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Biomedical subjects

R A Strauss

Publications and source records attributed to R A Strauss.

At least 19 recordsLinked to original sources
PubMed1994

Augmentation of the anterior temporal fossa after temporalis muscle transfer.

Pedicled transfer of the temporalis muscle has proven to be a reliable and versatile procedure in reconstructive craniomaxillofacial surgery. Excluding those complications related to the coronal incision, little specific attention has been given in the literature to the prevention or treatment of the esthetic defect that remains after muscle transfer. This article describes a case in which block porous high-density polyethylene was used to eliminate the residual defect of the anterior temporal fossa after transmaxillary pedicled transfer for closure of a large oral-antral communication. The implant provided an esthetically pleasing augmentation of the defect. A discussion and analysis of the implant materials available for reconstruction of this region is also presented.

Adult↗
PubMed1993

Tantalum implants as markers for evaluating postoperative orthognathic surgical changes.

The stability of sagittal split osteotomy advancements is not always 100% predictable. Assessment of postsurgical changes has historically relied on clinical evaluation of dental changes and superimposition of serial cephalograms, both of which have been shown to have serious drawbacks. A technique that improves the analysis of postsurgical changes is described in this paper; tantalum pin implants are placed in the osteotomized segments of patients undergoing surgical advancements. Implants eliminate many of the problems (orthodontic, growth, and remodeling changes) related to superimposition of presurgical and postsurgical cephalograms. Using this technique, surgical changes can be precisely analyzed, and the contribution of each factor of postsurgical relapse can be determined. This information, concerning the magnitude and direction of postsurgical changes, aids in following an individual's progress and increases the accuracy of large group studies by eliminating sources of variability in radiographic and clinical interpretation.

Bone Remodeling↗
PubMed1991

Effect of a resorbable bone graft material on orthodontic tooth movement through surgical defects in the cat mandible.

beta-Tricalcium phosphate ceramic, a resorbable synthetic bone material, was implanted into surgically created alveolar defects mesial to the mandibular first premolars of 12 adult male cats. Similar defects on the contralateral side were allowed to heal naturally. Six weeks later, nickel-titanium coiled springs were ligated between the mandibular canine and first premolar on both sides and activated to deliver 100 g of force. The distance between the canine and first premolar was measured with dial calipers at 0, 3, 6, and 9 weeks after appliance placement. Regression analysis of amount of tooth movement between the two teeth showed no significant difference between grafted and control sides. This suggests that placement of a resorbable synthetic bone material may have useful applications in situations where loss of alveolar width following extractions may compromise orthodontic tooth movement.

Animals↗
PubMed1991

Quantitation of rotational movements associated with surgical mandibular advancement.

Surgical mandibular advancement can be used to correct an anteroposterior and/or vertical malocclusion. The procedure of choice is often the bilateral sagittal split osteotomy (BSSO). By varying the amount of presurgical overbite correction, the rotational movement of the distal segment of the osteotomy can be controlled. Consequently, the malocclusion and the resultant vertical and anteroposterior facial form changes are predictably planned to produce both the desired occlusion as well as the optimal esthetic facial result. Opening rotation of the distal segment elongates the lower face height by varying amounts depending on the nature of the rotation. The amount and type of rotation can be determined and quantified by the technique presented in this paper, which is based on a geometric theorem used to determine the kinematic center of rotation of an object. This technique can shorten treatment time and produce more predictable results. The specific applications are: 1) treatment planning for individual patients, 2) uniform analyses of treatments and grouping of treatment types, and 3) development of more accurate computerized treatment planning programs.

Algorithms↗
PubMed1991

Computers and cephalometrics.

Computers have been adapted to cephalometric data acquisition and analysis. Traditional cephalometric radiographs provide images that are entered into computers by converting them to digital data. Other non-ionizing radiation forms of energy, such as sound, light and magnetism, are now used to create images. Newer methods of data acquisition are emerging that convert objects directly to digital data for computer entry without going through intermediate analogue forms. The analysis of cephalometric data for diagnostic use is aided by computers, but the automated treatment planning application of computers is limited. This limitation is not a function of the computer, but a function of our inability to reliably predict absolute biologic changes in the face of biologic variability.

Cephalometry↗
PubMed1990

Biotechnical and other factors affecting orthognathic surgery.

Orthognathic surgery is a rapidly growing biotechnologic interaction involving alterations of facial form and dental occlusion. This article describes some of the important and complex psychological, sociological, ethical, and public policy issues involved. Advances in the latter issues are necessary for advancement of the field.

Adolescent↗
PubMed1989

The association of mucocutaneous lichen planus and chronic liver disease.

