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Contains fulltext : 304954.pdf (Publisher’s version ) (Open Access)

01 april 2023, Item does not contain fulltext, BACKGROUND: Currently, assessment of acetabular fracture reduction is mainly performed by evaluating 2D slices of 3D CT scans. This subjective method can potentially be improved by using 3D models and objective analysis tools. In order to evaluate the potential value of digital 3D reconstructed models in the assessment of acetabular fracture reduction, 3D reconstructions of the fractured acetabulum were compared to the mirrored healthy contralateral side for both the pre-, and post-surgical setting. METHODS: Thirteen patients with one-sided acetabular fractures were included in the study. All patients received a pre-, and postoperative CT scan. The similarity between the healthy acetabulum and the contralateral fractured acetabulum was determined by two observers for both the pre-, and postoperative setting by completing the following four steps; (1) mirroring of the fractured acetabulum, (2) initial manual alignment of this mirrored 3D model to the contralateral version, (3) surface-based matching (iterative closest point registration) using the acetabular cartilage surface, and (4) calculating the surface distances between affected and healthy acetabular 3D models. Descriptive statistics showed the surface distance between pre-, and post-surgical reduction, as well as the interobserver variability. RESULTS: A total of 13 patients with an acetabular fracture were included; 11 males and 2 females with a mean ± SD age of 55.6 ± 14.7 years. Digital mirroring of the fractured acetabula to the healthy acetabula was successful for both preoperative and postoperative situations in all patients. The median distance between both fractured and mirrored healthy contralateral acetabula was significantly larger (p<0.01) for the preoperative group (2.21 mm (interquartile range (IQR): 1.30 mm)) compared to the postoperative group (0.93 mm (IQR: 0.59 mm)). The median distance deviation was not significantly different (p = 0.96) between observers. CONCLUSIONS: The results of compar

01 september 2023, Contains fulltext : 296791.pdf (Publisher’s version ) (Open Access), INTRODUCTION AND HYPOTHESIS: The objective was to compare the location and motion of pessaries between women with pelvic organ prolapse (POP) with a successful (fitting) and unsuccessful (non-fitting) pessary treatment on dynamic magnetic resonance imaging (dMRI). METHODS: A cross-sectional exploratory study of 15 women who underwent a mid-sagittal dMRI of the pelvic floor at rest, during contraction and during Valsalva with three different types of pessaries. The coordinates of the pessaries cross section, inferior pubic point (IPP) and sacrococcygeal junction (SCJ) were obtained and the location (position, orientation) and the motion (translation and rotation) were calculated. Differences between the groups and between the pessaries within the groups were compared. RESULTS: Nine women with a fitting pessary and 6 women with a non-fitting pessary were selected. In the non-fitting group, the pessaries were positioned more caudally and rotated more in clockwise direction and descended more, but not significantly, during Valsalva compared with the fitting group. The Falk pessary was positioned more anteriorly in the fitting group and more cranially in the non-fitting group compared with the ring and ring with support pessary. CONCLUSIONS: A non-fitting pessary was positioned more caudally at rest; on Valsalva, it rotated more clockwise and moved more caudally, suggesting that the dynamic characteristics of the pessary might play an important role in its effectiveness. Findings of this study serve as a basis for the development of new pessary designs.

Item does not contain fulltext, PURPOSE: A fully digital approach to oral prosthodontic rehabilitation requires the possibility of combining (i.e., registering) digital documentation from different sources. This becomes more complex in an edentulous jaw, as fixed dental markers to perform reliable registration are lacking. This validation study aimed to evaluate the reproducibility of 1) intraoral scanning and 2) soft tissue-based registration of an intraoral scan with a cone-beam computed tomography (CBCT) scan for a fully edentulous upper jaw. MATERIALS AND METHODS: Two observers independently performed intraoral scans of the upper jaw in 14 fully edentulous patients. The palatal vault of both surface models was aligned, and the inter-observer variability was assessed by calculating the mean inter-surface distance at the level of the alveolar crest. Additionally, a CBCT scan of all patients was obtained and a soft tissue surface model was generated using patient-specific gray values. This CBCT soft tissue model was registered with the intraoral scans of both observers, and the intraclass correlation coefficient (ICC) was calculated to evaluate the reproducibility of the registration method. RESULTS: The mean inter-observer deviation when performing an intraoral scan of the fully edentulous upper jaw was 0.10 ± 0.09 mm. The inter-observer agreement for the soft tissue-based registration method was excellent (ICC=0.94; 95% confidence interval, 0.81-0.98). CONCLUSION: Even when teeth are lacking, intraoral scanning of the jaw and soft tissue-based registration of an intraoral scan with a CBCT scan can be performed with a high degree of precision.

