Midpalatal Suture Density Evaluation after Rapid and Slow Maxillary Expansion with a Low-Dose CT Protocol: A Retrospective Study.

Background and objectives: The aim of the present paper is to use low-dose computed tomography (CT) to evaluate the changes in the midpalatal suture density in patients treated with rapid maxillary expansion (RME) and slow maxillary expansion (SME). Materials and Methods: Thirty patients (mean age 10.2 ± 1.2 years) were retrospectively selected from the existing sample of a previous study. For each patient, a low-dose computed tomography examination was performed before appliance placement (T0) and at the end of retention (T1), seven months later. Using the collected images, the midpalatal suture density was evaluated in six regions of interest. Results: No significant differences were found between the timepoints in the rapid maxillary expansion group. Three out of six regions of interest showed significant decreases between the timepoints in the slow maxillary expansion group. No significant differences were found in comparisons between the two groups. Conclusions: The midpalatal suture density showed no significant differences when rapid maxillary expansion groups were compared to slow maxillary expansion groups, suggesting that a similar rate of suture reorganization occurs despite different expansion protocols.

Bone and cortical bone characteristics of mandibular retromolar trigone and anterior ramus region for miniscrew insertion in adults.

INTRODUCTION: The aim of this study was to evaluate bone depth, cortical bone thickness, and vestibulolingual bone dimension of the mandibular retromolar trigone and anterior ramus region to evaluate what are its most suitable sites for miniscrew insertion in adults. METHODS: The sample included cone-beam computerized tomography (CBCT) records of 60 adult subjects retrospectively evaluated. All CBCT examinations were performed with the use of an i-CAT CBCT scanner (Imaging Sciences International). Each exam was converted into DICOM format and processed with the use of Osirix Medical Imaging software. On reproducible sagittal scan views, bone depth and cortical bone thickness were evaluated on specific lines parallel and at a 45° angle to the occlusal plane, and at 3 mm and at 6 mm distance from it. Vestibulolingual bone dimension was computed in 4 different cross-section scans and at 3 different levels of depth (0, 6, and 11 mm). RESULTS: All of the considered insertion sites showed on average more than 10 mm of bone depth. Inferential statistics showed significantly (P <0.05) greater bone depth (+3 mm) in cross-sectional scans parallel to the occlusal plane compared with those at a 45° angle to it. Cortical bone thickness showed average values from 3 mm to 5 mm. Vestibulolingual bone dimension showed a significant (P <0.05) reduction (-10 mm) in the posterior region of retromolar region. No significant differences were found between subjects with and without third molars. CONCLUSIONS: The retromolar trigone and anterior ramus region showed enough bone quantity and adequate bone quality for safe miniscrew insertion in adults.

Histomorphometric Evaluation of Two Different Bone Substitutes in Sinus Floor Augmentation Procedures.

The aim of this study is to compare the histomorphometric data of deproteinized bovine bone (DBB) and a fully synthetic bone substitute, poly (lactic-co-glycolic) acid/hydroxyapatite (PLGA/HA) applied for sinus floor augmentation technique. Twelve maxillary atrophic ridges of 8 patients requiring major maxillary sinus floor augmentation were studied; the sites were randomly assigned to the study groups and reexamined at 6 months after grafting using cone beam computed tomography scans and biopsy samples harvested during dental implant placement. Total bone volume, residual graft material volume, and new bone volume were assessed. Measurable biopsies were available from 67% of test sites and 100% of control sites. Poly (lactic-co-glycolic) acid/hydroxyapatite grafts showed no trace of graft material, whereas DBB grafts had a mean graft area of 16.60%. Mean percent of newly formed bone tended to be greater for PLGA/HA than for DBB group. Mean total bone volume percent did not differ significantly: PLGA/HA = 44.45% (CI, 16.42-72.48), DBB = 44.11% (CI, 36.61-51.60). Deproteinized bovine bone and PLGA/HA produced similar total bone volumes. Poly (lactic-co-glycolic) acid/hydroxyapatite appeared to be completely replaced by newly formed bone, whereas DBB presented significant amounts of residual graft material. Poly (lactic-co-glycolic) acid/hydroxyapatite necessitates of more clinical trials to be considered suitable for sinus floor augmentation.

Digital evaluation of nasal changes induced by rapid maxillary expansion with different anchorage and appliance design.

