bluuebunny/crossref_metadata_2025 huggingface dataset:
Chlorine Dioxide and Chlorhexidine Mouthrinses Compared in a 3‐Day Plaque Accumulation Model
Authors: Paraskevas Spiros , Rosema Nanning A.M. , Versteeg Paula , Van der Velden Ubele , Van der Weijden G.A.
Published: August 2008

Background: The aim of this study was to investigate the inhibiting effect of a chlorine dioxide mouthrinse as opposed to a mouthrinse containing chlorhexidine (0.20%) during 3 days of plaque accumulation.

Methods: At baseline, all participants (N = 77) received a professional prophylaxis and were randomly assigned to the test (chlorine dioxide) or (positive) control (chlorhexidine) group. On the following 3 days, both groups rinsed twice daily for 1 minute with 10 ml test or control solution. At the end of the experimental period, plaque was assessed, and the panelists filled out a questionnaire.

Results: Chlorhexidine inhibited plaque growth significantly more than the mouthrinse containing chlorine dioxide (plaque index = 1.39 versus 1.96, respectively; P <0.001). The results of the questionnaire showed that the panelists found chlorhexidine easier to use and more effective. However, they preferred the taste of the chlorine dioxide mouthrinse and experienced less taste alterations.

Conclusion: Chlorine dioxide mouthrinse seems to be a less potent plaque inhibitor than chlorhexidine.
The Effect of Smoking on Epithelial Proliferation in Healthy and Periodontally Diseased Marginal Gingival Epithelium
Authors: Gültekin Sibel Elif , Sengüven Burcu , Karaduman Burcu
Published: August 2008

Background: Smoking causes an increase in the thickness of gingival epithelium, which is the outcome of increased keratinocyte proliferation or loss. Smoking‐related changes in the proliferative activity of the gingival epithelium are largely uncharacterized for periodontal diseases. The aim of the present study was to determine the effects of smoking on the proliferation of the epithelium in periodontally diseased marginal gingiva by comparing the expression patterns of two different proliferation markers.

Methods: Gingival biopsies (N = 60) were obtained from smokers who had clinically healthy gingiva (n = 10), smokers with gingivitis (n = 10), smokers with periodontitis (n = 10), non‐smokers with clinically healthy gingiva (n = 10), non‐smokers with gingivitis (n = 10), and non‐smokers with periodontitis (n = 10). The quantitative measurement of maximum epithelial thickness was performed on hematoxylin and eosin–stained sections. The expression patterns for proliferating cell nuclear antigen (PCNA) and Ki67 were evaluated immunohistochemically.

Results: The percentage of PCNA‐positive cells was higher than the percentage of Ki67‐positive cells in all groups (P <0.001). When the mean values of PCNA and Ki67 were compared in each group, a statistically significant difference was observed only in the healthy smoker group (P = 0.003). Significant differences in PCNA proliferation indices were only found between the smoker group and the non‐smoker healthy group (P = 0.015).

Conclusions: Smoking had an affect on the proliferation of cells in the oral gingival epithelium, regardless of periodontal status. The increase in thickness of the epithelium was not associated with smoking; periodontal status and inflammation seemed to be more important factors. Smoking induced the replication activity of gingival epithelium and induced DNA repair.
Long‐Term Use of Medications and Destructive Periodontal Disease
Authors: Hujoel Philippe P. , Cunha‐Cruz Joana , Maupome Gerardo , Saver Barry
Published: August 2008

Background: Knowledge of typical medication use among patients with chronic periodontitis or destructive periodontal disease is limited. The aim of this study was to associate periodontitis severity with the use of different classes of medications.

Methods: Patients (N = 12,631) who had medical, dental, and pharmaceutical coverage with a health maintenance organization and whose severity of destructive periodontal disease was diagnosed by a dentist or specialist were included in the study. The rate of drug use over 7 years was related to the severity of destructive periodontal disease by means of Poisson regression models.

Results: Individuals with moderate to advanced periodontitis had significantly lower fill rates for the respiratory agents (antihistamines: −23%, 95% confidence interval [CI]: −10% to −34%; decongestants: −24%, 95% CI: −13% to −34%; and cough/cold medications: −12%, 95% CI: −3% to −21%) and anti‐infective agents (antibiotics: −12%, 95% confidence interval: −6% to −18%; urinary anti‐infectives: −36%, 95% CI: −6% to −56%; and topical antibiotics: −18%, 95% CI: −5% to −29%).

