bluuebunny/crossref_metadata_2025 huggingface dataset:
A Two-Step Flow of Influence?
Authors: Nisbet Matthew C. , Kotcher John E.
Published: January 2009

In this article, we review concepts, measures, and strategies that can be applied to opinion-leader campaigns on climate change. These campaigns can be used to catalyze wider political engagement on the issue and to promote sustainable consumer choices and behaviors. From past research, we outline six relevant categories of self-designated opinion-leaders, detailing issues related to identification, recruitment, training, message development, and coordination. We additionally analyze as prominent initiatives Al Gore's The Climate Project and his more recent We campaign, which combines the recruitment of digital opinion-leaders with traditional media strategies. In evaluating digital opinion-leader campaigns, we conclude that there are likely to be significant trade-offs in comparison to face-to-face initiatives. The challenge for both scholars and practitioners is to understand under what conditions are digital opinion-leaders effective and in which ways can online interactions strengthen or build on real-world connections.
Between the Professional and the Private
Authors: Goldblatt Hadass , Buchbinder Eli , Eisikovits Zvi , Arizon-Mesinger Ilana
Published: January 2009

This qualitative study examines the impact of working with intimate partner violence on therapists' marital relationships and gender identity. Data were collected by in-depth semistructured interviews with 14 experienced women social workers working in domestic violence treatment centers in Israel. Findings indicate that the boundaries between workers' private and professional lives are blurred and work experiences influence their intimate relationships and gender role identities, leading to overall questioning of their relationships. This newly rediscovered consciousness reshapes the meaning of workers' couple relationships. Such shift between private and professional should be considered when training workers to intervene with intimate partner violence.
Manipulation of motivational climate in physical education: Effects of a seven-month intervention
Authors: Barkoukis Vassilis , Tsorbatzoudis Haralambos , Grouios George
Published: January 2009

The objective of this study was to examine the impact of an intervention programme that manipulated task, authority, recognition, grouping, evaluation and time (TARGET) structures on the cognitive and affective response of students to their physical education (PE) lesson. The sample consisted of 374 high school students ( M age = 13.8, S.D. = .73) assigned to either an intervention or a control group. The students completed measures of perceptions of motivational (task- and ego-involving) climate, dispositional achievement goals (task and ego orientation), intrinsic motivation and trait anxiety (cognitive processes, somatic anxiety and worry). The questionnaires were administered at the beginning and at the end of the academic year, that is, within a period of seven months. In between the two measurements, PE teachers taught the intervention group using the TARGET structures. The results of a Multilevel Random Coefficient Modelling indicated that students in the intervention group reported higher levels of teachers' emphasis on learning orientation, students' learning orientation, students' task orientation, enjoyment and perceived competence, and lower levels of worry after the intervention. These findings support the positive influence of TARGET structures on cognitive and affective responses of the students to PE lessons.
`Does knowing stuff like PSHE and citizenship make me a better teacher?': Student teachers in the teacher training figuration
Authors: Velija Philippa , Capel Susan , Katene Will , Hayes Sid
Published: January 2009

One of the key elements of figurational sociology is the emphasis on understanding complex networks of interdependencies in which people are involved. The focal point of this paper is the process of initial teacher training (ITT) and the relationships of which student teachers are part during their ITT course. The paper does not look at what student teachers ought to think; rather, it is an exploration of why student teachers may think the way they do. The paper uses data which were collected as part of a larger project funded by a Teacher Training Agency small research grant. Results suggest that student teachers value aspects of their course differently. In particular, student teachers value university practical sessions and school-based experiences over university-based theory sessions, which are considered irrelevant to the actual practice of teaching. Despite attempts by university tutors to engage student teachers in academic discourses about the nature of physical education (PE), student teachers' perceptions of PE did not change during their course. Further, student teachers perceived conflict between the university-based theoretical elements and the school-based elements of the course.
Evaluating Development Learning
Authors: Lockheed Marlaine E.
Published: January 2009

Evidence-based evaluation of adult learning (training and capacity development) programs is essential for guiding investment decisions regarding such programs. But standard practice for evaluation of training and development programs relies on participants' self-reports regarding the quality, effectiveness, and impact of such training. More rigorous evaluation methods — including reliable measures of learning; evaluation designs that include multiple methods of data collection, scientific sampling, and randomized control trials (RCTs); and multivariate analyses — are rarely found in the training and development literature, which compromises the utility of these evaluations.This submission presents methods for increasing the rigor of evaluation of adult learning events, describes how these methods were put to use in one organization, and — drawing on these evaluations — identifies the features of effective programs.
Logic Models as a Tool for Sexual Violence Prevention Program Development
Authors: Hawkins Stephanie R. , Clinton-Sherrod A. Monique , Irvin Neil , Hart Laurie , Russell Sarah Jane
Published: January 2009

Sexual violence is a growing public health problem, and there is an urgent need to develop sexual violence prevention programs. Logic models have emerged as a vital tool in program development. The Centers for Disease Control and Prevention funded an empowerment evaluation designed to work with programs focused on the prevention of first-time male perpetration of sexual violence, and it included as one of its goals, the development of program logic models. Two case studies are presented that describe how significant positive changes can be made to programs as a result of their developing logic models that accurately describe desired outcomes. The first case study describes how the logic model development process made an organization aware of the importance of a program's environmental context for program success; the second case study demonstrates how developing a program logic model can elucidate gaps in organizational programming and suggest ways to close those gaps.
Factors Contributing to the Effectiveness of Four School-Based Sexual Violence Interventions
Authors: Clinton-Sherrod A. Monique , Morgan-Lopez Antonio A. , Gibbs Deborah , Hawkins Stephanie R. , Hart Laurie , Ball Barbara , Irvin Neil , Littler Nicole
Published: January 2009

