Can Critical Thinking Skills Be Transferred from the Accomplished Scientist to the Beginning Scientist?

We seldom apply rigorous methods to how scientists think as they make new discoveries and open new avenues of inquiry. The progress of science relies on one generation of scientists transferring their thought processes and methods to the next. In a culture of inquiry, respect, rigor, and role modeling, critical thinking can thrive as novices become accomplished scientists. Although scientists are typically judged on the basis of results (publication, symposium, etc.) rather than the thought process used to get that result, the thought process is of paramount importance for training the next generation of scientists. As a profession pays closer attention to the educational process whereby novices become accomplished scientists, a wider discussion of how accomplished scientists think is vital to help novice scientists positively advance through the early vulnerable years. Thinking critically about our goals and values-including the value of emulation, experience, biases, and doubt-is a necessary part of that process.

Isoflurane preconditioning protects neurons from male and female mice against oxygen and glucose deprivation and is modulated by estradiol only in neurons from female mice.

The volatile anesthetic, isoflurane, can protect the brain if administered before an insult such as an ischemic stroke. However, this protective "preconditioning" response to isoflurane is specific to males, with females showing an increase in brain damage following isoflurane preconditioning and subsequent focal cerebral ischemia. Innate cell sex is emerging as an important player in neuronal cell death, but its role in the sexually dimorphic response to isoflurane preconditioning has not been investigated. We used an in vitro model of isoflurane preconditioning and ischemia (oxygen and glucose deprivation, OGD) to test the hypotheses that innate cell sex dictates the response to isoflurane preconditioning and that 17ß-estradiol attenuates any protective effect from isoflurane preconditioning in neurons via nuclear estrogen receptors. Sex-segregated neuron cultures derived from postnatal day 0-1 mice were exposed to either 0% or 3% isoflurane preconditioning for 1 h. In separate experiments, 17ß-estradiol and the non-selective estrogen receptor antagonist ICI 182,780 were added 24 h before preconditioning and then removed at the end of the preconditioning period. Twenty-three hours after preconditioning, all cultures underwent 2 h of OGD. Twenty-four hours following OGD, cell viability was quantified using calcein-AM fluorescence. We observed that isoflurane preconditioning increased cell survival following subsequent OGD regardless of innate cell sex, but that the presence of 17ß-estradiol before and during isoflurane preconditioning attenuated this protection only in female neurons independent of nuclear estrogen receptors. We also found that independent of preconditioning treatment, female neurons were less sensitive to OGD compared with male neurons and that transient treatment with 17ß-estradiol protected both male and female neurons from subsequent OGD. More studies are needed to determine how cell type, cell sex, and sex steroids like 17ß-estradiol may impact on anesthetic preconditioning and subsequent ischemic outcomes in the brain.

Evidence-based care and the curriculum.

An evidence-based (EB) approach has been a significant driver in reforming healthcare over the past two decades. This change has extended across a broad range of health professions, including oral healthcare. A key element in achieving an EB approach to oral healthcare is educating our practitioners, both current and future. This involves providing opportunities integrated within simulated and actual clinical settings for practitioners to learn and apply the principles and processes of evidence-based oral healthcare (EBOHC). Therefore, the focus of this discussion will be on ways in which EBOHC and associated research activities can be implemented into curricula, with the aim of improving patient care. This paper will initially define the scope of EBOHC and research, what these involve, why they are important, and issues that we need to manage when implementing EBOHC. This will be followed by a discussion of factors that enable successful implementation of EBOHC and research into curricula. The paper concludes with suggestions on the future of EBOHC and research in curricula. Key recommendations related to curricula include strengthening of the culture of a scientific approach to education and oral healthcare provision; complete integration of EBOHC into the curriculum at all levels; and faculty development to implement EBOHC based on their needs and evidence of effective approaches. Key recommendations to support implementation and maintenance of EBOHC include recognition and funding for high-quality systematic reviews and development of associated methodologies relevant for global environments; building global capacity of EBOHC researchers; research into improving translation of effective interventions into education and healthcare practice, including patient-reported outcomes, safety and harms, understanding and incorporation of patient values into EB decision-making, economic evaluation research specific to oral healthcare and effective methods for changing practitioner (faculty) behaviours; and extend access to synthesized research in 'user friendly' formats and languages tailored to meet users' needs. Realizing these recommendations may help to improve access to effective healthcare as a basic human right.

Caries levels and patterns in the primary dentition of preschool children in Taiwan.

