Search PubMed⌕ Search

Biomedical subjects

R E Marx

Publications and source records attributed to R E Marx.

At least 19 recordsLinked to original sources
PubMed1998

Platelet-rich plasma: Growth factor enhancement for bone grafts.

Platelet-rich plasma is an autologous source of platelet-derived growth factor and transforming growth factor beta that is obtained by sequestering and concentrating platelets by gradient density centrifugation. This technique produced a concentration of human platelets of 338% and identified platelet-derived growth factor and transforming growth factor beta within them. Monoclonal antibody assessment of cancellous cellular marrow grafts demonstrated cells that were capable of responding to the growth factors by bearing cell membrane receptors. The additional amounts of these growth factors obtained by adding platelet-rich plasma to grafts evidenced a radiographic maturation rate 1.62 to 2.16 times that of grafts without platelet-rich plasma. As assessed by histomorphometry, there was also a greater bone density in grafts in which platelet-rich plasma was added (74.0% +/- 11%) than in grafts in which platelet-rich plasma was not added (55.1% +/- 8%; p = 0.005).

Antibodies, Monoclonal↗
PubMed1998

Bone structure, metabolism, and physiology: its impact on dental implantology.

When placing implants in the mandible or maxilla, it is important for clinicians to understand the process of bone remodeling, the different types of bone, and how these factors can affect the integration of osseous dental implants. Approximately 0.7% of a human skeleton is resorbed daily and replaced by new healthy bone. With aging and metabolic disease states, the normal turnover process may be reduced, resulting in an increase in the mean age of the present bone. This increase can affect the placement and integration of implants. Herein follows a discussion of different types of bone cells, the metabolism of bone, the microscopic, macroscopic, and molecular structure of bone, and the process of bone modeling and remodeling.

Bone Morphogenetic Proteins↗
PubMed1998

The use of implants in the reconstruction of oral cancer patients.

The spectrum of osseointegrated implant applications in cancer patients is quite varied today. In the future, it will be even wider and more varied, limited only by the ingenuity of practitioners, skills of reconstructive surgeons, biology of the reconstruction, and cost restraint efforts. Today's practitioners are challenged to preserve and enhance the benefits of osseointegrated implants in some of the patients who need them most, the cancer patient. It is done by improving one's own skills by research and by education.

Biology↗
PubMed1997

A feasibility study evaluating rhBMP-2/absorbable collagen sponge for maxillary sinus floor augmentation.

This 16-week open-label study assessed the safety and technical feasibility of implanting human recombinant bone morphogenetic protein-2 delivered on an absorbable collagen sponge (rhBMP-2/ACS) for two-stage maxillary floor sinus augmentation. This first use of rhBMP-2/ACS in human clinical maxillary sinus floor augmentation included 12 patients with inadequate bone height in the posterior maxilla. The total delivered dose of rhBMP-2 implanted varied from 1.77 to 3.40 mg per patient. The rhBMP-2/ACS device was easily handled. Significant bone growth was documented by computerized tomographic scans in all evaluable patients (11/12). The overall mean height response for the maxillary sinus floor augmentation was 8.51 mm (95% confidence interval 6.07 to 10.95). There were no serious or unexpected immunologic or adverse effects and no clinically significant changes in complete blood counts, blood chemistries, or urinalysis results. The most frequent adverse effects were facial edema, oral erythema, pain, and rhinitis. Eleven patients have received dental implants and follow-up examinations are still being conducted. Histologic examinations of core bone biopsies obtained at the time of dental implant placement confirmed the quality of the bone induced by rhBMP-2/ACS. These results tend to indicate that rhBMP-2/ACS may provide an acceptable alternative to traditional bone grafts and bone substitutes for maxillary sinus floor augmentation procedures in humans.

Absorbable Implants↗
PubMed1996

"Mandibular and facial reconstruction" rehabilitation of the head and neck cancer patient.

Cancer surgery and its reconstruction today can result in functional and cosmetically supportive results for most patients. Today's better understanding of malignant tumor kinetics has evolved preservative and precision extirpative surgery which has on one hand enhanced cure rates and on the other hand has preserved function and appearance in such patients. Today's reconstructive techniques have a sound basis in wound healing and bone regeneration science so as to be predictable and long lasting. We now consistently reconstruct cancer patients with minimal complications and without adding undue deformity and disability. Within just the past ten years the additional advancement of osseointegrated implants has taken functional results related to chewing force and efficiency to a higher level. These implants provide for an optimal return of eating ability to closely match those with natural dentitions. Such implants have also been taken a step further with their application to facial unit restorations. Today facial units with the excellent tissue color and consistency matches made possible by available elastic materials are worn with confidence and comfort by those who require them. The messy and ineffectual adhesives of the past have been discarded. At the time of this writing the hope for the immediate future is the availability of recombinant human BMP. As the next anticipated advance in complete cancer reconstruction it has the potential to regenerate physiologically normal bone without bone grafting. The reduction in morbidity and operating room time would be an enormous step forward, as would the applicability of reconstruction to more people at a reduced cost.

