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- Brasil, DM, et al.
(författare)
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Image quality optimization of narrow detector dental computed tomography for paediatric patients
- 2019
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Ingår i: Dento maxillo facial radiology. - : British Institute of Radiology. - 0250-832X. ; 48:5, s. 20190032-
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Tidskriftsartikel (refereegranskat)abstract
- Dental CBCT exposure parameters should be optimized according to patient-specific indications, mainly for children that are most vulnerable to harmful effects of ionizing radiation. The aim of this study was to determine optimized kV settings for paediatric acquisitions for a dental CBCT device. Methods: Clinical and quantitative evaluations of image quality were performed using 5 and 10 years old (y/o) anthropomorphic phantoms. Technical evaluation was performed with the SEDENTEXCT-IQ phantom. Images were obtained using a PaX-i3D Green CBCT (Vatech, Korea) device, combining tube voltages ranging from 85 to 110 kV and 2 fields of view (FOVs: 21 × 19 and 12 × 9 cm), while maintaining the radiation dose fixed by adjusting the mA accordingly. Clinically, observers assessed images based on overall quality, sharpness, contrast, artefacts, and noise. For quantitative evaluation, mean grey value shift, % increase standard deviation, % beam-hardening and contrast-to-noise ratio were calculated. For technical evaluation, segmentation accuracy, contrast-to-noise ratio and full width at half maximum were measured. Biplot graphs were used to choose representative parameters, from which the best kV was selected for each protocol and evaluation. kV values that had no statistical differences (p > 0.05) with the best kV chosen were considered as having the same quality. Results: Clinically, 95 kV was found as a cut-off value. From the quantitative aspect, 85 kV (p < 0.05) showed the worst quality, except in 12 × 9 cm 5 y/o. Technically, 85 and 110 kV in the large FOV showed significantly worse quality for the large FOV. Conclusion: For paediatric indications, 95 kV or higher (and correspondingly low mA values) was found as optimal.
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| 3. |
- De Wilde, Elisabeth A. W. J., et al.
(författare)
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The soft tissue immunologic response to hydroxyapatite-coated transmucosal implant surfaces : a study in humans
- 2015
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Ingår i: Clinical Implant Dentistry and Related Research. - : John Wiley & Sons. - 1523-0899 .- 1708-8208. ; 17:S1, s. e65-e74
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveTo evaluate the soft tissue response in humans immunologically and histologically after placement of mini-implants coated with or without nano-size hydroxyapatite coatings. Material and MethodsCommercially pure (cp) titanium mini-implants (n=13) or nano-hydroxyapatite-coated ones (n=12) were randomly placed into partially edentulous jaws. Crevicular fluid was sampled 1week after placement and subjected to quantitative polymerase chain reaction analysis to explore the inflammatory markers. After 8weeks, implants and surrounding soft and hard tissue were trephined, and undecalcified ground sections were prepared. Inflammatory cell accumulation within a defined region of interest in the soft tissue was quantified histomorphometrically. ResultsNo statistically significant differences in immunological response to the different implant surfaces were found for IL-6 (p=.438), TGF-2 (p=.467), MMP-8 (p=.758), CCL-3 (p=.758), IL-8 (p=.771), and IL-1 (0.771). Histomorphometric evaluation presented no statistically significant difference between the two mini-implant surfaces with regards to number of inflammatory cells (p=.669). ConclusionNano-hydroxyapatite-coated surfaces in the transmucosal region yielded similar inflammatory response and is suggested to be as biocompatible as commercially pure titanium surfaces.
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| 5. |
- Merheb, J., et al.
(författare)
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Relation between Spongy Bone Density in the Maxilla and Skeletal Bone Density
- 2015
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Ingår i: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899 .- 1708-8208. ; 17:6, s. 1180-1187
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Tidskriftsartikel (refereegranskat)abstract
- © 2015 Wiley Periodicals, Inc. Background and Purpose: Osteoporosis is a disease affecting more than 300 million people worldwide and is responsible for numerous medical complications. This study aimed to investigate the relation between skeletal and maxillary bone density. Materials and Methods: Seventy-three patients were recruited and divided between group A (osteoporosis), group B (healthy, control), and group C (osteopenia) on the basis of a dual-energy x-ray absorptiomery (DXA) scan. These patients also received a CT scan on which bone density measurements were performed at five sites: maxilla midline, retromolar tuberosities, incisor, premolars, and molar regions. Results: The bone density was lower in osteoporotic patients compared with the control patients. The bone mineral density (BMD) of the tuberosities showed the strongest correlations with the BMD of the hip and the spine (respectively, r=0.50 and r=0.61). The midline region showed moderate correlations with the hip (r=0.47) and the spine (r=0.46). For potential implant sites, the correlations with the BMD of the hip and spine were, however, small to insignificant. Based on measurements of bone density of the maxilla, it was possible to predict if the patient was osteoporotic or not with a sensitivity of 65% and a specificity of 83%. Conclusions: The maxillary bone density of subjects with osteoporosis is significantly lower than that of healthy patients. Moreover, there is a direct correlation between the density of the skeleton and the density of some sites of the maxilla. Using measurements of maxillary bone density in order to predict skeletal bone density might be a useful tool for the screening of osteoporosis.
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| 7. |
- Terhal, Paulien A., et al.
(författare)
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A Study of the Clinical and Radiological Features in a Cohort of 93 Patients with a COL2A1 Mutation Causing Spondyloepiphyseal Dysplasia Congenita or a Related Phenotype
- 2015
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Ingår i: American Journal of Medical Genetics. Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 167A:3, s. 461-475
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Tidskriftsartikel (refereegranskat)abstract
- Type 2 collagen disorders encompass a diverse group of skeletal dysplasias that are commonly associated with orthopedic, ocular, and hearing problems. However, the frequency of many clinical features has never been determined. We retrospectively investigated the clinical, radiological, and genotypic data in a group of 93 patients with molecularly confirmed SEDC or a related disorder. The majority of the patients (80/93) had short stature, with radiological features of SEDC (n=64), others having SEMD (n=5), Kniest dysplasia (n=7), spondyloperipheral dysplasia (n=2), or Torrance-like dysplasia (n=2). The remaining 13 patients had normal stature with mild SED, Stickler-like syndrome or multiple epiphyseal dysplasia. Over 50% of the patients had undergone orthopedic surgery, usually for scoliosis, femoral osteotomy or hip replacement. Odontoid hypoplasia was present in 56% (95% CI 38-74) and a correlation between odontoid hypoplasia and short stature was observed. Atlanto-axial instability, was observed in 5 of the 18 patients (28%, 95% CI 10-54) in whom flexion-extension films of the cervical spine were available; however, it was rarely accompanied by myelopathy. Myopia was found in 45% (95% CI 35-56), and retinal detachment had occurred in 12% (95% CI 6-21; median age 14 years; youngest age 3.5 years). Thirty-two patients complained of hearing loss (37%, 95% CI 27-48) of whom 17 required hearing aids. The ophthalmological features and possibly also hearing loss are often relatively frequent and severe in patients with splicing mutations. Based on clinical findings, age at onset and genotype-phenotype correlations in this cohort, we propose guidelines for the management and follow-up in this group of disorders.
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