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Biomedical subjects

Paul J W Stoelinga

Publications and source records attributed to Paul J W Stoelinga.

11 recordsLinked to original sources
PubMed2006

Bone-like tissue formation using an equine COLLOSS E-filled titanium scaffolding material.

COLLOSS, a bovine extracellular matrix product containing native BMPs has already shown osteoinductive properties. To overcome problems with risk of transmissable spongiform encephalopathy (TSE) infection, an equine derived version was investigated in this study, named COLLOSS E. Disc- and tube-shaped implants were made from titanium fibre mesh. The central space of tubes was filled and the discs were impregnated with the COLLOSS E material to assess osteo-induction. These implants and non-loaded controls were implanted subcutaneously into the back of Wistar rats. After implantation periods of 2, 8, and 12 weeks, the implants were retrieved and sections were made. Histology showed a thin fibrous capsule surrounding the titanium mesh and a very mild tissue reaction. The disc implants, loaded or non-loaded, showed no bone formation at all. After 2 weeks of implantation 3 out of 5 of the loaded tubes showed bone formation with a mean of 0.3 mm2 areas of new formed bone, after 8 weeks 3 out of 6 and 0.7 mm2, and after 12 weeks this increased to 6 out of 6 and 1.0 mm2. In the non-loaded tubes only connective tissue in growth was seen. In conclusion, it was demonstrated that COLLOSS E material, loaded in a titanium fibre mesh tube shows osteoinductive properties. The effect of COLLOSS E has to be investigated further in orthotopic sites, which resemble more the final clinical application for bone reconstruction.

Animals↗
PubMed2006

The effect of platelet-rich plasma on the bone healing around calcium phosphate-coated and non-coated oral implants in trabecular bone.

The effect of local application of autologous platelet-rich plasma (PRP) on bone healing in combination with the use of titanium implants with 2 different surface configurations was investigated. PRP fractions were obtained from venous blood sample of 6 goats and applied via gel preparation and subsequent installation in the implant site or via dipping of the implant in PRP liquid before insertion. Thirty-six implants (18 non-coated and 18 calcium phosphate (CaP) coated) were placed into the goat femoral condyles (trabecular bone). The animals were sacrificed at 6 weeks after implantation, and implants with surrounding tissue were processed for light microscopical evaluation. In addition to subjective description of the histological findings, histomorphometrical variables were also evaluated (the bone-implant contact and the bone mass adjacent to the implant). Significantly more interfacial bone-to-implant contact was observed for all 3 groups of CaP-coated implants and the titanium / liquid group (non-coated implant with PRP liquid) than for the other 2 non-coated titanium groups (with PRP gel or without PRP). The evaluation of the bone mass close to implant surface indicated that all the groups induced a significant increase of the bone mass except the PRP gel groups. On the basis of the observations, it was concluded that magnetron-sputtered CaP coatings can improve the integration of oral implants in trabecular bone. The additional use of PRP did not offer any significant effect on the bone response to the CaP-coated implants, whereas PRP in a liquid form showed a significant effect on bone apposition to roughened titanium implants during the early post-implantation healing phase.

Animals↗
PubMed2005

Bone SPECT reduces the number of unnecessary mandibular resections in patients with squamous cell carcinoma.

High percentages (35-78%) of resected mandibles without bone invasion have been reported in squamous cell carcinoma (SCC), adjacent or fixed to the mandible, stressing the need for accurate imaging methods. The aim of this study is to determine the value of bone single photon emission computed tomography (SPECT) for the evaluation of mandibular invasion by SCC. Seventy-nine patients with SCC, adjacent or fixed to the mandible, were included. The results of bone SPECT were compared to the histology of the resection specimens. Bone SPECT was positive in all 50 patients with mandibular invasion and negative in 17 of 29 patients without mandibular invasion. In conclusion, a negative bone SPECT rules out mandibular invasion. Important clinical implications are then that further imaging is not necessary and that the resection can be kept limited. Inclusion of SPECT in the preoperative assessment of these patients will lead to a considerable reduction of unnecessary mandibular resections.

Adult↗
PubMed2005

Health related quality of life after mandibular resection for oral and oropharyngeal squamous cell carcinoma.

The impact of several clinical parameters on health related quality of life (HrQOL) was evaluated in patients with squamous cell carcinoma adjacent or fixed to the mandible with special emphasis on postoperative radiotherapy and type of mandibular resection. One-hundred and five returned EORTC-questionnaires were available for this study. Correlation analyses were used to determine the relationship between clinical parameters and HrQOL. Postoperative radiotherapy was the clinical parameter that affected HrQOL most. The type of mandibular resection had no influence on HrQOL. The affected QOL-items were all associated with eating problems, i.e. use of a feeding tube, use of nutritional supplements, swallowing, social eating, mouth opening and dry mouth. Postoperative radiotherapy should only be applied if strictly indicated. This implies that the application of postoperative radiotherapy may need reconsideration in cases without strict criteria for postoperative radiotherapy.

