Paul H M Spauwen

University of Groningen, Groningen, Groningen, Netherlands

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Publications (122)301.46 Total impact

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    ABSTRACT: In an earlier study we have shown that transcervical chorionic villus sampling in excess of 90 mg increases the risk for hemangiomas of infancy three- to four-fold compared to amniocentesis. In the present study we investigated whether transabdominal chorionic villus sampling (TA-CVS), in which the samples are smaller, carries the same risk. Retrospectively, data were analyzed from 200 consecutive TA-CVS procedures and 200 consecutive amniocentesis procedures. Forty-two TA-CVS procedures and 27 amniocentesis procedures were excluded on predefined criteria. Questionnaires were sent to the parents asking if there was any skin mark on the child: vascular, pigmented or otherwise. All hemangiomas were clinically confirmed. In the TA-CVS group, 118/158 questionnaires (75%), and in the amniocentesis group 134/173 questionnaires (77%) were returned. Based on the results of the questionnaire (i.e. mentioning of any skin lesion), 24 children in the TA-CVS group and 42 children in the amniocentesis group qualified for a physical examination. In the TA-CVS group 11/118 children (9%) had one or more hemangiomas. In the amniocentesis group 6/134 children (4%) had one or more hemangiomas. There was no statistical difference between the two groups (P = 0134). These results suggest that TA-CVS does not cause an increase in the prevalence of hemangioma compared to amniocentesis. A larger series is, however, necessary to confirm this.
    Journal of Obstetrics and Gynaecology Research 02/2012; 38(2):371-5. DOI:10.1111/j.1447-0756.2011.01717.x · 0.93 Impact Factor
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    ABSTRACT: A randomized clinical trial was conducted to determine the effectiveness and safety of topical negative pressure therapy in patients with difficult-to-heal wounds. A total of 24 patients were randomly assigned to either treatment with topical negative pressure therapy or treatment with conventional dressing therapy with sodium hypochlorite. The study end point was 50% reduction in wound volume. The maximum follow-up time was 6 weeks. The median treatment time to 50% reduction of wound volume in the topical negative pressure group was 2.0 weeks (interquartile range = 1) versus 3.5 weeks (interquartile range = 1.5) in the sodium hypochlorite group (P < 0.001). The unadjusted hazard rate ratio for the time until 50% wound volume reduction was 0.123 (P < 0.001). After adjustment for relevant baseline characteristics in a Cox proportional hazards model treatment group, membership was found as the only and statistically significant indicator for the time to 50% wound volume reduction (hazard rate ratio of 0.117 [P < 0.001]). Subgroup analysis of spinal cord injured patients with severe pressure ulcers showed similar statistically significant results as in the total wound group. Topical negative pressure resulted in almost 2 times faster wound healing than treatment with sodium hypochlorite, and is safe to use in patients with difficult-to-heal wounds.
    Annals of plastic surgery 05/2011; 67(6):626-31. DOI:10.1097/SAP.0b013e31820b3ac1 · 1.46 Impact Factor
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    ABSTRACT: Hemangiomas of infancy can give rise to alarm because of their rapid growth and occasional dramatic appearance. The objective of this study was to investigate the growth pattern of hemangiomas and risk factors for residual lesions. A follow-up study was performed of patients with hemangiomas that were clinically monitored between 1985 and 2000 and who did not receive any treatment. The data were retrieved from medical files. Patients (parents) were asked to complete a questionnaire and invited to our outpatient clinic where the questionnaire was discussed and physical examination was performed. The growth phases of the hemangioma were documented, the timeline of these phases was constructed, and an assessment was made of the residual lesion if present. In 97 patients, 137 hemangiomas were evaluated. A precursor lesion was present in 48 percent of children. Maximum size was reached in 8 months. Involution started at a median age of 2 years and was completed at a median age of 4 years. Residual lesions were present in 69 percent of cases. Superficial nodular hemangiomas showed significantly more residual lesions (74 percent) than the deep hemangiomas (25 percent) (p < 0.001; odds ratio, 8.4; 95 percent confidence interval, 2.4 to 29.1). Untreated infection, ulceration, or bleeding produced a scar in 97 percent of the cases. Epidermal invasion of the hemangioma is of predictive value for residual lesions. There is no correlation between the growth pattern of a hemangioma and the risk for a residual lesion. This may add to a more detailed prediction of outcome and may help to decide which patient should be treated or not.