BACKGROUND: The specific caries experience and caries patterns have not been systematically studied in Taiwan. The purpose of this study was to determine the prevalence of caries patterns and caries levels for children aged 3 through 6 years in the northern Taiwan area. METHODS: Eight hundred fifty-one children were examined and their dentition classified according to five etiology-oriented caries patterns. RESULTS: The deft was 2.8 for 3-year-olds, 3.2 for 4-year-olds, 3.8 for 5-year-olds, and 3.7 for 6-year-olds. Nearly half the children (44.4%) had the "facial lingual/molar proximal" pattern; this pattern is consistent with bottle caries continuing to the smooth surfaces of molars. Only 15.4% were caries-free. CONCLUSION: We interpret the disease to be well established by age 3; prevention programs should thus begin before that age. The influence of bottle caries is interpreted from the high percentage of children with facial-lingual caries by age 3.

Response to Horowitz: research issues in early childhood caries.

Interest in early childhood caries (ECC) remains strong internationally, yet a name remains elusive. Baby bottle tooth decay (BBTD) was widely recognized by non-dental health professionals--a factor to consider in choosing a more appropriate name. Due to limits in historic data, progress against the disease remains difficult to determine. As reflected by Dr Horowitz's list of recommendations, a focused agenda is not at hand on research leading to specific interventions. We also struggle to develop a specific set of interventions suitable for public health settings. In the absence of research-based effective interventions, I hope we do not withdraw from efforts to reduce ECC.

The preschool "passage". An overview of dental health.

Children undergo major transformations between birth and approximately 5 years of age. The most common examples are personality development and the potential explosiveness of the course of the disease caries. Each demands recognition, assessment of degree of difficulty, and an adaptation by the dentist. Starting dental care for children early is based on the anticipated time children can develop disease, the fact that most dental disease is preventable, and the desire to gain the trust of the child by first, minimizing the need for invasive procedures. Dental trends set in the preschool period tend to carry for many years. The dentist's assessment of the degree of difficulty is the first key in successful care for each child. The general dentist and pediatric dentist both play important and complementary roles in the care of children. There are differences in the practice habits between the two. Self assessment of skills for common situations leads to improved care. Because children don't vote, a responsibility falls on the health care provider to advocate for children in the political and professional arenas.

Malocclusion in Labrador Inuit youth: a psychosocial, dental and cephalometric evaluation.

Epidemiological studies of malocclusion of world populations have been previously limited to dental parameters. This cross-sectional study examined the prevalence of malocclusion in the dentitions of Inuit (Eskimo) youth aged between 5-22 years from Labrador, Canada, using psychosocial, dental and skeletal (radiographic) parameters. Data were obtained from two communities, Nain (population 1079) and Hopedale (population 534). About 82% (n = 363) of the Inuit youth and 50% (n = 222) of their parents responded to the psychosocial questionnaires. In total, 78% (n = 348) of the Inuit youth were examined intraorally to determine the prevalence of malocclusion using the Treatment Priority Index (TPI), and 23% (n = 100) had cephalometric radiographs taken using a portable cephalometer. The results indicated that 95% of the Labrador Inuit youth examined had some degree of malocclusion, 10-16% were aware of their occlusal disharmonies, 55-65% wanted to have their teeth straightened, and 5% were teased by others because of their malocclusions. In addition, 63% of the parents seemed to be aware of their child's occlusal problems and 70% wished their children to wear orthodontic appliances if they were needed. Prevalence and awareness to malocclusion were positively correlated. According to the TPI, 18% had "severely handicapping" and 20% had "very severely handicapping" malocclusions. The TPI score increased with age from 5.25 in the young group to 8.05 in the older age group (mean 6.7). There were high prevalences of crowded anterior teeth, upper lingual posterior crossbites, and open or edge to edge bites. A prevalence of 35% Angle Class I, 49% Angle Class II and 16% Angle Class III molar relationships were observed. Cephalometric analysis demonstrated a mean wits measurement of -2.0 mm, a mean ANB angle of 4.7, a mean lower face height of 68.3 mm, a mean interincisal angle of 125 degrees and a mean frankfort mandibular plane angle of 31.3 degrees. A need for orthodontic care and further education were clearly indicated and highly recommended.

The prevalence and patterns of dental caries in Labrador Inuit youth.

OBJECTIVES: This study was undertaken to examine the prevalence of dental caries in Inuit (Eskimo) youth aged 5-22 years. METHODS: Both tooth-oriented indices and child-oriented caries patterns were recorded in a field study conducted in 1991 in Nain and Hopedale, Northern Labrador. Seventy-eight percent (N = 347) of all school-children in these two locations were examined by a single examiner. RESULTS: Three percent of the population were caries free and 88 percent of those with caries experience had untreated dental decay. The mean combined dmft and DMFT per child for all ages was 6.85, while the mean combined dmfs and DMFS was 15.72. About 38 percent of subjects had pit and fissure caries; 2 percent had hypoplastic lesions; 4 percent had faciolingual caries; 31 percent had molar-approximal caries and 22 percent had faciolingual and molar-approximal caries, the most destructive caries pattern. About 68 percent of the 5-6-year-olds and 26 percent of the 15-22-year-olds experienced the most destructive pattern of decay in their primary and permanent dentitions, respectively. CONCLUSIONS: Preventive measures should start well before the age of 5 years. Describing caries patterns according to the dentition type complemented the traditional indices.

