1,721,050 research outputs found
Siti implantari per miniviti: valutazione dello spessore osseo su crani secchi
No full textSTUDIO SU CRANI SECCHI DEGLI SPESSORI OSSEI IN 5 SITI IDONEI PER POSIZIONAMENTO DI MINIVIT
Temporary anchorage device stability: an evaluation of thread shape factor.
No full textCharacteristics of miniscrews related to primary stabilit
DISPOSITIVO ORTODONTICO PER TRAZIONE EXTRAORALE
No full textDispositivo ortodontico per trazione extraorale, comprendente almeno un corpo centrale (1), una o più porzioni di appoggio (2, 3, 4, 5) sulla testa del paziente ed una o più porzioni di trazione (6), le quali porzioni di trazione (6) si impegnano con un apparecchio intraorale, il quale dispositivo è provvisto di uno o più sensori (7, 8) per la misurazione della forza esercitata dalle porzioni di trazione (6)
Temporary anchorage device stability: an evaluation of thread shape factor
No full textThe resistance to extraction of temporary anchorage devices (TADs) depends on various factors, including miniscrew design, shear strength, and bone density. This research introduces the thread shape factor (TSF) as a new factor for the evaluation of TAD mechanical properties. The authors evaluated three TADs for a total of 27 tests: Mini-impianto autoforante (Leone, 1.75 mm diameter and 8 mm length), Orthoscrew (Leader Ortodonzia, 1.65 mm diameter and 9 mm length), and MAS (Miniscrew Anchorage System, 1.3 mm diameter and 11 mm length). For each TAD, the images were acquired via a 20.00 kV scanning electron microscopy to measure their respective mean depth of thread (D), pitch (P), and the relationship between the two (TSF). Subsequently, pullout tests on organic bone analogue were carried out using a testing machine; a crosshead speed of 2 mm/minutes was applied. A two-way analysis of variance was performed to evaluate the interaction between the type of miniscrew and the cortical thickness. A post hoc analysis for single comparisons was subsequently employed. In addition, if homogeneity of variances was not rejected, Scheffè's test was performed, while Tamhane's test was carried out if the homogeneity of variance assumption was not met. Univariate linear regression models were fitted to evaluate the relationship between the outcomes and TSF, D, and P separately. A P value of 0.05 was considered statistically significant. From univariate linear regression, TSF, D, and P were statistically significant predictors of 'peak load'. The tests showed that TSF has a statistical significance for describing the mechanical competency of TADs
Le miniviti per ancoraggio ortodontico. Caratteristiche strutturali ed indicazioni cliniche
No full textRecently, miniscrews have been planned and produced in order to strengthen anchorage during orthodontic treatment and to make patient’s cooperation unnecessary; this is particularly important in adult patients, when it is not possible to use typical anchorage devices, such as extra-oral traction. In this article miniscrew types now available are described, discussing structural features together with clinical indications following manufacturer’s instructions. This review will be useful for the orthodontist while choosing the proper miniscrew according to patient’s anatomy and orthodontic biomechanics. Nevertheless, both diagnosis and surgical treatment must be as accurate as possible in order to reduce any risk for the patient. Clinical and radiological examinations are essential to measure real bone dimensions of the site where miniscrew insertion is planned. Following these prescriptions, miniscrews will greatly help the orthodontist in the treatment of challenging orthodontic cases, especially in the adult patients with periodontal and occlusal problems
Six years long term evaluation of a class II division 1 patient treated with Herbst appliance and 2 miniscrews in the lower arch as anchorage reinforcement: A case report
No full textBackground > Efficacy of orthopaedic treatment of class II growing patients have been reported to be partially effective, depending on appliance efficacy, patient compliance, growth spurt and other variables. Different approaches have been proposed both removable and fix, with different results, and a dento-alveolar compensation was always reported. In order to limit or avoid such dental compensation skeletal anchorage reinforcement of functional appliances have been proposed, with promising results. Objective > The aim of the present report is to evaluate the dento-skeletal effects after 6 years of growing class II patient treated with Herbst and two miniscrews in the lower arch as anchorage reinforcement
Le miniviti per ancoraggio ortodontico
No full textDOSSIER SULLE CARATTERISTICHE DELLE MINISCREWS IN COMMERCI
Success rate of surface-treated and non-treated orthodontic miniscrews as anchorage reinforcement in the lower arch for the Herbst appliance: A single-centre, randomised split-mouth clinical trial
No full textBackground Surface treatment of miniscrews was implemented to determine whether its application increased bone-to-surface contact and enhanced the interlock between the device and the surrounding bone. Objectives To compare the success rate of surface-treated and non-treated orthodontic miniscrews used as reinforcement of anchorage during treatment with the Herbst appliance. Trial design Split-mouth design with an allocation ratio of 1:1. Methods Eligibility criteria to enrol patients were skeletal and dental class II patients with a retrusive chin, use of the Herbst appliance to correct malocclusion, need for skeletal anchorage using a miniscrew both in the left and right side of the mouth, absence of systemic diseases, absence of using drugs that alter bone metabolism, and good oral hygiene. Patients received self-drilling miniscrews without surface treatment and with surface treatment. Both types presented a 1.4 or 1.2 mm diameter. Miniscrews were inserted between the first molar and second premolars or between the two premolars. The force applied to the screws was an elastic chain from the head of the miniscrews to a direct button applied on the canines. The success rate of each type of miniscrew was considered the primary outcome, and the association of success with demographical, clinical, and geometrical characteristics was investigated. Differences were tested by the generalised linear mixed effects model for the split-mouth design. Differences with a P-value < 0.05 were selected as significant. Randomisation A randomisation list was created for the mouth side assignment. Blinding The study was single blinded with regard to the statistical analysis. Results Thirty-nine miniscrews of the non-treated type and 39 miniscrews of the surface-treated type were inserted in 39 patients (23 female and 16 male, mean age: 15.55 +/- 7.91) recruited between March 2018 and December 2020 with a split-mouth study design. The mean therapy duration was 9.3 months (SD = 1.31). No differences in failure rate were observed between miniscrew types. No serious harm was observed. Conclusions The success rate of surface-treated and non-treated miniscrews showed no significant differences. Registration This trial was not registered
Herbst Appliance Reinforced with an Hybrid Hyrax Expander and Two Miniscrews in the Lower Arch: Case Report
No full textIntroduction: Class II growing patients can be successfully treated with the Herbst appliance, nevertheless this therapy generally produces side effects, such as upper incisors retroclination and lower incisors proclination, which eventually could reduce mandibular forward advancement. Treatment objectives: The purpose of this article is to show a treatment of class II malocclusion with crowding in both arches by a skeletally reinforced Herbst appliance. Treatment description: Two miniscrews were applied in the lower arch to control lower incisors proclination and in the upper arch an Hybrid palatal expander was used. Results: the correction of the severe class II malocclusion was obtained with mandibular advancement, avoiding lower incisors proclination with control also of the upper incisors. Upper crowding with lack of space for upper canine alignment was corrected. Conclusions: Upper and lower miniscrews worked successfully as anchorage for the entire treatment
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