PubMed Health⌕ Search

Biomedical subjects

H Feifel

Publications and source records attributed to H Feifel.

At least 19 recordsLinked to original sources
PubMed2001

Aesthetic and functional results of harvesting radial forearm flap, especially with regard to hand function.

There is controversy in the literature regarding donor site morbidity following radial forearm flap harvesting. The aim of this study was to verify possible functional and aesthetic impairments at the donor site. Thirty-five patients who underwent maxillofacial reconstruction using radial forearm flap were asked to give their subjective assessment of the aesthetic outcome at the donor site and of postoperative hand function. They were also examined for trophic status; cold intolerance and tactile sensitivity of split-thickness skin graft, palm and finger pads; grip strength and finger-to-thumb pinch strength; range of movement for the wrist and finger joints; as well as functional hand testing. Slight impairments regarding hand strength and mobility were observed. However, due to their small extent they were of no clinical relevance, as shown by 85.7% of our patients displaying optimal functional hand testing values (80-100%), and 88.6% giving a positive subjective assessment (80-100%) of postoperative vs preoperative hand function. The results show that donor site morbidity following radial forearm flap harvesting is low.

Cold Temperature↗
PubMed2000

[Bone regeneration in Pro Osteon 500 alone and in combination with Colloss in the patellar gliding model of the rabbit].

In order to optimize osteoneogenesis, Pro Osteon 500 (coralline hydroxylapatite) was coated with the osteoinductive protein complex Colloss and implanted in distal rabbit femurs for 28, 84, 168, and 365 days. Uncoated material was placed contralaterally and examined for intraindividual control. No impairment of bone formation on the implant granules was noted upon histological examination, as well as after coating with Colloss. Both osteoid and chondroid were sparsely found. After 84 days the original woven bone had been largely transformed into lamellar bone. Formation of new bone increased up to 84 days and from then on ranged from 49.8% to 58.7% up to 365 days. This increase was independent of the lower density of the cancellous bone surrounding the graft. Coating with Colloss promoted osteoneogenesis to a maximum of 15.1%, which, however, was not statistically significant. The implant granules were not subject to resorption.

Animals↗
PubMed1999

[Microsurgical anastomosis of the bone transplant as implant site in the maxilla].

A total of 27 vascularized iliac crest segments and four vascularized scapula transplants were transferred to achieve masticatory rehabilitation in 31 patients suffering from extensive maxillary defects; 83 Brånemark implants and 16 IMZ implants were inserted 4-8 months after the bone transplantation. The implants were uncovered 6-8 months after insertion. All patients were provided with a bar-fixed, removable prosthesis. At an average insertion period of 4.5 years, the implant loss rate was 18.8%. The effectiveness of a combination of microsurgical bone transplantation and implantation in treating serious maxillary defects is thus demonstrated.

Alveolar Ridge Augmentation↗
PubMed1999

Palatal implant anchorage reinforcement of posterior teeth: A prospective study.

A new orthodontic implant anchor system (Orthosystem) has been developed. This 1-piece device made from titanium consists of a screw-type endosseous section (lengths of 4 and 6 mm), a cylindrical transmucosal neck, and an abutment. Clamp caps with slots provide for attachment of square orthodontic wires (transpalatal bars) to the implant. The aim of the present prospective study was to evaluate the anchorage capacity of palatally inserted Orthosystem implants for anchorage reinforcement of posterior teeth. The sample consisted of 9 dental Class II patients (age 15 to 35 years) whose treatment plan included extraction of the maxillary first premolars. Each of the patients received 1 implant inserted into the center of the anterior palate. After a mean unloaded implant healing period of 3 months, transpalatal bars were inserted to connect the posterior teeth to the implant. Retraction of the canines and incisors was accomplished without the use of compliance-dependent headgear or Class II elastics. The degree of anchorage loss as well as the amount of canine and incisor retraction were evaluated by measurements of the casts and lateral cephalograms. The mean anchorage loss was 0.7 mm on the right side and 1.1 mm on the left (P <.05). The right and left canines were retracted 6.6 and 6.4 mm, respectively, and the mean overjet reduction was 6.2 mm. Because clinical assessment and postremoval histologic assessment both revealed stability of the short implant, the small anchorage loss was most likely from the deformation of the transpalatal bars by the orthodontic forces. Nevertheless, the treatment goal was achieved in all patients without the use of compliance-dependent auxiliaries. The clinical experience during and after implant insertion, active orthodontic treatment, retrieval of the implant, and subsequent wound healing are described.

Adolescent↗
PubMed1998

[Correlation of odontogenic soft tissue infection and thermal effects with special reference to temperature sense. Statistical analysis of 2,111 patients].