    Plastic and Reconstructive Surgery 04/2011; 127(4):1643-8. DOI:10.1097/PRS.0b013e318208d2ac · 3.33 Impact Factor
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    ABSTRACT: This study was designed to compare the effects of transcervical chorionic villus sampling (CVS) and amniocentesis on the prevalence of hemangiomas of infancy. This is a cohort study of 250 consecutive assessable transabdominal amniocentesis procedures and 250 consecutive assessable transcervical CVS procedures performed between January and September 2002. Parents were asked to fill out a questionnaire regarding the presence of any type of skin lesions. Based on the responses to the questionnaire, children were invited to undergo a physical examination to confirm hemangiomas. Questionnaires were returned in 78% of the CVS group (195/250) and in 72% of the amniocentesis group (180/250). Based on the responses in the questionnaire, 78 children in the CVS group and 42 in the amniocentesis group underwent a physical examination. One or more hemangiomas were present in 53 of 195 (27.2%) children in the CVS group versus 17 of 180 (9.4%) children in the amniocentesis group (odds ratio 3.6, 95% CI: 2.0-6.5). There was no difference in congenital abnormalities between the two groups. Transcervical CVS is associated with a significantly increased prevalence of hemangiomas compared with amniocentesis. The clinical features of these hemangiomas do not differ from natural hemangiomas and complications of these hemangiomas are very rare.
    Prenatal Diagnosis 10/2010; 30(10):913-7. DOI:10.1002/pd.2562 · 3.27 Impact Factor
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    ABSTRACT: This study was performed to assess the bone healing supporting characteristics of porous calcium phosphate (Ca-P) cement when implanted in a rabbit segmental defect model as well as to determine the reliability of torque testing as a method to verify bone healing. The middiaphyseal radius was chosen as the area to create bilaterally increasing defect sizes (5, 10, and 15 mm), which were either filled with porous Ca-P cement or left open as a control. After 12 weeks of implantation, torque test measurements as well as histological and radiographic evaluation were performed. In two of the open 15 mm control defects, bone bridging was visible at the radiographic and histological evaluation. Bone was observed to be present in all porous Ca-P cement implants (5, 10, and 15 mm defects) after 12 weeks. No significant differences in torque measurements were observed between the 5 and 10 mm filled and open control defects using a t-test. In addition, the mechanical strength of all operated specimens was similar compared with nonoperated bone samples. The torsion data for the 15 mm open defect appeared to be lower compared with the filled 15 mm defect, but no significant difference could be proven. Within the limitation of the study design, porous Ca-P cement implants demonstrated osteoconductive properties and confirmed to be a suitable scaffold material in a weight-bearing situation. Further, the used torque testing method was found to be unreliable for testing the mechanical properties of the healed bone defect.
    Tissue Engineering Part C Methods 10/2010; 16(5):1051-8. DOI:10.1089/ten.TEC.2009.0071 · 4.64 Impact Factor
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    J M Franken · P Hupkens · P H M Spauwen
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    ABSTRACT: The treatment of large soft-tissue defects of the lower leg remains a challenge. The timing of the operation, the most suitable type of tissue, and the decision between local or free flap coverage still remains under discussion. Fifty-two patients were treated with local or free flap coverage after a traumatic soft-tissue defect of the lower leg. We compared the results after treatment with local versus free flaps and fasciocutaneous flaps versus musculocutaneous flaps. In the case of primary reconstruction, we also compared the results regarding the timing of the operation: patients treated within 72 h after the trauma versus patients treated after 72 h. Thirty-five patients (67%) have been treated because of posttraumatic soft-tissue defects and, therefore, insufficient fracture coverage. Seventeen patients (33%) were treated because of a chronic osteomyelitis that arose after the trauma. In our study, we did not find a statistically significant difference between the postoperative complications of local and free flaps. A significant increase could be demonstrated in the number of revisions after treatment with a free flap. Treatment with a fasciocutaneous flap in the entire study group was associated with significantly more postoperative complications than treatment with a musculocutaneous flap. There was no significant difference in results after early or late flap coverage. Patients treated with local or free flaps achieved equal outcomes, except for the number of postoperative revisions in which local flaps required lesser revisions. Treatment with a musculocutaneous flap is preferable to treatment with a fasciocutaneous flap regarding postoperative complications. The timing of operation proved not to be a discriminating factor.
