bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidative stress biomarkers and aggressive behavior in fish exposed to aquatic cadmium contamination
Authors: Almeida Jeane A. , Barreto Rodrigo E. , Novelli Ethel L. B. , Castro Fabio J. , Moron Sandro E.
Published: April 2009

The objective of this study was to investigate the possible link between cadmium exposure, hepatic markers of oxidative stress and aggressive behavior in Nile tilapia (Oreochromis niloticus). Fish were first exposed to 0.75 mg/L CdCl2 for 15 days (12 isolated fish for each group) and afterward a behavioral test was performed. Fish from the control and cadmium-exposed groups were paired for 1 h (6 pairs of fish per group) for determination of aggressiveness parameters. Immediately after the behavioral test, the animals were sacrificed and the liver was used to determine biochemical parameters. Cadmium decreased aggression in Nile tilapia. Subordinate animals exposed to cadmium showed decreased glutathione peroxidase (GSH-Px) activity compared to dominant ones. No alterations were observed in selenium-dependent glutathione peroxidase Se-GSH-P and Cu-Zn superoxide dismutase activities, but total superoxide dismutase activity was increased in subordinate animals exposed to cadmium compared to subordinate control. Catalase activity was increased in cadmium-exposed fish. Lipoperoxide concentrations also increased in cadmium exposed fish indicating that cadmium toxicity may affect oxidative stress biomarkers in Nile tilapia. Social stress induced lipoperoxidation in Nile tilapia, and subordinate animals exposed to cadmium responded with lower activities of liver antioxidant enzymes compared to dominant fish. The present study shows that cadmium exposure is capable of inducing changes in the social status and oxidative stress parameters in this species.
Bentonite THM behaviour at high temperatures: experimental and numerical analysis
Authors: Åkesson M. , Jacinto A. C. , Gatabin C. , Sanchez M. , Ledesma A.
Published: April 2009

The Temperature Buffer Test is a heated full-scale field experiment carried out at the Äspö Hard Rock Laboratory in Sweden, simulating repository conditions for radioactive waste. The initial thermo-hydro-mechanical (THM) evolution in the clay barrier was investigated in a separate mock-up test. The paper describes this laboratory experiment and the corresponding numerical simulations. Most of the related work refers to THM analyses of bentonite barriers well below 100°C, but here higher temperatures are considered. A 20 cm closed specimen of compacted MX-80 bentonite was subjected to a temperature gradient (84°C and 120°C at the end points). The evolution of temperature, relative humidity, pore pressure and stresses was monitored at several points. The test was allowed to reach steady-state conditions. The specimen was then sampled and analysed in terms of water content and bulk density. Several finite element analyses considering different coupled THM interactions were performed, and compared with measurements. Bentonite properties were obtained from independent tests. Additionally, retention properties were also obtained from measured saturation ratios and steady-state suction values. For the mechanical problem the Barcelona Expansive Model was used, which includes explicitly the two structural levels that actually exist in expansive clays (macro- and microstructure). This model made it possible to simulate the evolution of stresses as well as the expansion of bentonite at the ‘cold’ side and the compression at the ‘hot’ side, using a single set of parameters.
Experimental investigation of thermo-hydro-mechanical behaviour of an unsaturated silt
Authors: Uchaipichat A. , Khalili N.
Published: April 2009

Experimental research is conducted on a compacted sample of silt using a triaxial equipment modified for testing unsaturated soils at elevated temperatures. An extensive array of isothermal and non-isothermal tests is conducted, including temperature-controlled soaking and desaturation tests, temperature- and suction-controlled isotropic consolidation tests, and suction-controlled thermal loading and unloading tests. Temperature values applied ranged from 25°C to 60°C, and the suction values varied from 0 to 300 kPa. Baseline data are presented on the influences of temperature and suction on critical-state parameters, yield surface, preconsolidation pressure, strength properties, and water retention characteristics of the soil. All data are carefully analysed and prevailing trends are highlighted.
Solar heating of the soil and evaporation from a soil surface
Authors: Blight G.
Published: April 2009

In 1994 a system for classifying landfills for municipal solid waste by local climate was introduced in South Africa. If it can be shown that potential evaporation from the landfill surface will exceed average annual rainfall, it is accepted that no significant leachate will be generated in the landfill, and a leachate collection system, impervious underliner and leachate treatment system is not legally required. This represents very large financial savings on the establishment of a new landfill or the extension of an existing one. Hence the measurement and prediction of evaporation from a soil surface has become a subject of considerable importance to the waste disposal industries in South Africa and neighbouring countries (e.g. Botswana and Namibia) that have adopted similar climatic approaches. Over the past 20 years it has become apparent that the long-established solar energy balance approach to assessing evaporation from a soil may be in error. This is because it regards solar energy expended on heating the soil as reducing the energy available for supplying energy of evaporation. This paper describes experiments aimed at exploring the role of heating of the soil in the evaporation process, and concludes that, far from subtracting energy from the process, it actually provides most of the energy for evaporation.
The coupled thermal-hydraulic-mechanical behaviour of a large-scale in situ heating experiment
Authors: Thomas H. R. , Cleall P. J. , Dixon D. , Mitchell H. P.
Published: April 2009