Conclusions: More severe periodontitis was a marker for reduced medication use for allergies and infections. The associations between destructive periodontal disease, infections, allergies, and the hygiene hypothesis need further exploration.
Epigenetic Regulation of Gene Expression in the Inflammatory Response and Relevance to Common Diseases
Authors: Wilson Anthony G.
Published: August 2008

Epigenetics can be defined as all the meiotically and mitotically inherited changes in gene expression that are not encoded in the DNA sequence itself. Epigenetic modifications of chromatin and DNA have been recognized as important permissive and suppressive factors in controlling the expressed genome via gene transcription. Two major epigenetic mechanisms are the posttranslational modification of histone proteins in chromatin and the methylation of DNA itself, which are regulated by distinct, but coupled, pathways. It is clear that the epigenetic state is a central regulator of cellular development and activation. Emerging evidence suggests a key role for epigenetics in human pathologies, including in inflammatory and neoplastic disorders. The epigenome is influenced by environmental factors throughout life. Nutritional factors can have profound effects on the expression of specific genes by epigenetic modification, and these may be passed on to subsequent generations with potentially detrimental effects. Many cancers are associated with altered epigenetic profiles, leading to altered expression of the genes involved in cell growth or differentiation. Autoimmune and neoplastic diseases increase in frequency with increasing age, with epigenetic dysregulation proposed as a potential explanation. In support of this hypothesis, studies in monozygotic twins revealed increasing epigenetic differences with age. Differences in methylation status of CpG sites, monoallelic silencing, and other epigenetic regulatory mechanisms have been observed in key inflammatory response genes. The importance of the epigenome in the pathogenesis of common human diseases is likely to be as significant as that of traditional genetic mutations. With advances in technology, our understanding of this area of biology is likely to increase rapidly in the near future.
Cytokines That Promote Periodontal Tissue Destruction
Authors: Graves Dana
Published: August 2008

Although periodontal diseases are initiated by bacteria that colonize the tooth surface and gingival sulcus, the host response is believed to play an essential role in the breakdown of connective tissue and bone, key features of the disease process. An intermediate mechanism that lies between bacterial stimulation and tissue destruction is the production of cytokines, which stimulates inflammatory events that activate effector mechanisms. These cytokines can be organized as chemokines, innate immune cytokines, and acquired immune cytokines. Although they were historically identified as leukocyte products, many are also produced by a number of cell types, including keratinocytes, resident mesenchymal cells (such as fibroblasts and osteoblasts) or their precursors, dendritic cells, and endothelial cells. Chemokines are chemotactic cytokines that play an important role in leukocyte recruitment and may directly or indirectly modulate osteoclast formation. This article focuses on aspects of osteoimmunology that affect periodontal diseases by examining the role of cytokines, chemokines, and immune cell mediators. It summarizes some of the key findings that attempt to delineate the mechanisms by which immune factors can lead to the loss of connective tissue attachment and alveolar bone. In addition, a discussion is presented on the importance of clarifying the process of uncoupling, a process whereby insufficient bone formation occurs following resorption, which is likely to contribute to net bone loss in periodontal disease.
Controlling the Resolution of Acute Inflammation: A New Genus of Dual Anti‐Inflammatory and Proresolving Mediators
Authors: Serhan Charles N.
Published: August 2008

A well‐integrated host inflammatory response is essential in maintaining health and fighting disease. It is important to achieve a complete understanding of the cellular and molecular events that govern the resolution of acute inflammation. Because novel lipid‐derived mediators, called resolvins and protectins in animal models, control the duration and magnitude of inflammation, the mapping of these resolution circuits may provide new ways of understanding the molecular basis of many inflammatory diseases. This article provides an overview of recent studies on resolvin and protectin biosynthesis and of advances in understanding the actions of these novel anti‐inflammatory and proresolving lipid mediators. These new families of lipid‐derived mediators were originally isolated from experimental murine models of acute inflammation identified during the natural spontaneous resolution phase. They are biosynthesized from omega‐3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) and possess potent anti‐inflammatory, proresolving, and antifibrotic actions in vivo. Taken together, these findings suggest that defective resolution mechanisms may underlie the inflammatory phenotypes that are believed to characterize many common human diseases. The new families of endogenous proresolving and anti‐inflammatory agonists constitute a new genus of anti‐inflammatories.
Gene–Environment Interactions and Susceptibility to Metabolic Syndrome and Other Chronic Diseases
Authors: Ordovas Jose M. , Shen Jian
Published: August 2008

There is an intrinsic complexity in the pathogenesis of common diseases. The concept of gene–environment interaction is receiving support from emerging evidence coming primarily from studies involving diet and cardiovascular disease (CVD) and its various risk factors. The accumulating evidence shows that common variants at candidate genes for lipid metabolism, inflammation, and obesity are associated with altered plasma levels of classic and new biomarkers of metabolic syndrome and CVD risk. Major contributors to this knowledge have been a series of large population studies containing phenotype‐rich databases and dietary information to which genetic data have been added. Although this approach has provided strong evidence supporting the concept of gene–diet interactions modulating CVD risk factors, the strength of the individual effect is very small, and the replication among studies is rather disappointing. Current population studies are starting to incorporate experimental and analytical approaches that could provide more solid and comprehensive results. However, other limitations, such as the size of the populations required to examine higher‐level interactions, are still major obstacles to translating this knowledge into practical public health applications. Nevertheless, data from numerous molecular and genetic epidemiological studies provide tantalizing evidence suggesting that gene–environment interactions, i.e., the modulation by a genetic polymorphism of a dietary component effect on a specific phenotype (e.g., cholesterol levels and obesity), can interact in ways that increase the risk for developing chronic disease, including susceptibility to developing the metabolic syndrome. Once further experience is gained from patients and/or individuals at high risk, more personalized genetic‐based approaches may be applied toward the primary prevention and treatment of CVDs and other complex inflammatory diseases.
Inflammation and Bone Loss in Periodontal Disease
Authors: Cochran David L.
Published: August 2008