Contains fulltext : 251131.pdf (Publisher’s version ) (Open Access), The aim of this study was to evaluate a novel soft tissue-based method to register an intraoral scan (IOS) with a cone beam computed tomography (CBCT) scan. IOS and CBCT data were obtained from eight dentate patients (mean age 21±2 years; three male, five female) and 14 fully edentulous patients (mean age 56±9 years; eight male, six female). An algorithm was developed to create a soft tissue model of the CBCT scan, which allowed a soft tissue-based registration to be performed with the IOS. First, validation was performed on dentate jaws with registration of the palatal mucosal surface and accuracy evaluation at the level of the teeth. Second, fully edentulous jaws were registered using both the palatal and alveolar crest mucosal surfaces. Distance maps were created to measure the method accuracy. The mean registration error was 0.49±0.26mm for the dentate jaws. Registration of the fully edentulous jaws had a mean error of 0.16±0.08mm at the palate and 0.16±0.05mm at the alveolar crest. In conclusion, the high accuracy of this registration method may allow the digital workflow to be optimized when no teeth are available to perform a regular registration procedure.

Contains fulltext : 283839.pdf (Publisher’s version ) (Open Access)

Contains fulltext : 253369.pdf (Publisher’s version ) (Open Access)

Contains fulltext : 284085.pdf (Publisher’s version ) (Open Access)

Item does not contain fulltext, BACKGROUND: Flapless immediate implant placement and provisionalization (FIIPP) in the aesthetic zone is still controversial. Especially, an initial buccal crest thickness (BCT) of ≤1 mm is thought to be disruptive for the final buccal crest stability jeopardizing the aesthetic outcome. PURPOSE: To radiographically assess the BCT and buccal crest height (BCH) after 1 year and to calculate the correlation between initial and final achieved BCT. MATERIALS AND METHODS: The study was designed as a prospective study on FIIPP. Only patients were included in whom one maxillary incisor was considered as lost. In six centers, 100 consecutive patients received FIIPP. Implants were placed in a maximal palatal position of the socket, thereby creating a buccal space of at least 2 mm, which was subsequently filled with a bovine bone substitute. Files of preoperative (T0), peroperative (T1) and 1-year postoperative (T3) cone beam computed tomogram (CBCT) scans were imported into the Maxillim™ software to analyze the changes in BCT-BCH over time. RESULTS: Preoperatively, 85% of the cases showed a BCT ≤1 mm, in 25% of the patients also a small buccal defect (≤5 mm) was present. Mean BCT at the level of the implant-shoulder increased from 0.6 mm at baseline to 3.3 mm immediate postoperatively and compacted to 2.4 mm after 1 year. Mean BCH improved from 0.7 to 3.1 mm peroperatively, and resorbed to 1.7 mm after 1 year. The Pearson correlation of 0.38 between initial and final BCT was significant (p = 0.01) and therefore is valued as moderate. If only patients (75%) with an intact alveolus were included in the analysis, still a "moderate correlation" of 0.32 (p = 0.01) was calculated. CONCLUSIONS: A "moderate correlation" was shown for the hypothesis that "thinner preoperative BCT's deliver thinner BCT's" 1 year after performing FIIPP.

