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The purpose of this study was to assess by surface electromyography (sEMG) the changes in upper and lower orbicular oris (OO) muscles produced by a preformed functional device in subjects with Class II, division 1 malocclusion, deep bite, and labial incompetence. Twenty-eight subjects were selected: 13 subjects (mean age 9 ± 1.5 years) with Class II malocclusion, deep bite, and labial incompetence were treated with a preformed functional device, while 15 subjects (mean age 9.5 ± 0.8 years) with normal occlusion were used as control. Inclusion criteria for both groups were: presence of mixed dentition, no previous orthodontic treatment, and absence of speech disturbance. sEMG recordings were taken at the time of the first visit (T0), and after 3 (T1) and 6 months (T2) for the treated group, and at T0 and T2 for the control group. The sEMG recording was performed at rest, and while kissing, swallowing, opening the mouth, clenching the teeth, and during protrusion of the mandible, by placing electrodes at the area of muscle contraction. At T0, except during swallowing, the treated group always showed a lower sEMG activity of the lower OO muscle with respect to the control group, with significant differences at rest and during mandibular protrusion (p<0.05). In the treated group, a significant increase in muscle tone was observed for the lower OO muscle from T0 to T1, but only at rest. The upper OO muscle showed a significant increase during the protrusion of the mandible from T1 to T2. No significant change was observed in the control group during the follow-up. Muscular contractility of treated patients at T2 reached the same values as that of the control group at T2. Interceptive orthodontics seems to improve the form and function of the orofacial muscle structure. Improvement in muscle contraction after treatment was demonstrated by sEMG., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

This study aimed to evaluate whether there is an association between facial morphology on cephalometrics and surface electromyographic (sEMG) recordings of the head, neck, and trunk muscles. Forty-seven Caucasian adult females, 18-29years of age (average: 24), underwent lateral skull radiographs in "natural head position", obtained by having the subject look at a small mirror at eye level, and sEMG recordings for the following muscles: masseter, anterior temporal, digastric, posterior cervicals, sternocleidomastoid, and upper and lower trapezius. All muscles were monitored bilaterally at mandibular rest position and during maximal voluntary clenching (MVC). The maximal bite force was also measured to check MVC. Pearson's correlation coefficient revealed significant correlations (p<0.01): (i) between the variables concerning mandibular position and size and the sEMG activity of upper trapezius at mandibular rest position; (ii) between the topographic correlation between the maxillary and mandibular bases (called skeletal class) and the sEMG activity of upper trapezius at MVC; (iii) between the sEMG activity of sternocleidomastoid and the Frankfort to mandibular plane angle; and (iv) between the sEMG activity of masseter and the anterior cranial base to mandibular plane angle. Some associations between the cephalometric variables and the sEMG activity of the head, neck, and trunk muscles were observed. No certain conclusion, however, was possible on the mechanism concerning these results. Future longitudinal studies are required., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Introduction: The aim of this in-vitro study was to evaluate the frictional forces generated by various combinations of brackets and orthodontic wires by using an experimental model with 3 nonleveled brackets to gain a better understanding of the resistance to sliding during dental alignment and leveling., Methods: Two kinds of orthodontic brackets were tested: passive self-ligating brackets and conventional twin stainless steel brackets. The following wires were tested: 3 nickel-titanium (.014, .016, and .016 x .022 in), 2 stainless steel (multistranded .0155 and .016 in), and 1 beta-titanium alloy (.016 in). The ligatures used with conventional brackets were elastomeric modules (power 'O' 110) and preformed stainless steel ligature wire (.010). Each of the 10 bracket-archwire combinations was tested 10 times. Kinetic frictional forces were measured on a specially designed testing machine. The wires tested were pulled through a set of multiple nonleveled brackets at a speed of 4 mm per minute over a distance of 5 mm. All data were statistically analyzed., Results: The sliding of the wire in the 3-bracket nonaligned system was significantly influenced by wire cross-section dimension (P < 0.001), wire material (P < 0.001), number of wire strands (P < 0.001), and type of ligation (P < 0.001)., Conclusions: Frictional forces can be reduced during alignment by using self-ligating brackets, small dimensions, and less stiff wires, thereby inducing the wire to slide in the slots. Under such conditions, the force required by the orthodontic wire to overcome resistance to sliding is reduced. This allows the wire to exploit its mechanical characteristics more efficiently.

