Search results for "Orthodontics."
showing 10 items of 920 documents
Evaluation of the force generated by gradual deflection of 0.016-inch NiTi and stainless steel orthodontic wires in self-ligating metallic and esthet…
2019
Background The purpose of this study was to evaluate the deflection forces of 0.016-inch Nitinol and stainless steel orthodontic wires, in association to different self-ligating brackets. Material and Methods Specimens were mounted in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using a 10N load cell and ISO 15,841, as a protocol. Eight of these models were prepared, each one for the bonding of each set of self-ligating accessories to be tested: Damon Q, Damon Clear (Ormco), In-Ovation R, In-Ovation C (GAC), BioQuick, QuickClear (Forestadent), SmartClip and Clarity SL (3M). Data were subjected to One-way ANOVA, followed by Tukey tests (P<0.05). Re…
The role of the styloid apophysis of the temporal bone in the biomechanics of the tongue, mandible, hyoid system: A case study
2020
Temporomandibular disorders are characterized by ear pain, tinnitus, difficulty in chewing, dysphagia and also dizziness, cervical limitation of range of movement (ROM) and other less common disorders. Numerous recent studies associate the presence of these signs and symptoms with an elongated styloid apophysis, as in the case of Eagle syndrome. The purpose of this clinical case is to support the thesis of a common syndrome that temporomandibular joint (TMJ) disorders with an elongated styloid process affirming the relationship between temporal bone, mandibule, hyoid bone and tongue. The patient was a 57-year-old woman who reported having ear algia and tinnitus all on the right side with di…
Plywood Jig—A New Technique for Root Canal Curvature Measurement
2021
The successful outcome of endodontic treatment is dependent on complete cleaning, shaping as well as three dimensional obturation of the root canal system. A conventional radiograph is a two-dimensional replication of a three-dimensional object and does not provide any conclusive evidence for canal curvatures. An accurate knowledge of the tooth anatomy and curvature is essential to avoid procedural errors. 100 freshly extracted human teeth were used in this study. Digital images were obtained using the plywood JIG and Schneider’s technique. These images were analyzed using the VixWin Pro digital image analyzing software (Gendex system). Statistical analysis was done using paired t test. The…
In-Vitro Investigation of Fatigue and Fracture Behavior of Transmucosal versus Submerged Bone Level Implants Used in Fixed Prosthesis
2021
Background: The present in vitro study aimed to investigate the fatigue performance of different dental fixtures in two different emergence profiles. Biological failures are frequently reported because the problem canonly be solved by replacing a failing implant with a new one. Clinicians addressed minor mechanical failures, such as bending, loosening or the fracture of screws, abutment, or the entire prosthesis, by simply replacing or fixing them. Methods: Transmucosal and submerged bone-level dental implants underwent fatigue strength tests (statical and dynamical performance) by a standardized test: UNI EN ISO 14801:2016. Two types of emergence profiles (Premium sub-crestal straight impl…
Effectiveness of interceptive treatment of class III malocclusions with skeletal anchorage: A systematic review and meta-analysis
2017
Recently, new strategies for treating class III malocclusions have appeared. Skeletal anchorage appears to reduce the dentoalveolar effects while maximising the orthopaedic effect in growing patients. The purpose of this systematic review and meta-analysis is to examine the effectiveness of bone anchorage devices for interceptive treatment of skeletal class III malocclusions. Searches were made in the Pubmed, Embase, Scopus and Cochrane databases, as well as in a grey literature database, and were complemented by hand-searching. The criteria for eligibility were: patients who had undergone orthodontic treatment with skeletal anchorage (miniplates and miniscrews). Patients with syndromes or …
Root repair after damage due to screw insertion for orthodontic miniplate placement
2019
Background: The aim of this investigation was to describe the healing reactions following root damage caused by placement of a miniplate anchorage system.Material and Methods: In 4 beagle dogs, 4 titanium miniplates (2 self-tapping screws per miniplate) were placed in each maxilla, after drilling of pilot-holes. Six fixation screws were unintentionally inserted damaging the root of maxillary canines. Two weeks later, half of the miniplates were loaded with a coil spring. Two dogs were euthanized 7 weeks after placement of the miniplates, while the remaining two after 29 weeks. Histological sections were prepared, microradiographed, observed under U.V. light, then stained and analysed under …
Head, chest and femur injury in teenage pedestrian–SUV crash; mass influence on the speeds
2018
This work studies the teenage pedestrian–sport utility vehicle (SUV) crash; injury to the vital parts of the body, such as the head and chest, and to the femur is evaluated. More advanced injury criteria are applied, as provided in the rules. The multibody technique is applied by making use of SimWise software and of the teenager anthropomorphic model, the use of which is now consolidated. Head injury criterion (HIC) is used for the head, thoracic trauma index (TTI) criterion for the thorax in the case of side impact and 3 ms criterion in the case of frontal impact, while the force criterion is used for the femur. Both the TTI and femur load evaluation require non-substantial modifications…
Cariostatic effect of a light-cured, resin-reinforced glass-ionomer for bonding orthodontic brackets in vivo
1998
The aim of this study was to evaluate in vivo the cariostatic potential of the resin-reinforced glass-ionomer (Vitremer core build-up restorative; 3M Dental Product Division) when used as a bonding agent for orthodontic brackets. The mineral distribution and topography of the enamel surface adjacent to the bracket base was determined by quantitative microradiography (TMR) and confocal laser scanning microscopy (CLSM). The study was designed in split-mouth technique using 9 pairs of premolars to be extracted for orthodontic reasons. One tooth of each pair was bonded with the resin-reinforced glass-ionomer, and the control contralateral premolar with the non-fluoridated composite (Concise, 3M…
Impact of oral contraceptive use and menstrual phases on patellar tendon morphology, biochemical composition, and biomechanical properties in female …
2013
Sex differences exist with regards to ligament and tendon injuries. Lower collagen synthesis has been observed in exercising women vs. men, and in users of oral contraceptives (OC) vs. nonusers, but it is unknown if OC will influence tendon biomechanics of women undergoing regular training. Thirty female athletes (handball players, 18–30 yr) were recruited: 15 long-term users of OC (7.0 ± 0.6 yr) and 15 nonusers (>5 yr). Synchronized values of patellar tendon elongation (obtained by ultrasonography) and tendon force were sampled during ramped isometric knee extensor maximum voluntary contraction to estimate mechanical tendon properties. Furthermore, tendon cross-sectional area and lengt…
The effect of pregnancy on orthodontic tooth movement in rats
2012
Introduction: The purpose of this study was to investigate the effect of pregnancy on orthodontic tooth movement in Wistar rats. Material and Methods: Forty eight female three-month old Wistar rats with an average weight of 250 ±25 g r were selected and randomly divided into two experimental (pregnant) and control groups (non-pregnant). Maxillary central incisors were tipped distally by insertion of springs exerting 30g force. Two, seven and fourteen days after spring insertion animals were sacrificed. Then the mesioincisal distance between maxillary incisors were measured. Subsequently, histological sections were prepared to count osteoclasts under a light microscope. The data on the exten…