This study extends past research by examining factors associated with changes in attitudes, knowledge, and intended behaviors related to sexual assault. This study included 1,182 participants from four unique multiple-session school-based sexual violence interventions. Implementation and participant factors examined include single- versus mixed-gender groups, group setting versus classroom lecture setting, and participant gender. Participants completed self-administered, paper-and-pencil pre- and postsurveys. A significant desired overall effect was found on participants' reports of positive attitudes, beliefs, and behavior regarding sexual harassment and personal boundaries and positive dating relationship norms (from pretest to posttest). There were steeper increases over time in both measures, with larger mixed-gender/single-gender differences among boys than among girls. Differences in the impact of participating in mixed- versus single-gender groups depended on classroom versus small group settings. The implications of these findings are discussed for sexual assault prevention programs.
Patient Perceptions of a Community-Based Care Coordination System
Authors: Gimpel Nora , Marcee Alice , Kennedy Kambria , Walton James , Lee Shannon , DeHaven Mark J.
Published: January 2009

Community health workers (CHWs) work with health professionals to improve health outcomes by facilitating community-based health education and increase access and continuity to health services within a community. Uninsured, low-income participants of a community-based program, Project Access Dallas, participated in focus group sessions for determining participants’ perceptions of CHW effectiveness and participants’ abilities to independently manage their health needs. Of the 95 adults invited, 24 (25.3%) attended. Participants reported that CHWs are an invaluable asset in learning how to navigate the health care system, obtaining appointments and being better able to care for themselves with CHW emotional/psychological support. Results suggest that CHWs in a case management model improved patient comprehension of health issues, patient navigation through a health care system, and patients’ abilities to independently manage health issues. Implementation of CHWs within a case management model appears to be an effective mechanism for providing health services to underserved populations.
Empowerment Evaluation
Authors: Meltzer Graffunder Corinne , Charles Dyanna
Published: January 2009

The articles in this special issue all result from the employment of empowerment evaluation with the intention of furthering the field of sexual violence prevention. Centers for Disease Control and Prevention's goals were to build the science toward evidence-based programming and to build evaluation capacity among leaders in the sexual violence field. Other undefined benefits also resulted, including the facilitation of implementation of program improvements and the development of capacities that can be generalized across other aspects of the participants' work. These benefits are attributed to empowerment evaluation's intentional designation of evaluation activities to the same people responsible for program delivery. Empowerment evaluation's potential to make future contributions to the field of sexual violence prevention is discussed.
An Itemized Approach to Assessing Behavioral and Psychological Symptoms in Dementia
Authors: Gallo Jennifer L. , Schmidt Kara S. , Libon David J.
Published: January 2009

In an effort to obtain more detailed clinical information regarding behavioral and psychology symptoms in dementia, we submitted an existing, comprehensive measure of behavioral and psychology symptoms in dementia (Neuropsychiatric Inventory) to an alternate itemized scoring system. One hundred twenty-four caregivers of patients with dementia (mean Mini-Mental State Examination = 22.6) rated the frequency of individual symptoms across all domains of the measure. Internal reliability and factor structures for all domains were analyzed to assess the stability of this scoring approach. Internal consistency alphas for each domain ranged from .57 to .91. Alpha reliability for the total inventory was .96. Results indicate an itemized approach to assessing behavioral and psychological symptoms in dementia among patients with mild-to-moderate dementia can be reliable, has the power to capture multiple features of neuropsychiatric symptoms, and can produce a rich neurobehavioral profile adding valuable information to the diagnosis and treatment of these patients.
The Vascular and Biochemical Effects of Cilostazol in Diabetic Patients With Peripheral Arterial Disease
Authors: O'Donnell Mark E. , Badger Stephen A. , Sharif Muhammad A. , Makar Ragai R. , Young Ian S. , Lee Bernard , Soong C.V.
Published: January 2009

Objectives: Cilostazol improves walking in patients with peripheral arterial disease (PAD). We hypothesized that cilostazol reduces diabetic complications in PAD patients.

Methods: Diabetic PAD patients were prospectively recruited to a randomized double-blinded, placebo-controlled trial, using cilostazol 100mg twice a day. Clinical assessment included ankle-brachial index, arterial compliance, peripheral transcutaneous oxygenation, treadmill walking distance and validated quality of life (QoL) questionnaires. Biochemical analyses included glucose and lipid profiles. All tests were at baseline, 6, and 24 weeks.

Results: 26 diabetic PAD patients (20 men) were recruited. Cilostazol improved absolute walking distance at 6 and 24 weeks (86.4% vs. 14.1%, P = .049; 143% vs. 23.2%, P = .086). Arterial compliance and lipid profiles improved as did some QoL indices for cilostazol at 6 and 24 weeks. Blood indices were similar at baseline and at follow-up points for both treatment groups.