The thermo-hydraulic-mechanical behaviour of a large in situ heating test, the Buffer/Container Experiment (BCE), carried out at Atomic Energy of Canada's underground research laboratory, is considered. The work can be seen as an extension of the authors' previous research, investigating the behaviour of a large-scale test, the so-called ‘isothermal test’, to now include heating effects. Suggestions related to the micro–macro behaviour of bentonitic buffer materials subjected to resaturation in confined non-isothermal conditions are explored. Simulation of pre-heating phases of the experiment demonstrates the ability of the model to describe the hydraulic regime in the host rock and isothermal infiltration into the buffer. Consideration of the heating phase confirms that the temperature field is well understood, with a good correlation between the numerical and experimental results. In the moisture field it is found that the interaction between the emplaced buffer and host rock is of considerable importance. It is found that inclusion of micro–macro interaction effects, by way of consideration of the impact of swelling and micro–macro interactions on the hydraulic conductivity of the material, yielded significantly improved correlations between observed and calculated results in the moisture field. The results of the numerical simulations suggest that the interaction between the emplaced buffer and host rock is strongly influenced by the micro–macro behaviour of the bentonitic buffer material. It is concluded that the consideration of the impact of micro–macro interactions on moisture flow in bentonitic buffers is of considerable importance, and may be of some significance in considering the total resaturation time as part of the performance assessment of a nuclear waste disposal repository.
Improved Load Sharing Control Techniques for Inverters used in a Microgrid
Authors: Yao Wei , Qian Zhaoming
Published: April 2009

In this paper, an improved load sharing control scheme is presented, which is able to improve the transient response and power sharing accuracy of parallel-connected inverters used in microgrid. It also shows how the improved droop method can be easily adapted to account for the operation of parallel-connected inverters, providing good performance under the variation and disturbance of loads, as well as achieving good steady-state objectives and transient performance. Two DSP-based single-phase Microgrid inverters are designed and implemented. Simulation and experimental results are all reported, confirming the validity of the proposed control technique.
Understanding Power System Behavior through Mining Archived Operational Data
Authors: Das Sarasij , P S Nagendra Rao
Published: April 2009

This paper is the outcome of an attempt in mining recorded power system operational data in order to get new insight to practical power system behavior. Data mining, in general, is essentially finding new relations between data sets by analyzing well known or recorded data. In this effort we make use of the recorded data of the Southern regional grid of India. Some interesting relations at the total system level between frequency, total MW/MVAr generation, and average system voltage have been obtained. The aim of this work is to highlight the potential of data mining for power system applications and also some of the concerns that need to be addressed to make such efforts more useful.
Head Posture and Lower Arch Dental Crowding
Authors: Pachì Francesco , Turlà Ruggero , Checchi Alessandro Proietti
Published: April 2009

Objective: To test the null hypothesis that there is no relationship between the posture of the head and the neck and late lower arch crowding.

Materials and Methods: The sample comprised 55 subjects (23 female, 32 male), age 12–18 years, with complete permanent dentition and without previous orthodontic treatment. Space conditions were valued by Nance's space analysis on the study models. Craniovertical, craniocervical, and craniohorizontal postural variables were recorded from lateral cephalograms. Student's t-test was performed to assess the differences of the postural angles between the two groups.

Results: The results showed that the differences of the postural variables between the two groups are statistically significant. Subjects with more than 2 mm dental crowding had mean craniocervical angles (NSL/CVT, NSL/OPT, NL/CVT, NL/OPT) that were 5° to 6° larger than the subjects with the space conditions smaller than 2 mm (P ≤ .01). In addition, the mean craniohorizontal angles (CVT/Hor, OPT/Hor) in the subjects with lower dental crowding were 4° smaller than subjects without dental crowding (P < .05).

Conclusions: The hypothesis is rejected. A clear pattern of association between extended head posture and lower arch dental crowding was found.
Anteroposterior and Vertical Components of Class II division 1 and division 2 Malocclusion
Authors: Al-Khateeb Emad A. A. , Al-Khateeb Susan N.
Published: April 2009

Objective: To describe and analyze the skeletal and dental characteristics associated with Class II division 1 (Class II/1) and Class II division 2 (Class II/2) malocclusions in the anteroposterior and vertical dimensions.

Materials and Methods: A total of 551 lateral cephalograms were used; 293 films of Class II/1 and 258 films of Class II/2 malocclusions. Lateral cephalographs were traced and analyzed. Parameters for both malocclusions were compared with each other and with the norms calculated for the Jordanian population in another study.

Results: The maxilla was prognathic in both malocclusions. The mandible was retrognathic in Class II/1 and orthognathic in Class II/2. Vertically, LAFH was significantly reduced in patients with Class II/2 compared with subjects with Class II/1 who exhibited a significantly increased LAFH. In Class II/1, the lower incisors were proclined and the interincisal angle was reduced, while in Class II/2 the lower incisors were at a normal inclination and the interincisal angle was significantly increased.

Conclusions: Class II/2 may be considered as a separate entity which differs in almost all skeletal and dental features from Class I and Class II/1. A Class II skeletal pattern and reduced interincisal angle were common features of Class II/1 malocclusion, while a Class II skeletal pattern, increased interincisal angle, and skeletal deep bite were common features of Class II/2 malocclusion.
An M-CSF Receptor c-Fms Antibody Inhibits Mechanical Stress–Induced Root Resorption during Orthodontic Tooth Movement in Mice
Authors: Kitaura Hideki , Fujimura Yuji , Yoshimatsu Masako , Eguchi Toshiko , Kohara Haruka , Jang Insan , Morita Yukiko , Yoshida Noriaki
Published: April 2009

Objective: To examine the effect of anti-c-Fms antibody on odontoclastogenesis and root resorption in an orthodontic tooth movement mouse model.