Inflammation and bone loss are hallmarks of periodontal disease (PD). The question is how the former leads to the latter. Accumulated evidence demonstrates that PD involves bacterially derived factors and antigens that stimulate a local inflammatory reaction and activation of the innate immune system. Proinflammatory molecules and cytokine networks play essential roles in this process. Interleukin‐1 and tumor necrosis factor‐alpha seem to be primary molecules that, in turn, influence cells in the lesion. Antigen‐stimulated lymphocytes (B and T cells) also seem to be important. Eventually, a cascade of events leads to osteoclastogenesis and subsequent bone loss via the receptor activator of nuclear factor‐kappa B (RANK)–RANK ligand (RANKL)–osteoprotegerin (OPG) axis. This axis and its regulation are not unique to PD but rather are critical for pathologic lesions involving chronic inflammation. Multiple lines of evidence in models of PD clearly indicate that increases in RANKL mRNA expression and protein production increase the RANKL/OPG ratio and stimulate the differentiation of macrophage precursor cells into osteoclasts. They also stimulate the maturation and survival of the osteoclast, leading to bone loss. OPG mRNA expression and protein production do not generally seem to be increased in the periodontitis lesion. Studies of RANKL and OPG transgenic and knockout animals provide further support for the involvement of these molecules in the tissue loss observed in PD. Ironically, periodontal practitioners have focused on the bacterial etiology of PD and believed that plaque removal was aimed at eliminating specific bacteria or bacterial complexes. However, it seems that the reduction of inflammation and attenuation of the host's immune reaction to the microbial plaque, eventually leading to a decrease in the ratio of RANKL/OPG and a decrease in associated bone loss, are the actual and desired outcomes of periodontal therapy. Future therapeutic options are likely to have regulation of the RANK–RANKL–OPG axis as their goal.
The Role of Inflammatory Cytokines in Diabetes and Its Complications
Authors: King George L.
Published: August 2008

The prevalence of diabetes worldwide is increasing rapidly in association with the increase in obesity. Complications are a major fear of patients with diabetes. Complications of diabetes affect many tissues and organs, causing retinopathy, nephropathy, neuropathy, cardiovascular diseases, peripheral vascular diseases, stroke, and periodontal pathologies. Immunologic abnormalities are associated with type 1 and type 2 diabetes and diabetic complications. T cell abnormalities are believed to be the major cause of autoimmune disease in type 1 diabetes, leading to the destruction of pancreatic islets. In type 2 diabetes, inflammation and activation of monocytes are postulated to be important for enhancing insulin resistance and may contribute to the loss of insulin secretory function by islet cells. Many factors can enhance insulin resistance, including genetics, a sedentary lifestyle, obesity, and other conditions, such as chronic inflammation or infection. Increases in inflammation, such as activation of monocytes and increased levels of inflammatory markers, e.g., C‐reactive protein, plasminogen activator inhibitor‐1, and other cytokines, were reported in insulin‐resistant states without diabetes. One possible mechanism is that abnormal levels of metabolites, such as lipids, fatty acids, and various cytokines from the adipose tissue, activate monocytes and increase the secretion of inflammatory cytokines, enhancing insulin resistance. According to this model, obesity activates monocytes and enhances insulin resistance, increasing the risk for type 2 diabetes. Abnormalities in innate immunity might also participate in the development of diabetic complications. In general, hyperglycemia is the main initiator of diabetic retinopathy, nephropathy, and neuropathy, and it participates in the development of diabetic cardiovascular diseases. Although the precise role of inflammation in the development of diabetic microvascular diseases is still unclear, it is likely that inflammation induced by diabetes and insulin resistance can accelerate atherosclerosis in patients with diabetes. Also, it was shown that conditions with an inflammatory basis, such as obesity and type 2 diabetes, can contribute to periodontal disease, suggesting that periodontal abnormalities may be partly influenced by inflammatory changes. Further research is required to confirm the role of inflammation and the onset of diabetes, microvascular diseases, and periodontal pathologies.
Inflammation, C‐Reactive Protein, and Atherothrombosis
Authors: Ridker Paul M , Silvertown Josh D
Published: August 2008