Item does not contain fulltext, Measurement and production of traditional prosthetic sockets are time-consuming, labor-intensive, and highly dependent on the personnel involved. An alternative way to make prostheses is using computer-aided design (CAD) and computer-aided manufacturing (CAM). Fused Filament Fabrication (FFF) may be an alternative to make low-cost prosthetic sockets. This study investigates the tensile properties of potential printing materials suitable for FFF according to ISO527 (Standard Test Method for Tensile Properties of Plastics). To ensure that FFF-printed sockets are safe for patient usage, the structural integrity of the 3D-printed prosthesis will be investigated according to ISO10328 (International Standard Structural Testing of Lower Limb Prostheses). Tough PLA was the most suitable print material according to ISO 527 testing. The Tough PLA printed socket completed 2.27 million cycles and a static test target value of 4025 N. Future research remains necessary to continue testing new potential materials, improve print settings, and improve the socket design for the production of FFF-printed transtibial prosthetic sockets. FFF using Tough PLA can be used to create transtibial prostheses that almost comply with the International Standard for Structural Testing of Lower Limb Prostheses.

Contains fulltext : 241492.pdf (Publisher’s version ) (Open Access)

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Contains fulltext : 218707.pdf (publisher's version ) (Open Access), BACKGROUND: We described safety and functional one-year follow-up outcomes of individuals with lower limb amputation treated with bone-anchored prostheses using titanium press-fit osseointegration implants. METHODS: All consecutive individuals treated between March 2015 and June 2018 with curved osseointegration femur implant (OFI-C) indicated for a long femoral remnant, gamma osseointegration femur implant (OFI-Y) indicated for a short femoral remnant, or osseointegration tibia implant (OTI) were eligible for this study. All adverse events were evaluated, infections were graded as follows: grade 1 and 2: low- and high-grade soft tissue infection, respectively, grade 3: deep bone infection, grade 4: septic implant failure. Functional outcome measures included prosthesis wearing time (PUS), health-related quality of life (GS), and the overall situation as an amputee (GS Q3); evaluated with the Questionnaire of persons with trans-femoral amputation (Q-TFA) before surgery and at one-year follow-up. RESULTS: Ninety of 91 individuals were included (mean age: 54+/-14 yrs, 26 females); treated with 53, 16 and 21 OFI-C, OFI-Y and OTI, respectively. Soft tissue infections (grade 1: 11 events, grade 2: 10 events) were treated successfully with antibiotics except in two (OFI-C and OFI-Y), who required additional surgery due to recurrent stoma irritation and peri-stoma abscess drainage. One individual with dysvascular amputation (OTI) developed septic implant loosening and occlusion of the femoral artery resulting in a transfemoral amputation. No aseptic loosening's occurred. One individual (OFI-Y) required stoma surgical refashioning due to soft tissue redundancy. At baseline mean +/-SD and median (25th to 75th PCTL) Q-TFA PUS and GS were 52+/-39, 52(7-90) and 40+/-19, 42(25-50) and improved significantly to 88+/-18, 90 (90-100) and 71+/-15, 75 (67-83) at one-year follow-up. The GS Q3 improved over time. CONCLUSION: Titanium osseointegration implants can be safely used within

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Item does not contain fulltext, PURPOSE: To assess the reliability and accuracy of linear measurements on three-dimensional (3D) cross-sectional images, both acquired with cone beam computed tomography (CBCT) and multi-detector row CT (MDCT). Bone thickness was evaluated with regard to image-guided planning of craniofacial implant surgery. MATERIALS AND METHODS: Five dry human skulls were used. Cuts were made with a circular bone saw at the ideal implant positions in the nasal, orbital, and temporal regions prior to acquisition of CBCT and MDCT scans. After imaging examination, bone width was assessed by three independent observers using a caliper and defined as a reference. In the next step, cross-sectional images of the regions with the aforementioned cuts were reconstructed from 3D virtual models generated from the digital DICOM datasets with the use of 3D image-based planning software. Subsequently, linear measurements were performed. The systematic difference and interobserver and intraobserver variation of MDCT and CBCT linear measurements were compared with the physical measurements at different locations in the nasal, orbital, and temporal region, respectively. Also, the potential influence of different gray-level values was investigated. The quantitative accuracy of distance measurements was performed using a two-way analysis of variance (ANOVA) and variance component analyses. Only differences with P values < .05 were considered significant. RESULTS: All radiologic measurements showed a significant overestimation of the bony dimensions, reaching more than the used voxel sizes of 0.3 mm for CBCT and 0.5 mm for MDCT. For CBCT, an average measurement bias of 0.39 to 0.53 mm and for MDCT of 0.57 to 0.59 mm was found. MDCT images showed less interobserver variation in linear measurements on cross-sectional images from 3D virtual models compared with CBCT images. Contrast settings statistically significantly influenced linear measurements of bone width for CBCT images (P < .0015) and interobse