Materials and Methods: We used orthodontic tooth movement in which an Ni-Ti coil spring was inserted between the upper incisors and the upper first molar. Root resorption occurred in this model. Anti-c-Fms antibody was injected daily into a local site for 12 days during mechanical loading. Odontoclastogenesis and root resorption were assessed by histology and scanning electron microscopy.

Results: The anti-c-Fms antibody significantly inhibited odontoclastogenesis and root resorption during orthodontic tooth movement.

Conclusion: M-CSF and/or its receptor is a potential therapeutic target in mechanical stress– induced odontoclastogenesis, and injection of an anti-c-Fms antibody might be useful for inhibition of mechanical stress–induced root resorption during orthodontic tooth movement.
Low-Intensity Pulsed Ultrasound Stimulation of Condylar Growth in Rats
Authors: Oyonarte Rodrigo , Zárate Mariana , Rodriguez Francisco
Published: April 2009

Objective: To test the hypothesis that low-intensity pulsed ultrasound (LIPUS) stimulation does not histologically affect the growth of mandibular condylar cartilage.

Materials and Methods: Thirty-five 20-day-old Sprague-Dawley rats were assigned to experimental and control groups. Experimental rats were stimulated with LIPUS in the temporomandibular joint (TMJ) region unilaterally, for 10 or 20 minutes for 20 days. After euthanasia, histological specimens were analyzed qualitatively and histomorphometrically at the anterior and posterior aspects of the mandibular condyle, including the condylar cartilage and the area and perimeter of subchondral bony trabeculae.

Results: LIPUS stimulation may alter the histological arrangement of the condylar bone and cartilage, showing qualitative differences on specimens treated for 10 or 20 minutes daily compared with controls. Cartilaginous layer thickness was not affected by LIPUS stimulation to a significant level, but was modified at the relative layer thickness within the cartilage at the anterior aspect of the condyle (P < .05). At the subchondral bone level, 20-minute stimulation significantly increases trabecular perimeter (P = .01).

Conclusions: LIPUS application may affect mandibular growth pattern in rats acting at the cartilage and bone level. The effect of LIPUS on the growing condyle is expressed through a variation in trabecular shape and perimeter. A greater response is achieved when stimulated for 20 minutes instead of 10 minutes daily.
Functional Changes of Temporomandibular Joint Mechanoreceptors Induced by Reduced Masseter Muscle Activity in Growing Rats
Authors: Ishida Takayoshi , Yabushita Tadachika , Soma Kunimichi
Published: April 2009

Objective: To determine the influence of masseter muscle activity during growth on the functional characteristics of temporomandibular joint (TMJ) mechanoreceptors.

Materials and Methods: Sixty-six 3-week-old male Wistar rats were divided into an experimental group, in which the masseter muscles were bilaterally resected at 3 weeks of age, and a control group. Single-unit activities of the TMJ mechanoreceptors were evoked by indirect stimulation of passive jaw movement. Electrophysiologic recordings of TMJ units were made at 5, 7, and 9 weeks of age.

Results: During this period, the firing threshold of the TMJ units was significantly lower and the maximum instantaneous frequency of the TMJ units was significantly higher in the experimental group than in the control group.

Conclusion: Reduced masseter activity during the growth period alters the response properties of TMJ mechanoreceptors.
Variations in the Inclination of the Condylar Path in Children and Adults
Authors: Reicheneder Claudia , Gedrange Tomas , Baumert Uwe , Faltermeier Andreas , Proff Peter
Published: April 2009

Objective: To test the null hypothesis that there are no differences between children and adults in the condylar path inclination angle on the right and left sides.

Materials and Methods: A group of 80 children aged 6 to 10 years (subgroups I through V, according to chronologic age) was compared with an adult group with regard to the condylar path inclination angle (CPIA) on the right and left sides. The CPIA was measured using the ultrasonic JMA-System for registration.

Results: During development of the temporomandibular joint the condylar path inclination angle increased with age in the subgroups of children. A significant difference was found in the CPIA between the groups of adults and children. In the group with the oldest children (mean age: 10.3 years) the condylar path inclination angle had reached 81.87% on the right side and 78.85% on the left side compared with the adult group at a 5 mm protrusive path. In the pooled group of children the CPIA amounted to 73.08% on the right side and 72.13% on the left side compared with the values for the adults. No significant difference was found between the right and left CPIA in any group.

Conclusion: The hypothesis is rejected. The CPIA on the right and left sides increased with age in the group of children and was significantly smaller in the group of children compared with the group of adults.
Prevalence of Nickel Allergy and Longitudinal Evaluation of Periodontal Abnormalities in Orthodontic Allergic Patients
Authors: Pazzini Camila Alessandra , Júnior Gilberto Oliveira , Marques Leandro Silva , Pereira Cássio Vicente , Pereira Luciano José
Published: April 2009

Objective: To determine the prevalence of nickel allergy in a sample of orthodontic patients and longitudinally compare the clinical periodontal status of these individuals with that of a group of nonallergic patients.