Adult↗
PubMed2005

A 4-year prospective study on epidemiology and clinicopathological presentation of odontogenic tumors in Tanzania.

This study, conducted between 1999 and 2003, included all patients with odontogenic tumors referred from all dental clinics and other health facilities in Tanzania to the only 4 referral centers. Demographic data and clinical and histopathologic findings were recorded. Histopathologic specimens were examined by expert pathologists. Ameloblastoma had the highest relative frequency (80.1%) and an incidence rate of 0.68 per million, followed by odontogenic myxoma (7.0%) with an incidence rate of 0.07 per million. Follow-ups of between 6 months and 4 years were carried out. Two patients developed recurrences of ameloblastoma. The incidence of ameloblastoma in this exclusively black African population did not differ from that of European countries. This is contrary to the belief that ameloblastoma has a higher incidence in black Africans as compared to Caucasians.

Adolescent↗
PubMed2005

The influence of the sagittal split osteotomy on the condylar cartilage structure and the subchondral vascularization of the temporomandibular joint: a preliminary study in goats.

OBJECTIVE: The concern that a sagittal split osteotomy of the mandibular ramus could compromise the subchondral vascularization and especially the venous outflow in the condylar area, which in turn could influence the structure of the condylar cartilage, prompted this preliminary study on goats. STUDY DESIGN: A sagittal split osteotomy was performed in the mandibular ramus at 1 side in each of 6 young adult goats. The contralateral side served as control. The animals were killed after different postoperative periods, ranging from 1 to 15 days. Histomorphometric analyses were performed after perfusion of the vascular system with India ink. CONCLUSION: Based on the observed cartilage thickening, the sagittal split osteotomy may influence the condylar cartilage in the first days postoperatively through a disturbance of the vascular supply.

Animals↗
PubMed2004

Rational approach to diagnosis and treatment of ameloblastomas and odontogenic keratocysts.

We present decision trees on the treatment of cystic lesions of the jaws based on their location. We give special consideration to the treatment of potentially aggressive lesions such as odontogenic keratocysts and cystic ameloblastomas. The treatment plan is based on a retrospective study of 19 ameloblastomas and similar published studies combined with a prospective study of keratocysts.

Acetic Acid↗
PubMed2004

Odontogenic myxoma: a clinicopathological study of 33 cases.

Odontogenic myxoma, a rare tumour that occurs in the jaws, has been reported to be the second commonest odontogenic tumour in many countries. Few studies, however, provide detailed clinicopathological findings of a large series of cases and no study so far has attempted to calculate the incidence of this condition. Retrospective and prospective studies were carried out in Tanzania from 1982 to 1998 (16 years) and 1999 to 2002 (4 years), respectively. A total of 33 cases of myxomas were found with a male:female ratio of 1:1.83. Most of the tumours were located in the mandible compared to the maxilla and were predominantly multilocular. Pain, diasthesia, ulceration, invasion of the soft tissues and tooth mobility were among the symptoms that patients presented with although the majority had no clinical signs or symptoms. Based on the prospective study only, an annual incidence of 0.07 per million can be ascertained. Late reporting was a common feature in this group of patients. Radical surgery with resection of the tumour with a safe margin is advocated.

Adolescent↗
PubMed2003

Non-surgical treatment of condylar fractures in adults: a retrospective analysis.

PURPOSE: The aim of the study was to investigate the results of non-surgical treatment of condylar fractures in a group of 60 patients with 71 condylar fractures, in order to establish a protocol to select patients for surgical treatment of condylar fractures. MATERIAL: Out of a group of 91 patients treated in a non-surgical fashion, 60 patients with a total of 71 condylar fractures responded to the request for follow-up. METHODS: Retrospective study, including clinical analysis of occlusion, asymmetry at rest and during mouth opening, maximum interincisal distance, signs of TMJ-dysfunction and analysis of radiographic data, i.e. shortening of the ascending ramus as measured on sequential orthopantomograms. RESULTS: There were five patients (8%) with an unacceptable malocclusion of which one also had considerably limited mouth opening. Fifty-five patients (92%) had none or only minor signs of TMJ-dysfunction not requiring further treatment. CONCLUSION: Only in selected patients with shortening of the ascending ramus of 8mm or more and/or considerable displacement of the condylar fragment, surgical repositioning and rigid internal fixation should be considered.

Adult↗