Atherothrombosis of the coronary and cerebral vessels is understood to be a disorder of inflammation and innate immunity, as well as a disorder of lipid accumulation. From a vascular biology perspective, the processes of cellular adhesion, monocyte and macrophage attachment, and transmigration of immune cells across the endothelium are crucial steps in early atherogenesis and in the later stages of mature plaque rupture, particularly the transition of unstable plaque at the time of acute thrombosis. There is abundant clinical evidence demonstrating that many biomarkers of inflammation are elevated years in advance of first ever myocardial infarction (MI) or thrombotic stroke and that these same biomarkers are highly predictive of recurrent MI, recurrent stroke, diabetes, and cardiovascular death. In daily practice, the inflammatory biomarker in widest use is high‐sensitivity C‐reactive protein (hsCRP); when interpreted within the context of usual risk factors, levels of hsCRP <1, 1 to 3, and >3 mg/l denote lower, average, and higher relative risk for future vascular events. Risk‐prediction models that incorporate hsCRP, such as the Reynolds Risk Score, have been developed that improve risk classification and the accuracy for global risk prediction, particularly for those deemed at “intermediate risk” by usual algorithms, such as the Framingham Risk Score. With regard to cerebral vessels, increased biomarkers of inflammation, including hsCRP, have been associated with increased stroke risk as well as an increased rate of atherosclerosis progression in the carotid vessels. Although the proportion of variation in hsCRP explained by genetic factors may be as large as 20% to 40%, diet, exercise, and smoking cessation remain critical tools for risk reduction and CRP reduction. Statin therapy reduces hsCRP in a largely low‐density lipoprotein (LDL)‐independent manner, and the “anti‐inflammatory” properties of these agents have been suggested as a potential mechanism beyond LDL reduction for the efficacy of these agents. The ongoing multinational Justification for the Use of statins in Primary prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) trial of 17,802 initially healthy men and women with low levels of LDL cholesterol but increased levels of hsCRP will help to define whether vascular protection can be achieved with statin therapy, even in the absence of hyperlipidemia. Targeted anti‐inflammatory therapies are being developed that may provide a direct method of translating the biology of inflammation into new clinical treatments across multiple vascular beds. This article summarizes data supporting a role for inflammation in cardiovascular disease and offers the possibility that other disorders characterized by inflammation, such as periodontal disease, may have an indirect role by influencing the risk, manifestation, and progression of vascular events.
Why Do Dentists Refer to Specific Orthodontists?
Authors: Hall Jason F. , Sohn Woosung , McNamara James A.
Published: August 2008

Objective: This study tested the hypothesis that the quality of treatment outcomes and overall patient satisfaction are of equal importance in influencing a general dentist to refer a patient to an orthodontist for treatment. The investigation also attempted to determine what specific aspects of an orthodontically treated occlusion comprise an outstanding result in the opinion of the general dentist.

Materials and Methods: Self-administered surveys containing 35 questions were distributed to a random sample of 1000 general dentists in the midwestern United States.

Results: Three-quarters responded that the quality of previous orthodontic treatment and patient/ parental satisfaction were of equal importance in the orthodontic referral decision. If additional factors were considered, the quality of the treated result as judged by the general dentist was far more important than the location of the orthodontist's office, the reputation of the orthodontist, or the anticipated cost of treatment. With regard to desired postorthodontic occlusal and functional characteristics, the majority of the dentists ranked canine guidance as most important. Other characteristics were Class I molar and canine relationships, even contact of all teeth in centric occlusion, amount of overjet and overbite, absence of spacing, and absence of balancing interferences.

Conclusions: The decision of the general dentist to refer a patient to one orthodontist over another is based on a number of interactive factors. It behooves the orthodontic clinician to provide high-quality treatment, to interact well with his or her patients and their families, and to maintain good communications with general practitioners in the community.
Immediate and Post-Retention Effects of Rapid Maxillary Expansion Investigated by Computed Tomography in Growing Patients
Authors: Ballanti Fabiana , Lione Roberta , Fanucci Ezio , Franchi Lorenzo , Baccetti Tiziano , Cozza Paola
Published: August 2008

Objective: To determine by low-dose computed tomography (CT) protocol the dental and periodontal effects of rapid maxillary expansion (RME).

Materials and Methods: The sample comprised 17 subjects (7 males and 10 females), with a mean age at first observation of 11.2 years. Each patient underwent expansion of 7 mm. Multislice CT scans were taken before rapid palatal expansion (T0), at the end of the active expansion phase (T1), and after a retention period of 6 months (T2). On scanned images, measurements were performed at the dental and periodontal levels. Mean differences between measurements at T0, T1, and T2 were examined through analysis of variance (ANOVA) for repeated measures with post-hoc tests.

Results: All interdental transverse measurements were significantly increased at both T1 and T2 with respect to T0. In the evaluation of T0-T1 changes, periodontal measurements were significant on the buccal aspect of banded teeth with a reduction in alveolar bone thickness corresponding to the mesial (−0.5 mm; P < .05) and distal (−0.4 mm; P < .05) roots of the right first molar and to the mesial root of the left first molar (−0.3 mm; P < .05). In the evaluation of overall T0-T2 changes, the lingual bone plate thickness of both first molars was found to be significantly increased (+0.6 mm; P < .05).

Conclusions: RME therapy induces a significant increase in the transverse dimension of the maxillary arch in growing subjects without causing permanent injury to the periodontal bony support of anchoring teeth discernible on CT imaging.
Is Herbst-Multibracket Appliance Treatment More Efficient in Adolescents than in Adults?
Authors: von Bremen Julia , Bock Niko , Ruf Sabine
Published: August 2008

Objective: To determine whether Herbst treatment is more efficient in adolescent than in adult Class II division 1 subjects.