BACKGROUND: Scientific evidence showed that rapid maxillary expansion (RME) affects naso-maxillary complex, increasing nasal width and volume. This study aimed to evaluate nasal changes induced by rapid maxillary expansion with different anchorage and appliance design by using low dose and cone beam computed tomography. METHODS: A total of 44 patients (20 males, mean age 8y 8 m ± 1y 2 m; 24 females mean age 8y 2 m ± 1y 4 m) were included in the investigation and divided into three groups according to the appliance: Hyrax-type expander anchored to permanent teeth, modified Hyrax-type expander anchored to deciduous teeth, modified Haas-type expander anchored to deciduous teeth. Maxillary expansion was performed until overcorrection and the expander was passively kept in situ for 7 months at least. All patients had three-dimensional imaging before expansion (T0) and after the retention period (T1). Nasal floor width, nasal wall width, maxillary inter-molar width were measured by means of Mimics software. The paired sample t-test was employed to assess the significance of the differences between the time points; the analysis of variance test (ANOVA) was used to compare differences between groups. RESULTS: The statistical analysis revealed significant differences between T0 and T1 for each recorded measurement in each group; no significant differences were found by comparing groups. CONCLUSIONS: Rapid maxillary expansion produces a significant skeletal transverse expansion of nasal region in growing patients. No significant differences in nasal effects are expected when the appliance is anchored onto deciduous teeth, with or without the palatal acrylic coverage.

Indirect orthodontic bonding using an original 3D method compared with conventional technique: A narrative review.

As well known success in orthodontics is related to a correct diagnosis and to a carefull treatment planning. Our study aims to provide clinician with a reproducible and precise method, for orthodontic indirect bonding, thanks to CBCT images and due to a CAD-CAM process. METHODS: A case of an orthodontic treatment plan, of a female patient, 37 years old, was selected. Plaster models were digitally acquired using the Extra-Oral scanner Maestro 3D and processed within the Studio Maestro 3D software. CBCT images in DICOM format were imported into the MIMICS software, in order to perform the segmentation of the dental elements, and to obtain a three-dimensional coronal-root dental arches model. The DICOM file thus processed was exported in an STL file, reworked with Meshmixer software to improve image quality, and imported into the 3D Maestro software to be superimposed on the digital model. In this way a three-dimensional real model of the dental arches was developed. After an accurate orthodontic virtual set-up, we proceeded to brackets positioning on the 3D model of the dental arches. Subsequently, a virtual transfer template was created, in order to carry out the digital printing of a thermo-printed mask necessary to perform an indirect bonding of the orthodontic appliance. RESULTS: The original digital workflow proposed in this study allows the development of a real and non-ideal three-dimensional coronal-root model of the dental arches; this model can be used for indirect orthodontic bonding eliminating any errors in the expression of 1st, 2nd and 3rd order information of the pre-informed orthodontic appliance. CONCLUSIONS: Technological advancements in oral scanning and 3D printing will allow the achievement of an easy and reproducible ideal positioning of the orthodontic brackets.

Proposal of a hybrid workflow to create a device treating the nutritional disability of an infant with cleft lip and palate: Case report.

INTRODUCTION: Cleft lip-palate is the most common craniofacial congenital anomaly. Patients with Cleft lip palate require treatment with a multidisciplinary approach from birth to enable independent feeding and physiological growth. In the past, the fabrication of therapeutic devices for a child with a cleft lip palate was executed through conventional dental impression materials , with the risk of suffocation. The use of a digital workflow minimizes impression-related risks and streamlines procedures. METHODS: This study aims to propose a hybrid workflow that can combine the advantages of digital workflow with the advantages of analog workflow that can be applied daily by clinicians treating cleft lip-palate-affected patients. RESULTS: The device created was immediately accepted by the patient allowing autonomous nutrition. Evaluation of the effectiveness of the device was done by body weight assessment every 15 days. CONCLUSION: The patient had growth comparable to that of a child born healthy.

Evaluation of the Clinical Variables Affecting Attachment Reproduction Accuracy during Clear Aligner Therapy.