Conclusions: Cilostazol is a well-tolerated and efficacious treatment, which improves claudication distances in diabetic PAD patients with further benefits in arterial compliance, lipid profiles, and QoL.
Activation of Adenosine-receptor-enhanced iNOS mRNA Expression by Gingival Epithelial Cells
Authors: Murakami S. , Yoshimura N. , Koide H. , Watanabe J. , Takedachi M. , Terakura M. , Yanagita M. , Hashikawa T. , Saho T. , Shimabukuro Y. , Okada H.
Published: January 2009

A series of reports has revealed that adenosine has a plethora of biological actions toward a large variety of cells. In this study, we investigated the influence of adenosine receptor activation on iNOS mRNA expression in human gingival epithelial cells (HGEC) and SV-40-transformed HGEC. HGEC expressed adenosine receptor subtypes A1, A2a, and A2b, but not A3 mRNA. Ligation of adenosine receptors by a receptor agonist, 2-chloroadenosine (2CADO), enhanced iNOS mRNA expression by both HGEC and transformed HGEC. In addition, the adenosine receptor agonist enhanced the production of NO2 -/NO3 -, NO-derived stable end-products. An enhanced expression of iNOS mRNA and NO2 -/NO3 - was also observed when SV40-transformed HGEC were stimulated with CPA or CGS21680, A1- or A2a-selective adenosine receptor agonists, respectively. These results provide new evidence for the possible involvement of adenosine in the regulation of inflammatory responses by HGEC in periodontal tissues.
Matrilysin (Matrix Metalloproteinase-7) Expression in Human Junctional Epithelium
Authors: Uitto V.-J. , Salonen J.I. , Firth J.D. , Jousimies-Somer H. , Saarialho-Kere U.
Published: January 2009

Matrilysin is a matrix metalloproteinase expressed in exocrine and mucosal epithelium in many human tissues. Immunohistochemical staining showed that matrilysin is expressed in suprabasal cells of junctional epithelium facing the teeth and in epithelial cell rests of Malassez. No matrilysin expression was seen in the periodontal pocket tissue. In a tissue culture model mimicking junctional epithelium, matrilysin expression was also observed in suprabasal epithelial cells. Of 13 anaerobic oral bacterial species tested, F. nucleatum, F. necrophorum, P. endodontalis, and P. denticola stimulated matrilysin expression in porcine periodontal ligament epithelial cells from 2.5- to 5.7-fold, compared with untreated cells. The enzyme was localized in intracytoplasmic vesicles that also reacted with antibodies against lysosomal membrane protein h-lamp-1. The results indicate that matrilysin may play an important role in the normal physiology of junctional epithelium.
Basal Circadian Cortisol Secretion in Women with Temporomandibular Disorders
Authors: Korszun A. , Young E.A. , Singer K. , Carlson N.E. , Brown M.B. , Crofford L.
Published: January 2009

Muscular temporomandibular disorder (TMD) is a common stress-related condition showing marked comorbidity with depression and fibromyalgia (FM), both of which are associated with dysregulation of cortisol secretion. We measured cortisol levels in 15 women with well-defined TMD and 15 matched controls by sampling blood at 10-minute intervals over 24 hours in a controlled environment. TMD patients showed markedly increased daytime cortisol levels 30% to 50% higher than those of controls (p = 0.0032) and a one-hour phase delay in the timing of maximum cortisol levels (p = 0.048). Increased activation of the stress hormone axis by conscious pain perception is a likely explanation, but the magnitude of the increase could indicate that pain in the facial region acts as a greater stimulus than pain elsewhere in the body.
Risk Factors for Diagnostic Subgroups of Painful Temporomandibular Disorders (TMD)
Authors: Huang G.J. , LeResche L. , Critchlow C.W. , Martin M.D. , Drangsholt M.T.
Published: January 2009

Temporomandibular Disorders (TMD) encompass several entities, which may have differing etiologies. To test this hypothesis, we investigated risk factors for three diagnostic subgroups of painful TMD. Ninety-seven subjects with myofascial pain only, 20 with arthralgia only, 157 with both myofascial pain and arthralgia, and 195 controls without TMD pain met criteria for study eligibility. Investigated risk factors included both physical and psychological variables. Adjusted odds ratios were calculated by multiple logistic regression analyses. Myofascial pain occurring alone was significantly associated with trauma (Odds Ratio {OR} = 2.0), clenching (OR = 4.8), third molar removal (OR = 3.2), somatization (OR = 3.7), and female gender (OR = 4.2). Myofascial pain with arthralgia was significantly associated with trauma (OR = 2.1), clenching (OR = 3.3), third molar removal (OR = 4.0), somatization (OR = 5.1), and female gender (OR = 4.7). No significant associations were found for the small-arthralgia-only group.
Reducing Patients' State Anxiety in General Dental Practice: A Randomized Controlled Trial
Authors: Dailey Y.-M. , Humphris G.M. , Lennon M.A.
Published: January 2009