    Chirurgia Plastica 06/2010; 33(3):129-133. DOI:10.1007/s00238-010-0405-9
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    ABSTRACT: Informed consent (IC) is a process requiring a competent doctor, adequate transfer of information, and consent of the patient. It is not just a signature on a piece of paper. Current consent processes in surgery are probably outdated and may require major changes to adjust them to modern day legislation. A literature search may provide an opportunity for enhancing the quality of the surgical IC (SIC) process. Relevant English literature obtained from PubMed, Picarta, PsycINFO, and Google between 1993 and 2009 was reviewed. The body of literature with respect to SIC is slim and of moderate quality. The SIC process is an underestimated part of surgery and neither surgeons nor patients sufficiently realize its importance. Surgeons are not specifically trained and lack the competence to guide patients through a legally correct SIC process. Computerized programs can support the SIC process significantly but are rarely used for this purpose. IC should be integrated into our surgical practice. Unfortunately, a big gap exists between the theoretical/legal best practice and the daily practice of IC. An optimally informed patient will have more realistic expectations regarding a surgical procedure and its associated risks. Well-informed patients will be more satisfied and file fewer legal claims. The use of interactive computer-based programs provides opportunities to improve the SIC process.
    World Journal of Surgery 04/2010; 34(7):1406-15. DOI:10.1007/s00268-010-0542-0 · 2.35 Impact Factor
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    ABSTRACT: Despite the availability of numerous animal models for testing the biological performance of dental and orthopedic implants, the selection of a suitable model is complex. This paper presents a new model for objective and standardized evaluation of bone responses to implants using the iliac crest in goats. The feasibility of the iliac crest model regarding anatomy and implant positioning was determined using two cadaveric specimens and the bone structure was evaluated and compared with that of the goat femoral condyle. Additionally, the validity of the model was tested by performing an in vivo study. By means of a rather simple, safe, fast and reproducible surgical procedure, the iliac crest in goats could be approached and allowed the implantation of maximally five dental implants per iliac crest. Because of the bilateral implantation possibility, statistical comparisons between groups on either side of the goat could be performed, resulting in a high statistical power, and hence a reduction in the number of animals required to obtain significant data. In terms of surgical approach, anatomy and implant positioning, the iliac crest is the preferred model over the femoral condyle model. The iliac crest implantation model is suitable for evaluation of the osteogenic response to bone implant materials and represents a justified and deliberate alternative to the already existing animal models.
    Clinical Oral Implants Research 04/2010; 21(4):414-23. DOI:10.1111/j.1600-0501.2009.01872.x · 3.12 Impact Factor
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    ABSTRACT: Recent trends in clinical implantology include the use of endosseous dental implant surfaces embellished with nano-sized modifications. The current study was initiated to evaluate the mechanical properties, as well as the potential beneficial effects, of electrosprayed CaP nanoparticle-coated (nano-CaP) implants on the in vivo osteogenic response, compared with grit-blasted, acid-etched (GAE) implant surfaces as controls. For this purpose nano-CaP coatings were deposited on cylindrical screw-type (St) implants and implanted bilaterally into the iliac crest of goats for 6weeks. In addition to histological and histomorphometrical analyses, insertion torque and removal torque values were measured on implant placement and retrieval, respectively. The present study showed similar insertion and removal torque values for nano-CaP-coated and GAE control implants, with no statistically significant increase in torque value during the implant period for either group. With regard to bone-implant contact and peri-implant bone volume, no significant differences were found between nano-CaP-coated and GAE implants after 6weeks implantation. In conclusion, this study has demonstrated that in situations in which implants are placed in a non-compromised situation using a standard press fit implantation strategy the performance of electrosprayed nano-CaP coatings is comparable with GAE implants, both with respect to implant fixation and bone healing response.
