Escamosas/patologia , Comorbidade , Feminino , Fíbula/patologia , Sobrevivência de Enxerto , Humanos , Masculino , Neoplasias Mandibulares/patologia , Reconstrução Mandibular/efeitos adversos , Reconstrução Mandibular/métodos , Pessoa de Meia-Idade , Países Baixos , Complicações Pós-Operatórias/patologia , Qualidade de Vida , Estudos Retrospectivos , Resultado do Tratamento
11.
J Steroid Biochem Mol Biol ; 156: 32-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26625962

RESUMO

The metabolite 1,25-dihydroxyvitamin D (1,25(OH)2D) is synthesized from its precursor 25-hydroxyvitamin D (25(OH)D) by human osteoblasts leading to stimulation of osteoblast differentiation in an autocrine or paracrine way. Osteoblast differentiation is also stimulated by mechanical loading through activation of various responses in bone cells such as nitric oxide signaling. Whether mechanical loading affects osteoblast differentiation through an enhanced synthesis of 1,25(OH)2D by human osteoblasts is still unknown. We hypothesized that mechanical loading stimulates the synthesis of 1,25(OH)2D from 25(OH)D in primary human osteoblasts. Since the responsiveness of bone to mechanical stimuli can be altered by various endocrine factors, we also investigated whether 1,25(OH)2D or 25(OH)D affect the response of primary human osteoblasts to mechanical loading. Primary human osteoblasts were pre-incubated in medium with/without 25(OH)D3 (400 nM) or 1,25(OH)2D3 (100 nM) for 24h and subjected to mechanical loading by pulsatile fluid flow (PFF). The response of osteoblasts to PFF was quantified by measuring nitric oxide, and by PCR analysis. The effect of PFF on the synthesis of 1,25(OH)2D3 was determined by subjecting osteoblasts to PFF followed by 24h post-incubation in medium with/without 25(OH)D3 (400 nM). We showed that 1,25(OH)2D3 reduced the PFF-induced NO response in primary human osteoblasts. 25(OH)D3 did not significantly alter the NO response of primary human osteoblasts to PFF, but 25(OH)D3 increased osteocalcin and RANKL mRNA levels, similar to 1,25(OH)2D3. PFF did not increase 1,25(OH)2D3 amounts in our model, even though PFF did increase CYP27B1 mRNA levels and reduced VDR mRNA levels. CYP24 mRNA levels were not affected by PFF, but were strongly increased by both 25(OH)D3 and 1,25(OH)2D3. In conclusion, 1,25(OH)2D3 may affect the response of primary human osteoblasts to mechanical stimuli, at least with respect to NO production. Mechanical stimuli may affect local vitamin D metabolism in primary human osteoblasts. Our results suggest that 1,25(OH)2D3 and mechanical loading, both stimuli of the differentiation of osteoblasts, interact at the cellular level.


Assuntos
Calcitriol/metabolismo , Osteoblastos/metabolismo , Vitamina D/análogos & derivados , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/genética , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/metabolismo , Adulto , Células Cultivadas , Feminino , Humanos , Masculino , Óxido Nítrico/metabolismo , Osteoblastos/citologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Calcitriol/metabolismo , Vitamina D/metabolismo , Suporte de Carga
12.
Ultrastruct Pathol ; 39(5): 299-305, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26214246

RESUMO

The surface structure of the superficial cells of the oral mucosa is decorated with numerous membrane ridges, termed microplicae (MPLs). The MPL structure is typical of the epithelial surfaces that are covered with protective mucus. Cell membrane MPLs are no longer seen as passive consequences of cellular activity. The interaction between MPLs and the mucins has been demonstrated, however the role of MPL structure seen on the upper surface of the oral epithelial cells is speculative. The cell surface is of potentially great significance, as it harbors many markers for refined prognosis and targets for oral mucosal diseases and cancer therapy. With these aspects in mind, we conducted the present review of the MPL structure and function in order to form the basis for further studies of MPLs of the oral epithelial cells.