A possible correlation between the thermal effects of the weather and the frequency of odontogenic soft-tissue infections was investigated with special regard to the so-called felt temperature (gT). Clinical data of 2111 patients of the years 1992-1996 in whom an incision was made because of an odontogenic soft-tissue infection were evaluated retrospectively and correlated to meteorological data for Aachen, collected or calculated by the "Deutsche Wetterdienst". In order to describe the thermal exchange between the human organism and the surroundings in a satisfactory way, the gT was chosen. The gT is a complexly calculated meteorological parameter which allows physiologically adequate estimation of the thermic surroundings of humans. Over the whole study time there was no impressive correlation between course and changing of the gT and the frequency of odontogenic soft-tissue infections. This result agrees with our finding that there was no seasonal accumulation of odontogenic soft-tissue infections over the year in Aachen. Nevertheless, there was a statistically significant negative correlation between values or weighted changes of the gT and the frequency of abscess and/or infiltration in the winter and less in springtime. A similar statistically significant correlation could not be found for summer or autumn.

Adolescent↗
PubMed1997

Primary surgery of skeletal dysgnathias.

Three case studies from the patient population of the University Hospital of Aachen (RWTH) are used to describe indications for primary surgical intervention in skeletal dysgnathia. Such preconditions may apply in the case of mandibulo-alveolar protrusion, anomalies where there is little or no option to fixing orthodontic appliances (enamel hypoplasia or shortened crowns), severe transversal discrepancies and skeletal dysgnathia with pronounced malpositioning in the alveolar process and the teeth. The advantages are improved compliance (through the patient experiencing success at the outset of treatment) and limitation of postoperative orthodontic treatment to occlusive fine adjustments of the occlusion, resulting in an appreciable reduction in both the degree and duration of tooth movement and tissue damage.

Adult↗
PubMed1996

Integration of three-dimensional cephalometry and 3D-skull models in combined orthodontic/surgical treatment planning.

In 15 adult patients with severe dentomaxillofacial deformities we integrated 3-dimensional cephalometry and 3D-model surgery with individually milled or stereolithographically built skull models in our combined orthodontic/surgical diagnosis and treatment planning. After the generation of contiguous axial CT-scans the CT data sets were transferred to a commonly used computing system (IBM-PC) to reconstruct 3D-images from any point of view. After the definition of measurement points, distances and angles at the skin and bone surface a 3-dimensional cephalometric analysis could be performed directly in the 3D-objects on the monitor. This allows a quantitative assessment of skeletal asymmetries. The transfer of CT data to life-size 3D-skull models and replacement of imprecise dental arches by dental casts different orthodontic and surgical treatment concepts could be evaluated. The 3D-model surgery represents a new quality of treatment prediction in the individual dentomaxillofacial morphology. The orthodontic set-up and 3D-model surgery permit a verification of the feasibility of the most suitable mobilization and placement of bone segments. The clinical treatment sequences indicated that the integration of 3-dimensional cephalometry and 3D-model surgery in patients with severe asymmetric dentomaxillofacial deformities allowed a higher precision of diagnosis and treatment planning.

Adult↗
PubMed1996

[Conservative versus surgical therapy of unilateral fractures of the collum mandibulae--anatomic and functional results with special reference to computer-assisted 3-dimensional axiographic registration of condylar paths].

A clinical, radiographic and computer-assisted axiographic follow-up was carried out on 60 patients who had been treated for unilateral subcondylar fractures. These were patients of the Department of oral, maxillofacial and facial plastic surgery of the Medical Faculty of the University of Technology in Aachen, Germany. After surgical reduction of the condyle with fixation by osteosynthesis where results were positive, 27 patients exhibited a shortening of the condyle paths on the side operated on by up to 16.4%. Although conservative therapy produced slighter straightening of the condyle with more or less strongly marked condylar deformations in two-thirds of the cases, functionally more positive results were obtained by markedly slighter limitation of the condyle paths on the traumatized side. These results would appear to indicate operative therapy of unilateral subcondylar fractures in the case of luxation fractures, condylar dislocation in excess of 50 degrees, and in those cases where intermaxillary immobilization is not feasible. In the remaining cases, conservative treatment is preferred, due to it showing functionally more positive results.

Adult↗
PubMed1994

High resolution computed tomography of the inferior alveolar and lingual nerves.

Coronal and axial high resolution computed tomography of the mandible extends facilities in dentoalveolar surgery. Preoperatively the relationship between the mandibular canal and the roots of deeply displaced third molars can be determined precisely. After surgical removal of lower wisdom teeth iatrogenic defects of the lingual cortical bone can be detected. The additional information obtained when compared with conventional radiographs is demonstrated in case descriptions. Indications for this technique, radiation exposure and implications for surgery are discussed.