    Acta biomaterialia 11/2009; 6(6):2227-36. DOI:10.1016/j.actbio.2009.11.030 · 5.68 Impact Factor
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    ABSTRACT: The enzyme alkaline phosphatase (ALP) was recently proposed as an implant coating material in order to improve the biological performance of orthopedic and dental implants. The present study evaluated the in vivo bone response to electrosprayed coatings, consisting of ALP, calcium phosphate (CaP) or a combination thereof (composite coating: ALP+CaP) compared to non-coated controls (gritblasted and acid etched). A total of 80 implants (n=10) with a gap of 1.0mm, was implanted intramedullary and bilaterally into the femurs of 80 rats. After 1 and 4 weeks, bone response was evaluated qualitatively (histology) and quantitatively (histomorphometry). The results of this study show that all electrosprayed coatings (ALP, CaP, ALP+CaP) significantly improve osteoconduction compared to non-coated controls after 4 weeks of implantation, without significant differences among these coated groups. Consequently, the results indicate that ALP-coatings improve the osteogenic response to a comparable extent as CaP-coatings or an ALP+CaP composite coating. In conclusion, the current study proofs that ALP-coatings have potential as bone implant coatings, though long-term data remain to be obtained. From a clinical perspective, it was observed that the process of osteoconduction is related to positional determinants, which needs to be taken into account when analyzing data on bone response.
    Biomaterials 09/2009; 30(32):6407-17. DOI:10.1016/j.biomaterials.2009.08.001 · 8.31 Impact Factor
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    ABSTRACT: In the present study, the effects of implant design and surface properties on peri-implant bone response were evaluated with both conventional histomorphometry and micro-computed tomography (micro-CT), using two geometrically different dental implants (Screw type, St; Push-in, Pi) either or not surface-modified (non-coated, CaP-coated, or CaP-coated+TGF-beta1). After 12 weeks of implantation in a goat femoral condyle model, peri-implant bone response was evaluated in three different zones (inner: 0-500 microm; middle: 500-1000 microm; and outer: 1000-1500 microm) around the implant. Results indicated superiority of conventional histomorphometry over micro-CT, as the latter is hampered by deficits in the discrimination at the implant/tissue interface. Beyond this interface, both analysis techniques can be regarded as complementary. Histomorphometrical analysis showed an overall higher bone volume around St compared to Pi implants, but no effects of surface modification were observed. St implants showed lowest bone volumes in the outer zone, whereas inner zones were lowest for Pi implants. These results implicate that for Pi implants bone formation started from two different directions (contact- and distance osteogenesis). For St implants it was concluded that undersized implantation technique and loosening of bone fragments compress the zones for contact and distant osteogenesis, thereby improving bone volume at the interface significantly.
    Biomaterials 07/2009; 30(27):4539-49. DOI:10.1016/j.biomaterials.2009.05.017 · 8.31 Impact Factor
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    ABSTRACT: Previous studies demonstrated that the addition of biodegradable polymer microparticles to calcium phosphate (CaP) cement improves the cement's degradative behavior without affecting its handling characteristics, especially its injectability and moldability. We investigated the influence of molecular weight of polymeric microparticles included in CaP cement on implant degradation and bone formation in critical-sized defects. Forty rats received cranial defects filled with formulations of CaP cement and poly(DL-lactic-co-glycolic acid) (PLGA) microparticles. Microparticles consisted of 100% high- (HMW) or low-molecular-weight (LMW) PLGA or mixtures of these (25%, 50%, or 75%). Implantation time was 12 weeks. Porosity measurements showed that the 100% HMW group was significantly less porous than the other groups. Histology and histomorphometry revealed significantly greater implant degradation in the 100% LMW group. Defect bridging was mainly seen in the 75% and 100% LMW groups, with the highest amount of bone in the 100% LMW formulation. These results suggest that LMW PLGA microparticles are associated with better bone formation than HMW PLGA, which is most likely explained by the greater degradation of LMW PLGA microparticles. In conclusion, CaP cement composites with high percentages of LMW PLGA microparticles show good bone transductive behavior, with complete defect bridging. The 100% LMW group turned out to be the best formulation.