Materials and Methods: The initial sample consisted of 96 patients selected randomly from a databank of patients who sought orthodontic care at a teaching institution. Following the selection and beginning of treatment, periodontal status was assessed over a 12-month period (one evaluation every 3 months—T1, T2, T3, T4) using the Loe index. The evaluations were performed blindly by a single, calibrated examiner and were followed by prophylaxis and orientation regarding oral hygiene. The prevalence of nickel allergy was determined by the patch test 9 months after the beginning of treatment and occurred in 16 individuals (17.2%). Two groups were then established: the allergic group (AG, n = 16) and the age-paired nonallergic control group (NAG, n = 16). Data were analyzed using the Mann-Whitney U-test and Friedman's analysis of variance (ANOVA) tests (P ≤ .05).

Results: Significant differences were present between groups at the T3 and T4 evaluations for the LOE index (P = .045 and .009), with allergic individuals showing higher mean values than nonallergic individuals (hyperplasia, change in color, and bleeding). No significant differences were found in the intragroup evaluations between the four evaluations (P > .05).

Conclusions: The results suggest a cumulative effect from nickel throughout orthodontic treatment associated with clinically significant periodontal abnormalities in allergic individuals over time.
Computational Formulation of Orthodontic Tooth-Extraction Decisions
Authors: Takada Kenji , Yagi Masakazu , Horiguchi Eriko
Published: April 2009

Objective: To develop a mathematical model that simulates whether or not to extract teeth in optimizing orthodontic treatment outcome and to formulate the morphologic traits sensitive to optimizing the tooth-extraction/nonextraction decisions.

Materials and Methods: A total of 188 conventional orthodontic records of patients with good treatment outcomes were collected, and dentofacial morphologic traits, along with their degrees of influence in the optimized model, were determined.

Results: The rate of coincidence between the recommendations given by the optimized model and the actual treatments performed was found to be 90.4%. The major morphologic traits and their corresponding influences in improving the simulation accuracy of the model were the incisor overjet (3.0) and the size of the basal arch relative to the sum of the mesiodistal crown diameters of the upper dentition (2.4) and the lower dentition (2.0). The remaining 22 morphologic-trait variables were also found to be indispensable in achieving robust simulation readings.

Conclusion: A mathematical model that simulates whether or not to extract teeth in optimizing orthodontic treatment outcomes with a success rate of 90.4% at its prediction performance was developed. This model has 25 morphologic traits with four major categories (sagittal dentoskeletal and soft tissue relationship, vertical dentoskeletal relationship, transverse dental relationship, and intra-arch conditions) that affected the accuracy in determining optimal tooth extractions/nonextractions.
Computational Formulation of Orthodontic Tooth-Extraction Decisions
Authors: Yagi Masakazu , Ohno Hiroko , Takada Kenji
Published: April 2009

Objective: To develop a mathematical model that simulates optimum site(s) for tooth extraction and to examine what kinds of dentoskeletal traits, in the model, influence optimizing decisions for extraction site(s).

Materials and Methods: Conventional orthodontic records were obtained for 193 women who had received orthodontic tooth-extraction treatments judged as excellent treatment outcomes. The feature vector-elements that represented dentoskeletal traits, and weights of their contributions to achieving optimum simulation in the model, were determined.

Results: The rate of coincidence between recommendations made by the optimized model and the actual judgments was found to be 86.0%. The elements that were sensitive to increasing the rate of coincidence and corresponding weights in judging the site(s) of tooth extraction were: protrusiveness of the upper and lower incisors (2.0), overjet and overbite (1.5), the membership grade for the skeletal Class II jaw relationship, molar relationship in the sagittal direction, the mandibular plane angle, and the severity of tooth crowding in the lower dentition (1.0). The remaining 10 feature vector-elements were also found to be indispensable for the model.

Conclusions: A mathematical model that simulates optimum site(s) for orthodontic tooth extraction, with a high agreement rate (86.0%) between the system's recommendations and the actual judgments given by orthodontists, was developed. The dentoskeletal structural traits that affected optimizing decisions for orthodontic tooth-extraction site(s) were formulated and subdivided into five major categories, ie, the sagittal dentoskeletal and soft tissue relationship, the vertical dentoskeletal relationship, the transverse dental relationship, the intra-arch conditions, and the pathological conditions.
Trigeminal Expression of N-Methyl-D-Aspartate Receptor Subunit 1 and Behavior Responses to Experimental Tooth Movement in Rats
Authors: Yang Zhi , Wang Yan , Luo Wei , Hua Xiaochuan , Wamalwa Peter , Wang Jing , Zhao Zhihe , Lu Yun , Liao Zhengyu , Lai Wenli
Published: April 2009

Objective: To test the hypothesis that peripheral N-methyl-D-aspartate (NMDA) receptors play a role in pain induced by experimental tooth movement.

Materials and Methods: Male Sprague-Dawley rats weighing between 200 g and 300 g were used in this study. Expression of NMDA receptors subunit 1 (NMDAR1) in the mandibular portion of the trigeminal ganglion (TG) was determined by Western blotting 4 hours and 1, 2, 3, 5, 7, and 14 days after tooth movement. Changes in the time taken by the rats on nocifensive behavior then effects of NMDA receptor antagonist MK-801 and force magnitude on these changes in behavior and NMDAR1 expression were evaluated.

