Biomedical subjects

Winnie Pradel

Publications and source records attributed to Winnie Pradel.

5 recordsLinked to original sources

PubMed2006

Bone regeneration after enucleation of mandibular cysts: comparing autogenous grafts from tissue-engineered bone and iliac bone.

OBJECTIVE: The aim of this study was to compare bone regeneration after grafting enucleated mandibular cyst cavities using either autogenous osteoblasts cultured on a biomaterial or autogenous spongiose iliac bone. STUDY DESIGN: Twenty patients with 22 mandibular cysts were assessed. Eleven cysts were filled in with tissue-engineered bone (autogenous osteblasts cultured on demineralized bone matrix Osteovit) and 11 with spongiose iliac bone as controls. Panoramic radiographs were taken preoperatively, immediately postoperatively, and 3, 6, and 12 months after surgery. Radiolucency was computer analyzed using gray-level histograms. RESULTS: In both groups bone regeneration took place in a similar fashion. After 3 and 6 months there were few differences in bone density between the groups. However, in radiographic controls after 12 months ossification was considerably stronger in cysts grafted with tissue-engineered bone. CONCLUSION: These results advocate for the clinical application of tissue-engineered bone as an alternative viable filling material for cysts.

Adolescent↗

PubMed2006

[Secondary midfacial reconstruction using different surgical techniques and computer assisted surgery].

AIM: Aim of this retrospective study was to assess the outcome after secondary midfacial reconstruction using different operation techniques and computer assisted surgery. Functional and aesthetic aspects as well as experiences are reported. PATIENTS AND METHODS: 18 patients were assessed for enophthalmos, diplopia, and aesthetics during a follow-up period of up to 2.5 years. RESULTS: In 40% of the patients several techniques for soft and hard tissue reconstruction were used. In 5 of the 9 patients diplopia was improved; in 4 patients there was no change. A significant enophthalmos was corrected in 8 out of 12 patients. After additional surgery 6 patients had a good aesthetic result, 7 a satisfactory and 5 a poor. CONCLUSION: For secondary midfacial reconstruction often a combination of different surgical techniques is necessary. Bony asymmetries and enophthalmos were successfully corrected, however, functional and aesthetic impairment due to bad soft tissue condition are difficult to correct. Computer assisted surgery is helpful for dissection within the orbit, for graft placement, and for positioning of osteotomized segments.

Adolescent↗

PubMed2006

Efficacy of computer-assited surgery in secondary orbital reconstruction.

PURPOSE: In this study the efficacy of computer-assisted surgery (CAS) used for secondary orbital reconstruction after midfacial fractures was evaluated, comparing the clinical outcome with that after conventional surgery (CS). Special consideration was given to whether CAS can reduce the number of secondary corrections. PATIENTS AND METHODS: Twenty consecutive patients (24 orbits; 12 in each group) were assessed for enophthalmos, diplopia, and aesthetics during a follow-up period of up to 3 years. RESULTS: After CAS, enophthalmos was fully corrected in 8 of 11 orbits but after CS in only 6 of 10 orbits. Improvement of diplopia was achieved in 1 of 7 (CAS) and in 3 of 4 (CS) patients. The aesthetic result after secondary reconstruction and additional surgery was better in the CAS group. Additional surgery to correct bony structures was only necessary in 3 patients of the CS group. Additional soft tissue surgery was necessary in both groups. CONCLUSION: CAS can improve the clinical outcome of reconstructive bone surgery reducing the amount of additional hard tissue procedures. It was helpful during dissection of the scarred orbital tissue and placement of a graft. However, it had no impact on soft tissue correction especially with respect to function.

Adolescent↗

PubMed2006

Influence of Cyclosporin A on human gingival keratinocytes in vitro.

PURPOSE: Gingival hyperplasia is a well known side effect of Cyclosporine A therapy. The aetiology of this is not totally understood and there is debate whether it is hyperplasia of the gingival epithelium or of the submucosal connective tissue, or both, and what roles play factors like age and gender of the patients, duration and dosage of the drug. MATERIAL AND METHODS: The influence of different Cyclosporine A concentrations (10(-6) g/ml; 5 x 10(-7) g/ml; 10(-9) g/ml) and of no medication (controls) on growth and proliferation of cultured human gingival keratinocytes was investigated after a culture period of 3, 6 and 9 days. Cell proliferation was assessed by counting anti Ki-67 stained nuclei, cell growth by counting total number of nuclei and by the EZ4U-assay. RESULTS: There was no significant correlation of the cell proliferation rate and cellular growth with either gender (p > 0.568) or duration of medication (p > 0.876); but Cyclosporine A concentration showed a highly significant influence on cellular growth (p = 0.0001). Inhibition of cell growth was dependent on drug dosage, but a low concentration of 10(-9) g/ml even stimulated cell growth. CONCLUSIONS: There is evidence that Cyclosporine A in low concentrations (10(-9) g/ml as applied in long-term therapy) stimulates gingival keratinocyte growth and therefore might be related to hyperplasia of the gingiva. However, high Cyclosporine A concentrations may inhibit cell growths and factors like gender of the patient did not show any influence in-vitro.

Adolescent↗

PubMedDate not supplied

Influence of harvesting technique and donor site location on in vitro growth of osteoblastlike cells from facial bone.

PURPOSE: Donor morbidity is minimized when tissue engineering is applied to produce osteogenic grafts by growing osteoblasts on biomaterials. However, limiting factors are the origin, proliferation, and differentiation of osteoblasts. Therefore, the aim of this study was to evaluate the efficacy of growing osteoblasts from different types of bone samples and to assess the influence of the donor site. MATERIALS AND METHODS: From 28 patients 37 bone specimens were obtained during removal of third molars in the maxilla and mandible. Seventeen specimens were bone chips and 20 were bone sludge. After subculturing primary cultures, histochemical and immunhistochemical tests (EZ4U test, BrdU labeling, ALP histochemistry, type I collagen immunohistochemistry, osteocalcin ELISA) were performed to determine cell proliferation, viability, and differentiation. RESULTS: Both bone chips and bone sludge from the mandible and maxilla are suitable for culturing human osteoblastlike cells. However, bone chips were superior to bone sludge with respect to ability to grow cells, and maxillary bone was superior to mandibular bone in this regard. Harvesting technique had only little influence on the expression of cell differentiation markers (ALP, type I collagen, osteocalcin). DISCUSSION AND CONCLUSION: Chips from human membrane bone, especially from the maxilla, are suitable for culturing high numbers of differentiated osteoblastlike cells. These cells may be used to tissue engineer bone grafts, which may be used to enhance the implant placement site.

Adolescent↗