bluuebunny/crossref_metadata_2025_split huggingface dataset:
Longitudinal Evaluation of the Intermaxillary Relationship in Class III Malocclusions
Authors: Chen Fengshan , Terada Kazuto , Wu Liping , Saito Isao 
Published: May 2007

Abstract
Objective: To analyze the sagittal, vertical, and transverse relationship of the maxilla and mandible in Japanese girls with Class III malocclusions.
Materials and Methods: This longitudinal study utilized biannual posteroanterior and lateral cephalograms of 44 untreated subjects from age 8 to 14 years (Class I, 23 girls; Class III, 21 girls). Sagittal and vertical growths were analyzed on the basis of lateral cephalograms, and transverse growth was analyzed on the basis of posteroanterior cephalograms.
Results: There was no significant difference in sagittal intermaxillary relationships in Class III malocclusion from age 8 to 14 years, whereas significant difference in vertical and transverse intermaxillary relationships appeared with ages during this period. When comparing Class III to Class I malocclusions at the same age point, there were significant differences in sagittal and transverse intermaxillary relationships, whereas significant difference in vertical intermaxillary relationship appeared after 12 years of age.
Conclusion: The results suggest that the sagittal intermaxillary relationships in Class III malocclusions were established before 8 years of age and remained through puberty and that the vertical and transverse intermaxillary relationships in Class III malocclusions changed with ages from 8 to 14 years.
An Adult Bimaxillary Protrusion Treated with Corticotomy-Facilitated Orthodontics and Titanium Miniplates
Authors: Iino Shoichiro , Sakoda Sumio , Miyawaki Shouichi 
Published: May 2007

Abstract
We performed an orthodontic treatment combined with corticotomy and the placement of titanium miniplates in an adult patient who desired a shortened treatment period. The patient had an Angle Class I malocclusion with flaring of the maxillary and mandibular incisors. First, titanium miniplates were placed into the buccal alveolar bone of the maxilla for absolute orthodontic anchorage. Second, an edgewise appliance was applied to the maxillary and mandibular teeth. Then, the maxillary first premolars and mandibular second premolars were extracted. At the same time, a corticotomy was performed on the cortical bone of the lingual and buccal sides in the maxillary anterior as well as the mandibular anterior and posterior regions. Leveling was initiated immediately after the corticotomy. The extraction spaces were closed with conventional orthodontic force (approximately 1 N per side). The edgewise appliance was adjusted once every 2 weeks. The total treatment time was 1 year. Cephalometric superimpositions showed no anchorage loss, and panoramic radiographs showed neither significant reduction in the crest bone height nor marked apical root resorption. A corticotomy-facilitated orthodontic treatment with titanium miniplates might shorten an orthodontic treatment period without any anchorage loss or adverse effects.
Intraoral Maxillary Molar Distalization
Authors: Karlsson Ingela , Bondemark Lars 
Published: May 2007

Abstract
Objective: To evaluate the maxillary molar distalization and anchorage loss in two groups, one before (MD 1 group) and one after (MD 2 group) eruption of second maxillary molars.
Materials and Methods: After a sample size calculation, 20 patients were recruited for each group from patients who fulfilled the following criteria: no orthodontic treatment before distal molar movement, Class II molar relationship defined by at least end-to-end molar relationship, space deficiency in the maxilla, and use of an intra-arch NiTi coil appliance with a Nance appliance to provide anchorage. Patients in the MD 1 group were without any erupted second molars during the distalization period, whereas in the MD 2 group both the first and second molars were in occlusion at start of treatment. The main outcome measures to be assessed were: treatment time, ie, time in months to achieve a normal molar relation, distal movement of maxillary first molars, and anterior movement of maxillary incisors (anchorage loss). The mean age in the MD 1 group was 11.4 years; in the MD 2 group, 14.6 years.
Results: The amount of distal movement of the first molars was significantly greater (P &lt; .01) and the anchorage loss was significantly lower (P &lt; .01) in the group with no second molars erupted. The molar distalization time was also significantly shorter (P &lt; .001) in this group, and thus the movement rate was two times higher.
Conclusions: It is more effective to distalize the first maxillary molars before the second molars have erupted.
Microleakage beneath Ceramic and Metal Brackets Photopolymerized with LED or Conventional Light Curing Units
Authors: Arıkan Serdar , Arhun Neslihan , Arman Ayça , Cehreli Sevi Burcak 
Published: May 2007