Item does not contain fulltext, OBJECTIVE: To identify clinical features and investigate treatment outcomes of patients with idiopathic pain related to a percutaneous bone-anchored hearing implant (BAHI) and to propose management recommendations. STUDY DESIGN: Retrospective chart analysis. SETTING: Tertiary referral center. PATIENTS: The clinical data of 14 patients who were treated for idiopathic pain around their percutaneous BAHI between May 2007 and February 2018 at our tertiary referral center were reviewed. MAIN OUTCOME MEASURES: Pain after treatment and implant loss. RESULTS: All 14 patients received treatment with oral antibiotics. Nine patients received oral antibiotic combination therapy for 4 weeks, whereafter pain resolved in 4. Out of the five other patients, receiving either antibiotic monotherapy or shortened antibiotic combination therapy, pain resolved in two. In case of persistent pain (57.1%) after initial treatment, other pain management therapies were attempted, however all with only limited effect. Six patients (42.8%) underwent elective removal of the implant. In two patients spontaneous implant loss occurred. In two of the four patients who underwent reimplantation, pain relapsed. In one of these, pain resolved after the removal of the new implant. In the other patient, pain persisted, despite abutment removal. With exception of this latter patient, all other 13 patients were pain free at the latest follow-up. Cone beam computed tomography did not offer additional information regarding diagnosis or treatment. CONCLUSION: Idiopathic pain in BAHI is a rare but bothersome symptom which can result in implant removal. After oral antibiotic combination treatment, symptoms resolved in approximately 40% of patients. Therefore, we think conservative treatment with these antibiotics before implant removal surgery, is worth considering.

Contains fulltext : 203193.pdf (publisher's version ) (Open Access), PURPOSE: Not long after the introduction of osseointegrated implants outside the oral cavity, auricular prostheses are retrained on osseointegrated implants. New insights have been gained with the next-generation percutaneous osseointegrated titanium implants for bone conduction hearing since its introduction in 2010. As a result, the same technology was introduced in the Vistafix((R)) system (VXI implant) to retain auricular prostheses. The aim of this study is to evaluate the surgical procedure, clinical outcome, and satisfaction of the patient of osseointegration-retained auricular prosthesis using VXI implants. MATERIALS AND METHODS: 11 patients who received an auricular prosthesis using VXI implants between December 2012 and November 2017 were evaluated retrospectively. The patient's medical files were reviewed to assess clinical complications and the necessity for revision surgery. The subjective outcome was measured using the Glasgow benefit inventory (GBI). RESULTS: In total, 31 implants were placed in 11 patients. None of these implants were lost nor revision surgery needed. An adverse skin reaction was observed in 13.0% of the implants and in 27.2% of the patients, adequately treated with an antibiotic ointment. The average follow-up time was 2 years and 7 months. The GBI displayed a positive score in every patient. CONCLUSIONS: The VXI implants used are a safe and reliable treatment option for retaining auricular prostheses in patients with an absent auricle. Patients were satisfied with their auricular prosthesis and showed benefit in quality of life. Studies with larger numbers and preferably a prospective character are needed to draw statistically significant conclusions.