A possible association between mucocutaneous lichen planus and chronic liver disease has been previously postulated in the medical literature. Despite the frequency with which lichen planus occurs in the oral cavity, little mention of such a relationship has been made in the dental literature. A case of lichen planus occurring in a patient with primary biliary cirrhosis and a review of the subject are therefore presented.

Aged↗
PubMed1987

Hyperbaric oxygen in the treatment of osteoradionecrosis: a review of its use and efficacy.

Hyperbaric oxygen (HBO) therapy is an established technology that is proving to be effective in the treatment of osteoradionecrosis. However, the studies that have shown this treatment modality to be effective have not established the optimum pressures, times of exposure, and frequency and number of treatment necessary for healing. In addition, most of the studies used HBO as an adjunctive treatment in the management of refractory osteoradionecrosis. The efficacy of HBO as a primary treatment modality has not as yet been established. Strictly controlled clinical trials are necessary for identification of patients who are likely to respond to HBO without aggressive surgery, to delineate a timetable for treatment of patients with HBO, and to coordinate surgery with HBO to resolve osteoradionecrosis when a significant amount of bone loss is involved.

Humans↗
PubMed1985

Spurious elevated platelet counts associated with bacteremia.

Spuriously elevated automated platelet counts secondary to in vivo bacteremia have not been reported previously. Two patients are described with blood cultures positive for Escherichia coli and Klebsiella pneumoniae, respectively, and bacteria present on peripheral blood smear. Those bacteria caused falsely elevated platelet counts to be generated by the Ortho ELT-8. These cases illustrate an unusual artifact and demonstrate that spurious counts can be generated by laser optical blood cell counters.

Adult↗
PubMed1985

Acute cytoreduction techniques in the early treatment of hyperleukocytosis associated with childhood hematologic malignancies.

Early and effective cytoreduction for high peripheral white blood cell counts in pediatric patients with acute leukemia may be helpful in preventing complications secondary to hyperviscosity. It also may be a useful adjunct to systemic chemotherapy. As an alternative to automated apheresis for this purpose, manual exchange transfusion is efficacious and does not require hemapheresis instrumentation and disposables and the related special staff. Two patients, a neonate with acute myeloblastic leukemia and a white blood cell count of 422.2 k/microliter as well as a 2 1/2-year-old with an admission diagnosis of acute promyelocytic leukemia and a white blood cell count of 617.4 k/microliter, underwent manual exchange hemotherapy for acute cytoreduction. The procedures were tolerated well, and significant leukocyte removal was achieved, with the respective leukocyte reductions being 81.1 and 68.7%. The techniques available for pediatric cytoreduction are compared, with emphasis on their efficiency and safety and appropriateness for very small children.

Acute Disease↗
PubMed1983

Anaphylactic transfusion reaction associated with a possible anti-A2m(1).

A 42-year-old leukaemic black male developed shortness of breath, itching, hot flushes, substernal pain, marked hypotension, and cardiorespiratory arrest after the infusion of 50 ml of pooled platelet concentrates. The patient had had one previous and uneventful red blood cell transfusion. Serologic studies of this patient's post-transfusion serum showed the presence of an antibody against one denatured IgA2 protein with the phenotype A2m(1 + 2-). All of the platelet donors were A2m(1) positive. The patient was successfully transfused with platelets from donors with the phenotype A2m(1 - 2+). Although 35.8% of Blacks and 30.0% of Chinese are A2m(1) negative, this is the first reported transfusion reaction associated solely with the occurrence of a possible anti-A2m(1) in an individual of the type A2m(1 - 2+).

Adult↗
PubMed1980

Cost accounting in plateletpheresis: comparison of two techniques.

Cost comparison of two comparably effective techniques of plateletpheresis, a manual method and an automated discontinuous flow centrifugation technique, is presented using a hypothetical model. The former procedure costs $62.48 per pheresis for disposables and labour as opposed to $78.32 per pheresis for disposables and labour for the latter. The annual volume of plateletpheresis at which the accumulated costs equal the total charges, i.e. the 'break-even' point, is calculated and found to be 63.7 for the automated technique and 10.9 for the manual method, if the charge for each is $200.00. For the manual method at a current charge of $80.00, the break even point is 85.8. The assumptions underlying this hypothetical model are examined, and the effects of deviation from these assumptions are analyzed in terms of the break even point. Cost accounting of plateletpheresis is shown to be dependent upon the choice of approach to allocation of costs, the assumptions of the cost accounting model, and the selection of an appropriate charge.

Blood Transfusion↗