Materials and Methods: All Class II division 1 patients with a full secondary dentition who had been treated at the orthodontic department of the University of Giessen with a Herbst appliance between 1990 and 2000 were considered. The complete records of 77 patients were available. According to their skeletal maturity, as assessed on hand-wrist radiographs, the subjects were divided into an adolescent group (MP3-F to MP3-H; n = 49; mean age 13.5 years) and an adult group (R-IJ to R-J; n = 28; mean age 20.7 years). Pretreatment and posttreatment dental casts were evaluated using the Peer Assessment Rating (PAR) Index. The reductions in PAR scores of the two groups were compared.

Results: Before treatment, both groups had a severe Class II division 1 malocclusion. The average PAR score of the adolescent patients was slightly lower (27.8) than that of the adult patients (28.8). After treatment, good results were reached for both groups, and the average PAR scores of the two groups were comparable (adolescents: 4.5; adults: 4.8). The average reductions in PAR score were 82.7% (23.3 points) for the adolescent group and 82.9% (24.0 points) for the adults, indicating great improvement in both groups.

Conclusions: Because good treatment results were achieved, with substantial improvement of the pretreatment situation in both groups, Herbst treatment can be considered equally efficient in adolescent and in adult Class II division 1 subjects.
Self-Concept and the Perception of Facial Appearance in Children and Adolescents Seeking Orthodontic Treatment
Authors: Phillips Ceib , Beal Kimberly N. Edwards
Published: August 2008

Objective: To examine, in adolescents with mild to moderate malocclusion, the relationship between self-concept and demographic characteristics, a clinical assessment of malocclusion, self-perception of malocclusion, and self-perception of facial attractiveness.

Methods and Materials: Fifty-nine consecutive patients ages 9 to 15 years scheduled for initial records in a graduate orthodontic clinic consented to participate. Each subject independently completed the Multidimensional Self-Concept Scale (MSCS), the Facial Image Scale, and the Index of Treatment Need–Aesthetic Component (IOTN-AC). Peer Assessment Rating (PAR) scores were obtained from the patients' diagnostic dental casts. Forward multiple-regression analysis with a backward overlook was used to analyze the effect of the demographic, clinical, and self-perception measures on each of the six self-concept (MSCS) domains.

Results: Self-perception of the dentofacial region was the only statistically significant predictor (P < .05) for the Global, Competence, Affect, Academic, and Physical domains of self-concept, while age, parental marital status, and the adolescent's self-perception of the dentofacial region were statistically significant predictors (P < .05) of Social Self-Concept.

Conclusion: The self-perceived level of the attractiveness or “positive” feelings toward the dentofacial region is more strongly related to self-concept than the severity of the malocclusion as indicated by the PAR score or by the adolescent's perception of their malocclusion.
Surface Anatomy of the Lip Elevator Muscles for the Treatment of Gummy Smile Using Botulinum Toxin
Authors: Hwang Woo-Sang , Hur Mi-Sun , Hu Kyung-Seok , Song Wu-Chul , Koh Ki-Seok , Baik Hyoung-Seon , Kim Seong-Taek , Kim Hee-Jin , Lee Kee-Joon
Published: August 2008

Objective: To propose a safe and reproducible injection point for botulinum toxin-A (BTX-A) as a supplementary method for the treatment of gummy smile, as determined by assessment of the morphologic characteristics of three lip elevator muscles.

Materials and Methods: A total of 50 hemi-faces from 25 adult cadavers (male 13, female 12; ages, 47 to 88 years) were used in this study. Topographic relations and the directions of the lip elevator muscles (ie, levator labii superioris [LLS], levator labii superioris alaeque nasi [LLSAN], and zygomaticus minor [ZMi]), were investigated. Possible injection points were examined through the study of predetermined surface landmarks.

Results: The insertion of the LLS was covered partially or entirely by the LLSAN and the ZMi, and the three muscles converged on the area lateral to the ala. The mean angle between the facial midline and each muscle vector was 25.8 ± 4.8 degrees for the LLS, 55.7 ± 6.4 degrees for the ZMi, and −20.2 ± 3.2 degrees for the LLSAN; no significant differences were noted between male and female subjects or between left and right sides. The three vectors passed near a triangular region formed by three surface landmarks. The center of this triangle, named the “Yonsei point”, was suggested as an appropriate injection point for BTX-A. The clinical effectiveness of the injection point was demonstrated in selected cases with or without orthodontic treatment.

Conclusions: Under careful case selection, BTX-A may be an effective treatment alternative for patients with excessive gingival display caused by hyperactive lip elevator muscles.
Experimentally Created Nonbalanced Occlusion Effects on the Thickness of the Temporomandibular Joint Disc in Rats
Authors: Sun Lei , Wang Meiqing , He Jianjun , Liu Lei , Chen Shuang , Widmalm Sven E.
Published: August 2008

Objectives: To test the hypothesis that experimentally created physiologically nonbalanced occlusion will not affect the thickness of the temporomandibular joint (TMJ) discs in rats.

Material and Methods: Twenty-four 8-week-old Sprague-Dawley rats were equally divided into a control group that was left untreated and an experimental group where a nonbalanced occlusion was created. Elastic rubber bands, 1 mm in diameter, were inserted and 1 week later were replaced by plastic material between the first and the second molars of the left maxillary and the right mandibular dentitions to move the first molars about 0.8 mm mesially. This created and maintained a physiologically nonbalanced occlusion. The animals were euthanized 8 weeks later, and the TMJ disc thickness was measured on histologically prepared slices using an electronic meter. Two-way univariate analysis of variance was used to compare the groups (α level = .05).