Anxiety assessment by questionnaire provides information for the dentist and may also confer a psychological benefit on patients. This study tested the hypothesis that informing dentists about patients' dental anxiety prior to commencement of treatment reduces patients' state anxiety. A randomized controlled trial was conducted involving eight General Dental Practitioners in North Wales. Participants included patients attending their first session of dental treatment, and accumulating a score of 19 or above, or scoring 5 on any one question, of the Modified Dental Anxiety Scale (MDAS). Patients (n = 119) completed Spielberger's state anxiety inventory (STAI-S) pre- and post-treatment and were randomly allocated to intervention (dentist informed of MDAS score) and control (dentist not informed) groups. Intervention patients showed greater reduction in mean change STAI-S scores (F[1,119] = 8.74, P < 0.0001). Providing the dentist with information of the high level of a patient's dental anxiety prior to treatment, and involving the patient in this, reduced the patient's state anxiety.
Establishment of Porphyromonas gingivalis Heat-shock-protein-specific T-cell Lines from Atherosclerosis Patients
Authors: Choi J.-I. , Chung S.-W. , Kang H.-S. , Rhim B.Y. , Kim S.-J. , Kim S.-J.
Published: January 2009

Human atherosclerotic plaques contain heat-shock proteins which may serve as potential targets of the immune response in atherosclerosis. Since periodontal infections are suggested as risk factors for the development of cardiovascular diseases, we undertook the present study to evaluate the T-cell immune responses specific to Porphyromonas gingivalis ( P. gingivalis) heat-shock protein (hsp)60 in patients suffering from atherosclerosis. Anti- P. gingivalis hsp60 IgG antibody titers were elevated in all patients. We could establish P. gingivalis hsp-specific T-cell lines from the atheroma lesions and the peripheral blood. The T-cell lines were a mixture of CD4+ and CD8+ cells producing the cytokines characteristic of both Th1 and Th2 subsets. The present findings suggest that the T-cell immune response specific to P. gingivalis hsp60 may be involved in the immunopathologic process of atherosclerotic diseases.
Expression of N-acetyltransferases in Periodontal Granulation Tissue
Authors: Meisel P. , Giebel J. , Peters M. , Foerster K. , Cascorbi I. , Wulff K. , Fanghaenel J. , Kocher Th.
Published: January 2009

Smoking is a major risk of periodontal diseases. At the site of first contact, the gingiva is exposed to aromatic amines and polycyclic hydrocarbons. These are metabolized by the N-acetyltransferases (NAT), leading to local detoxification and/or activation reactions contributing to the risk of periodontal destruction in smokers. The purpose of this study was to detect the expression of N-acetyltransferase isoenzymes NAT1 and NAT2 in periodontal granulation tissue. In 24 specimens obtained from periodontitis patients or control subjects, mRNA encoding for NAT1 and NAT2 was detected by RT-PCR, and proteins were identified by immunohistochemistry. In periodontal granulation tissues, immunoreactivity for NAT1 and NAT2 was detected in infiltrating leukocytes and fibroblasts. In normal gingiva, both enzymes were found in epithelial cells, whereas NAT1 was also detected in endothelial cells. The results suggest that these enzymes may play a role in the defense against xenobiotics and the accelerated progression of periodontal disease in smokers.
1H and 13C NMR Spectroscopic Analysis of Human Saliva
Authors: Silwood C.J.L. , Lynch E. , Claxson A.W.D. , Grootveld M.C.
Published: January 2009

We have explored the ability of high-resolution NMR techniques to (1) index salivary biomolecules and (2) provide valuable data regarding intra- and inter-subject variability in the concentrations of a series of components readily determinable by this technique (organic acids and malodorous amines). Experiments were conducted on ‘whole’ saliva samples collected from 20 patients, either randomly during their daily activities, or, for investigations involving the quantification of salivary biomolecules, immediately after they woke in the morning throughout a three-day period. These NMR techniques permitted us to detect greater than 60 metabolites, together with agents arising from dietary, oral health care product, and pharmaceutical sources. Highly significant “between-subject” differences in the a.m. waking salivary metabolite concentrations were found for 9 out of 11 components monitored. It is concluded that NMR spectroscopy serves as a powerful technique for the multicomponent analysis of human saliva.
Materials Design of Ceramic-based Layer Structures for Crowns
Authors: Lawn B.R. , Deng Y. , Lloyd I.K. , Janal M.N. , Rekow E.D. , Thompson V.P.
Published: January 2009

Radial cracking has been identified as the primary mode of failure in all-ceramic crowns. This study investigates the hypothesis that critical loads for radial cracking in crown-like layers vary explicitly as the square of ceramic layer thickness. Experimental data from tests with spherical indenters on model flat laminates of selected dental ceramics bonded to clear polycarbonate bases (simulating crown/dentin structures) are presented. Damage initiation events are video-recorded in situ during applied loading, and critical loads are measured. The results demonstrate an increase in the resistance to radial cracking for zirconia relative to alumina and for alumina relative to porcelain. The study provides simple a priori predictions of failure in prospective ceramic/substrate bilayers and ranks ceramic materials for best clinical performance.
Patient Preferences and the Measurement of Utilities in the Evaluation of Dental Technologies
Authors: Birch S. , Ismail A.I.
Published: January 2009