Abstract
Objective: To test the null hypotheses that (1) the type of light curing unit used (quartz-tungsten-halogen [QTH] or light-emitting diode [LED]) would not affect the amount of microleakage observed beneath brackets, and (2) the bracket type used (ceramic or metal) would not influence the amount of microleakage observed beneath brackets.
Materials and Methods: 40 freshly-extracted human premolars were randomly assigned into 4 bonding groups (n = 10/group): group 1, metal bracket + LED-cured Transbond XT; group 2, ceramic bracket + LED-cured Transbond XT; group 3, metal bracket + QTH-cured Transbond XT; and group 4, ceramic bracket + QTH-cured Transbond XT. The teeth were kept in distilled water for 1 month, and thereafter subjected to 500 thermal cycles. Then, specimens were sealed with nail varnish, stained with 0.5% basic fuchsin for 24 hours, sectioned, and photographed under a stereomicroscope. Microleakage was scored with regard to the adhesive-tooth interface and the bracket-adhesive interface at both incisal and gingival margins. Statistical analysis was accomplished by Kruskal-Wallis and Mann-Whitney U-tests with Bonferroni correction.
Results: Microleakage was observed in all groups. When an LED curing unit was used for adhesive polymerization, ceramic brackets displayed significantly less microleakage than metal brackets in both tooth-adhesive and bracket-adhesive interfaces. When a QTH curing unit was used, ceramic brackets displayed significantly less microleakage than metal brackets in the bracket-adhesive interface in both gingival and incisal margins.
Conclusions: Ceramic brackets cured with LED units were the best combination, demonstrating the lowest microleakage scores.
Three Palatal Arches Used to Correct Posterior Dental Crossbites
Authors: Martinelli Fernando Lima , Couto Priscilla Sobral , Ruellas Antonio Carlos Oliveira 
Published: May 2007

Abstract
Objective: To assess the force, resilience, and elasticity modulus produced by the Coffin appliance, “W” arch, and quad-helix made with 0.032-inch and 0.036-inch stainless steel wire.
Materials and Methods: Two groups of 15 arches were made as Coffin appliances, two groups of 15 arches were made as “W” arches, and two groups of 15 arches were made as quad-helices. One group of each appliance was formed in 0.032-inch and one group in 0.036-inch stainless steel wire. All arches (6 groups of 15 each) were submitted to compression trials in the mechanical testing machine EMIC DL-10000, simulating 5-, 8-, 10-, and 12-mm activation. The force and resilience means received a one-way ANOVA statistical analysis.
Results: The results showed that the mechanical properties depended on the shape of the appliance, the diameter of the wire used, and the amount of activation.
Conclusions: The three appliances assessed produce appropriate forces for orthodontic treatment as long as they are correctly planned during clinical application.
Effect of Enamel Etching on Tensile Bond Strength of Brackets Bonded In Vivo with a Resin-reinforced Glass Ionomer Cement
Authors: Rosenbach Gabriella , Cal-Neto Julio Pedrae , Oliveira Silvio Rosan , Chevitarese Orlando , Almeida Marco Antonio 
Published: May 2007

Abstract
Objective: To evaluate the influence of enamel etching on tensile bond strength of orthodontic brackets bonded with resin-reinforced glass ionomer cement.
Materials and Methods: The sample group consisted of 15 patients who had indications for extraction of four premolars for orthodontic reasons, equally divided into two different groups according to bracket and enamel preparation. Brackets were bonded in vivo, by the same operator, using a split mouth random technique: Group 1 (control), phosphoric acid + Fuji Ortho LC; Group 2, Fuji Ortho LC without acid conditioning. The teeth were extracted after 4 weeks using elevators. An Instron Universal Testing Machine was used to apply a tensile force directly to the enamel-bracket interface at a speed of 0.5 mm/min. The groups were compared using a Mann-Whitney U-test and Weibull analysis.
Results: Mean results and standard deviations (in MPa) for the groups were: Group 1, 6.26 (3.21), Group 2, 6.52 (2.73). No significant difference was observed in the bond strengths of the two groups evaluated (P = .599).
Conclusions: Fuji Ortho LC showed adequate shear bond strength and may be suitable for clinical use.
Dentoskeletal Effects and “Effective” Temporomandibular Joint, Maxilla and Chin Changes in Good and Bad Responders to van Beek Activator Treatment
Authors: Ruf Sabine , Bendeus Margareta , Pancherz Hans , Hägg Urban 
Published: May 2007

