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Biomedical subjects

F W Neukam

Publications and source records attributed to F W Neukam.

At least 73 records · Page 4Linked to original sources
PubMed1995

The use of basic fibroblast growth factor (bFGF) for enhancement of bone ingrowth into pyrolized bovine bone.

This pilot study aimed to investigate whether in vivo cultivation of bone in porous scaffolds can be enhanced by the use of growth factors. Four adult Göttingen minipigs received subperiosteal implantation of a block of pyrolized bovine bone on either side of the mandible. The blocks were covered with polylactic membrane. On one side, the implants were loaded with 240 micrograms of lyophilized basic fibroblast growth factor (bFGF). After 5 months, bone ingrowth was found throughout the whole block into the peripheral pore layers regardless of whether or not the scaffolds had been loaded with bFGF. Fluorescence labels likewise showed no significant differences in bone formation.

Animals↗
PubMed1995

Long-term quality of life after ablative intraoral tumour surgery.

The aim of the present retrospective study was to determine the long-term quality of life of patients who had undergone intraoral tumour resection. 135 patients with a malignant tumour located in the floor of the mouth and the adjacent area were enrolled in the study. A standard questionnaire was used to determine the physical functional status, the psychological status and social functioning of cancer patients (Schipper et al., 1984). The results were related to the T-stage, the size and the location of the intraoral soft tissue defect, the mode of reconstruction and the postoperative interval. The results showed a significant correlation of the Functional Living Index-Cancer (FLIC) score with the Karnowsky-Index. The values were significantly lower in the higher T-stages. The location of the soft tissue defect, the type of soft tissue reconstruction and discontinuity resections of the mandible were crucial for postoperative quality of life, inasmuch as bilateral defects with loss of mandibular continuity and myocutaneous flap reconstructions showed significantly lower FLIC values. Reconstruction of mandibular continuity did not contribute to an increase in FLIC values. Dysphagia, reflux of food through the lips and nose during meals, decreased appetite and persistent pain significantly decreased the FLIC scores. It is concluded, that the FLIC is suitable for the determination of life quality in cancer patients since the score has shown the potential to reflect differences in postoperative life quality with regard to surgical procedures and functional sequelae.

Adult↗
PubMed1995

[Clinical and roentgenologic outcome evaluation after apicoectomy with zirconium oxide ceramic pins--a prospective study of 112 apicoectomy teeth].

We post-examined 112 apicectomies in 93 patients after an average placement period of 4.8 months (3-15.3 months) both clinically and radiologically in a prospective study to evaluate the security of success using zirconoxide ceramic pins. Clinical functioning was examined by means of the clinical mobility test, the periotest method, the sulcusfluidflowrate (periotrontest), measurements of the depths of parodontal pockets at 6 points and the papillary bleeding index in comparison to the contralateral comparative tooth. To assess the osseous regeneration of the resection defect, we carried out planimetric evaluations of standardized X-ray tooth film exposures during surgery as well as at the post-examination. The resected teeth revealed an average loosening of 10.2 in periotest. The sulcusfluidflowrate came to an average of 26.1 (control group: 22.7); the parodontal pockets were an average of 0.2 mm deeper than those of the control teeth. After 4.8 months, 63.54% of the resection defect showed complete osseous regeneration. Considering the clinical and the radiological criteria, the rate of success was 85%. Clinical use of zirconoxide ceramic pins is recommended. The high radiolucency of zirconoxide ceramics permits a safe assessment of the osseous regeneration and therefore a safe assessment of resection success.

Adolescent↗
PubMed1995

[Clinical and roentgenologic evaluation of the outcome of therapeutic tooth movement for occlusal adjustment].

The indication of therapeutic tooth luxation in partly impacted teeth as the only method of occlusal adjustment has up to the present been rare. It was therefore the aim of this retrospective, long-term study to include clinical and X-ray results following therapeutic molar luxation (OK 6, UK 7). After an average observation period of 5.3 years, all teeth (7) with incomplete root formation at the time of luxation were rated "successful" following molar luxation. On the other hand, only 2 out of 4 teeth were hand, only classified as "successful" following molar luxation with complete root formation. The results have shown that therapeutic tooth luxation for occlusal adjustment of partly retained molars has a high rate of success when the indication is correctly handled. Because the prognosis is determined according to the stage of root formation, the surgical approach of tooth luxation should be used solely in teeth whose root development has the 1/2 to 3/4 of the expected definitive root length and whose Foramen apicale is open at the time of operation. When an atraumatic operation technique is used, further root formation and a maintained sensibility of the pulp can be reckoned with.

Adolescent↗
PubMed1994

Bone scintigraphy in the evaluation of bone grafts used for mandibular reconstruction.