Caries pattern identification in primary dentition: a comparison of clinician assignment and clinical analysis groupings.

The purpose of this study was to compare the assessment of caries patterns by clinical definition and by cluster analysis. One of five etiology-oriented caries patterns was assigned to Head Start children in primary dentition. Cluster analysis grouped children based on carious tooth surfaces for each child. One hundred twenty-seven of the 155 children with at least one carious lesion fell into clusters of at least four children. At least two-thirds of the subjects in each cluster were assigned to a single caries pattern. The largest cluster of 70 children had 66 of its subjects assigned to the pit and fissure pattern. The second largest cluster of 26 children had 20 of its subjects assigned to the faciolingual pattern (intended to identify bottle caries). This study is interpreted to reinforce the notion that caries in the primary dentition occurs in fairly distinct patterns.

Intra- and inter-individual variations in energy expenditure of 14-15-year-old schoolgirls as determined by indirect calorimetry.

Eleven 14-15-year-old schoolgirls were investigated four times within 1 year to determine variations in energy expenditure between individuals (inter-individual variability) and within subjects (intra-individual variability). Indirect calorimetry was used to determine metabolic rates in the fasting and resting state (RMR), and during physical activities which were grouped into standardized and non-standardized activities. Analyses of variance supplied information about intra- and inter-individual variabilities of rates of energy expenditure. The mean resting metabolic rate in adolescent girls was 4.41 (SD 0.40) kJ/min. The overall coefficient of variation (9.1%) was approximately twice as high as the mean coefficient within subjects (4.3%). The reproducibility of the RMR of the girls was high (significant F value of variance analysis), even over a prolonged investigation of 1 year. This seemed to depend primarily on the constant body weight during the period of investigation. A workload of 30 W on a bicycle ergometer and walking at an individually chosen speed did not reveal significant differences between inter- and intra-individual variabilities of energy metabolic rates. However, in most non-standardized activities, e.g. relaxation at home, washing dishes and vacuum cleaning, inter-individual variability was significantly higher than intra-individual variability. There are true differences in energy expenditure rates between subjects which may be demonstrated by duplicated measurements. Conclusions on future experimental design were drawn, where differences between groups rather than between individuals are to be studied.

The role of the pediatrician in identifying and treating dental caries.

Although dental caries has been reduced greatly in the last two generations, this infectious disease persists. The pediatrician can play a direct and indirect role in preventing dental caries. The pediatrician can provide counseling on feeding practices to prevent baby bottle tooth decay as well as identify children at risk. Dental caries of the grooves of molar teeth now accounts for dental caries in more children than any other form of caries. Dental sealants are recommended to coat the grooves and prevent dental caries. Restoration of decayed teeth is the most direct means of treating dental caries.

Prevention of intraoral trauma in sports.

Dental, oral, facial, and cranial injuries can be reduced by the use of mouthguards and faceguards. Disadvantages of mouthguard use are based mostly on lack of information. There is a growing endorsement for the use of mouthguards and faceguards, presenting the dental profession with a major opportunity to improve the oral health of athletes.

MR imaging of the sellar and juxtasellar regions.

Multiplanar capability and superior tissue contrast differentiation render magnetic resonance (MR) imaging the preferred method for examining patients with pituitary axis dysfunction or visual field deficits. In a review of 131 sellar or juxtasellar abnormalities, 76% were common lesions with distinctive features that helped establish their diagnosis: macroadenoma (n = 51), microadenoma (n = 20), meningioma (n = 14), craniopharyngioma (n = 10), and aneurysm (n = 5). On T1-weighted images, microadenomas were usually hypointense relative to normal pituitary gland, and macroadenomas and meningiomas were isointense relative to gray matter. Both microadenomas and meningiomas were more conspicuous immediately after contrast material administration. Craniopharyngiomas were the most heterogeneous of all the sellar lesions due to their cystic and solid components. MR images of aneurysms showed flow void and heterogeneous increased signal intensity in areas of slower turbulent flow. Other characteristics such as extrasellar versus intrasellar location, nature of contrast material enhancement, the presence of cystic components, and clinical findings permitted differentiation among less common lesions, including granulomatous disease, metastases, chiasmatic glioma, arachnoid cyst, hypothalamic glioma, schwannoma, germinoma, epidermoid, Rathke cyst, chordoma, chondrosarcoma, colloid cyst, and hamartoma.

MR of progressive neurodegenerative change in treated Menkes' kinky hair disease.

MR examinations of a male child with Menkes' kinky hair disease, a genetic disorder of copper metabolism, at four months and 30 months, document the progression of neurodegenerative changes despite parenteral copper therapy. These changes include severe cortical and cerebellar atrophy, deranged cerebral vasculature, and subdural fluid collection.