Results: Experimental tooth movement led to a statistically significant increase in NMDAR1 expression at protein level from day 1 to 7 after force application initiating tooth movement. Time spent on nocifensive behavior dramatically increased from day 1 to 7. The rhythm in NMDAR1 expression in the TG and behavioral activities correlated well with the initial orthodontic pain responses. The magnitude of the nocifensive behavior and NMDAR1 expression were both force magnitude dependent and could be reduced by peripheral NMDA receptor antagonist MK-801.

Conclusions: The hypothesis is accepted. Peripheral NMDA receptors are modulated by experimental tooth movement and involved in the development of tooth movement pain.
Maxillary Incisor Proclination Effect on the Position of Point A in Class II division 2 Malocclusion
Authors: Al-Nimri Kazem S. , Hazza'a Abdalla M. , Al-Omari Rami M.
Published: April 2009

Objective: To test the hypothesis that the magnitude of alteration in the position of point A is not associated with proclination of the upper incisors in Class II division 2 malocclusion.

Materials and Methods: Cephalometric films were taken for 30 Class II division 2 patients (8 males and 22 females; average age, 18.3 years) before and after upper incisor proclination. The total change in the position of point A was measured by superimposing the pretreatment and postproclination lateral cephalograms on the sella-nasion line at the sella. To determine the local effect of alveolar bone remodeling associated with upper incisor proclination on the position of point A, postproclination tracing of the maxilla was superimposed on the pretreatment tracing according to the Bolton template of maxillary superimposition.

Results: The total vertical displacement in Point A position was downward by 0.84 mm (P = .002), and the total horizontal displacement was forward by 0.45 mm (P = .054). Assessment of local changes in point A revealed that the position of point A had moved backward by 0.60 mm (P = .001). No significant change was observed in the value of the sella-nasion–point A angle (SNA).

Conclusion: The hypothesis is rejected. The position of point A is affected by local bone remodeling associated with proclination of the upper incisor in Class II division 2 malocclusion, but this minor change does not significantly affect the SNA angle.
Head Orientation in CBCT-generated Cephalograms
Authors: Cevidanes Lucia , Oliveira Ana E. F. , Motta Alexandre , Phillips Ceib , Burke Brandon , Tyndall Donald
Published: April 2009

Objective: To determine the reliability of obtaining two-dimensional cephalometric measurements using two virtual head orientations from cone-beam computed tomography (CBCT) models.

Materials and Methods: CBCT scans of 12 patients (6 class II and 6 class III) were randomly selected from a pool of 159 patients. An orthodontist, a dental radiologist, and a third-year dental student independently oriented CBCT three-dimensional (3D) renderings in either visual natural head position (simulated NHP) or 3D intracranial reference planes (3D IRP). Each observer created and digitized four CBCT-generated lateral cephalograms per patient, two using simulated NHP and two using 3D IRP at intervals of at least 3 days. Mixed-effects analysis of variance was used to calculate intraclass correlation coefficients (ICCs) and to test the difference between the orientations for each measure.

Results: ICC indicated good reliability both within each head orientation and between orientations. Of the 50 measurements, the reliability coefficients were ≥0.9 for 45 measurements obtained with 3D IRP orientation and 36 measurements with simulated NHP. The difference in mean values of the two orientations exceeded 2 mm or 2° for 14 (28%) of the measurements.

Conclusions: The reliability of both virtual head orientations was acceptable, although the percentage of measurements with ICC >0.9 was greater for 3D IRP. This may reflect the ease of using the guide planes to position the head in the 3D IRP during the simulation process.
Face Mask Therapy Effects in Two Skeletal Maturation Groups of Female Subjects with Skeletal Class III Malocclusions
Authors: Yavuz İbrahim , Halıcıoğlu Koray , Ceylan İsmail
Published: April 2009

Objective: To examine the effects of face mask therapy in adolescent and young adult female subjects with skeletal Class III malocclusion characterized by maxillary retrognathism.

Materials and Methods: The material consisted of pretreatment and posttreatment lateral cephalometric radiographs of 28 subjects with Class III malocclusions treated with a face mask. Twenty-eight patients age 10 to 16 years were divided into two groups: the adolescent group (15 female patients) and the young adult group (13 female patients). Within group and between group comparisons were made by paired t-test and Student's t-test, respectively.

Results: Forward displacement of the maxilla and clockwise rotation of the mandible occurred in both the adolescent and young adult groups. Maxillary-mandibular relationship exhibited an increase in the ANB angle and Wits appraisal, and the soft-tissue changes resulted in a more convex profile. The maxillary incisors moved forward while the mandibular incisors moved backward.

Conclusions: Face mask therapy improves skeletal Class III malocclusions by a combination of skeletal and dental changes. Although early treatment may be most effective, face mask treatment can provide a viable option for older children as well.
Microbial Adhesion on Different Bracket Types in vitro
Authors: Gastel Janvan , Quirynen Marc , Teughels Wim , Pauwels Martine , Coucke Wim , Carels Carine
Published: April 2009

Objective: To test the hypothesis that there are differences in total bacterial counts and capacity for biofilm formation between seven different bracket types.