BACKGROUND: The purpose of this study was to evaluate some of the clinical variables that influence the accuracy of reproducing the planned attachment shape. The following clinical variables were considered: the template material, type of composite, and pressure application on the template during attachment curing. METHODS: In this study, the evaluated materials for the thermoplastic transfer template construction are Erkolen 0.8 (polyethylene: PE) and Erkodur 0.8 (polyethylene terephthalate glycol-PET-G), and two types of composite resins: Enaflow (light-curing low-viscosity composite resin) and Enamel plus dentina HRI (light-curing high-viscosity composite resin). Two different light-curing lamps were used: Valo cordless color with no pressure and push light pressure (SCS). The 26 models included in the study were imported into the 3 Shape Ortho System 2022 (ver. 85.0.20 3 Shape, Denmark), and attachments were virtually placed on the dental elements of the first premolar and on both sides of the first upper molars. The accuracy of the attachment reproduction was evaluated through linear and angular evaluations against the reference model (MCAD). Three physical models were obtained: model A (MA), which was printed with attachments; model B (MB) with attachments made with a PE template; and model C (MC) with attachments made with a PET-G template. RESULTS: The results showed statistically significant differences (p < 0.05) between the PE and PET-G templates with greater precision using the PET-G template. Statistically significant differences (p < 0.05) were found among the high-viscosity composite and low-viscosity composite with pressure curing. CONCLUSIONS: In light of the obtained data, using a PET-G template is recommended. The pressure application during composite curing reduces the reproduction accuracy with a low-viscosity composite.

Body Image and Psychological Impact of Dental Appearance in Adolescents with Malocclusion: A Preliminary Exploratory Study.

BACKGROUND: Body image and psychosocial functioning represent central challenges during adolescence and early adulthood. Malocclusion, defined as an irregularity in the alignment of the teeth, is known to negatively influence psychological outcomes. The current study aimed to elucidate the role of malocclusion, together with age, gender, and dental class, in body image and psychological functioning. METHODS: A total of 126 participants aged from 12 to 19 years old (mean: 15.87, SD: 2.35, female participants: 52.4%, male participants: 47.6%) were recruited. Participants were visited at the University Hospital of Messina, Italy, and completed a sociodemographic questionnaire, the Body Image Concern Inventory (I-BICI), and the Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ). RESULTS: Significant correlations were found between age, dental class, the BICI, and the PIDAQ. In particular, age showed a positive and significant correlation with PIDAQ-total score. The correlations between occlusal status and the BICI variables were all significant and positive. All correlations between occlusal status and the PIDAQ variables were all significant and positive, except for dental self-confidence. The correlations between the variables of the PIDAQ and BICI instruments were all significant and positive, except for dental self-confidence, where the directions were significant and negative. Moreover, age, gender, and occlusal status predicted BICI and PIDAQ scores. Age was a positive predictor for PIDAQ self-confidence, gender for BICI and PIDAQ total scores, along with dysmorphic symptoms, social impact, psychological impact, and aesthetic concerns. Several significant gender differences were highlighted by the analyses, with higher scores in the female group on all the BICI variables, except symptom interference, and all the PIDAQ variables, except dental self-confidence. CONCLUSIONS: Malocclusion appeared to play a central role in the psychological, representational, and psychosocial life of the participants. This research suggests that malocclusion and dental issues influence the psychological, representational, and psychosocial life of adolescents. Further research is required to examine the psychological impact of dental problems.

Application of Third Molar Maturity Index (I3M) for Assessing Adult Age of 18 Years in a Southern Italian Population Sample.

OBJECTIVE: Age estimation of living or dead individuals has a strategic importance in medicine, anthropology, and forensic science, in the context of mass disasters and in civil or criminal matters such as adoption or asylum. Teeth play a major role in this context in particular, the third molars are useful for determining whether an individual has reached the legal age of 18 years because they are still in development from the age of 14. MATERIALS AND METHODS: In this study, a sample of 307 panoramic radiographs performed on healthy subjects aged between 13 and 23 was analyzed to consider the correlation between the maturity index of the third molar (I3M) and age to verify the reliability of the cutoff 0.08 indicated by Cameriere et al in a sample of Italian subjects living in the Province of Messina (Sicily, South Italy) to discern the adult subjects from the minors. STATISTICAL ANALYSIS: The analysis of 307 panoramic radiographs resulted in a sensitivity of 89.2% with a confidence interval of 95%, a specificity of 96.5% with a confidence interval of 95%, and a positive predictive value of 96.7%. RESULTS: The method proved itself reliable in estimating adulthood in the population of the Messina- Sicily, but the I3M should not be used as the sole indicator to determine whether a person is younger or older than 18 years because age estimation based on dental methods alone has limitations as the third molars suffer from many variations related to their morphology, their location, and their development. CONCLUSION: We recommend a combination of several methods that are available to increase accuracy of age estimation, depending on the different legal requirements in civil or criminal cases.