Bone scintigraphy was applied in the follow-up of 24 patients who received bone grafts for reconstruction of the mandible after partial resection. Semiquantitative assessment of the grafts was done with a six-grade scoring system, based on comparison of tracer uptake in the graft and in the calvarium (as an internal control). Sixty-nine bone scans were evaluated. Late planar imaging was carried out in all cases, and single-photon emission tomography (SPET) was performed additionally in 34 of these cases. Complications were observed in four grafts. They occurred less frequently in revascularized grafts than in non-revascularized grafts. Planar scintigrams performed within 14 days after reconstruction showed a significantly higher tracer uptake in grafts with an uncomplicated further course than in those which developed complications. Follow-up scintigrams after 1 and 3 months revealed a significant increase in tracer uptake in grafts with an uncomplicated course. This was not apparent in grafts which developed complications. The tracer uptake was estimated to be higher on the basis of the SPET scans as compared with the planar scintigrams. It is concluded that bone scintigraphy is of prognostic value in the evaluation of bone grafts used for mandibular reconstruction. SPET seems to be more sensitive than planar imaging for the assessment of graft viability.

Bone Transplantation↗
PubMed1994

Immediate insertion of two types of implants into vascularized bone grafts used for mandibular reconstruction in miniature pigs.

Reaction of bone tissue was investigated after placement of two different types of implants in vascularized iliac bone grafting. After the mandibles of six Göttingen minipigs were reconstructed with vascularized bone of the iliac crest, hydroxyapatite-coated implants and titanium screw implants were placed in the graft. The animals were killed at 14, 28, and 56 days after the implantation, and the healing processes were examined histologically. In the vascularized bone graft, new bone formed well around the implants, but some of the implant surfaces were covered with soft tissue by advancing bone resorption. The results suggest that a hydroxyapatite-coated implant as well as a titanium screw-type implant might be applied with a vascularized bone graft for jaw reconstruction. However, implants placed simultaneously with the vascularized bone graft had less osteointegration than implants placed in nongrafted control sites.

Animals↗
PubMed1994

Enhancement of bone ingrowth into a porous hydroxylapatite-matrix using a resorbable polylactic membrane: an experimental pilot study.

The objective of this pilot study was to study bone ingrowth into porous hydroxylapatite (HA) blocks using a polylactic membrane for guided tissue regeneration. Porous HA blocks were placed on both sides of the mandible and of the ilium in five Göttingen minipigs. On one side a polylactic membrane was used to cover the blocks. After 5 months, the blocks with the membrane covering showed complete bony penetration of the HA matrix both in the mandible and the ilium. The blocks without the membrane covering showed substantially less and irregular bone ingrowth after placement on the mandible and poor ingrowth after placement on the ilium. The newly formed bone in the blocks from the ilium showed a cancellous structure while bone tissue inside the blocks from the mandible exhibited a dense cortical appearance. The polylactic membrane was nearly completely degraded at the time of investigation.

Animals↗
PubMed1994

Long-term results of blood flow and cutaneous sensibility of flaps used for the reconstruction of facial soft tissues.

PURPOSE: The aim of this study was to determine the blood flow and the cutaneous sensibility of flaps after the repair of tumor-related defects of the facial skin. PATIENTS AND METHODS: Fifty restorations (27 local flaps, 6 island flaps, 7 free skin grafts, and 10 microvascular grafts) were examined using laser Doppler flowmetry, two-point discrimination, and a pain and thermal sensibility testing device. The average postoperative interval was 62 months. Measurements were performed on the flap surface, the donor site, and the contralateral areas corresponding to the donor site and the former defect. Paired t-tests were used to assess statistically significant differences between the sites of measurement. RESULTS: Results showed a rate of both blood flow and two-point discrimination on the surface of local flaps and island flaps that was not statistically different from the corresponding area of the unoperated side. Free skin grafts exhibited incomplete restoration of thermal sensibility and increased blood flow rates compared with the donor site. Large microvascular flaps showed complete loss of cutaneous sensibility in six cases, whereas partial restitution without reproducible two-point discrimination was found in the remaining patients after an average interval of 39 months. Flowmetry rates of microvascular flaps corresponded to those of the donor site and were significantly lower than those of the recipient site in the head and neck area.

Face↗
PubMed1994

Reconstruction of facial soft tissues after resection of skin tumors.

The aim of the present study was to analyse the results of various reconstruction techniques of the facial skin with regard to general parameters such as the patients' age and health condition and to surgical parameters such as defect size, contamination of surgical fields and the type of reconstruction. 273 cases were evaluated, comprising local flaps (217), island flaps (21), free skin grafts (22) and cutaneous or myocutaneous distant flaps (13). The overall rate of major complications was 13.5%. No correlation was found with the age or impaired health of the patients nor did contamination by oral/nasal bacterial flora or the type of restoration show any significant correlation. The size of the defect turned out to be the only variable significantly related to the occurrence of complications (p = 0.0108). The complication rate observed following the repair of defects smaller than 30 mm in diameter was 7.5% while it rated 19.1% following the repair of defects larger than 30 mm. The overall rate of partial or total flap necrosis was low (2.9%). Secondary corrections and further surgical re-entry were required in 4.7% of all patients.