    Tissue Engineering Part A 05/2009; 15(10):3183-91. DOI:10.1089/ten.TEA.2008.0694 · 4.64 Impact Factor
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    ABSTRACT: Despite the high success rates in implantology, the desire to use oral implants in more challenging clinical situations drives the need for continuing refinements in implant design and surface properties. In the present study, the effect of implant geometry on implant bone response was evaluated using two geometrically different implant types, i.e. screw type (St) and push-in type(Pi). Furthermore, the potential beneficial effect of an electrosprayed calcium phosphate (CaP) coating, either or not enriched with the osteoinductive growth factor TGF-beta1, on the osteogenic response was examined. A total of 54 implants, divided into six groups (n=9), were inserted into the femoral condyles of nine goats. After an implantation period of 12 weeks, retrieved specimens were evaluated histologically and histomorphometrically. Measurements were statistically evaluated using SPSS 14.0 and analyzed using a linear regression model. With respect to implant design, St-implants showed an overall superior biological healing response compared with Pi-implants. Considering surface properties, the deposition of an electrosprayed CaP (2-3 microm) coating onto implants significantly increased the amount of bone-implant contact for both implant types. Additional enrichment of the CaP coating with the osteoinductive growth factor TGF-beta1 did not significantly affect peri-implant bone response. The results of this study indicate that a substantial improvement of the osteogenic response to titanium implants can be achieved by the deposition of an electrosprayed CaP coating. The enrichment of the coating with 1 microg TGF-beta1 has only a marginal effect.
    Clinical Oral Implants Research 05/2009; 20(4):421-9. DOI:10.1111/j.1600-0501.2008.01657.x · 3.12 Impact Factor
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    ABSTRACT: DNA-based coatings possess beneficial properties useful for medical and dental implants. The present study evaluated the potential in vivo bioactivity of DNA-based coatings, either or not pretreated in simulated body fluid (SBF). DNA-based coatings were generated on titanium cylinders using layer-by-layer deposition, with bis-ureido-surfactant as the cationic component and DNA as the anionic component. Noncoated titanium implants and CaP-coated implants served as controls. A total of 80 implants, divided in four experimental groups (n = 10) were implanted unilaterally into the lateral femoral condyles of 80 rats. After implantation periods of 1 and 4 weeks, the bone-to-implant contact and bone volume around the implants were determined histomorphometrically. The results of this study showed that DNA-based coatings and CaP coatings increased bone-to-implant contact after 1 week compared to noncoated controls. After 4 weeks of implantation, bone-to-implant contact increased significantly for SBF pretreated DNA coatings and CaP coatings, whereas DNA-coated implants showed no additional effect. The bone-to-implant contact of noncoated controls increased to the level of the DNA-coated implants. Consequently, this study demonstrates that DNA-based coatings are histocompatible and favor early bone responses. SBF-pretreated DNA-based coatings were found to increase both early and late peri-implant bone responses.
    Journal of Biomedical Materials Research Part A 04/2009; 92(3):931-41. DOI:10.1002/jbm.a.32446 · 3.37 Impact Factor
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    ABSTRACT: To perform a systematic review of the literature to assess the clinimetric properties of instruments measuring limitations of activity. The Medline, Cochrane Library, Picarta, Occupational Therapy-seeker, and CINAHL databases were searched for English or Dutch language articles published between 2001 and 2006. Two reviewers independently reviewed the identified publications for eligibility (based on the title and abstract), methodologic criteria, and clinimetric properties. To evaluate the available information of the clinimetric properties, the quality criteria for instrument properties were used. All the clinimetric properties of the 23 instruments were described based on the publications that were included. In total, 103 publications were retrieved, 79 of which were eligible for inclusion. Of these, 54 met the methodologic quality criteria. Twenty-three instruments were reviewed, divided into (1) pegboard tests measuring fine hand use only; (2) instruments measuring fine hand use only, by picking up, manipulating, and placing different objects; (3) instruments measuring single tasks (and fine hand use) by scoring task performance; and (4) questionnaires. The reliability, validity, and responsiveness of only 5 instruments were adequately described in the literature; the description of the clinimetric properties of the other instruments was inadequate. None of the instruments had a positive rating for all the clinimetric properties.