Effects of Composite Attachments on Orthodontic Clear Aligners Therapy: A Systematic Review.

This systematic review aims to highlight the differences between different clear aligner therapies that differ in the presence of attachments or in attachment configuration. Eight electronic databases were searched up to March 2020. Two authors independently proceeded to study selection, data extraction, and risk of bias assessment. The analysis of the results was carried out examining six groups of movements (mesio-distal tipping/bodily movement; anterior bucco-lingual tipping/root torque; posterior bucco-lingual tipping/expansion; intrusion; extrusion; rotation). Five clinical trials were selected and all of them showed a medium risk of bias. Literature showed that attachments mostly increase the effectiveness of orthodontic treatment with clear aligners, improving anterior root torque, rotation, and mesio-distal (M-D) movement; they are also important to increase posterior anchorage. However, some articles showed contradictory or not statistically significant results. Attachments also seem to improve intrusion, but the evidence about this movement, as well as extrusion, is lacking. No studies evaluated posterior bucco-lingual tipping/expansion. Further clinical trials are strongly suggested to clarify the influence of attachments and their number, size, shape, and position on each orthodontic movement.

Psychological and Social Effects of Oral Health and Dental Aesthetic in Adolescence and Early Adulthood: An Observational Study.

BACKGROUND: Is well known that oral health and dental aesthetic have significant effects on the sociality of human beings. The aim of the present study was to assess some aspects of oral health with possible repercussions in adolescent and youth, with particular reference to gender differences. METHODS: A total of 190 subjects with female prevalence (F = 62.6%, M = 37%) and ages between 14 and 29 years old (Mean = 23.8; SD = 3.27) participated. Evaluation was carried using standardized instruments to assess quality of oral life (PIDAQ), negative impact of oral conditions (OHIP-14), and self-esteem (Rosenberg Self Esteem Scale). Correlational and difference analyses and linear regressions were performed. RESULTS: Significant gender differences were found in terms of gender, in reference to variables such as self-confidence and convictions. Positive correlations emerged between psychological impact and social impact, aesthetic concern and social impact, convictions and self-confidence, oral health with psycho-social impact, and aesthetic concern, self-esteem with oral health. Inverse correlations emerged between psycho-social impact and self-confidence, aesthetic concern and self-confidence, oral health, and self-confidence. Multivariate linear regression indicated relations between age and psychological impact, sex and self-confidence, crooked teeth and conviction. CONCLUSIONS: The impact of oral health on the psychological well-being of young people is relevant. These factors, if considered within clinical practice, can improve the quality of life of the subject.

A Full Diagnostic Process for the Orthodontic Treatment Strategy: A Documented Case Report.

The need for extractions in orthodontic treatment has always been a controversial topic. However, to date there is not a specific clinical guideline that can help the clinicians deciding to plan an extractive or a non-extractive orthodontic treatment. In this respect, clinicians must deal with patients' occlusal, functional, periodontal and aesthetics characteristics before planning an orthodontic treatment including extraction. Considering the absence of specific guidelines, the choice to extract teeth or not is complicated, particularly in borderline cases. In this case report, we present a borderline case of a patient with the skeletal Class III pattern and significant crowding in both arches that could be treated with or without extraction, illustrating the diagnostic and decision-making processes that were conducted for the orthodontic treatment strategy.

Correlation between Caries, Body Mass Index and Occlusion in an Italian Pediatric Patients Sample: A Transverse Observational Study.

BACKGROUND: The aim of this study was to evaluate the correlation between caries, body mass index (BMI) and occlusion in a sample of pediatric patients. METHODS: The study group included 127 patients (72 female, 55 male) aged between 6 and 16 years (mean age 10.2) and selected between January and June 2019 at the Department of Pediatric Dentistry, University of Messina. Caries incidence was evaluated using the decayed, missing and filled teeth (DMFT) index. On the basis of BMI values, using a table adjusted for age and gender, patients were grouped into four categories (underweight, normal weight, risk of overweight, overweight). RESULTS: There was no significant correlation between BMI and DMFT in the whole sample. The study of the correlation between BMI and DMFT in patients with different types of malocclusion showed a significant inverse correlation for patients affected by II class and deepbite malocclusion. CONCLUSIONS: The incidence of caries does not seem to be significantly related to BMI and occlusal patterns, but it decreases with increasing age.

