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- Calon, T. G. A., et al.
(författare)
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Cytokine expression profile in the bone-anchored hearing system: 12-week results from a prospective randomized, controlled study
- 2018
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Ingår i: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899. ; 20:4, s. 606-616
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveTo study the effect of implanting the percutaneous bone-anchored hearing system (BAHS) itself and inflammation of the peri-abutment skin warrant clarification. In this study, we aimed to acquire further insight into the immune responses related to BAHS surgery and peri-implant skin inflammation. Materials and MethodsDuring surgery and 12 weeks post-implantation, skin biopsies were obtained. If applicable, additional biopsies were taken during cases of inflammation. The mRNA expression of IL-1, IL-6, IL-8, TNF, IL-17, IL-10, TGF-ss, MIP-1, MMP-9, TIMP-1, COL11, VEGF-A, FGF-2 TLR-2, and TLR-4 was quantified using qRT-PCR. ResultsThirty-five patients agreed to the surgery and 12-week biopsy. Twenty-two patients had mRNA of sufficient quality for analysis. Ten were fitted with a BAHS using the minimally invasive Ponto surgery technique. Twelve were fitted with a BAHS using the linear incision technique with soft-tissue preservation. Five biopsies were obtained during episodes of inflammation. The post-implantation mRNA expression of IL-1 (P = .002), IL-8 (P = .003), MMP9 (P = .005), TIMP-1 (P= .002), and COL11 (P < .001) was significantly up-regulated. IL-6 (P = .009) and FGF-2 (P=.004) mRNA expression was significantly down-regulated after implantation. Within patients, no difference between post-implantation mRNA expression (at 12 weeks) and when inflammation was observed. Between patients, the expression of IL-1 (P = .015) and IL-17 (P = .02) was higher during cases of inflammation compared with patients who had no inflammation at 12-week follow-up. ConclusionsAs part of a randomized, prospective, clinical trial, the present study reports the molecular profile of selected cytokines in the soft tissue around BAHS. Within the limit of this study, the results showed that 12 weeks after BAHS implantation the gene expression of some inflammatory cytokines (IL-8 and IL-1) is still relatively high compared with the baseline, steady-state, expression. The up-regulation of anabolic (COL11) and tissue-remodeling (MMP-9 and TIMP1) genes indicates an ongoing remodeling process after 12 weeks of implantation. The results suggest that IL-1, IL-17, and TNF- may be interesting markers associated with inflammation.
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- Calon, T. G. A., et al.
(författare)
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Microbiome on the Bone-Anchored Hearing System: A Prospective Study
- 2019
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- The bone-anchored hearing system (BAHS) has evolved to a common treatment option for various types of hearing revalidation. The BAHS consists of an implant in the skull that breeches the skin. Soft tissue reactions are a common complication associated with BAHS and are generally poorly understood. This study aims to investigate the influence of BAHS and associated skin reactions around the implant. A total of 45 patients were prospectively followed from implantation up to at least 1 year. Swabs were obtained at baseline, 12 weeks follow-up and during cases of inflammation (Holgers score >= 2). The microbiota was assessed using IS-proTM, a bacterial profiling method based on the interspace region between the 16S-23S rRNA genes. Detection of operational taxonomic units, the Shannon Diversity Index, sample similarity analyses and Partial Least Squares Discriminant Analysis (PLS-DA) were employed. Staphylococcus epidermidis, Streptococcus pneumoniae/mitis, Propionibacterium acnes, Staphylococcus capitis, Staphylococcus hominis, Bifidobacterium longum, Haemophilus parainfluenzae, Lactobacillus rhamnosus, Bordetella spp., Streptococcus sanguinis, Peptostreptococcus anaerobius, Staphylococcus aureus, Lactococcus lactis, Enterobacter cloacae, and Citrobacter koseri were the most commonly found bacterial species. S. pneumoniae/mitis was significantly more often observed after implantation, whereas P. acnes was significantly less observed after implantation compared with baseline. The relative abundance of S. epidermidis (17%) and S. aureus (19.4%) was the highest for the group of patients with inflammation. The Shannon Diversity Index was significantly increased after implantation compared with pre-surgical swabs for Firmicutes, Actinobacteria, Fusobacteria, Verrucomicrobia (FAFV), but not for other phyla. When combining all phyla, there was no significant increase in the Shannon Diversity Index. The diversity index was similar post-surgically for patients experiencing inflammation and for patients without inflammation. With a supervised classifier (PLS-DA), patients prone to inflammation could be identified at baseline with an accuracy of 91.7%. In addition, PLS-DA could classify post-surgical abutments as non-inflamed or inflamed with an accuracy of 97.7%. This study shows the potential of using IS-proTM to describe and quantify the microbiota associated with the percutaneous BAHS. Furthermore, the results indicate the possibility of an early identification of patients susceptible to adverse skin reaction following implantation. Both S. aureus and S. epidermidis should be considered as relevant bacteria for BAHS-associated inflammation.