    Archives of physical medicine and rehabilitation 02/2009; 90(1):151-69. DOI:10.1016/j.apmr.2008.06.024 · 2.44 Impact Factor
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    ABSTRACT: The healing of large bone defects can be improved by osteogenic bone graft substitutes, due to growth factor inclusion. A sustained release of these growth factors provides more efficient bioactivity when compared with burst release and might reduce the dose required for bone regeneration, which is desirable for socioeconomical and safety reasons. In this study, we compared different rhBMP-2 loadings in a sustained release system of CaP cement and PLGA-microparticles and were able to couple kinetic to biological activity data. Fifty-two rats received a critical-size cranial defect, which was left open or filled with the cement composites. The implants consisted of plain, high, and five-fold lower dose rhBMP-2 groups. Implantation time was 4 and 12 weeks. Longitudinal in vivo release was monitored by scintigraphic imaging of (131)I-labeled rhBMP-2. Quantitative analysis of the scintigraphic images revealed a sustained release of (131)I-rhBMP-2 for both doses, with different release profiles between the two loadings. However, around 70% of the initial dose was retained in both implant formulations. Although low amounts of rhBMP-2 were released (2.4 +/- 0.8 mug in 5 weeks), histology showed defect bridging in the high-dose implants. Release out of the low-dose implants was not sufficient to enhance bone formation. Implant degradation was limited in all formulations, but was mainly seen in the high-dose group. Low amounts of sustained released rhBMP-2 were sufficient to bridge critically sized defects. A substantial amount of rhBMP-2 was retained in the implants because of the slow release rate and the limited degradation.
    Journal of Biomedical Materials Research Part A 12/2008; 87(3):780-91. DOI:10.1002/jbm.a.31830 · 3.37 Impact Factor
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    ABSTRACT: Cleft palate repair leaves full-thickness mucosal defects on the palate. Healing might be improved by implantation of a mucosal substitute. However, the genetic and phenotypic deviations of cleft palate cells may hamper tissue engineering. The aim of this study was to construct mucosal substitutes from cleft palate cells, and to compare these with substitutes from normal palatal cells, and with native palatal mucosa. Biopsies from the palatal mucosa of eight children with cleft palate and eight age-matched control individuals were taken. Three biopsies of both groups were processed for (immuno)histochemistry; 5 were used to culture mucosal substitutes. Histology showed that the substitutes from cleft-palate and non-cleft-palate cells were comparable, but the number of cell layers was less than in native palatal mucosa. All epithelial layers in native palatal mucosa and mucosal substitutes expressed the cytokeratins 5, 10, and 16, and the proliferation marker Ki67. Heparan sulphate and decorin were present in the basal membrane and the underlying connective tissue, respectively. We conclude that mucosal cells from children with cleft palate can regenerate an oral mucosa in vitro.
    Journal of Dental Research 08/2008; 87(8):788-92. DOI:10.1177/154405910808700806 · 4.14 Impact Factor
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    ABSTRACT: To evaluate the effect of infant orthopedics (IO) on facial appearance of 54 patients with unilateral cleft lip and palate (UCLP), aged 4 and 6 years. Prospective two-arm randomized controlled clinical trial in three Cleft Palate Centers in the Netherlands (Dutchcleft-trial). Patients were divided randomly into two groups. Half of the patients (IO+) had a plate until surgical closure of the soft palate at the age of +/- 52 weeks; the other half (IO-) received no intervention. Facial appearance at 4 and 6 years of age assessed on full face photographs and photographs showing only nose and mouth. Ratings were performed on a VAS-scale by professionals and laymen. At 4 years of age the full face pictures of IO+ children were scored to be more attractive than those of IO- children. However, this difference had disappeared at 6 years of age. At the age of 6, only professionals saw a significant difference on nasolabial photographs between IO+ and IO-. Regression analysis showed a minor effect of occlusion, lip revision, or type of nose reconstruction on the esthetic results. IO had a positive effect on full facial appearance of UCLP children at the age of 4 years, but at the age of 6, only professionals saw a positive effect of IO on the nasolabial photographs. This is irrelevant for UCLP patients since they deal with laymen in their daily life.