Assuntos
Mucosa Bucal/ultraestrutura , Boca/ultraestrutura , Humanos , Microscopia Eletrônica de Varredura
13.
Biochimie ; 95(12): 2304-13, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24028822

RESUMO

The secretome of stem cells strongly determines the outcome of tissue engineering strategies. We investigated how the secretome of human adipose stem cells (hASCs) can be affected by substrate, BMP-2 treatment, and degree of differentiation. We hypothesized that as differentiation progresses, hASCs produce increasingly more gene products associated with processes such as angiogenesis and bone remodeling. Human ASCs were treated for 15 min with BMP-2 (10 ng/ml) to enhance osteogenic differentiation, or with vehicle. Subsequently, hASCs were seeded on plastic or on biphasic calcium phosphate (BCP) consisting of 60% hydroxyapatite and 40% ß-tricalcium phosphate. A PCR array for ~150 trophic factors and differentiation-related genes was performed at day 21 of culture. A limited set of factors was quantified by qPCR at days 0, 4, 14 and 21, and/or ELISA at day 21. Compared to plastic, BCP-cultured hASCs showed ≥2-fold higher expression of ~20 factors, e.g. cytokines such as IL-6, growth factors such as FGF7 and adhesion molecules such as VCAM1. Expression of another ~50 genes was decreased ≥2-fold on BCP vs. plastic, even though hASCs differentiate better on BCP than on plastic. BMP-2-treatment increased the expression of ~30 factors by hASCs seeded on BCP, while it decreased the expression of only PGF, PPARG and PTN. Substrate affected hASC secretion of Activin A and seemed to affect P1NP release. No clear association between hASC osteogenic differentiation and growth factor expression pattern was observed. Considering our observed lack of association between the degree of differentiation and the expression of factors associated with angiogenesis and bone remodeling by hASCs, future bone regeneration studies should focus more on systematically orchestrating the secretome of stem cells, rather than on inducing osteogenic differentiation of stem cells only. Short incubation with BMP-2 may be a promising treatment to enhance both osteogenic differentiation and environmental modulation.


Assuntos
Proteína Morfogenética Óssea 2/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular/biossíntese , Células-Tronco/metabolismo , Transcriptoma/fisiologia , Tecido Adiposo/citologia , Diferenciação Celular , Células Cultivadas , Humanos , Hidroxiapatitas , Osteogênese , Células-Tronco/efeitos dos fármacos , Engenharia Tecidual
14.
Ned Tijdschr Tandheelkd ; 120(3): 136-41, 2013 Mar.
Artigo em Holandês | MEDLINE | ID: mdl-23600178

RESUMO

Rapid prototyping is a method which makes it possible to produce a three-dimensional model based on two-dimensional imaging. Various rapid prototyping methods are available for modelling, such as stereolithography, selective laser sintering, direct laser metal sintering, two-photon polymerization, laminated object manufacturing, three-dimensional printing, three-dimensional plotting, polyjet inkjet technology,fused deposition modelling, vacuum casting and milling. The various methods currently being used in the biomedical sector differ in production, materials and properties of the three-dimensional model which is produced. Rapid prototyping is mainly usedforpreoperative planning, simulation, education, and research into and development of bioengineering possibilities.


Assuntos
Anatomia , Odontologia/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Modelos Anatômicos , Desenho Assistido por Computador , Humanos
16.
Ned Tijdschr Tandheelkd ; 118(12): 633-9, 2011 Dec.
Artigo em Holandês | MEDLINE | ID: mdl-22292356

RESUMO

Patients with an edentulous mandible often have difficulty retaining conventional dentures. It was formerly the case that, as a rule, 4 implants were placed in the interforaminal area of the mandible in order to provide retention for the mandibular denture. A large body of research, however, revealed good results with 2 implants with various mesostructures. The 2 implant overdenture in the mandible has since become standard for edentulous patients. Research results indicate that this treatment should be the primary option under certain conditions. The appropriate types of care which are indicated by these conditions should, however, be carefully distinguished. Under certain anatomical conditions, such as a low and narrow alveolar ridge, exposed mandibular nerves, very low density alveolar bone (Class IV bone) and very sensitive mucous membranes, 4 implants are indicated. Patients who are less manually dextrous might be better served with 2 implants and a single mesostructure.