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- Calon, Tim G A, et al.
(författare)
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Minimally Invasive Ponto Surgery compared to the linear incision technique without soft tissue reduction for bone conduction hearing implants: study protocol for a randomized controlled trial.
- 2016
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Ingår i: Trials. - : Springer Science and Business Media LLC. - 1745-6215. ; 17:1
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Tidskriftsartikel (refereegranskat)abstract
- Over the last years, less invasive surgical techniques with soft tissue preservation for bone conduction hearing implants (BCHI) have been introduced such as the linear incision technique combined with a punch. Results using this technique seem favorable in terms of rate of peri-abutment dermatitis (PAD), esthetics, and preservation of skin sensibility. Recently, a new standardized surgical technique for BCHI placement, the Minimally Invasive Ponto Surgery (MIPS) technique has been developed by Oticon Medical AB (Askim, Sweden). This technique aims to standardize surgery by using a novel surgical instrumentation kit and minimize soft tissue trauma.A multicenter randomized controlled trial is designed to compare the MIPS technique to the linear incision technique with soft tissue preservation. The primary investigation center is Maastricht University Medical Center. Sixty-two participants will be included with a 2-year follow-up period. Parameters are introduced to quantify factors such as loss of skin sensibility, dehiscence of the skin next to the abutment, skin overgrowth, and cosmetic results. A new type of sampling method is incorporated to aid in the estimation of complications. To gain further understanding of PAD, swabs and skin biopsies are collected during follow-up visits for evaluation of the bacterial profile and inflammatory cytokine expression. The primary objective of the study is to compare the incidence of PAD during the first 3 months after BCHI placement. Secondary objectives include the assessment of parameters related to surgery, wound healing, pain, loss of sensibility of the skin around the implant, implant extrusion rate, implant stability measurements, dehiscence of the skin next to the abutment, and esthetic appeal. Tertiary objectives include assessment of other factors related to PAD and a health economic evaluation.This is the first trial to compare the recently developed MIPS technique to the linear incision technique with soft tissue preservation for BCHI surgery. Newly introduced parameters and sampling method will aid in the prediction of results and complications after BCHI placement.Registered at the CCMO register in the Netherlands on 24 November 2014: NL50072.068.14 . Retrospectively registered on 21 April 2015 at ClinicalTrials.gov: NCT02438618 . This trial is sponsored by Oticon Medical AB.
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- Calon, T. G. A., et al.
(författare)
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The Use of cone Beam computed Tomography in Assessing the Insertion of Bone conduction hearing Implants
- 2017
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Ingår i: Frontiers in Surgery. - : Frontiers Media SA. - 2296-875X. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Objective: This study aimed to compare postoperative cone beam CT (CBCT) imaging to implant stability quotient (ISO) measurement and direct caliper measurements as a suitable technique to assess bone conduction hearing implant (BCHI) seating and insertion depth. Methods: in vitro, BCHIs were completely (n = 9) and partially inserted (n = 9) in bone blocks of different densities and subsequently scanned. Scans were processed using 3DSlicer 4.3.1 and Mathematica 10.3. ISO measurements were obtained for all BCHIs mounted with different abutment lengths (9, 12, and 14 mm). CBCT imaging was performed for patients with a clinical indication. Results: In vitro, 95% prediction intervals for partially inserted and completely inserted BCHIs were determined. ISO values significantly decreased with partial insertion, low -density artificial bone, and longer abutment lengths. Evaluation of in vitro and in vivo 3D models allowed for assessment of insertion depth and inclination. Conclusion: CBCT imaging allows to study implant seating and insertion depth after BCHI surgery. This can be useful when visual confirmation is limited. It is possible to distinguish a partial BCHI insertion from a complete insertion in artificial bone blocks. This technique could prove to be a valuable research tool. In vitro, ISO values for Ponto BCHIs relate to abutment length, insertion depth, and artificial bone density.
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- Calon, Tim, et al.
(författare)
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Multimodal analysis of the tissue response to a bone-anchored hearing implant. : 11. Calon TGA, Johansson ML, Omar O, Shah FA, Budding D, Trobos M, Thomsen P, Stokroos RJ, Palmquist
- 2019
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Ingår i: 2nd Politzer Society Meeting/2nd World Congress of Otology, 28 May - 1 June, 2019, Warsaw, Poland..
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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