Abstract
Objective: To assess possible differences in dentoskeletal effects and “effective” temporomandibular joint, maxilla, and chin changes between good and bad responders to van Beek activator treatment.
Materials and Methods: The subject material consisted of 20 consecutive normodivergent male Class II division 1 patients treated with a van Beek activator. Because of insufficient cooperation, four patients were excluded. Lateral head films were taken 6 months before treatment, at start of treatment, and after 12 months of treatment. The patients were placed into a good responder group (successful, n = 8) and a bad responder group (unsuccessful, n = 8). An overjet reduction ≥4 mm was considered successful.
Results: During the van Beek treatment period, the good responders showed a significantly larger improvement in overjet and molar relationship than did the bad responders. The good responders exhibited a significant posterior development of condylion, less anterior mandibular autorotation, retrusion of upper incisors, protrusion of lower incisors, distalization of maxillary molars, and a mesial movement of mandibular molars. No significant dental movements were seen in the bad responders.
Conclusions: Although van Beek activator treatment affected the direction of condylar growth, as well as the direction of maxilla and chin changes, it can be concluded that skeletal changes did not contribute to the Class II correction. Instead, overjet reduction during van Beek activator treatment was found to be due to a favorable dental reaction.
Tumor Necrosis Factor–α Levels during Two Different Canine Distalization Techniques
Authors: Karacay Seniz , Saygun Işıl , Bengi Ali Osman , Serdar Muhittin 
Published: May 2007

AbstractObjectives: To compare levels of tumor necrosis factor (TNF)-α while applying continuous and heavy interrupted forces.Materials and Methods: A hybrid retractor was used in the first group. In the second group, rapid canine distalization through periodontal distraction was performed. Gingival crevicular fluid samples were collected from the distal sides of the canine teeth before attaching the appliances and at 1 hour, 24 hours, and 1 week after the force was applied.Results: In the hybrid reactor group, concentration of TNF-α decreased at 1 week according to 24-hour measurements. In the rapid canine distalization group, it severely increased at 1 hour. In the evaluation of between-group differences, significantly higher values were determined in the rapid canine distalization group at 1 hour and 1 week.Conclusions: Heavy interrupted force induces a rapid release of TNF-α, and the tissue response continues for a longer time period. To avoid the harmful effects of heavy interrupted force, there might be feedback mechanisms that prevent the mediators from increasing excessively.
Niche expansion of a cryptic primate,Callimico goeldii, while in mixed species troops
Authors: Porter Leila M. , Garber Paul A. 
Published: May 2007

AbstractWe examined the effects of polyspecific associations on the behavior of one group ofCallimico goeldiiin northwestern Bolivia. Data were collected for 1 year using focal animal sampling at 5‐min intervals, for a total of 1,375 observation hours. In total,C. goeldiiformed mixed species troops with five groups ofSaguinus fuscicollisand six groups ofS. labiatus, and these were maintained during 81% of observations.C. goeldiirested more and traveled less while alone than while associated, but neither vigilance behavior in the understory nor habitat use were affected by association status. The composition of the group's diet was different while alone (higher in structural carbohydrates [fungi] and lower in simple sugars [ripe fruits] and protein [insects]) than while associated (fungi 65 vs. 37%; fruits 13 vs. 32%; insects 5 vs. 15%). We propose therefore, thatC. goeldiihas a lower quality and more narrowly based diet while alone as compared to while associated. The factors that allow for this dietary expansion while in mixed species troops require further investigation. Am. J. Primatol. 69:1340–1353, 2007. © 2007 Wiley‐Liss, Inc.
Habituation of western gorillas: the process and factors that influence it
Authors: Doran‐Sheehy Diane M. , Derby Abigail M. , Greer David , Mongo Patrice 
Published: May 2007