Assuntos
Prótese Dentária Fixada por Implante/métodos , Prótese Dentária Fixada por Implante/normas , Revestimento de Dentadura , Arcada Edêntula/reabilitação , Satisfação do Paciente , Humanos , Mandíbula , Resultado do Tratamento
17.
Clin Oral Implants Res ; 21(2): 201-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19958374

RESUMO

OBJECTIVES: In this study, we evaluated the quality and quantity of bone formation in maxillary sinus floor elevation procedure using a new fully synthetic biphasic calcium phosphate (BCP) consisting of a mixture of 60% hydroxyapatite and 40% of beta-tricalcium phosphate (Straumann Bone Ceramic). MATERIAL AND METHODS: A unilateral maxillary sinus floor elevation procedure was performed in six patients using 100% BCP. Biopsy retrieval for histological and histomorphometric analysis was carried out before implant placement after a 6-month healing period. RESULTS: In this study, the maxillary sinus floor elevation procedure with the use of BCP showed uneventful healing. Radiological evaluation after 6 months showed maintenance of vertical height gained immediately after surgery. Primary stability was achieved with all Straumann SLA dental implants of 4.1 mm diameter and 10 or 12 mm length. The implants appeared to be osseointegrated well after a 3-month healing period. Histological investigation showed no signs of inflammation. Cranial from the native alveolar bone, newly formed mineralized tissue was observed. Also, osteoid islands as well as connective tissue were seen around the BCP particles, cranial from the front of newly formed mineralized tissue. Close bone-to-substitute contact was observed. Histomorphometric analysis showed an average bone volume/total volume (BV/TV) of 27.3% [standard deviation (SD) 4.9], bone surface/total volume (BS/TV) 4.5 mm(2)/mm(3) (SD 1.1), trabecula-thickness (TbTh) 132.1 mum (SD 38.4), osteoid-volume/bone volume (OV/BV) 7.5% (SD 4.3), osteoid surface/bone surface (OS/BS) 41.3% (SD 28.5), osteoid thickness (O.Th) 13.3 mum (SD 4.7) and number of osteoclasts/total area (N.Oc/Tar) 4.4 1/mm (SD 5.7). CONCLUSIONS: Although a small number of patients were treated, this study provides radiological and histological evidence in humans confirming the suitability of this new BCP for vertical augmentation of the atrophied maxilla by means of a maxillary sinus floor elevation procedure allowing subsequent dental implant placement after a 6-month healing period. The newly formed bone had a trabecular structure and was in intimate contact with the substitute material, outlining the osteoconductive properties of the BCP material. Bone maturation was evident by the presence of lamellar bone.


Assuntos
Aumento do Rebordo Alveolar/métodos , Substitutos Ósseos/uso terapêutico , Cerâmica/uso terapêutico , Seio Maxilar/cirurgia , Procedimentos Cirúrgicos Pré-Protéticos Bucais/métodos , Osseointegração/fisiologia , Osteogênese/fisiologia , Adulto , Idoso , Materiais Biocompatíveis/uso terapêutico , Biópsia , Feminino , Humanos , Masculino , Seio Maxilar/diagnóstico por imagem , Seio Maxilar/fisiologia , Pessoa de Meia-Idade , Radiografia Panorâmica , Resultado do Tratamento , Cicatrização/fisiologia
18.
Int J Oral Maxillofac Surg ; 39(3): 256-9, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20018490

RESUMO

This study retrospectively investigates the incidence and risk factors for venous thromboembolism (VTE) in patients undergoing maxillofacial surgery. Data were obtained from patients treated between January 2005 and June 2006. Patients' records were reviewed for complaints and information relating to deep venous thrombosis (DVT) and pulmonary embolism (PE). All patients completed a questionnaire on complaints relating to DVT and PE. The patients were classified according to risk and the incidence of reported DVT and PE was calculated. The study population comprised 411 patients with a mean age of 32 (+/- 17) years. The median postoperative follow-up period was 53 (23-639) days. None of the patients received thromboembolism prophylaxis. The incidence of VTE in the study group was 0.5%. Logistic regression analysis demonstrated a relationship between body mass index and hospital stay with thromboembolism (p<0.05). Patients undergoing pre-implant surgery with bone graft proved to be at risk (p=0.07). The incidence of VTE in oral and maxillofacial surgery seems to be low, but thromboembolism prophylaxis may be justified in patients with clear potential risk factors.