Many antineoplastic drugs have been found to have carcinogenic, mutagenic and teratogenic activity and so hospital personnel handling these substances are potentially exposed to health risk. Understanding this risk derived from protracted occupational exposure has great relevance even if the workers normally adopt individual and environmental protective measures. To address this question we have studied the presence of DNA and chromosome damage in a population of nurses employed in Italian oncology units and in matched controls. We used the comet assay to evidence the presence of DNA strand breaks, due to both acute and chronic exposure, and the micronucleus (MN) test, which is a measure of clastogenic and aneugenic events. Furthermore, since the individual response to the exogenous insults may be genetically determined, we studied the possible influence of single nucleotide polymorphism in XRCC1 and XRCC3 DNA repair genes on induced genetic damage. We also considered the effects of confounding factors like smoking, age and gender. The results indicated that the exposed subjects had significantly high levels of genetic damage. Age and gender were associated with increased values in MN, both in control and in exposed groups; the smoking habit affects MN frequency in controls, but not in workers. Furthermore we found that exposed subjects bearing at least one XRCC1 variant allele (399Gln) show higher values of MN. The present data provide the evidence to show that occupational exposure to antineoplastic drugs, even if in safety controlled conditions, represents a serious health risk. Furthermore we have shown that the presence of XRCC1 genetic polymorphism could contribute to increase the genetic damage in susceptible individuals who are occupationally exposed to dangerous substances.

This article describes a new method of preparing trays for indirect bracket bonding. Computer-aided technology is used to design the individualized trays, which are then produced with a rapid prototyping procedure. Application in clinical practice and the advantages of time savings and accurate bracket placement are discussed.

Basal cell carcinoma (BCC) is one of the most common neoplasms in the world and its incidence has been increasing worldwide in recent years. BCCs are caused by an interplay between genetic and environment factors. We conducted a case-control association study in BCC patients and controls from Sweden and Finland. Fifteen single nucleotide polymorphisms (SNPs), IL-6-174G/C, -634G/C, and -597G/A; IL-10-1082G/A and -592C/A; IL-1beta-511C/T; NBS1 exon 5 Glu185Gln; XPC exon 15 Lys939Gln; XPD exon 23 Lys751Gln; XRCC1 exon 10 Arg399Gln; XRCC3 exon 7 Thr241Met; cyclin D1 exon 4 G870A; MTHFR exon 4 Ala222Val and exon 7 Glu429Ala; HFE exon 4 C282Y were performed by Pyrosequencing and RFLP techniques. Most of the genotype distributions were in accordance with the Hardy-Weinberg equilibrium (HWE), except for IL-10-1082G/A, where cases with BCC showed a significant deviation from HWE (P = 0.04). Linkage disequilibrium was observed between the -174 and -597 alleles in the IL-6 gene in the present populations. No difference between BCC and controls appeared in any of the SNPs analyzed. Only the combined distributions of TT/AA genotypes in MTHFR exon 4 (C/T) and exon 7 (A/C) showed slight increase in BCC compared to controls (P < 0.07, OR: 1.94; 95% CI: 0.96-3.89).

This study examines the aspartate aminotransferase activity in the pulp of orthodontically treated teeth. Seventeen healthy male and female subjects (ages: 14.5-19.6; mean 16.8 +/- 1.6 years) who needed extraction of the maxillary first premolars for orthodontic reasons were enrolled in the study. One randomly chosen maxillary first premolar, included in a straight-wire fixed orthodontic appliance and supporting orthodontic force, was considered as the test tooth. The contralateral first premolar, included in the orthodontic appliance but not subjected to mechanical stress, was used as the control tooth. After a week of treatment, the dental pulp tissues were extracted from both experimental teeth. Aspartate aminotransferase activity was significantly elevated in the test teeth as compared with the control teeth. These results demonstrate that in the early phases of treatment, orthodontic force application to the teeth can lead to significant metabolic changes in the pulp of these teeth.