Bone Transplantation↗
PubMed1995

The potential for HIV transmission through allogeneic bone. A review of risks and safety.

Over the past two decades, oral and maxillofacial surgeons have gained a greater appreciation for the biology of allogeneic bone healing, resulting in a dramatic increase in its indications and use. Unfortunately, this time period has also ushered in near epidemic proportions of HIV-infected persons, some of whom might be considered as potential donors of allogeneic bone. As this article will discuss, surgeons and tissue bank teams alike must be aware of the clinical and serologic criteria associated with an acceptable donor. Only in this way can contamination-free specimens be obtained and surgically implanted.

Autopsy↗
PubMed1994

Isolation of Actinomyces species and Eikenella corrodens from patients with chronic diffuse sclerosing osteomyelitis.

Cultures from 26 patients with chronic diffuse sclerosing osteomyelitis of the mandible were studied. In most cases there was a mutualistic infection involving any one of the known human Actinomyces species together with Eikenella corrodens. In a few cases, Arachnia species were substituted for Actinomyces and gram-negative anaerobes for E corrodens. The specific culture protocol used to identify these organisms from clinical specimens is described. Taxonomic and experimental evidence that supports an infectious etiology are presented.

Actinomyces↗
PubMed1993

Tissue banking safety: caveats and precautions for the oral and maxillofacial surgeon.

Oral and maxillofacial reconstructive surgeons using allogeneic tissues have expressed justifiable concern over the safety of these tissues as they relate to the transmission of infectious disease. This report reviews cases of infectious disease transmission from inadequately screened donors of allogeneic tissues, as well as those related to improper sterilization and cataloging of these tissues. It is concluded that good judgment and attention to good science on the part of the tissue bank as well as the surgeon can maximize the ability to place contamination-free specimens, thereby avoiding complications similar to those described.

Adult↗
PubMed1991

Creutzfeldt-Jakob disease from allogeneic dura: a review of risks and safety.

Surgeons and the lay public have recently expressed concern over the safety of allogeneic dura as it relates to the transmission of Creutzfeldt-Jakob Disease. Indeed, two cases have resulted from use of tissue procured from a commercial agency that did not adhere to criteria accepted by the American Association of Tissue Banks or the Southeast Organ Procurement Foundation. This review discusses the risks and safety of allogeneic dura. The findings should reassure the surgeon of the safety of allogeneic dura when it is properly processed and catalogued by a bona fide, reputable tissue bank. To date, there have been no documented cases reported to the Center for Disease Control in which Creutzfeldt-Jakob Disease was transmitted from allogeneic dura obtained from a registered tissue bank.

Adult↗
PubMed1990

Introducing the 'walk-up' flap.

Reconstructive oral and maxillofacial surgeons often find the need for additional soft tissue even when a myocutaneous flap has been previously placed. This article introduces the principles, technique, and results of 32 "walk-up" muscle flaps derived from existing myocutaneous flaps. The anastomotic vascular ingrowth at the original myocutaneous flap's distal end permits its proximal detachment and axial vessel ligation to rotate the proximal two thirds to a tissue-deficient site. In our experience at the University of Miami, these flaps have been predictable (97% viable transfer rate), have provided vascular soft tissue in deficient areas, and have been skin grafted at their surface to increase oral lining or skin cover, among several other uses.

Axillary Artery↗
PubMed1990

An improved technique for development of the pectoralis major myocutaneous flap.

The pectoralis major myocutaneous flap is the most commonly employed muscle skin transfer used in soft-tissue reconstruction of defects of the upper neck and jaw region. This article presents conceptual and technical changes in the development of the pectoralis major myocutaneous flap that preserve a greater vascular pedicle and enhance the flap's arc of rotation. Data from 54 consecutive cases using this modified approach show a reduction in complications, a greater range of use, and consistent healing in radiated and nonradiated tissues without requiring sectioning or removing the clavicle or causing significant chest deformities. These modifications have produced a more predictable transfer compared with other reported techniques.

Adolescent↗