AbstractHabituation of western gorillas to human presence is generally an expensive, lengthy and difficult process. Here we describe the habituation process for two groups of western gorillas at the Mondika Research Center, with the hope that the lessons we learned will facilitate future gorilla studies. We expand upon earlier studies by describing the process through complete habituation for both males and females, and for more than one group. The major obstacle to habituation was developing sufficient tracking skills to follow gorilla trail on a daily basis. Once this was achieved, the silverback became semi‐habituated (i.e. ignoring human presence during half of contacts) within a year, although the majority of group females continued to avoid humans. As female presence at contacts increased, a period of male recidivism followed, requiring an additional year before his complete habituation was reached. Habituating the females took longer than the male, but we found, contrary to earlier studies, that it consisted of the same stages, including avoidance, aggression, and curiosity before habituation. We compare results between groups and across sites and discuss how factors such as tracking abilities, group size and cohesion, population density and home range overlap, and the manner of approaching gorillas during contacts influence the habituation process. Am. J. Primatol. 69:1354–1369, 2007. © 2007 Wiley‐Liss, Inc.
The effect of pulsed electromagnetic fields on secondary skin wound healing: An experimental study
Authors: Athanasiou Athanasios , Karkambounas Spiridon , Batistatou Anna , Lykoudis Efstathios , Katsaraki Afroditi , Kartsiouni Theodora , Papalois Apostolos , Evangelou Angelos 
Published: May 2007

AbstractA variety of pulsed electromagnetic fields (PEMFs) have already been experimentally used, in an effort to promote wound healing. The aim of the present study was to investigate the effects of short duration PEMF on secondary healing of full thickness skin wounds in a rat model. Full thickness skin wounds, 2 by 2 cm, were surgically inflicted in two groups of male Wistar rats, 24 animals each. In the first group (experimental group ‐ EG), the animals were placed and immobilized in a special constructed cage. Then the animals were exposed to a short duration PEMF for 20 min daily. In the second group (control group ‐ CG), the animals were also placed and immobilized in the same cage for the same time, but not exposed to PEMF. On days 3, 6, 9, 12, 18, and 22, following the infliction of skin wounds, the size and healing progress of each wound were recorded and evaluated by means of planimetry and histological examination. According to our findings with the planimetry, there was a statistically significant acceleration of the healing rate for the first 9 days in EG, whereas a qualitative improvement of healing progress was identified by histological examination at all time points, compared to the control group. Bioelectromagnetics 28:362–368, 2007. © 2007 Wiley‐Liss, Inc.
Lack of promotion of mammary, lung and skin tumorigenesis by 20 kHz triangular magnetic fields
Authors: Lee Hae‐June , Choi Soo‐Yong , Jang Ja‐June , Gimm Youn‐Myoung , Pack Jeong‐Ki , Choi Hyung‐Do , Kim Nam , Lee Yun‐Sil 
Published: May 2007

AbstractIn order to evaluate possible tumorigenic effects of a 20 kHz intermediate frequency triangular magnetic field (IF), a frequency emitted from TV and PC monitors at 6.25 µT rms, which is the regulated exposure limit of magnetic field for the public in Korea, mammary tumors were produced in female Sprague–Dawley rats by oral intubation of dimethylbenz(a)anthracene (DMBA), lung tumors in ICR mice by scapular region injection of benzo(a)pyrene (BP), and skin tumors in female ICR mice by topical application of DMBA and tetradecanoylphorbolester (TPA). IF was applied 8 h/day for 14 weeks beginning the day after DMBA treatment for mammary tumor experiment, for 6 weeks after weaning for lung tumor, and for 20 weeks beginning 1 week after DMBA application for skin tumor experiment. For skin tumors, TPA was applied once a week for 19 weeks. Results showed no significant differences in tumor incidence, mean tumor number and volume, and histological patterns between IF magnetic‐field exposed and sham control rats in the above three tumor models. Therefore, we conclude that within the limitation or number of animals and the experimental conditions, 20 kHz IF triangular magnetic field exposure of 6.25 µT does not appear to be a strong co‐tumorigenic agent in the chosen murine mammary, lung and skin models. Bioelectromagnetics 28:446–453, 2007. © 2007 Wiley‐Liss, Inc.
The effect of GSM and TETRA mobile handset signals on blood pressure, catechol levels and heart rate variability
Authors: Barker Anthony T. , Jackson Peter R. , Parry Helen , Coulton Leslie A. , Cook Greg G. , Wood Steven M. 
Published: May 2007