Adult↗
PubMed1994

Measurement of mandibular bone density after iliac crest grafting.

Nonvascularized and microsurgically revascularized iliac bone grafts used for mandibular reconstruction behave differently during healing. Quantitative computer tomography (QCT) was used to investigate these differences with respect to mineralization and macrostructure of the grafts after a period of adequate functional loading. It was shown that in nonvascularized grafts, reactive sclerosis occurs, as a sign of an irregularly reparative metaplastic process and mineralization. In comparison with the intact iliac crest, the bone density of the graft was markedly increased. The microsurgically revascularized grafts, however, showed retention of structural differentiation into homogeneous cancellous bone, and a smoothly demarcated cortex with essentially unchanged bone density. Possible explanations of these differences are discussed.

Absorptiometry, Photon↗
PubMed1993

Quantitative computed tomography--a new method in the assessment of autologous augmentation of the mandible.

Following autologous alveolar ridge augmentation with microsurgically revascularized iliac crest segments, quantitative computed tomography was used for the first time to examine mandible and graft. The results are shown by the example of 2 cases. Sufficient mineralization of the graft could be demonstrated macromorphologically as well as by means of bone densitometry. Insignificant variations of the grade of mineralization in the separate segments of the graft may exist, caused by the operation. There were no distinct reactive scleroses indicating an extensive process of transformation and adaptation.

Alveolar Ridge Augmentation↗
PubMed1992

Effect of constituents of burned skin and in vivo skin burning on the respiratory activity of rat liver mitochondria.

The formation of toxic substances in the skin, due to the influence of thermal energy, is supposed to be one possible mechanism responsible for the high mortality rate after severe burns covering large areas of the body surface. The effects of low-molecular-weight volatile substances (dry distillates) generated after burning mouse skin were investigated. They led to reductions of the respiratory activity of rat liver mitochondria. Among other substances carbon disulphide, methylethylketone and pyrrole were isolated and characterized using gas chromatography. All of them had strong uncoupling effects on mitochondrial respiration. In a second study respiratory measurements were made on mitochondria from rats with 20-30 per cent TBSA full skin thickness burns. A decreased respiratory control ratio and thus uncoupling of mitochondrial respiration was found on days 1, 2 and 5 postburn. The basal mitochondrial respiration was significantly decreased on day 5, which could be important for the mortality mentioned above. Finally after cross-transplantations rats having burned skin grafted showed a reduction of the RCR when compared with rats with the unburned graft. Thus it can be concluded that toxic substances must have been present in burned skin.

Animals↗
PubMed1992

Long-term follow-up of subcondylar fractures in children by electronic computer-assisted recording of condylar movements.

Twenty-eight patients have been followed up for an average of 15.1 years after uni- or bilateral subcondylar fractures sustained during their growth period. The conservative treatment, using orovestibular plates, has been evaluated with special reference to clinical, radiographic and functional parameters. TMJ function was tested using an electronic computer-assisted recording system. Condylar remodelling occurred in only about half of the individuals. Nevertheless, because of the good esthetic and functional results there seems to be no indication for operative reduction of the displaced condyle during the growth period.

Adolescent↗
PubMed1992

Esthesioneuroblastoma. A case report.

Esthesioneuroblastoma (ENB) is a rare neuroectodermal tumor originating from the olfactory mucosa and therefore usually arising from the nasopharynx. A case in which the diagnosis was made in connection with the extraction of a tooth is reported. Manifestation in the dento-alveolar region is unusual for this tumor. The case presented is also unusual in that the classic symptoms of ENB were not present. Diagnosis, classification, and therapy are described with a brief review of the literature.

Female↗
PubMed1992

[Changes in the condyle path following fractures with dislocation of the maxilla].

In spite of rigid internal fixation with miniplates after midfacial fractures, dislocation of the previously mobilized fragment in the dorsal direction is conceivable. Thus, the mandible would be forced into a dorsal position over the occlusion. As a result, changes of the condyle paths, such as limitations or deviations from the normal, would be possible. Six patients, who had sustained midfacial fractures with mobilization or dislocation of the maxilla, were followed up. The condyle paths were recorded at the earliest time possible after rigid internal fixation and after removal of the miniplates. We used the electronic computer-assisted registration system (ECRS), which allows three-dimensional registration without occlusal interferences. The patterns of the TMJ movements were not impaired, arguing against the dorsal transposition of the maxilla. The extent of the movements during the first postoperative weeks, however, was significantly reduced in some cases, even if intermaxillary fixation was not carried out. In our opinion, this is due to the periarticular infiltration and a varying elasticity of the articular capsule in different directions.

Adult↗