Advances in life sciences that are predicted in the 21st century will present many challenges for health professionals and policy-makers. The major questions will be how to allocate resources to pay for costs of new technologies and who will best benefit from advances in new diagnostic and treatment methods. We review in this paper the concept of utility and how it can be applied and expanded to provide data to help health professionals make decisions that are preferred by patients and the public at large. Utility is a measure of people's well-being or preferences for outcomes. The measurement of utilities of a new diagnostic technology, for example, can be carried out with the use of simple methods that do not incorporate all of the uncertainties and potential outcomes associated with providing the test, or with more complex methods that can incorporate most uncertainties. This review describes and critiques the different measurement methods of utilities.
Biological Interpretation of the Correlation of Emergence Times of Permanent Teeth
Authors: Parner E.T. , Heidmann J.M. , Kjær I. , Væth M. , Poulsen S.
Published: January 2009

The eruption mechanism is not fully understood. It is known that the dental follicle is essential and that experimentally provoked denervation influence the process of eruption. Accordingly, the purpose of this study was to elucidate the eruption pattern in a human population and relate this pattern to the pattern of jaw innervation. The eruption pattern was evaluated from the correlation between the emergence times of different teeth in the permanent dentition based on longitudinal data from a large national registry (12,642 boys and 12,095 girls). Correlations coefficients were generally high (>0.5) and higher between teeth within the same tooth groups ( i.e. incisors, canines and premolars, and molars) than between teeth from different tooth groups. It was shown that the correlation in emergence of teeth closely followed the pattern of innervation of the jaws. Thus the study supported the hypothesis concerning a possible association between eruption and innervation.
Task-dependence of Activity/ Bite-force Relations and its Impact on Estimation of Chewing Force from EMG
Authors: Proeschel P.A. , Morneburg T.
Published: January 2009

Estimation of chewing force from electromyograms (EMGs) calibrated in isometric biting yielded strikingly high force values. We tested the hypothesis that EMG-based force predictions are excessive because of differing activity/bite-force relations in mastication and isometric biting. In nine patients, unilateral bite forces and EMGs of 4 elevator muscles were recorded during chewing and isometric clenching on a bite-fork. We estimated chewing force by substituting chewing EMGs of each muscle into isometric activity/bite-force regressions. The estimates were compared with actual chewing forces recorded by intra-oral transducers. In all muscles except the balancing-side masseter, the activity/bite-force ratio was significantly higher in chewing than in isometric biting. The actual mean chewing force amounted to 220 N, while EMG-based estimates ranged from 273 to 475 N, depending on the muscle used for estimation. The results indicate that different activity/force characteristics in dynamic and isometric biting can cause overestimation when chewing force is predicted from masticatory EMGs.
Reliability and Properties of Ground Y-TZP-Zirconia Ceramics
Authors: Luthardt R.G. , Holzhüter M. , Sandkuhl O. , Herold V. , Schnapp J.D. , Kuhlisch E. , Walter M.
Published: January 2009

Yttria-stabilized zirconia ceramics is a high-performance material with excellent biocompatibility and mechanical properties, which suggest its suitability for posterior fixed partial dentures. The hypothesis under examination is that the strength and reliability of Y-TZP zirconia ceramics are affected by the inner surface grinding of crowns, and vary with the grinding parameter. Flexural strength, surface roughness, and fracture toughness were determined on samples machined by face and peripheral grinding with varied feed velocities and cutting depths. Results have been compared with those on lapped samples. Analysis of variance and Weibull parameter were used for statistical analysis. It was found that inner surface grinding significantly reduces the strength and reliability of Y-TZP zirconia compared with the lapped control sample. Co-analysis of flexural strength, Weibull parameter, and fracture toughness showed counteracting effects of surface compressive stress and grinding-introduced surface flaws. In conclusion, grinding of Y-TZP needs to be optimized to achieve the CAD/CAM manufacture of all-ceramic restorations with improved strength and reliability.
Quantitative Trait Loci on Chromosomes 10 and 11 Influencing Mandible Size of SMXA RI Mouse Strains
Authors: Dohmoto A. , Shimizu K. , Asada Y. , Maeda T.
Published: January 2009

Predicting the mandible size before the termination of growth of the maxillofacial bones is essential in pedodontics as well as for the predictions needed for genetic analysis. Here, Quantitative Trait Locus (QTL) analysis was used to detect the chromosomal regions responsible for the mandible length between the menton and gonion in an SMXA recombinant inbred strain of mice. Around the region 60 cM from the centromere in chromosome 10, the logarithm of the odds score showed a higher than suggestive level. Around the regions 13 cM and 16 cM in chromosome 11, two significant QTLs were detected. Analysis of genotypes from loci corresponding to those QTLs revealed a large mandible when the region between the markers Hba and D11Mit163 and D10Mit70 and D10Mit136 indicated the genotype from the A/J and SM/J alleles, respectively. These results suggest that the major gene(s) responsible for mandible length are located in these regions.
Occlusion and Temporomandibular Disorders (TMD): Still Unsolved Question?
Authors: Alanen Pentti
Published: January 2009

The rejection of the occlusal hypothesis cannot be justified with the present empirical evidence.
Stem Cell Properties of Human Dental Pulp Stem Cells
Authors: Gronthos S. , Brahim J. , Li W. , Fisher L.W. , Cherman N. , Boyde A. , DenBesten P. , Robey P. Gehron , Shi S.
Published: January 2009