During orthodontic treatment, the early response of periodontal tissues to mechanical stress involves several metabolic changes that allow tooth movement. Many studies have evaluated such modifications by analysis of various host metabolites released into the gingival crevicular fluid (GCF). This study used a cross-sectional design to examine the lactate dehydrogenase (LDH) activity in GCF to assess whether GCF LDH can be proposed as a sensitive marker for periodontal tissue modifications during orthodontic tooth movement. Thirty-seven subjects, 16 males and 21 females (mean age 18.7 years, range 14.0 to 26.7 years), participated in this study. Each subject underwent a session of professional oral hygiene and received oral hygiene instructions; 2 weeks later, a fixed orthodontic appliance was placed on the maxillary arch. A randomly selected maxillary canine was considered as the test tooth, and its antagonist, which had no appliance, was used as the control tooth. From 2 to 12 weeks after orthodontic appliance placement, GCF was harvested from both experimental teeth at the mesiobuccal angle, for GCF volume and LDH activity determinations. Clinical monitoring consisted of recording supragingival plaque presence, bleeding on probing, and probing depth at the same collection sites. The results showed that no differences in clinical conditions and GCF volume occurred between the experimental teeth. On the contrary, GCF LDH activity in the test teeth was significantly greater than that of the control teeth (P <.01). Moreover, no differences were found in the enzymatic activity between the sexes by experimental tooth, and no significant correlation was present between GCF LDH activity and patients' ages within experimental teeth. Our enzymatic results initially indicated a possible role of GCF LDH during the early phases of orthodontic treatment and therefore warrant further study as a possible diagnostic tool for tissue response during orthodontic treatment.

Doñana Park (Spain), a protected area in Europe, was affected by an environmental disaster in April 1998 that caused the spreading of acidic water and mud full of toxic metals from the Aznalcollar pyrite mine. In order to assess the contamination in the area and to monitor the possible biological effects of the toxic spill, a series of coordinated studies was performed utilizing several animal species living in that area. We performed genotoxicity monitoring using the Comet assay on peripheral blood leukocytes of the Algerian mouse (Mus spretus), a nonprotected rodent suitable as a bioindicator. The mice were sampled in different areas 6 months after the ecological disaster and again 1 year later. Our results showed that in 1998 all the areas examined were contaminated, as determined by an increase in the Comet assay parameters in the analyzed animals, whereas a significant decrease in the values of these parameters was observed in the 1999 samples, which were collected in a riverside area subject to tide flows. Thus, the Comet assay has proven to be an interesting and sensitive tool in studies of environmental genotoxicity.

Bone remodeling that occurs during orthodontic tooth movement is a biologic process involving an acute inflammatory response in periodontal tissues. A sequence characterized by periods of activation, resorption, reversal, and formation has been recently described as occurring in both tension and compression tooth sites during orthodontic tooth movement. We used a longitudinal design to investigate alkaline phosphatase (ALP) activity in gingival crevicular fluid (GCF) to assess whether it can serve as a diagnostic aid in orthodontics. Sixteen patients (mean age, 15.5 years) participated in the study. The maxillary first molars under treatment served as the test teeth (TT) in each patient; in particular, 1 first molar was to be retracted and hence was considered the distalized molar (DM), whereas the contralateral molar (CM) was included in the fixed orthodontic appliance but was not subjected to the distal forces. The DM antagonist first molar (AM), free from any orthodontic appliance, was used as the baseline control. The GCF around the experimental teeth was harvested from mesial and distal tooth sites immediately before appliance activation, 1 hour after, and weekly over the following 4 weeks. The clinical gingival condition was evaluated at the baseline and at the end of the experimental term. ALP activity was determined spectrophotometrically at 30 degrees C, and the results were expressed as total ALP activity (mUnits/sample). GCF ALP activity was significantly elevated in the DMs and the CMs as compared with the AMs at 1, 2, 3, and 4 weeks; conversely, in the AMs, GCF ALP activity remained at baseline levels throughout the experiment. Moreover, the enzyme activity in the DMs was significantly greater than in the CMs. In the DMs, a significantly greater ALP activity was observed in sites of tension compared with sites of compression. This difference was not seen with the CMs, in which the enzyme activity increased to the same extent in tension and compression sites. These results suggest that ALP activity in GCF reflects the biologic activity in the periodontium during orthodontic movement and therefore should be further investigated as a diagnostic tool for monitoring orthodontic tooth movement in clinical practice.