Treatment with Luteolin Improves Lipopolysaccharide-Induced Periodontal Diseases in Rats.

Periodontitis is a dental disease that produces the progressive destruction of the bone surrounding the tooth. Especially, lipopolysaccharide (LPS) is involved in the deterioration of the alveolar bone, inducing the release of pro-inflammatory mediators, which cause periodontal tissue inflammation. Luteolin (Lut), a molecule of natural origin present in a large variety of fruits and vegetables, possess beneficial properties for human health. On this basis, we investigated the anti-inflammatory properties of Lut in a model of periodontitis induced by LPS in rats. Animal model predicted a single intragingival injection of LPS (10 µg/µL) derived from Salmonella typhimurium. Lut administration, was performed daily at different doses (10, 30, and 100 mg/kg, orally), starting from 1 h after the injection of LPS. After 14 days, the animals were sacrificed, and their gums were processed for biochemical analysis and histological examinations. Results showed that Lut (30 and 100 mg/kg) was equally able to reduce alveolar bone loss, tissue damage, and neutrophilic infiltration. Moreover, Lut treatment reduced the concentration of collagen fibers, mast cells degranulation, and NF-κB activation, as well as the presence of pro-inflammatory enzymes and cytokines. Therefore, Lut implementation could represent valid support in the pharmacological strategy for periodontitis, thus improving the well-being of the oral cavity.

3D Assessment of Endodontic Lesions with a Low-Dose CBCT Protocol.

Background: Cone beam computed tomography (CBCT) is often used in different fields of dental science, especially in complex anatomical districts like the endodontic one. The aim of this study is to propose a low-dose CBCT protocol useful in cases of endodontic lesions. Methods: The device used was a MyRay Hyperion X9-11x5; the low dose setting of the machine was 90 Kv, 27 mAs, CTDI/Vol 2.89 mGy. The absorbed organ doses have been evaluated with an anthropomorphic phantom loaded with thermoluminescent dosimeters positioned at the level of sensitive organs like brain, bone marrow, salivary glands, thyroid, esophagus, oral mucosa, extrathoracic airways, and lymph nodes. Equivalent and effective doses have been calculated; the last one has been calculated using the recommendations approved by the Main Commission of ICRP (International Commission Radiological Protection) in March 2007. For the assessment of image quality, five senior clinicians, independent and experienced clinicians, were asked to state if CBCT scans were accurate enough to assess endodontic lesions. Results: The use of a low-dose CBCT acquisition produced the lowest organ dose (5.01 microSv) at the level of the esophagus. Image quality has been considered accurate enough for endodontic diagnostic needs. Conclusions: CBCT low-dose protocol can be used over the standard one in endodontic special cases because it provides a significantly lower radiation dose to the patients while ensuring good image quality. However, further studies are necessary to evaluate the opportunity of low-dose CBCT exams in endodontic clinical practice.

Maxillary Orthodontic Expansion Assisted by Unilateral Alveolar Corticotomy and Low-Level Laser Therapy: A Novel Approach for Correction of a Posterior Unilateral Cross-Bite in Adults.

Introduction: The treatment of a true unilateral posterior crossbite often requires asymmetric maxillary expansion; however, this is challenging to achieve with conventional expansion methods because of several biomechanical limitations. In this paper, we introduce a new protocol for the treatment of a unilateral posterior crossbite in adults based on maxillary orthodontic expansion assisted by corticotomy and low-level laser therapy (LLLT) performed on the crossbite side. Methods: The study sample included 15 adults (8 females, 7 males) affected by a true unilateral posterior crossbite, with a mean age of 21.6 ± 3.1 years at the at the beginning of treatment. After the application of orthodontic appliances (palatal expander and self-ligating brackets), corticomy was performed at the buccal aspect of the crossbite side while LLLT was monthly administered up to the correction of the crossbite. The efficacy of the technique was evaluated through measurements performed on maxillary digital models. Results: All subjects reported successful correction of the posterior unilateral crossbite, and functional occlusion was achieved as well. The average expansion was greater at the crossbite side compared to the unaffected side and such difference was significant at the levels of first premolars (P < 0.05), second premolars (P < 0.05) and first molars (P < 0.05). Conclusion: Orthodontic maxillary expansion assisted by unilateral corticotomy and LLLT was effective in the treatment of the true unilateral crossbite.

An immunohistochemical, histological, and electron-microscopic study of the human periodontal ligament during orthodontic treatment.