In this study, we characterized the self-renewal capability, multi-lineage differentiation capacity, and clonogenic efficiency of human dental pulp stem cells (DPSCs). DPSCs were capable of forming ectopic dentin and associated pulp tissue in vivo. Stromal-like cells were reestablished in culture from primary DPSC transplants and re-transplanted into immunocompromised mice to generate a dentin-pulp-like tissue, demonstrating their self-renewal capability. DPSCs were also found to be capable of differentiating into adipocytes and neural-like cells. The odontogenic potential of 12 individual single-colony-derived DPSC strains was determined. Two-thirds of the single-colony-derived DPSC strains generated abundant ectopic dentin in vivo, while only a limited amount of dentin was detected in the remaining one-third. These results indicate that single-colony-derived DPSC strains differ from each other with respect to their rate of odontogenesis. Taken together, these results demonstrate that DPSCs possess stem-cell-like qualities, including self-renewal capability and multi-lineage differentiation.
The Effects of the Solubility of Artificial Fissures on Plaque pH
Authors: Zaura E. , Buijs M.J. , ten Cate J.M.
Published: January 2009

Dissolution of the fissure walls may buffer acids formed in plaque and thus prevent the penetration of acids into the fissure. To test this, five volunteers wore dentin, enamel, and polyacrylate specimens with narrow grooves for 7 days to accumulate plaque. Temporal (pre- and post-glucose) and spatial (0-0.7 mm) pH profiles were recorded in the grooves in a flow-through reactor with pH microsensors. Mineral loss was assessed by transverse microradiography. We observed that resting pH did not differ among substrata. The median pH 1 hr post-glucose at the bottoms of dentin, enamel, and polyacrylate grooves was 6.7, 6.2, and 5.7, respectively (p < 0.01). On subject level, lesions formed in dentin correlated with pH changes in polyacrylate, where no buffering of acids due to mineral dissolution occurred. We conclude that fluoride-deficient tissue at the bottom of a fissure is at increased risk for caries, if acids are not buffered near the entrance to the fissure.
Characteristics of Mastication in the Anodontic Mouse
Authors: Kobayashi M. , Masuda Y. , Kishino M. , Ishida T. , Maeda N. , Morimoto T.
Published: January 2009

Teeth and periodontal mechanoreceptors play important roles in regulating jaw movements during mastication. However, little is known concerning how jaw movements develop without tooth eruption. To answer this question, we studied masticatory behavior in the osteopetrotic mouse, where tooth eruption does not occur and periodontal mechanoreceptors are missing. A masticatory sequence of the osteopetrotic mouse was divided into two stages: incision and chewing. Incision is characterized by small amplitude and rapid (7 Hz) open-close jaw movements, while slow (5 Hz) and large amplitude open-close jaw movements characterize chewing. The frequency and properties of jaw movements were comparable with those in the normal mouse, though the osteopetrotic mouse had a higher cycle number during incision than did the normal mouse. These results indicate that conversion from sucking to mastication occurs in the anodontic mouse, and the central pattern generator producing the masticatory rhythm develops almost normally without tooth eruption.
The Localization of Matrix Metalloproteinase-20 (MMP-20, Enamelysin) in Mature Human Teeth
Authors: Sulkala M. , Larmas M. , Sorsa T. , Salo T. , Tjäderhane L.
Published: January 2009

MMP-20 (enamelysin), the matrix metalloproteinase family member discovered in the enamel organ, has also been detected in odontoblasts during dentin formation. We studied the presence and localization of MMP-20 in mature human teeth in health and disease. In immunohistochemistry, MMP-20-positive staining was observed most intensively in the radicular odontoblastic layer and also in dilated dentinal tubuli of caries lesions. By Western blotting, MMP-20 was detected in odontoblasts and pulp tissue of both sound and carious teeth, in dentinal fluid and dentin of sound teeth, but not in soft carious dentin. We conclude that MMP-20 produced during primary dentinogenesis is incorporated into dentin and may be released during caries progression. The main cellular source of MMP-20 in the dentin-pulp complex is the odontoblasts, which secrete MMP-20 into the dentinal fluid.
Dynamic Properties of Bovine Temporomandibular Joint Disks Change with Age
Authors: Tanaka E. , Aoyama J. , Tanaka M. , Murata H. , Hamada T. , Tanne K.
Published: January 2009

The temporomandibular joint disk exhibits morphological and biochemical age-related changes. However, the possible age-related changes of the dynamic viscoelasticity in the disk are unclear. We tested the hypothesis that the dynamic viscoelastic properties of the disk change with age. Thirty-six disks from young-adult, adult, and mature-adult cattle were used for dynamic tensile tests. In all disks, the magnitudes of the complex modulus, the storage modulus, and the loss modulus increased as the frequency increased. The mature-adult disks had higher values of these moduli than did the younger disks. The loss tangent ranged from 0.1 to 0.3, which means that the disk has relatively large elasticity and relatively small viscosity. It was concluded that both the elasticity and viscosity of the disk increase with age. This may reflect age-related changes in biochemical composition.
A Nanoleakage Perspective on Bonding to Oxidized Dentin
Authors: Yiu C.K.Y. , García-Godoy F. , Tay F.R. , Pashley D.H. , Imazato S. , King N.M. , Lai S.C.N.
Published: January 2009