Contains fulltext : 201271.pdf (publisher's version ) (Closed access)

Radboud University, 20 juni 2018, Promotores : Meijer, G.J., Bergé, S.J. Co-promotor : Maal, T.J.J., Contains fulltext : 191616.pdf (publisher's version ) (Open Access)

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1 mei 2017, Item does not contain fulltext, A healthy 72-year-old man presented with retention problems concerning the dentures in his maxilla. On account of extreme resorption, placement of implants without prior bone augmentation was not an option. The proposal was to use autologous bone harvested from the iliac crest. After a healing period of 4 months, a cone beam computed tomography scan was made, following which the virtual implant planning of 6 implants was carried out. With the help of a template supported by osteosynthesis screws, which had already been inserted during the augmentation procedure, the plan was applied to the patient. The precision of the fit between the planning and the actual placement of the implants has become so high that it was decided to place a 3D-printed dental bridge immediately following implant placement. The treatment trajectory and the costs can thus be significantly reduced whilst the patient gets to enjoy the implant-supported dentures sooner.

01 februari 2016, Item does not contain fulltext, AIM: To assess the feasibility of a new method to augment the three-dimensional virtual skull model with a detailed surface model of the dentition produced by intra-oral scanning, compared to the conventional triple scan procedure. MATERIALS & METHODS: In four patients who were planned for bimaxillary orthognathic surgery, the conventional triple scan procedure was carried out to create an augmented model. During scanning the patient wears a modified wax bite containing radio-opaque markers. An additional CBCT and laser scan of the wax bite and an intra-oral scan of the dentition were acquired. Surface-based and marker-based matching procedures were performed to integrate the intra-oral scans into the CBCT scan of the patient. The accuracy of the proposed method was assessed by measuring the distance between the occlusal surfaces of the registered intra-oral scans and the augmented model. RESULTS: Mean distances between the ios-dental cast registration and the augmented model were 0.30 mm (SD 0.20) and 0.27 mm (SD 0.20) for the upper and lower jaw, respectively. CONCLUSION: Intra-oral scans provide an accurate representation of the dental arches compared to the AlgiNot-dental casts and can be fused with CBCT scans.

Contains fulltext : 154285.pdf (publisher's version ) (Closed access), Orthognathic surgery aims to improve both the function and facial appearance of the patient. Translation of the maxillomandibular complex for correction of malocclusion is always followed by changes to the covering soft tissues, especially the nose and lips. The purpose of this study was to evaluate the changes in the nasal region and upper lip due to orthognathic surgery using combined cone beam computed tomography (CBCT) and three-dimensional (3D) stereophotogrammetry datasets. Patients who underwent a Le Fort I osteotomy, with or without a bilateral sagittal split osteotomy, were included in this study. Pre- and postoperative documentation consisted of 3D stereophotogrammetry and CBCT scans. 3D measurements were performed on the combined datasets and analyzed. Anterior translation and clockwise pitching of the maxilla led to a significant volume increase in the lip. Cranial translation of the maxilla led to an increase in the alar width. The combination of CBCT DICOM data and 3D stereophotogrammetry proved to be useful in the 3D analysis of the maxillary hard tissue changes, as well as changes in the soft tissues. Measurements could be acquired and compared to investigate the influence of maxillary movement on the soft tissues of the nose and the upper lip.

Item does not contain fulltext, OBJECTIVES: A novel, 3D technique to measure the differences in tooth crown morphology between the MSX1 cases and non-affected controls was designed to get a better understanding of dental phenotype-genotype associations. MATERIALS AND METHODS: Eight Dutch subjects from a single family with tooth agenesis, all with an established nonsense mutation c.332 C > A, p. Ser 111 Stop in exon 1 of MSX1, were compared with unaffected controls regarding several aspects of tooth crown morphology of incisor and molar teeth. A novel method of quantitative three-dimensional analysis was used to detect differences. RESULTS: Statistically significant shape differences were observed for the maxillary incisor in the MSX1 family compared with the controls on the following parameters: surface area, buccolingual dimension, squareness, and crown volume (P