    The Cleft Palate-Craniofacial Journal 08/2008; 45(4):407-13. DOI:10.1597/07-043.1 · 1.24 Impact Factor
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    ABSTRACT: Provision of adequate patient information may contribute to a "satisfying" surgical treatment. The patient's views on successful transfer of information concerning operative characteristics may not be in concert with the surgeon's. The aim of the present study was to determine opinions of both surgeons and patients about issues of surgical information. A group of surgeons (n = 24) and surgical patients (n = 125) responded to a questionnaire that included 80 topics involving domains of information on disease, physical examination, preoperative period, anesthesia, operation, postoperative period, self care, and general hospital issues. Both groups were asked for their opinion on what they considered important and useful preoperative information for patients. Questions were scored with a visual analog scale. The reliability of the questionnaire was calculated with Cronbach's alpha. Differences in opinions between surgeons and patients were analyzed with Student's t-test. The Cronbach's alpha of the questionnaire was high (0.91), indicating its high reliability. Patients scored significantly higher (p < 0.001) in most domains, including preoperative period, anaesthesia, operation, postoperative period, self care, and general hospital information. Women demonstrated a significantly higher need for information than men did. These findings were independent of patient age or complexity of operation. In contrast, surgeons thought that their patients desired more extensive information on cause, effect, and prognosis of the disease itself (p < 0.001). Surgeons generally underestimate their patients' desire for receiving extensive information prior to a surgical procedure of any complexity. Surgeons should develop strategies to bridge this informational mismatch.
    World Journal of Surgery 07/2008; 32(6):964-70. DOI:10.1007/s00268-008-9581-1 · 2.35 Impact Factor
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    ABSTRACT: The effect of platelet-rich plasma (PRP) on bone formation was investigated in a rabbit segmental radial defect model. The purpose of the study was to evaluate the bone inductive properties of PRP with titanium fiber mesh and autologous bone chips in a 15-mm rabbit radial defect model. Eighteen New Zealand white rabbits were divided into three groups: I, PRP with autologous bone (PRP-Ti-Bone); II, autologous bone (Ti-Bone); III, control group (Ti). The implants were placed in the radial defect for 12 weeks. After sacrifice, all specimens were harvested for histological, histomorphometrical and radiographic analysis. Histomorphometrical analysis showed that bone formation was higher in the implants with PRP (PRP-Ti-Bone: 37+/-8%) than in those without PRP (Ti-bone: 25+/-6% and Ti: 25+/-5%) after 12 weeks of implantation. It was concluded that PRP has a stimulatory effect on bone formation in titanium fiber mesh filled with autologous bone graft in segmental bone defects. Titanium fiber mesh was also shown to be an excellent scaffold material for the application of autologous bone grafts with or without PRP.
    International Journal of Oral and Maxillofacial Surgery 07/2008; 37(6):542-9. DOI:10.1016/j.ijom.2008.01.009 · 1.36 Impact Factor

Publication Stats

3k Citations
301.46 Total Impact Points


  • 1991–2011
    • University of Groningen
      • • Department of Surgery
      • • Department of Plastic Surgery
      Groningen, Groningen, Netherlands
  • 2010
    • Amphia Ziekenhui
      Breda, North Brabant, Netherlands
  • 1994–2010
    • Radboud University Medical Centre (Radboudumc)
      • Department of Biochemistry
      Nymegen, Gelderland, Netherlands
  • 1993–2009
    • Radboud University Nijmegen
      • • Plastic Surgery Clinic
      • • Department of Orthodontics
      Nymegen, Gelderland, Netherlands
  • 2008
    • Erasmus Universiteit Rotterdam
      • Department of Obstetrics and Gynaecology
      Rotterdam, South Holland, Netherlands
    • Catharina Hospital
      Eindhoven, North Brabant, Netherlands
  • 2002
    • University of Toronto
      • Department of Speech-Language Pathology
      Toronto, Ontario, Canada
    • Rice University
      Houston, Texas, United States
  • 1997
    • University Medical Center Utrecht
      • Plastic Surgery
      Utrecht, Provincie Utrecht, Netherlands
  • 1992–1993
    • Universitair Medisch Centrum Groningen
      Groningen, Groningen, Netherlands
    • Academic Medical Center (AMC)
      Amsterdamo, North Holland, Netherlands