The mechanism responsible for sodium-hypochlorite-induced reduction in dentin bond strength and its reversal with reducing agents is unknown. This study examined the relationship between nanoleakage and reversal of compromised bonding to oxidized dentin. Acid-etched dentin was completely depleted of demineralized collagen matrix when sodium hypochlorite was used. Specimens were bonded with two single-bottle dentin adhesives. They were immersed in ammoniacal silver nitrate for 24 hrs before being processed for transmission electron microscopy. For both adhesives, tensile bond strengths of acid-etched dentin were significantly reduced after sodium hypochlorite treatment, but were reversed when sodium ascorbate was used. After sodium hypochlorite application, reticular nanoleakge patterns in hybrid layers were replaced by vertical, shag-carpet-like patterns along the demineralization front. This type of nanoleakage was completely eliminated after sodium ascorbate treatment with the materials tested. Residual sodium hypochlorite within the porosities of mineralized dentin may result in incomplete resin polymerization, and hence compromised bond strength.
HEMA Bound to Self-protein Promotes Auto-antibody Production in Mice
Authors: Sandberg E. , Bergenholtz G. , Eklund C. , Dahlgren U.I.
Published: January 2009

While several studies report that acrylic monomers contained in dental materials may cause hypersensitivity reactions, little is known of the associated immune response. Here we address the potential of 2-hydroxyethyl-methacrylate (HEMA) to bind to endogenous protein and elicit auto-antibody production in vivo. Albumin was incubated with HEMA at various times and pH. Following confirmation of the conjugation by inhibition of trinitrophenyl (TNP) binding, female Balb/c mice received HEMA conjugated to mouse serum albumin (MSA) in Freund’s incomplete adjuvant or saline subcutaneously. ELISA was used to determine the serum antibody responses to native and modified MSA. IL-2 production in spleen cell cultures stimulated with HEMA-conjugated MSA was measured. HEMA reacted with serum albumin at physiological conditions. HEMA-conjugated MSA induced IL-2 secretion and production of IgG antibodies to native MSA. The results suggest that modification of an endogenous protein like serum albumin with HEMA may defeat the control of immune responses to this self-protein.
An Abbreviated Caries Clinical Trial Design Validated over 24 Months
Authors: Chesters R.K. , Pitts N.B. , Matuliene G. , Kvedariene A. , Huntington E. , Bendinskaite R. , Balciuniene I. , Matheson J.R. , Nicholson J.A. , Gendvilyte A. , Sabalaite R. , Ramanauskiene J. , Savage D. , Mileriene J.
Published: January 2009

Conventional caries trials last from 24 to 36 months. This study evaluated whether the previously established difference in efficacy between 1000- and 2500-ppm-fluoride dentifrices could be detected after 12 months. Caries was assessed by clinical visual assessment (CVA-simplified version of Dundee Selectable Threshold Method - DSTM), bitewing radiography, and Fiber Optic Transillumination (FOTI). Changes in status for individual surfaces were classified by means of pre-prepared matrices as 0 (unchanged), +1 (initiation or progression), or -1 (regression) and summed for each subject to yield an event score. Mean group event scores were calculated for each product. DSTM at the D1 [enamel and dentin] threshold showed significant inter-group differences in mean event scores (p < 0.003) and D1MFS increment (< 0.007) at 12 months; these were confirmed at 24 months by traditional increment analysis (CVA & FOTI at the D3 (dentin only) threshold + radiography, p < 0.03). This study confirms the validity of an abbreviated trial protocol.
Effect of Sustained Contraction on Motor Unit Action Potentials and EMG Power Spectrum of Human Masticatory Muscles
Authors: Chung J.W. , Kim C. , McCall W.D.
Published: January 2009

The sequelae of a sustained clench are incompletely understood. Our experimental questions were to compare the responses of men and women, to compare masseter and anterior temporalis muscles, and to test hypotheses for the reduction of the median frequency of power spectra. We recorded duration, amplitude, number of phases, and area of the motor unit action potential before and after a sustained clench and the median frequency of the electromyographic power spectrum in 41 subjects. After the clench, the median frequency was lower, the action potential duration longer, the number of phases increased, and the area larger, but the amplitude was not different. Males and females failed to differ. Compared with the temporalis, the masseter had a lower median frequency, longer duration, larger number of phases, and increased area. Our results are consistent with a decrease in the conduction velocity of the muscle action potential as an explanation of the spectral shift.
Materials Science: Biological Aspects
Authors: Schmalz Gottfried
Published: January 2009

The author discusses the biological aspects of dental materials and their applications as integral parts of both dentistry and medicine.
Microarray Analysis of Gene Expression Changes in Aging in Mouse Submandibular Gland
Authors: Hiratsuka K. , Kamino Y. , Nagata T. , Takahashi Y. , Asai S. , Ishikawa K. , Abiko Y.
Published: January 2009

Little is known about the effect of salivary gland function during aging based on gene expression. Recently emerged DNA array technology provides a sensitive, quantitative, rapid approach to the monitoring of the global pattern of gene expression. In this study, we used high-density oligonucleotide arrays to monitor the changes of gene expression levels in the submandibular gland (SMG) by comparing adult mice with elderly adult mice. Of the 1328 genes screened, 160 genes (12.0%) showed more than two-fold changes; 154 (96.3%) of these genes, associated with transcription regulation, transport, signal transduction, and enzymes in the elderly mice, exhibited decreased expression levels. The remaining 6 genes (3.7%) in the elderly mice showed increased expression levels. In mouse SMG, analysis of these data suggests that aging may lead the gene expression to decrease than increase. Thus, DNA array technology can be a powerful tool for the identification of age-associated candidate genes for further analysis in aging.
TGF-beta-3 Promotes Scarless Repair of Cleft Lip in Mouse Fetuses
Authors: Kohama K. , Nonaka K. , Hosokawa R. , Shum L. , Ohishi M.
Published: January 2009