Assuntos
Procedimentos Cirúrgicos Bucais/estatística & dados numéricos , Tromboembolia Venosa/epidemiologia , Adolescente , Adulto , Índice de Massa Corporal , Transplante Ósseo/estatística & dados numéricos , Feminino , Seguimentos , Neoplasias de Cabeça e Pescoço/cirurgia , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Procedimentos Cirúrgicos Pré-Protéticos Bucais/estatística & dados numéricos , Procedimentos Cirúrgicos Ortognáticos/estatística & dados numéricos , Osteogênese por Distração/estatística & dados numéricos , Embolia Pulmonar/epidemiologia , Procedimentos de Cirurgia Plástica/estatística & dados numéricos , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Trombose Venosa/epidemiologia , Adulto Jovem
19.
Poult Sci ; 88(8): 1601-7, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19590074

RESUMO

Rous sarcoma virus (RSV)-induced tumor growth was examined in congenic lines of chickens with different major histocompatibility (B) complex recombinant haplotypes on the highly inbred line UCD 003 (B17B17) genetic background. Males bearing an individual B complex recombinant were mated to UCD 003 females followed by 10 backcross generations. Matings among heterozygotes for each recombinant produced homozygous chickens estimated to contain 99.9% of the line UCD 003 background genome. The 5 lines having distinct serologically identified MHC recombinant haplotypes, which arose from separate recombinational events, were as follows: 003.R1, 003.R2, 003.R4, 003. R5, and 003.R6. Chicks from each of the recombinant lines were challenged with 10 pfu subgroup A RSV at 6 wk of age. Tumors were scored for size 6 times over 10 wk postinoculation. Each bird was assigned a tumor profile index (TPI) based on the 6 tumor size scores. Hatch and B genotype were main effects in the statistical analysis. Least squares ANOVA was used to evaluate rank-transformed TPI values and mean tumor sizes through a repeated measures design. Tumor growth and TPI values were greater for 003.R1 and 003.R4 chickens than for the other 3 congenic lines. Among serologically similar recombinants 003.R2 and 003.R4, higher tumor growth and TPI in 003.R4 indicate unique genetic variation affecting RSV tumors compared with 003.R2. The similar tumor growth of 003.R5 and 003.R6 chickens, which have BF/BL21 but different BG regions, demonstrated no BG effect on RSV tumors.


Assuntos
Galinhas/genética , Predisposição Genética para Doença , Complexo Principal de Histocompatibilidade/genética , Doenças das Aves Domésticas/genética , Sarcoma Aviário/genética , Animais , Galinhas/imunologia , Feminino , Genótipo , Masculino , Doenças das Aves Domésticas/imunologia
20.
Ned Tijdschr Tandheelkd ; 115(4): 215-23, 2008 Apr.
Artigo em Holandês | MEDLINE | ID: mdl-18512520

RESUMO

Soft and hard tissue defects in the head and neck region after benign or malignant tumour resection, can be reconstructed by surgical techniques, such as tissue transplantation, and/or prostheses. The aim of reconstruction is to restore the original esthetics and functions of the bone and soft tissues that have been resected. The introduction of free vascularized osteomyocutaneous fibula and iliac crest flaps improved the surgical possibilities of reconstructing the mandible and the maxilla. With respect to oral rehabilitation, a reconstruction of the mandible and the maxilla should be carried out in such a way that it provides an adequate base for inserting endosseous implants, which will retain a removable or fixed prosthesis This requires good interdisciplinary planning, in which the plan for prosthetic treatment determines, in part, the choice of reconstruction method.


Assuntos
Implantação Dentária Endóssea/métodos , Neoplasias de Cabeça e Pescoço/reabilitação , Satisfação do Paciente , Procedimentos de Cirurgia Plástica/métodos , Transplante Ósseo , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Mandíbula/cirurgia , Maxila/cirurgia , Retalhos Cirúrgicos
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