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Biomedical subjects

R T Bergman

Publications and source records attributed to R T Bergman.

11 recordsLinked to original sources
PubMed1999

Cephalometric soft tissue facial analysis.

My objective is to present a cephalometric-based facial analysis to correlate with an article that was published previously in the American Journal of Orthodontic and Dentofacial Orthopedics. Eighteen facial or soft tissue traits are discussed in this article. All of them are significant in successful orthodontic outcome, and none of them depend on skeletal landmarks for measurement. Orthodontic analysis most commonly relies on skeletal and dental measurement, placing far less emphasis on facial feature measurement, particularly their relationship to each other. Yet, a thorough examination of the face is critical for understanding the changes in facial appearance that result from orthodontic treatment. A cephalometric approach to facial examination can also benefit the diagnosis and treatment plan. Individual facial traits and their balance with one another should be identified before treatment. Relying solely on skeletal analysis, assuming that the face will balance if the skeletal/dental cephalometric values are normalized, may not yield the desired outcome. Good occlusion does not necessarily mean good facial balance. Orthodontic norms for facial traits can permit their measurement. Further, with a knowledge of standard facial traits and the patient's soft tissue features, an individualized norm can be established for each patient to optimize facial attractiveness. Four questions should be asked regarding each facial trait before treatment: (1) What is the quality and quantity of the trait? (2) How will future growth affect the trait? (3) How will orthodontic tooth movement affect the existing trait (positively or negatively)? (4) How will surgical bone movement to correct the bite affect the trait (positively or negatively)?

Adolescent↗
PubMed1993

Facial keys to orthodontic diagnosis and treatment planning. Part I.

The purpose of this article is twofold (1) to present an organized, comprehensive clinical facial analysis and (2) to discuss the soft tissue changes associated with orthodontic and surgical treatments of malocclusion. Facial examination leads to avoidance of potential orthodontic and surgical facial balance decline and enhances diagnosis, treatment planning, treatment, and quality of results. Patients are examined in natural head position, centric relation, and relaxed lip posture. Nineteen key facial traits are analyzed. By examining the patient in this format, reliable facial-skeletal traits can be recorded that enhance all aspects of care. Orthodontics and surgery used to correct the bite alter facial traits; alteration should reverse negative traits and maintain positive traits. This cannot be achieved without a complete understanding of the face before treatment. Tooth movement (orthodontic or surgical) used to correct the bite can negatively impact facial esthetics, especially if pretreatment esthetics are not defined before treatment. Treating the bite based on model analysis or on osseous cephalometric standards without examination of the face is not adequate. Three questions are asked regarding the 19 facial traits before treatment: (1) What is the quality of the existing facial traits? (2) How will orthodontic tooth movement to correct the bite affect the existing traits (positively or negatively)? (3) How will surgical bone movement to correct the bite affect the existing traits (positively or negatively)? This article is for orthodontists, and yet, much surgical information is included. This is intentional. We only treat what we are educated to see. The more we see, the better the treatment we render our patients.

Cephalometry↗
PubMed1993

Cryopreserved venous allografts: effects of immunosuppression and antiplatelet therapy on patency and function.

PURPOSE: Experiments were designed to determine the function of the endothelium and smooth muscle in cryopreserved and fresh canine saphenous vein allografts. METHODS: Reversed interposition saphenous vein grafts were implanted into the femoral arteries of two groups of dogs: group 1 received one freshly harvested saphenous vein allograft and group 2 received one cryopreserved saphenous vein allograft. The contralateral femoral artery in each group was replaced with a freshly harvested autogenous saphenous vein. Animals received oral cyclosporine alone (n = 3) or in combination with aspirin (325 mg/day; n = 20). RESULTS: Four weeks after surgery, none of the cryopreserved grafts was patent in the group treated with cyclosporine alone. All grafts were patent in animals treated with cyclosporine and aspirin. At 4 weeks, blood flow through cryopreserved allografts was significantly greater than in freshly harvested allografts. Platelet deposition was comparable in cryopreserved and freshly harvested allografts immediately after implantation and at 4 weeks. Rings cut from the grafts were suspended for the measurement of isometric force in organ chambers. alpha-Adrenergic agonists and endothelin caused concentration-dependent contractions in fresh autografts and allografts. After submaximal contraction with prostaglandin F2 alpha in these same grafts, calcium ionophore and thrombin caused relaxations in rings with endothelium, and nitric oxide caused relaxations in rings without endothelium. Cryopreserved allografts did not respond to any of the agonists tested. Histologic examination of the tissue indicated smooth muscle cells in cryopreserved grafts; evidence of rejection was observed in all allografts. CONCLUSION: These results indicate that cryopreserved allografts remain patent with antiplatelet and immunosuppressive therapy in spite of loss of functional smooth muscle.