TGF-β3 mediates epithelial-mesenchymal transformation during normal fusion of lip and palate, but how TGF-β3 functions during cleft lip repair remains unexplored. We hypothesize that TGF-β3 promotes fetal cleft lip repair and fusion by increasing the availability of mesenchymal cells. In this investigation, we demonstrated that cleft lips in mouse fetuses were repaired by fetal surgery, producing scarless fusion. At the site of the operation, we first observed an infusion of platelets expressing TGF-β3, followed by increased expression of cyclin D1 and tenascin-C, and coupled with increased mesenchymal cell proliferation. In an ex vivo serumless culture system, cleft lip explants fused in the presence of exogenous TGF-β3. Cultured lips also showed up-regulation in cyclin D1 and tenascin-C expression. These findings suggest that microsurgical repair of cleft lip in the fetus that produced scarless fusion is mediated by TGF-β3 regulation of mesenchymal cell proliferation and migration at the site of repair.
Mechanical Significance of the Trabecular Microstructure of the Human Mandibular Condyle
Authors: van Ruijven L.J. , Giesen E.B.W. , van Eijden T.M.G.J.
Published: January 2009

The human mandibular condyle has a parasagittal plate-like trabecular structure. We tested the hypothesis that this structure reflects the mechanical loading of the condyle. We developed a finite element model of the condyle to analyze the strains occurring during static compressive loading. The principal strains in the trabecular bone were primarily oriented in the sagittal plane. The first component was compressive and oriented supero-inferiorly. The second component was negligibly small and oriented medio-laterally. The third component was tensile, oriented antero-posteriorly, and almost equal to the compressive strain. This tensile strain was caused by antero-posterior bulging of the cortex. This means that the trabecular structure is also subjected to significant tensile forces. The orientation of the parasagittal strains followed the direction of the applied load. It was concluded that the trabecular structure of the mandibular condyle is optimal in resisting the compressive and tensile strains to which it is subjected.
Diurnal Variation in the Response of the Mandible to Orthopedic Force
Authors: Yamada S. , Saeki S. , Takahashi I. , Igarashi K. , Shinoda H. , Mitani H.
Published: January 2009

Bone and cartilage metabolism is known to be more active during rest than during periods of activity. The purpose of this study was to examine the hypothesis that mandibular retractive force could be more effective when applied to rats during rest. Mandibular retractive force caused a considerable reduction in the condylar length in experimental groups, and the magnitude of this reduction was greater in the Light-period (08:00-20:00) group than in the Dark-period (20:00-08:00) group. The differentiation and proliferation of chondrocytes were inhibited in animals in the Light-period group, compared with those in the Dark-period group. These results suggest that the orthopedic effects of mandibular retractive force vary depending on the time of day the force is applied, and that such force may be more effective while animals are resting than while they are active.
Mechanobiology of Craniofacial Sutures
Authors: Mao J.J.
Published: January 2009

Craniofacial sutures are soft connective-tissue joints between mineralized skull bones. Suture mechanobiology refers to the understanding of how mechanical stimuli modulate sutural growth. This review's hypothesis is that novel mechanical stimuli can effectively modulate sutural growth. Exogenous forces with static, sinusoidal, and square waveforms induce corresponding waveforms of sutural strain. Sutural growth is accelerated upon small doses of oscillatory strain, as few as 600 cycles delivered 10 min/day over 12 days. Interestingly, both oscillatory tensile and compressive strains induce anabolic sutural responses beyond natural growth. Mechanistically, oscillatory strain likely turns on genes and transcription factors that activate cellular machinery via mechanotransduction pathways. Thus, sutural growth is determined by hereditary and mechanical signals via the common pathway of genes. It is concluded that small doses of oscillatory mechanical stimuli have the potential to modulate sutural growth effectively: either accelerating it or initiating net sutural bone resorption for various therapeutic objectives.
Cementum: A Phosphate-sensitive Tissue
Authors: Nociti F.H. , Berry J.E. , Foster B.L. , Gurley K.A. , Kingsley D.M. , Takata T. , Miyauchi M. , Somerman M.J.
Published: January 2009

Ectopic calcification within joints has been reported in humans and rodents exhibiting mutations in genes that regulate the level of extracellular pyrophosphate, e.g., ank and PC-1; however, periodontal effects of these mutations have not previously been examined. These initial studies using ank and PC-1 mutant mice were done to see if such mineral deposition and resulting ankylosis were occurring in the periodontium as well. Surprisingly, results indicated the absence of ankylosis; however, a marked increase in cementum formation on the root surfaces of fully developed teeth of these mutant mice was noted. Examination of ank mutant mice at earlier ages of tooth root formation indicated that this striking observation is apparent from the onset of cementogenesis. These findings suggest that cells within the periodontal region are highly responsive to changes in phosphate metabolism. This information may prove valuable in attempts to design successful therapies for regenerating periodontal tissues.