Material and Methods: By means of an in vitro experiment, seven commercially available bracket systems (Damon [A], Clarity [B], Mystique [C], Speed [D], Victory MBT [E], Micro-loc [F], and Generus [G]) were compared. A total of 25 premolar brackets of each bracket system were incubated in brain heart infusion medium containing the saliva and bacteria of two orthodontic patients. After 72 hours, the amounts of aerobe and anaerobe bacteria were determined by counting the colony-forming units (CFU). The CFU ratio (aerobe/anaerobe) also was calculated, and the black pigmented bacteria were analyzed.

Results: Significant differences between the different bracket types in terms of biofilm formation were found. Bracket types can be arbitrarily divided into low, intermediate, and high plaque-retaining brackets. The group with low adhesion consists of bracket types E, F, and G; the group with high adhesion of bracket types A, B, and C; and type D exhibits intermediate adhesion. The group with high microbial adhesion (A, B, and C) did present significantly lower CFU ratios (aerobe/anaerobe) than were exhibited by the other bracket systems (P < .05).

Conclusion: The hypothesis is accepted. Orthodontic brackets serve as different loci for biofilm formation; in this in vitro study, significant differences were noted between the different types of brackets.
Occlusal Contact Changes with Removable and Bonded Retainers in a 1-Year Retention Period
Authors: Sari Zafer , Uysal Tancan , Başçiftçi Faruk Ayhan , Inan Ozgur
Published: April 2009

Objective: To test the hypothesis that there is no difference in the number of occlusal contacts in centric occlusion in patients treated with bonded and removable retention procedures and a control group during a 1-year retention period.

Materials and Methods: Twenty-five patients received a removable Hawley retainer, and 25 patients received maxillary and mandibular bonded retainers. The retainer patients were compared with 20 control subjects with normal occlusions. Silicone-based impression bites were used to record occlusal contacts. Paired-sample t-test, analysis of variance (ANOVA), and Tukey tests were used to evaluate intragroup and intergroup differences.

Results: An increased number of occlusal contacts were recorded in total-arch and posterior combined (actual/near) teeth during the retention period as compared with the control group. In the Hawley group, actual and total contacts on the first and second molar and actual contacts on the premolar and canine showed statistically significant increases. In the bonded retainer group, near and total contacts on the first and second molars and premolars showed statistically significant increases. Slight occlusal changes were seen in the control sample during the observation period, presumably from growth and development. ANOVA comparisons of total contacts of anterior and posterior teeth indicated statistically significant differences in the three groups on posterior segments.

Conclusions: The hypothesis is rejected. Both retention procedures allowed relative vertical movement of the posterior teeth, but the number of contacts on the posterior segment was increased more in the bonded retainer group than in the Hawley and control groups at the end of retention.
Midline Mandibular Osteotomy in an Asymmetric Patient
Authors: Anghinoni M. L. , Magri A. S. , Di Blasio A. , Toma L. , Sesenna E.
Published: April 2009

This case report shows the possibility of the application of a mandibular osteotomy to resolve mandibular asymmetry with independent and discordant movements of both bony segments. The authors report the case of a 25-year-old woman referred for mandibular asymmetry, with a transverse excess of the right hemi mandible and vertical defect of the left one. The patient underwent a bilateral sagittal split osteotomy, midline osteotomy, and genioplasty, which corrected the mandibular asymmetry with contraction of the entire right hemi mandible. A slight left vertical increase was also obtained through the surgically created lateral open bite. In the follow-up assessment, the patient's face appeared symmetrical with normalization of the bizygomatic-bigonial relationships, and the facial shape corresponded to ideal anthropometric features. This technique resulted in resolution of mandibular asymmetry. In addition, mandibular osteotomy permits the esthetic management of the shape of the entire mandibular body in relation to the other third of the face.
Facial Morphologies of an Adult Egyptian Population and an Adult Houstonian White Population Compared Using 3D Imaging
Authors: Seager Dennis Craig , Kau Chung How , English Jeryl D. , Tawfik Wael , Bussa Harry I. , Ahmed Abou El Yazeed M.
Published: April 2009

Objective: To compare the facial morphologies of an adult Egyptian population with those of a Houstonian white population.

Materials and Methods: The three-dimensional (3D) images were acquired via a commercially available stereophotogrammetric camera capture system. The 3dMDface System photographed 186 subjects from two population groups (Egypt and Houston). All of the participants from both population groups were between 18 and 30 years of age and had no apparent facial anomalies. All facial images were overlaid and superimposed, and a complex mathematical algorithm was performed to generate a composite facial average (one male and one female) for each subgroup (EGY-M: Egyptian male subjects; EGY-F: Egyptian female subjects; HOU-M: Houstonian male subjects; and HOU-F: Houstonian female subjects). The computer-generated facial averages were superimposed based on a previously validated superimposition method, and the facial differences were evaluated and quantified.

Results: Distinct facial differences were evident between the subgroups evaluated, involving various regions of the face including the slant of the forehead, and the nasal, malar, and labial regions. Overall, the mean facial differences between the Egyptian and Houstonian female subjects were 1.33 ± 0.93 mm, while the differences in Egyptian and Houstonian male subjects were 2.32 ± 2.23 mm. The range of differences for the female population pairings and the male population pairings were 14.34 mm and 13.71 mm, respectively.