Animals↗
PubMed1992

The role of intravenous fluorescein in the detection of colon ischemia during aortic reconstruction.

Intravenous fluorescein is an accurate predictor of small bowel viability, but its effectiveness in assessing colon perfusion during aortic surgery has not been evaluated. Over a 10 year period 186 of 3,306 patients undergoing aortic reconstruction received 500 to 1000 mg of intravenous fluorescein intraoperatively to evaluate colon viability. Prior history of colectomy, hypogastric or mesenteric arterial occlusive disease, or ruptured aneurysm placed these patients at risk to develop ischemic colitis. Patients were operated on for aneurysmal disease (n = 94), occlusive disease (n = 66), or a combination of both (n = 26): 171 exhibited uniform normal perfusion patterns under Wood's lamp illumination, while in 11 it was "patchy." None of these patients developed full-thickness ischemic colitis (observed specificity: 100%). Fluorescence of the rectosigmoid was absent in four patients. One of these patients with a ruptured aneurysm underwent immediate sigmoid resection, while three underwent inferior mesenteric artery reimplantation. The fluorescein pattern subsequently normalized in two patients, but one underwent sigmoid resection for an expanding mesenteric hematoma. The second patient recovered without complications. The final patient continued to show a segmental sigmoid defect and postoperatively developed full-thickness injury requiring sigmoidectomy. During the same period 18 other patients developed transmural colon ischemia from 3,120 aortic reconstructions (0.6%), with a mortality rate of 56%. None had received intraoperative fluorescein. Selective use of intravenous fluorescein may reduce the mortality of ischemic colitis following aortic reconstruction.

Aorta, Abdominal↗
PubMed1980

Complications of transurethral resection of bladder tumors: prevention, recognition and treatment.

Between 1931 and 1971, 373 patients underwent transurethral resection of bladder tumors for cure or for control of the neoplasms. Complications included perforation of the bladder wall (5 per cent), hemorrhage requiring transfusion (13 per cent), infection (24 per cent) and postoperative mortality (1.3 per cent). Patients in whom perforations occurred had approximately twice as many infections and twice as much hemorrhage as the entire group but there were no postoperative deaths of those with perforations. Morbidity and mortality can be reduced in patients with perforation by 1) using isotonic irrigating fluid, 2) avoiding over-distension of the bladder, 3) maintaining postoperative free drainage through the catheter and 4) diagnosing and treating hyponatremia.

Hemorrhage↗
PubMed1976

Forty years of transurethral prostatic resections.

The 4 consecutive series of transurethral prostatic resections compared were done by the senior authors during a period of nearly 40 years: 420 cases in 1937 to 1938, 520 cases in 1940 to 1945, 480 cases in 1950 to 1955 and 270 cases in 1972 to 1973. The most notable improvements in the recent series are the fewer patients with temperatures more than 100 degrees (69 virsus 29 per cent) and the improved mortality rate (5.5 verus 0.7 per cent). In our opinion these improvements are owing to antibacterial medication, improved instruments, more skillful performance of the operation, the use of isotonic irrigating fluid and improved postoperative care.

Fever↗
PubMedDate not supplied

Failure of selective shunting to intercostal arteries to prevent spinal cord ischemia during experimental thoracoabdominal aortic occlusion.

Paraplegia from spinal cord ischemia during thoracoabdominal aneurysm repair remains an unpredictable and unpreventable complication. In an effort to prevent spinal cord ischemia during aortic cross-clamping, preoperative angiographic localization of the blood supply to the spinal cord was performed in dogs. Sixteen animals underwent 60 minutes of thoracoabdominal aortic cross-clamping either without (control, n = 8) or with (shunted, n = 8) a selective shunt. Shunting was performed from the aortic arch to that isolated aortic segment angiographically shown to supply the thoracolumbar anterior spinal artery. Spinal cord blood flow was measured with microspheres just prior to cross-clamping, at 5 and 60 minutes after cross-clamping and at 5 minutes after restoration of aortic blood flow. Functional neurologic outcome was evaluated in animals at 24 hours postoperatively. Shunting did not decrease spinal cord injury. Seven of the 8 animals in the control group and 7 of the 8 in the shunted group developed paraplegia or paraparesis. Thoracic, but not lumbar spinal cord blood flow, was significantly increased in shunted animals. Spinal cord blood supply in dogs may be more segmental than previously believed. Technical problems in angiographic localization, spinal artery spasm, loss of spinal cord autoregulation or poor collateral circulation from the distal thoracic to the lumbar cord may also account for these results. Although shunting to aortic segments supplying the anterior spinal artery during thoracoabdominal aortic clamping may be attractive in humans, no benefit could be shown in this experimental model.

Angiography↗