Results: The intermediate zone was thicker in the experimental group than in the control group (P = .003), but no differences were found between groups regarding the anterior and posterior bands. There were no significant sex-related effects on this observation.

Conclusion: The hypothesis is rejected. The results indicate that the intermediate zone of rat TMJ disc has the ability to adapt to the alteration of the space between condyle and fossa caused by occlusion changes. Further studies on larger groups that are followed for longer times are needed.
Preventive Effect of Ozone on the Development of White Spot Lesions during Multibracket Appliance Therapy
Authors: Kronenberg Otmar , Lussi Adrian , Ruf Sabine
Published: August 2008

Objective: To test the null hypotheses: (1) there is no difference in the caries protective effect of ozone and Cervitec/Fluor Protector during multibracket (MB) appliance therapy, and (2) DIAGNOdent and quantitative light-induced fluorescence (QLF) are not superior to a visual evaluation of initial caries lesions.

Materials and Methods: Twenty right-handed patients with a very poor oral hygiene who required full MB appliance therapy were analyzed during 26 months. In a split-mouth-design, the four quadrants of each patient were either treated with ozone, a combination of Cervitec and Fluor Protector, or served as untreated controls. The visible plaque index (VPI) and white spot formation were analyzed clinically. DIAGNOdent and QLF were used for a quantitative assessment of white spot formation.

Results: The average VPI in all four dental arch quadrants amounted to 55.6% and was independent of the preventive measure undertaken. In the quadrants treated with Cervitec/Fluor Protector, only 0.7% of the areas developed new, clinically visible white spots. This was significantly (P < .05) less than in the quadrants treated with ozone (3.2%). The lesions detected with QLF only partially corresponded to the clinically detected white spots, while DIAGNOdent proved to be unable to detect any changes at all.

Conclusions: The caries protective effect of Cervitec/Fluor Protector during MB therapy was superior to ozone, and a visual evaluation of initial caries lesions was superior to both DIAGNOdent and QLF.
The Relationship between Digital Model Accuracy and Time-Dependent Deformation of Alginate Impressions
Authors: Alcan Toros , Ceylanoğlu Cenk , Baysal Bekir
Published: August 2008

Objectives: To investigate the effects of different storage periods of alginate impressions on digital model accuracy.

Materials and Methods: A total of 105 impressions were taken from a master model with three different brands of alginates and were poured into stone models in five different storage periods. In all, 21 stone models were poured and immediately were scanned, and 21 digital models were prepared. The remaining 84 impressions were poured after 1, 2, 3, and 4 days, respectively. Five linear measurements were made by three researchers on the master model, the stone models, and the digital models. Time-dependent deformation of alginate impressions at different storage periods and the accuracy of traditional stone models and digital models were evaluated separately.

Results: Both the stone models and the digital models were highly correlated with the master model. Significant deformities in the alginate impressions were noted at different storage periods of 1 to 4 days. Alginate impressions of different brands also showed significant differences between each other on the first, third, and fourth days.

Conclusions: Digital orthodontic models are as reliable as traditional stone models and probably will become the standard for orthodontic clinical use. Storing alginate impressions in sealed plastic bags for up to 4 days caused statistically significant deformation of alginate impressions, but the magnitude of these deformations did not appear to be clinically relevant and had no adverse effect on digital modeling.
Microleakage under Orthodontic Brackets Using High-Intensity Curing Lights
Authors: Ulker Mustafa , Uysal Tancan , Ramoglu Sabri Ilhan , Ertas Huseyin
Published: August 2008

Objective: To compare the microleakage of the enamel-adhesive-bracket complex at the occlusal and gingival margins of brackets bonded with high-intensity light curing lights and conventional halogen lights.

Materials and Methods: Forty-five freshly extracted human maxillary premolar teeth were randomly separated into three groups of 15 teeth each. Stainless steel brackets were bonded in all groups according to the manufacturer's recommendations. Specimens (15 per group) were cured for 40 seconds with a conventional halogen light, 20 seconds with light-emitting diode (LED), and 6 seconds with plasma arc curing light (PAC). After curing, the specimens were further sealed with nail varnish, stained with 0.5% basic-fuchsine for 24 hours, sectioned and examined under a stereomicroscope, and scored for microleakage for the enamel-adhesive and bracket-adhesive interfaces from both the occlusal and gingival margins. Statistical analyses were performed using Kruskal-Wallis and Mann-Whitney U-tests with a Bonferroni correction.

Results: The type of light curing unit did not significantly affect the amount of microleakage at the gingival or occlusal margins of investigated interfaces (P >.05). The gingival sides in the LED and PAC groups exhibited higher microleakage scores compared with those observed on occlusal sides for the enamel-adhesive and adhesive-bracket interfaces. The halogen light source showed similar microleakage at the gingival and occlusal sides between both adhesive interfaces.