Conclusions: The average adult Egyptian and white Houstonian face possess distinct differences. Different populations and ethnicities have different facial features and averages.
Long-Term Outcomes of Class III Treatment with Mandibular Cervical Headgear Followed by Fixed Appliances
Authors: Baccetti Tiziano , Rey Diego , Oberti Giovanni , Stahl Franka , McNamara James A.
Published: April 2009

Objective: To evaluate the stability of the outcomes of mandibular cervical headgear (MCH) and fixed appliance–treated Class III patients at a long-term posttreatment (5 years) observation, compared with well-matched untreated Class III controls, following a previous report on the short-term outcomes of this protocol.

Materials and Methods: The treated group consisted of 20 patients with dentoskeletal Class III malocclusions treated with a two-phase protocol consisting of MCH and fixed appliances, while the control group comprised 18 untreated subjects with similar dentoskeletal Class III malocclusion. Lateral cephalograms of both patients and controls were analyzed at two time points: posttreatment (PT), after two-phase treatment; and long term (LT). All patients were at a postpubertal stage of skeletal maturity at PT, and they showed CS6 at LT, thus revealing completion of pubertal craniofacial growth.

Results: In the long term, the treatment group showed significantly smaller values for mandibular length (Co-Gn), SNB angle, maxillomandibular differential, and molar relation. When compared with the controls, the treated patients exhibited also greater values for ANB angle, Wits appraisal, and overjet at LT. No significant difference between the two groups was found for the changes occurring from PT to LT.

Conclusions: Favorable dentoskeletal outcomes induced by MCH and fixed appliances remained stable in the long term; untreated Class III malocclusion did not show any tendency toward self-improvement during the postpubertal interval.
Adolescent Patients' Treatment Motivation and Satisfaction with Orthodontic Treatment
Authors: Anderson Lauren E. , Arruda Airton , Inglehart Marita Rohr
Published: April 2009

Objective: To determine whether adolescents' satisfaction with orthodontic treatment outcomes is correlated with the degree to which (1) the adolescents focused on and (2) were energized by imagining their posttreatment possible selves before the treatment, and whether parents' assessments of their children's pretreatment motivation would correlate with their children's posttreatment satisfaction.

Methods: Data were collected from 75 former adolescent orthodontic patients (28 male, 47 female; 60 European American, 14 other) and from 72 parents (59 female, 12 male, 1 missing) with mailed questionnaires. Satisfaction with the treatment outcome was assessed with a revised version of Kiyak's Post-Surgical Patient Satisfaction Questionnaire.

Results: The more the patients had focused on the posttreatment esthetics and functioning and the more they were energized by thinking about their posttreatment possible selves before the treatment, the more satisfied they were with the outcomes (r = .337, P = .004; r = .231, P = .053; r = .465, P < .001). The more the parents believed that their children were energized by thinking about posttreatment possible selves, the more satisfied the parents were with the outcomes (r = .326, P = .007).

Conclusions: Increasing adolescents' possible self considerations before orthodontic treatment is likely to increase their own and their parents' posttreatment satisfaction.
Forces and Moments Generated with Various Incisor Intrusion Systems on Maxillary and Mandibular Anterior Teeth
Authors: Sifakakis Iosif , Pandis Nikolaos , Makou Margarita , Eliades Theodore , Bourauel Christoph
Published: April 2009

Objective: To evaluate the comparative intrusive forces and torquing moments in the sagittal plane generated during anterior intrusion using different incisor intrusion mechanics in the maxillary and mandibular anterior teeth.

Materials and Methods: Five wire specimens were used for each of the following intrusive arches: non–heat-treated, 0.016 × 0.016-inch blue Elgiloy utility arch, 0.017 × 0.025-inch TMA utility arch, and 0.017 × 0.025-inch TMA Burstone intrusion arch. The wires were constructed according to the specifications given by their inventors and were inserted on bracketed dental arches on Frasaco models, segmented mesial to the canines. Simulated intrusion from 0.0–1.5 mm was performed on the Orthodontic Measurement and Simulation System (OMSS), and forces and moments were recorded at 0.1 mm vertical displacement increments. All measurements were repeated five times for each specimen, and maximum values recorded at 1.5 mm for all wires were used for all statistical evaluations. The data were analyzed with two-way analysis of variance (ANOVA) with forces and moments serving as the dependent variables, separately, and wire type and jaw as the independent variables. Post hoc multiple comparisons were performed using the Tukey test (.05 error rate).

Results: The 0.017 × 0.025-inch TMA Burstone intrusion arch exerted the lowest intrusive forces, followed by the 0.017 × 0.025-inch TMA utility and the 0.016 × 0.016-inch blue Elgiloy utility arch. The lowest anterior moment in the sagittal plane in this experiment was generated from the 0.017 × 0.025-inch TMA Burstone intrusion arch.

Conclusions: The intrusive forces, as well as the generated moments, were always higher in the mandible, where significant differences were observed among the configurations tested.
Sensitivity of Lipid Metabolism and Insulin Signaling to Genetic Alterations in Hepatic Peroxisome Proliferator–Activated Receptor-γ Coactivator-1α Expression
Authors: Estall Jennifer L. , Kahn Mario , Cooper Marcus P. , Fisher ffolliott Martin , Wu Michele K. , Laznik Dina , Qu Lishu , Cohen David E. , Shulman Gerald I. , Spiegelman Bruce M.
Published: April 2009

OBJECTIVE

The peroxisome proliferator–activated receptor-γ coactivator (PGC)-1 family of transcriptional coactivators controls hepatic function by modulating the expression of key metabolic enzymes. Hepatic gain of function and complete genetic ablation of PGC-1α show that this coactivator is important for activating the programs of gluconeogenesis, fatty acid oxidation, oxidative phosphorylation, and lipid secretion during times of nutrient deprivation. However, how moderate changes in PGC-1α activity affect metabolism and energy homeostasis has yet to be determined.