The periodontal ligament lies between the hard tissues of alveolar bone and cementum of teeth and serves to anchor the tooth to the alveolus and functions as a cushion between these hard tissues to migrate occlusal force during mastication. This tissue is always exposed to mechanical stress during mastication. When occlusal forces exceed the adaptive capacity of the periodontal ligament, the periodontal ligament tissue will be injured and then occlusal trauma will occur. The different modifications of periodontal ligament during load deformation can be monitored by analysis of the expression of different collagen types and fibronectin, with immunohistochemical techniques, and by morphological study of ligament, with light- and transmission electron-microscopic techniques. The use of continued and light orthodontic force generates a pressure of ligament with ejection of parodontal fluid externally and partial closing of vessels. On these basis we performed a study in order to evaluate periodontal ligament collagen types I and IV and the fibronectin modifications induced by application of a precalibrated orthodontic strength. We integrated these results, with light and transmission electron-microscopic observations, in order to evaluate the morphological modifications of periodontal tissue. Our observations showed that the type I collagen immunofluorescence staining is increased in the pressure side; in the tension side, it shows prior to treatment an increase, and after 72 h of treatment, a diminution of the staining pattern. Type IV collagen staining is reduced in both sides, but increased gradually after 7 days from treatment; finally, fibronectin staining pattern is gradually increased in the pressure side and reduced in the tension side. In light and transmission electron-microscopic observations it is possible to show a reduction of vessels at 72 h from treatment, and an increase of vessels after 7 days from treatment. The Malassez's epithelial residues are decreased at 72 h, while they are increased after 7 days from treatment. The modifications of immunofluorescence staining patterns of tested proteins revealed angiogenesis and reparative processes, and a thickening of fibrillar matrix as a defensive reply to mechanical stress. The modification of normal staining patterns of tested protein in our observations, could be determined by variation of scaffold geometry of periodontal ligament. The reduced movements of contraction and relaxation of periodontal ligament, due to orthodontic treatment, provoke a loss of mechanical stresses transmitted over ligament surface. Mechanical signals, therefore, could be integrated with other environmental signals and transduced into biochemical signals through force-dependent changes in scaffold geometry. Physical forces of gravity, hemodynamic stresses, and movement play a critical role in tissues, since the cells use tensegrity architecture for their structural organization.

Evaluation of frictional forces during dental alignment: an experimental model with 3 nonleveled brackets.

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.

Oxidative Stress Evaluation in Patients Treated with Orthodontic Self-ligating Multibracket Appliances: An in Vivo Case-Control Study.

OBJECTIVE: Oxidative stress is a pathologic event induced by a prevalence of oxidant agents on the antioxidant ones, with a consequent alteration of oxide-reducing balance. INTRODUCTION: Freeradicals produce damages both in cellular and extra-cellular components; phospholipid membranes, proteins, mitochondrial and nuclear DNA, are the target of the oxidative stress, that can finally cause cellular death due to apoptosis. MATERIALS & METHODS: Orthodontic appliances such as brackets, wires, resins and soldering have some components that can be considered as potential allergen, carcinogenic, cytotoxic and gene mutation factors. The primary aim of this research is to evaluate oxidative stress in the saliva of patients treated with multibracket self-ligating vestibular orthodontic appliances; the secondary purpose is to investigate the influence of orthodontic multibracket therapy on oral hygiene and the consequent effect on oxidative stress. Salivary specimens has been collected in a sample of 23 patients were enrolled (12 Female, 11 Male) between 12 and 16 years of age (mean age 14.2). For each patient has been collected a salivary specimen at the following time points; before orthodontic bonding (T1), five weeks (T2) and ten weeks (T3) after orthodontic appliance bonding. RESULTS: Samples has been analysed with a photometer due to SAT Test (Salivary Antioxidant Test). Data obtained show a mean of 2971 mEq/l of anti-oxidant agents before orthodontic treatment, and after five weeks from the bonding the mean was decreased to 2909 mEq/l, instead at ten weeks was increased to 3332 mEq/l. Repeated measures ANOVA did not reveal statistically significant differences between the time points (P = 0.1697). The study did not reveal any correlation between the level of dental hygiene and that of oxidative stress (Pearson Correlation Coefficient R = 0). CONCLUSION: Orthodontic treatment with multibrackets vestibular metallic appliance seems to be not able to affect oxidative stress during the first ten weeks of therapy.