Conclusions: High-intensity curing units did not cause more microleakage than conventional halogen lights. This supports the use of all these curing units in routine orthodontic practice.
Bond Strength of Amorphous Calcium Phosphate–Containing Orthodontic Composite Used as a Lingual Retainer Adhesive
Authors: Uysal Tancan , Ulker Mustafa , Akdogan Gulsen , Ramoglu Sabri Ilhan , Yilmaz Esra
Published: August 2008

Objective: To evaluate the shear bond strength and fracture mode difference between amorphous calcium phosphate (ACP)–containing adhesive and conventional resin-based composite material used as an orthodontic lingual retainer adhesive.

Materials and Methods: Forty crowns of extracted lower human incisors were mounted in acrylic resin, leaving the buccal surface of the crowns parallel to the base of the molds. The teeth were randomly divided into two groups: experimental and control, containing 20 teeth each. Conventional lingual retainer composite (Transbond-LR, 3M-Unitek) and ACP-containing orthodontic adhesive (Aegis-Ortho) were applied to the teeth surface by packing the material into the cylindrical plastic matrices with a 2.34-mm internal diameter and a 3-mm height (Ultradent) to simulate the lingual retainer bonding. For shear bond testing, the specimens were mounted in a universal testing machine, and an apparatus (Ultradent) attached to a compression load cell was applied to each specimen until failure occurred. The shear bond data were analyzed using Student's t-test. Fracture modes were analyzed by χ2 test.

Results: The statistical test showed that the bond strengths of group 1 (control Transbond-LR, mean: 24.77 ± 9.25 MPa) and group 2 (ACP-containing adhesive, mean: 8.49 ± 2.53 MPa) were significantly different from each other. In general, a greater percentage of the fractures were adhesive at the tooth-composite interface (60% in group 1 and 55% in group 2), and no statistically significant difference was found between groups.

Conclusion: The ACP-containing Aegis-Ortho adhesive resulted in a significant decrease in bond strength to the etched enamel surface.
Hard and Soft Tissue Stability of Orthognathic Surgery
Authors: Kitahara Toru , Nakasima Akihiko , Kurahara Shinichi , Shiratsuchi Yuji
Published: August 2008

Objective: To test the hypothesis that there is no difference in the stability of the hard and soft tissue changes following a surgical mandibular setback using a sagittal split ramus osteotomy or an intraoral vertical ramus osteotomy.

Materials and Methods: The samples consisted of 45 female patients with mandibular prognathism, who were divided into two groups. Twenty-three underwent a sagittal split ramus osteotomy (SSRO) with rigid fixation by titanium mini-screws and maxillomandibular fixation (MMF) for 14.0 ± 0.7 days. Twenty-two underwent intraoral vertical ramus osteotomy (IVRO) without rigid fixation, and MMF was released 21.5 ± 3.3 days after surgery. Data were collected from standardized cephalometric radiographs taken at the start of preoperative orthodontic treatment (T1), immediately after surgery (MMF, T2), and the completion of postoperative treatment (T3). Angular measurements were compared on each of T1, T2, and T3.

Results: There were no significant differences in the pretreatment hard and soft tissue morphology between the SSRO and IVRO. However, when fixation was released, the mandible was posteriorly positioned in the IVRO group. In the soft tissue profile, the mental region was located backward in the IVRO group at postoperative stage (T3).

Conclusions: The hypothesis is rejected. The soft tissue profile of the IVRO group especially showed a retromandibular position after postoperative treatment in comparison with the SSRO group. This tendency of the IVRO group would contribute to the database for treatment planning and prediction.
Evaluation of two-dimensional accelerometers to monitor behavior of beef calves after castration
Authors: White Brad J. , Coetzee Johann F. , Renter David G. , Babcock Abram H. , Thomson Daniel U. , Andresen Daniel
Published: August 2008

Objective—To determine the accuracy of accelerometers for measuring behavior changes in calves and to determine differences in beef calf behavior from before to after castration.

Animals—3 healthy Holstein calves and 12 healthy beef calves.

Procedures—2-dimensional accelerometers were placed on 3 calves, and data were logged simultaneous to video recording of animal behavior. Resulting data were used to generate and validate predictive models to classify posture (standing or lying) and type of activity (standing in place, walking, eating, getting up, lying awake, or lying sleeping). The algorithms developed were used to conduct a prospective trial to compare calf behavior in the first 24 hours after castration (n = 6) with behavior of noncastrated control calves (6) and with presurgical readings from the same castrated calves.

Results—On the basis of the analysis of the 2-dimensional accelerometer signal, posture was classified with a high degree of accuracy (98.3%) and the specific activity was estimated with a reasonably low misclassification rate (23.5%). Use of the system to compare behavior after castration revealed that castrated calves spent a significantly larger amount of time standing (82.2%), compared with presurgical readings (46.2%).

Conclusions and Clinical Relevance—2-dimensional accelerometers provided accurate classification of posture and reasonable classification of activity. Applying the system in a castration trial illustrated the usefulness of accelerometers for measuring behavioral changes in individual calves.
Relative expression of matrix metalloproteinase-2 and -9 in synovial fluid from healthy calves and calves with experimentally induced septic arthritis
Authors: Francoz David , Desrochers André , Simard Nathalie , Saint Pierre Yves , Fecteau Gilles , Latouche Jean Sébastien , Fortin Mado
Published: August 2008

Objective—To identify changes over time in relative expression of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) in synovial fluid from healthy calves and calves with experimentally induced septic arthritis.