RESEARCH DESIGN AND METHODS

To identify key metabolic pathways that may be physiologically relevant in the context of reduced hepatic PGC-1α levels, we used the Cre/Lox system to create mice heterozygous for PGC-1α specifically within the liver (LH mice).

RESULTS

These mice showed fasting hepatic steatosis and diminished ketogenesis associated with decreased expression of genes involved in mitochondrial β-oxidation. LH mice also exhibited high circulating levels of triglyceride that correlated with increased expression of genes involved in triglyceride-rich lipoprotein assembly. Concomitant with defects in lipid metabolism, hepatic insulin resistance was observed both in LH mice fed a high-fat diet as well as in primary hepatocytes.

CONCLUSIONS

These data highlight both the dose-dependent and long-term effects of reducing hepatic PGC-1α levels, underlining the importance of tightly regulated PGC-1α expression in the maintenance of lipid homeostasis and glucose metabolism.
Association of Type 2 Diabetes Candidate Polymorphisms in KCNQ1 With Incretin and Insulin Secretion
Authors: Müssig Karsten , Staiger Harald , Machicao Fausto , Kirchhoff Kerstin , Guthoff Martina , Schäfer Silke A. , Kantartzis Konstantinos , Silbernagel Günther , Stefan Norbert , Holst Jens J. , Gallwitz Baptist , Häring Hans-Ulrich , Fritsche Andreas
Published: April 2009

OBJECTIVE

KCNQ1 gene polymorphisms are associated with type 2 diabetes. This linkage appears to be mediated by altered β-cell function. In an attempt to study underlying mechanisms, we examined the effect of four KCNQ1 single nucleotide polymorphisms (SNPs) on insulin secretion upon different stimuli.

RESEARCH DESIGN AND METHODS

We genotyped 1,578 nondiabetic subjects at increased risk of type 2 diabetes for rs151290, rs2237892, rs2237895, and rs2237897. All participants underwent an oral glucose tolerance test (OGTT); glucagon-like peptide (GLP)-1 and gastric inhibitory peptide secretion was measured in 170 participants. In 519 participants, a hyperinsulinemic-euglycemic clamp was performed, in 314 participants an intravenous glucose tolerance test (IVGTT), and in 102 subjects a hyperglycemic clamp combined with GLP-1 and arginine stimuli.

RESULTS

rs151290 was nominally associated with 30-min C-peptide levels during OGTT, first-phase insulin secretion, and insulinogenic index after adjustment in the dominant model (all P ≤ 0.01). rs2237892, rs2237895, and rs2237897 were nominally associated with OGTT-derived insulin secretion indexes (all P < 0.05). No SNPs were associated with β-cell function during intravenous glucose or GLP-1 administration. However, rs151290 was associated with glucose-stimulated gastric inhibitory polypeptide and GLP-1 increase after adjustment in the dominant model (P = 0.0042 and P = 0.0198, respectively). No associations were detected between the other SNPs and basal or stimulated incretin levels (all P ≥ 0.05).

CONCLUSIONS

Common genetic variation in KCNQ1 is associated with insulin secretion upon oral glucose load in a German population at increased risk of type 2 diabetes. The discrepancy between orally and intravenously administered glucose seems to be explained not by altered incretin signaling but most likely by changes in incretin secretion.
Diabetes Quality of Care and Outpatient Utilization Associated With Electronic Patient-Provider Messaging: A Cross-Sectional Analysis
Authors: Harris Lynne T. , Haneuse Sebastien J. , Martin Diane P. , Ralston James D.
Published: April 2009

OBJECTIVE

To test the hypothesis that electronic patient-provider messaging is associated with high care quality for diabetes and lower outpatient utilization.

RESEARCH DESIGN AND METHODS

We conducted a cross-sectional analysis of electronic patient-provider messaging over a 15-month period between 1 January 2004 and 31 March 2005. The study was set at Group Health Cooperative—a consumer-governed, nonprofit health care system that operates in Washington and Idaho. Participants included all patients aged ≥18 years with a diagnosis of diabetes. In addition to usual care, all patients had the option to use electronic messaging to communicate with their care providers. The primary outcome measures were diabetes-related quality-of-care indicators (A1C, blood pressure, and LDL cholesterol) and outpatient visits (primary care, specialty care, and emergency).

RESULTS

Nineteen percent of patients with diabetes used electronic messaging to communicate with their care providers during the study period (n = 2,924) (overall study cohort: 15,427 subjects). In multivariate models, frequent use of electronic messaging was associated with A1C <7% (relative risk [RR] 1.36 [95% CI 1.16–1.58]). Contrary to our hypothesis, frequent use of electronic messaging was also associated with a higher rate of outpatient visits (1.39 [1.26–1.53]).

CONCLUSIONS

Frequent use of electronic secure messaging is associated with better glycemic control and increased outpatient utilization. Electronic patient-provider communication may represent one strategy to meet the health care needs of this unique population. More research is necessary to assess the effect of electronic messaging on care quality and utilization.