Age Factors↗
PubMed1994

[Postoperative monitoring of microvascular flap repair with pulse oximetry--initial experience].

The surgical success of microvascular free flaps or pedicled flaps depends on the function of the nutritive vessels. Complications such as thrombosis or vessel kinking, are dangerous and may result in flap loss. During the last decade, different methods were tested for their capability of monitoring flap perfusion. We report our preliminary experience with the continuous and non-invasive pulse oximetry by using a special reflection sensor positioned on the surface of the flap.

Adult↗
PubMed1994

[Functional and esthetic reconstruction of complex facial defects after tumor resection and trauma].

Nowadays, free revascularized myocutaneous and osteomyocutaneous flaps are available as grafts of high biological value, which allow functional and esthetic rehabilitation after tumor resection and trauma. The use of these flaps however must be considered carefully, since these techniques require a good general physical condition of the patient for extensive surgery and a considerable operation time. Therefore we consider these flaps as adequate solely in cases of poor recipient site conditions after previous irradiation or chronic infection, in cases of extensive scar formation and in large bone and soft tissue defects. In these cases revascularized grafts from the iliac crest have proven to be useful in mandibular reconstruction while scapular grafts has been useful in restorations of the midface.

Bone Transplantation↗
PubMed1994

[Defect bridging and augmentation of the mandible by transplantation of locally cultured bone in a porous matrix].

In the present study, 9 Göttingen Minipigs received one porous hydroxylapatite block each on the buccal cortex of their mandibles. Autogenous bone was gained inside these blocks by using a polylactic membrane covering for guided tissue regeneration. The blocks showed thorough penetration by bone tissue after 5 months and were transplanted as onlay grafts and for restoration of mandibular defects. The onlay grafts were fixed by titanium fixtures and miniplates respectively. Histologic examination 3 months after transplantation showed maintenance and remodelling of the transplanted bone inside the pores of the blocks in most specimens. There war a soft tissue free contact between the transplanted bone and the inserted fixtures and screws. Results indicate that autogenous bone may be gained inside a porous matrix of calcium phosphate and be transplanted for reconstruction of contour and discontinuity defects.

Animals↗
PubMed1994

[Microsurgical reanastomosis of scapula transplants for maxillofacial bone reconstruction].

Between 1989 and April 1993 29 grafts from the scapula region have been harvested for reconstruction in the head and neck area. 7 out of 20 osteocutaneous grafts have been used for reconstructions in the maxillary/midface area. In this area, one graft was completely lost due to venous congestion and another loss of the soft tissue component of one graft occurred. The complication rate in the maxilla seems to be higher than in application of the flap for mandibular reconstruction. Reconstruction in the maxillary/midface area most often requires several surgical steps. In special situations, as for example when unfavorable conditions regarding the recipient vessels exist, primary soft tissue reconstruction with a technically less demanding flap and a longer vascular pedicle (for example m. latissimus dorsi) and secondary free bone grafting may be indicated.

Bone Transplantation↗
PubMed1993

Metal release from titanium fixtures during placement in the mandible: an experimental study.

Titanium screw taps and titanium fixtures were investigated by SEM before and after experimental use. Peri-implant bone surfaces were examined immediately after surgery and 5 months after implantation by SEM using the SE mode, backscattered electron imaging, and EDX analysis to detect titanium contamination of the bone specimens. The Ti content of the livers, kidneys, and lungs of six Göttingen minipigs, which had received two screw implants each, was determined using flameless atomic absorption spectroscopy and compared to a control group with no implants. Results showed that Ti particles were abraded and deposited on the bone surface during the preparation of implant beds. Five months after placement, particles were no longer observed on the bone surface next to the implants. Determination of the Ti concentration of the inner organs showed that the lungs contained the highest amount of titanium. The Ti content of the kidneys and livers was much lower. All values differed significantly from those of the control group (P < .01).

Alveolar Process↗
PubMed1992

Restoration of the lateral sinus wall using a collagen type I membrane for guided tissue regeneration.

A collagen type I membrane prepared from bovine pericard was used to restore and thicken the lateral sinus wall after resection in 6 Göttingen minipigs. One rehydrated collagen type I membrane was placed on the intact sinus mucosa. A hydroxyapatite block was placed on this membrane and covered with a second membrane. After 6 months there was complete, bony regeneration in the space between the 2 membranes and thickening of the new bone plate compared to the untreated control side. This study shows that a collagen membrane can be applied for guided tissue regeneration.

Animals↗