AbstractAn acute rise in blood pressure has been reported in normal volunteers during exposure to signals from a mobile phone handset. To investigate this finding further we carried out a double blind study in 120 healthy volunteers (43 men, 77 women) in whom we measured mean arterial pressure (MAP) during each of six exposure sessions. At each session subjects were exposed to one of six different radio frequency signals simulating both GSM and TETRA handsets in different transmission modes. Blood catechols before and after exposure, heart rate variability during exposure, and post exposure 24 h ambulatory blood pressure were also studied. Despite having the power to detect changes in MAP of less than 1 mmHg none of our measurements showed any effect which we could attribute to radio frequency exposure. We found a single statistically significant decrease of 0.7 mmHg (95% CI 0.3–1.2 mmHg, P = .04) with exposure to GSM handsets in sham mode. This may be due to a slight increase in operating temperature of the handsets when in this mode. Hence our results have not confirmed the original findings of an acute rise in blood pressure due to exposure to mobile phone handset signals. In light of this negative finding from a large study, coupled with two smaller GSM studies which have also proved negative, we are of the view that further studies of acute changes in blood pressure due to GSM and TETRA handsets are not required. Bioelectromagnetics 28:433–438, 2007. © 2007 Wiley‐Liss, Inc.
One Parameter Model for Three‐Factor Interactions in Contingency Tables
Authors: Ama Njoku O. 
Published: May 2007

AbstractThis paper shows that the sum of products models for three and higher order interactions in contingency tables can be reparameterized in the spirit of TUKEY (1949) to yield chi‐square tests with one degree of freedom. The merits of this new test over the other known tests for the same hypotheses are discussed.
On the Estimation of Relative Risks and Longevities of a Class of Cancer Patients Based on Randomly Censored Data
Authors: Biswas Suddhendu , Jha Shishir Kumar 
Published: May 2007

AbstractAn attempt has been made to measure the relative risks and longevities of a group of cancer patients using a Weibull model whose parameters are function of covariatcs (viz treatment and condition of the patient). The methodology is Cox's Partial Likelihood and the Maximum Likelihood techniques for randomly censored data. The data consists of the records of 134 patients under a clinical trial in the treatment of Carcinoma of the Oro Pharynx as quoted by Kalbfleisch and Prentice (1980).
The Probability of a Negative Linear Combination of Independent Mean Squares
Authors: Khuri Andrea I. 
Published: May 2007

AbstractSATTERTHWAITE'S (1941) approximation of the distribution of a linear combination, of independent mean squares is a commonly used technique in the analysis of variance. Confidence intervals and test statistics based on this approximation require that be positive. In this article, the probability that will be negative is considered in situations in which the mean squares are associated with a general balanced mixed model. Expressions are given for exact and approximate values of this probability in terms of the expected values and degrees of freedom of the mean squares. An example is presented to illustrate the implementation of the proposed methodology.
Test of Independence Against a Class of Ordered Alternatives in an R × C Contingency Table
Authors: Oluyede Broderick O. 
Published: May 2007

AbstractTest procedures are developed for testing the hypotheses of independence in a two‐way contingency table against a class of ordered alternatives defined in terms of pooled crossproduct ratios. The alternatives hypotheses of “positive dependence” defines new notions of dependence. The distribution of the test statistics is obtained. Admissibility of the test is deduced and power comparison with some known test procedures are given. A numerical example is presented to illustrate the techniques developed.
Weighted Diallel Analysis Across Environments: Combining Ability and Heterotic Pattern Models
Authors: Hohls T. , Clarke G. P. Y. , Gevers H. O. 
Published: May 2007

AbstractThe matrix algebra needed for analysing data from diallel experiments across several environments is provided. Practical considerations for subdividing large incidence matrices and appending constraint matrices are discussed to allow large experiments to be analysed on desk top computers. In particular, a combining ability model and heterotic pattern model have been used to show how heterogeneous variances can be accommodated by weighting. The models provide valuable information on the performance of lines in crosses, the heterotic patterns of the lines, and the heterotic groups to which they belong. The methodology is illustrated by application to a diallel cross conducted among 12 elite white modified opaque‐2 maize inbred lines.