Animals—12 Holstein calves.

Procedures—In 7 calves, Escherichia coli was injected in the right tarsal joint on day 1. Joint lavage was performed on day 2, and calves were treated with ceftiofur from days 2 through 21. Synovial fluid samples were collected on days 1 (before inoculation), 2 (before joint lavage), 3, 4, 8, 12, 16, 20, and 24. In the remaining 5 calves, joint lavage was performed on day 2 and synovial fluid samples were collected from the left tarsal joint. Relative expression of MMP-2 and MMP-9 was determined by means of gel zymography.

Results—On day 1, MMP-2 was detected in all synovial fluid samples but MMP-9 was not detected. In calves with septic arthritis, values for relative expression of MMP-9 monomer and dimer were significantly increased on days 2 through 20 and days 2 through 24, respectively, and relative expression of MMP-2 was significantly increased on days 3 through 20. There were significant linear associations between relative expression of the monomer and dimer forms of MMP-9 and between neutrophil count and relative expression of the MMP-9 monomer and dimer forms.

Conclusions and Clinical Relevance—Results indicated that relative expression of MMP-9 and MMP-2 increased in synovial fluid from calves with experimentally induced septic arthritis, with relative expression remaining high for several days after infection.
Assessment of alterations in triglyceride and glycogen concentrations in muscle tissue of Alaskan sled dogs during repetitive prolonged exercise
Authors: McKenzie Erica C. , Hinchcliff Kenneth W. , Valberg Stephanie J. , Williamson Katherine K. , Payton Mark E. , Davis Michael S.
Published: August 2008

Objective—To assess changes in muscle glycogen (MG) and triglyceride (MT) concentrations in aerobically conditioned sled dogs during prolonged exercise.

Animals—54 Alaskan sled dogs fed a high-fat diet.

Procedures—48 dogs ran 140-km distances on 4 consecutive days (cumulative distance, up to 560 km); 6 dogs remained as nonexercising control animals. Muscle biopsies were performed immediately after running 140, 420, or 560 km (6 dogs each) and subsequently after feeding and 7 hours of rest. Single muscle biopsies were performed during recovery at 28 hours in 7 dogs that completed 560 km and at 50 and 98 hours in 7 and 6 dogs that completed 510 km, respectively. Tissue samples were analyzed for MG and MT concentrations.

Results—In control dogs, mean ± SD MG and MT concentrations were 375 ± 37 mmol/kg of dry weight (kgDW) and 25.9 ± 10.3 mmol/kgDW, respectively. Compared with control values, MG concentration was lower after dogs completed 140 and 420 km (137 ± 36 mmol/kgDW and 203 ± 30 mmol/kgDW, respectively); MT concentration was lower after dogs completed 140, 420, and 560 km (7.4 ± 5.4 mmol/kgDW; 9.6 ± 6.9 mmol/kgDW, and 6.3 ± 4.9 mmol/kgDW, respectively). Depletion rates during the first run exceeded rates during the final run. Replenishment rates during recovery periods were not different, regardless of distance; only MG concentration at 50 hours was significantly greater than the control value.

Conclusions and Clinical Relevance—Concentration of MG progressively increased in sled dogs undergoing prolonged exercise as a result of attenuated depletion.
Pharmacokinetics of orally administered tramadol in domestic rabbits (Oryctolagus cuniculus)
Authors: Souza Marcy J. , Greenacre Cheryl B. , Cox Sherry K.
Published: August 2008

Objective—To determine the pharmacokinetics of an orally administered dose of tramadol in domestic rabbits (Oryctolagus cuniculus).

Animals—6 healthy adult sexually intact female New Zealand White rabbits.

Procedures—Physical examinations and plasma biochemical analyses were performed to ensure rabbits were healthy prior to the experiment. Rabbits were anesthetized with isoflurane, and IV catheters were placed in a medial saphenous or jugular vein for collection of blood samples. One blood sample was collected before treatment with tramadol. Rabbits were allowed to recover from anesthesia a minimum of 1 hour before treatment. Then, tramadol (11 mg/kg, PO) was administered once, and blood samples were collected at various time points up to 360 minutes after administration. Blood samples were analyzed with high-performance liquid chromatography to determine plasma concentrations of tramadol and its major metabolite (O-desmethyltramadol).

Results—No adverse effects were detected after oral administration of tramadol to rabbits. Mean ± SD half-life of tramadol after administration was 145.4 ± 81.0 minutes; mean ± SD maximum plasma concentration was 135.3 ± 89.1 ng/mL.

Conclusions and Clinical Relevance—Although the dose of tramadol required to provide analgesia in rabbits is unknown, the dose administered in the study reported here did not reach a plasma concentration of tramadol or O-desmethyltramadol that would provide sufficient analgesia in humans for clinically acceptable periods. Many factors may influence absorption of orally administered tramadol in rabbits.