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Biomedical subjects

D W Lewis

Publications and source records attributed to D W Lewis.

At least 73 records · Page 4Linked to original sources
PubMed1991

A statistical assessment of orthodontic practices, product usage, and the development of skin lesions.

Recently there has been great interest in skin lesions on the hands of orthodontic personnel who are exposed to a wide variety of metals, bonding agents, and other materials. Thus this 1985 national survey of 448 Canadian orthodontists (response rate 49%) was undertaken to examine orthodontic practice activities, bonding agent and wire product use, and prevalence of skin lesions on the hands and their possible association with these products. About 13% of the 213 responding orthodontists and at least one other staff member in 18% of the orthodontic practices reported the occurrence of hand lesions (reactions) over the preceding 3 years typical of exposure to dental materials. In nearly one fourth of the offices, at least one person was affected. Regarding product use. Concise, Mono-Lok, and Endur bonding agents and stainless steel, Nitinol, and Elgiloy wires were used most often. The orthodontists reported frequent involvement in bonding activities and infrequent use of gloves. Of all the individual and combined materials and practice characteristics and activities tested singly and multivariately for statistical association with hand lesions, only the orthodontists' use of Mono-Lok, gloves, and the activity of frequently cleaning excess bonding agent were statistically related to the lesions. Multiple logistic regression suggested that the statistical effects of Mono-Lok use and removal of excess bonding agent were independent; thus removal of excess agent may have consequences for lesion development separate from Mono-Lok use.

Bisphenol A-Glycidyl Methacrylate↗
PubMed1991

Comparison of self-instruction methods for teaching diagnostic testing.

In a randomized controlled trial, self-teaching booklets and computer media were evaluated for teaching diagnostic testing to dental students as a foundation for further development of clinical decision making skills. Effectiveness was assessed by pre- and post-tests. Reliability of these test instruments was examined by analyzing the pre- and post-test scores of 49 first year dental students who received no instruction. Forty-one second year dental students were exposed to clinical epidemiological principles applied to endodontic diagnosis through either self-teaching booklets or computer media. No statistically significant difference was found between the mean test scores of the students through self-teaching booklets and computer media. Although first and second year students showed a statistically significant improvement between the pre-test and post-test, the improvement in the second year class was greater. An addendum was later made to the main trial to compare the self-teaching booklet to the traditional lecture format in teaching endodontic diagnosis. Seventy-one third year dental students were exposed to these same materials through either a lecture or the self-teaching booklet and then similarly tested. There was no significant difference between the self-teaching booklet and traditional lecture for the third year students.

Computer-Assisted Instruction↗
PubMed1990

Retention and maintenance of fissure sealants over 10 years.

The long-term efficacy (retention and caries prevention) of fissure sealants is well documented. However, the effectiveness of contemporary sealants under sometimes less than ideal field conditions is not so well reported, nor are the clinical issues of the long-term extent of partial sealant loss, resealing needs and sealant replacement under such conditions. The results of a 10-year follow-up of 8,340 chemically-cured sealants placed between 1978 and 1985 in selected "high-risk", first permanent molars of children of moderate to severe decay susceptibility are presented. These children were annual participants in the Prince Edward Island Children's Dental Care Program. Complete sealant retention was 89 per cent after one year and 60 per cent after 7-9 years. One year after insertion, 6 per cent of sealants required maintenance resealing; thereafter it was 2 per cent to 4 per cent per year. Sealant removals because of MO amalgam placement or occlusal decay were very low, about 2 per cent and 1 per cent, respectively, in each of the first five years. The overall annual sealant success of 96 per cent after one year and 85 per cent after 8-10 years supports the careful application of chemically-cured sealants under field conditions and the use of annual recalls to allow minimal sealant maintenance.

Adolescent↗
PubMed1988

Economic considerations in geriatric oral health care: the Canadian experience.

Two different provincial programs for geriatric oral health care are described. Their relevance to the United States requires an understanding of the universal, national hospital (1961), and medical (1971) care programs of Canada and the different sociopolitical philosophy of its people. Ontario's new geriatric preventive dentistry program provides free preventive dental services to elderly residents of collective living centers by province-wide dental public health staff. Although it covers only 7% of Ontario's older population in these centers, initiatives are underway to include other elderly persons and to provide cost subsidization for referred treatment, if required. Since 1973, Alberta has provided, through dentists and denturists in private practice, comprehensive free dental benefits to all residents over 64 years of age. About 38% of eligibles now use the plan annually. Cost escalation per dentist user has been quite modest but less so for denturist users. The future of these two models and the problems associated with them are discussed.

Aged↗
PubMed1986

Central nervous system involvement in cat scratch disease.

Cat scratch disease is a cause of benign regional adenopathy which is rarely associated with CNS complications. Two children with cat scratch disease associated with alterations of mental status and convulsions are presented. One patient had a focal cerebral abnormality on neurologic examination, EEG, and computed axial tomography. The spectrum of CNS involvement is reviewed for this usually benign disease. Prognosis is generally excellent. The pathogenesis of the CNS complications has not been elucidated.

Adolescent↗
PubMed1986

Incidence, presentation, and outcome of spinal cord disease in children with systemic cancer.

During a 40-month period, in 24 of 643 (4%) newly diagnosed patients with systemic cancer younger than 18 years of age (range: 3 months to 17 years) spinal cord disease developed. Patients with spinal cord disease included 21 children with metastatic spinal cord compression, two with treatment-related transverse myelopathies, and one with an anterior spinal artery stroke. Spinal cord disease occurred in 13 of 102 children (12%) with sarcomas, six of 82 (7%) with neuroblastomas, and four of 94 (4%) with lymphomas. Spinal cord compression occurred as the presenting sign of malignancy in six children (four with sarcomas and two with lymphomas). In the remaining 15 patients, cord compression occurred a median of 13 months after initial diagnosis, and in four patients it occurred at the time of first relapse. Symptoms of metastatic cord compression included back pain in 17 patients (80%), weakness in 14 (67%), sphincter dysfunction in 12 (57%), and sensory abnormalities in three (14%). Findings on plain radiographs of the spine were abnormal in only seven of 20 patients with cord compression, and myelography was needed to differentiate compression from other causes of spinal cord disease. Treatment included high-dose corticosteroids followed by operation (seven patients) or radiotherapy (14 patients). After treatment, nine of 15 nonambulatory patients became ambulatory, and five of 10 incontinent patients regained sphincter control. None of the patients with nonmetastatic spinal cord disease had a satisfactory outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Vertebral artery dissection and alternating hemiparesis in an adolescent.

A case report of vertebral artery dissection and alternating hemiparesis in an adolescent boy is presented. The diagnosis was confirmed by findings on a computed tomographic brain scan and a four-vessel cerebral arteriogram. The patient has been treated with aspirin for 2 years and has had no further transient ischemic attacks.

Adolescent↗
PubMed1985

Weight bearing: its lack of effect on fracture healing.

The load transmitted through fresh fractures of the tarsometatarsus of adult chickens was varied by 40% more, or less, than the body weight to determine the effect of load-bearing on fracture healing. The healing fracture was examined for size and strength at 14 days, but no significant differences were detected in any group. The technique was sensitive enough to detect the differences between healing fractures at 7, 10 and 14 days. In this experiment load transmission was not found to be an important factor in fracture healing.

Animals↗