Resveratrol (3,5,4'-trihydroxystilbene) is a natural occurring molecule, synthesized by plants in response to different stresses. Recent literature data seem to converge in indicating Resveratrol as an agent possessing protective effects against oxidative stresses through different mechanisms. Furthermore conflicting data are present in relation to its activity of free radical scavenger. Here we studied the antioxidant activity actually exerted by the agent against reactive oxygen species induced by H(2)O(2) treatments in CHO cells. Our attention has been focused on two major potential mechanisms: scavenging activity and interference with oxidative metabolism, by the analysis of three important targets: intracellular oxidation (Dichlorofluorescein Test), primary DNA damage (Comet Assay) and fixed DNA damage (chromosomal aberrations). Cells were treated with a single H(2)O(2) dose (2x10(-4) M) in order to induce Reactive Oxygen Species and than challenged with Resveratrol to test its ability in modulating damage. Two experimental protocols have been applied: (i) simultaneous treatment and (ii) a 3 h Resveratrol pre-treatment. In our experimental conditions Resveratrol does not appear able, 'per se', to induce primary DNA damage whereas a slight increase in endogenous oxidation and chromosomal aberrations at the highest dose have to be noticed. In combined treatments the molecule appears to differently affect primary and fixed DNA damage.

In a program coordinated by the Italian Ministry of Works, we tested in vitro four pesticides widely employed in a developed agricultural region of central Italy. The four commercial agents were chosen on the basis of their diffusion in agricultural practice, knowledge of their active principle(s), and scant availability of data concerning their toxic and genotoxic activity. The agents were Cirtoxin, Decis, Tramat Combi (TC), and Lasso Micromix (LM). All substances were tested in three in vitro systems: Chinese hamster ovary (CHO) cells, a metabolically competent hamster cell line (Chinese hamster epithelial liver; CHEL), and root tips of Vicia faba (VF). The cytotoxic and genotoxic end points challenged were micronuclei and root tip length (RTL) in VF and mitotic index (MI), proliferation index (PI), cell survival (CS), cell growth (CG), cell cycle length (CCL), sister chromatid exchanges, chromosomal aberrations, and single-cell gel electrophoresis, or comet assay, in CHEL and CHO cells. Tested doses ranged from the field dose up to 200x the field dose to take into account accumulation effects. On the whole, tested agents appear to induce genotoxic damage only at subtoxic or toxic doses, indicating a low clastogenic risk. MI, PI, CS, CG, RTL, and CCL appear to be the less sensitive end points, showing no effects in the presence of a clear positive response in some or all of the other tests. Using cytogenetic tests, we obtained positive results for TC and LM treatments in CHO but not in CHEL cells. These data could be accounted for by postulating a detoxifying activity exerted by this cell line. However, cytogenetic end points appear to be more sensitive than those referring to cytotoxicity.

A high prevalence of Actinobacillus actinomycetemcomitans (Aa) in subgingival plaque in patients for orthodontia already has been observed. The present study had the following aims: 1) to ascertain a direct relationship between the orthodontic appliance placement and the subgingival colonization by Aa, and 2) to determine whether the Aa growth specifically occurred on teeth with braces attached or whether the presence of orthodontic appliances could also cause the isolation of Aa in teeth free from therapeutic appliances. Twenty-four young systemically and periodontally healthy subjects with malaligned and crowded teeth in the anterior sextants of both dental arches participated in this study. After 1 session of ultrasonic scaling with oral hygiene instructions during the first experimental session, the mesiobuccal sites of the first molars and the distobuccal sites of the lateral incisors in both dental arches in each participant were subjected to clinical and microbiologic examination for the recovery of Aa. Clinical examination consisted of recording the presence of plaque and the examination of gingival bleeding on probing and probing depth. Microbiologic sampling was obtained with the insertion of 3 sterile paper points at the deepest part of each gingival sulcus. Altogether, 192 periodontal sites were examined. After the examinations, the patients received fixed orthodontic appliances in only 1 dental arch (test sites) and the other one was left free from appliances (control sites). Clinical examination and microbiologic sampling were repeated in the same experimental test and control sites after 4, 8, and 12 weeks. At the 12-week session, the orthodontic appliance was removed from the test arch, and, 4 weeks later, a further clinical and microbiologic examination was performed. The results showed that, during the period with orthodontic appliances, the presence of plaque scores and the gingival bleeding on probing scores were increased significantly and that Aa, initially absent from all but 1 subject, was isolated in 19 and 20 subjects after 4 and 8 weeks, respectively. Furthermore, no gingival sites from the control teeth (free from Aa colonization at baseline) showed positive results for the sought-after bacterium throughout the entire length of the study. It was concluded that the placement of orthodontic appliances promotes the subgingival growth of Aa; this specific microbial change is specifically restricted to subgingival plaque from orthodontic appliance-bearing teeth. The presence of orthodontic bands and brackets therefore cannot affect the microbiologic condition of the whole mouth.