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The Angle Orthodontist Nov 2021To analyze the biomechanical system of anterior retraction with clear aligner therapy (CAT) with and without an anterior mini-screw and elastics.
OBJECTIVES
To analyze the biomechanical system of anterior retraction with clear aligner therapy (CAT) with and without an anterior mini-screw and elastics.
MATERIALS AND METHODS
Models including a maxillary dentition (without first premolars), maxilla, periodontal ligaments (PDLs), attachments, and aligners were constructed and imported to finite element software. Three model groups were created: (1) control (CAT alone), (2) labial elastics (CAT with elastics between the anterior mini-screw and buttons on central incisors), and (3) linguoincisal elastics (CAT with elastics between the anterior mini-screw and precision cuts on the lingual sides of the aligner). Elastic forces (0-300 g, in 50 g increments) were applied.
RESULTS
CAT alone caused lingual tipping and extrusion of the incisors. Labial elastics caused palatal root torquing and intrusion and mesial tipping of the central incisors, while linguoincisal elastics produced palatal root torquing and intrusion of both central and lateral incisors. Second premolars were intruded in all three groups, with less intrusion in the linguoincisal elastics group. For the control group, stress was concentrated on both labial and lingual root surfaces, alveolar ridge, and cervical and apical PDLs. Stress was more concentrated in the labial elastics group and less concentrated in the linguoincisal elastics group.
CONCLUSIONS
CAT produced lingual tipping and extrusion of incisors during anterior retraction. Anterior mini-screws and elastics can achieve incisor intrusion and palatal root torquing. Linguoincisal elastics are superior to labial elastics with a lower likelihood of buccal open bite. Root resorption and alveolar defects may occur in CAT, more likely for labial elastics and less likely for linguoincisal elastics.
Topics: Bone Screws; Incisor; Orthodontic Appliances, Removable; Tooth Movement Techniques; Torque
PubMed: 34061964
DOI: 10.2319/120420-982.1 -
BioMed Research International 2022Miniscrew has been used widely as an effective orthodontic anchorage with reliable stationary quality, ease of insertion and removal techniques, immediate or early... (Review)
Review
Miniscrew has been used widely as an effective orthodontic anchorage with reliable stationary quality, ease of insertion and removal techniques, immediate or early loading, flexibility in site insertion, less trauma, minimal patient cooperation, and lower price. Nonetheless, it is not free of complications, and they could impact not only the miniscrew success rate but also patients' oral health. In this article, literature was searched and reviewed electronically as well as manually to evaluate the complications of orthodontic miniscrew. The selected articles are analyzed and subcategorized into complications during and after insertion, under loading, and during and after removal along with treatment if needed according to the time. In addition, the noteworthy associated factors such as the insertion and removal procedures, characteristics of both regional and local anatomic structures, and features of the miniscrew itself that play a significant role in the performance of miniscrews are also discussed based on literature evidence. Clinicians should notice these complications and their related factors to make a proper treatment plan with better outcomes.
Topics: Bone Screws; Humans; Orthodontic Anchorage Procedures
PubMed: 35958810
DOI: 10.1155/2022/8720412 -
Scientific Reports Feb 2022The objective of this study was to evaluate the effect of bone-miniscrew contact percentage (BMC%) and bone quality and quantity on orthodontic miniscrew stability and...
The objective of this study was to evaluate the effect of bone-miniscrew contact percentage (BMC%) and bone quality and quantity on orthodontic miniscrew stability and the maximum insertion torque value (ITV). Orthodontic miniscrews of five different dimensions and several bovine iliac bone specimens were used in the evaluation. Miniscrews of each dimension group were inserted into 20 positions in bovine iliac bone specimens. The experiment was divided into three parts: (1) Bone quality and quantity were evaluated using cone-beam computed tomography (CBCT) and microcomputed tomography. (2) The 3D BMC% was calculated. (3) The ITVs during miniscrew insertion were recorded to evaluate the stability of the orthodontic miniscrews. The results indicated that longer and thicker miniscrews enabled higher ITVs. CBCT was used to accurately measure cortical bone thickness (r = 0.939, P < 0.05) and to predict the bone volume fraction of cancellous bone (r = 0.752, P < 0.05). BMC% was significantly influenced by miniscrew length. The contribution of cortical bone thickness to the ITV is greater than that of cancellous bone structure, and the contribution of cortical bone thickness to BMC% is greater than that of cancellous bone structure. Finally, the higher is BMC%, the greater is the ITV. This study concludes that use of CBCT may predict the mechanical stability of orthodontic miniscrews.
Topics: Animals; Bone Screws; Cancellous Bone; Cattle; Cortical Bone; Humans; Ilium; Maxilla; Stress, Mechanical; Titanium
PubMed: 35181736
DOI: 10.1038/s41598-022-06851-y -
Orthopaedics & Traumatology, Surgery &... Feb 2021In France, 11,294 proximal tibia fractures occurred in 2018 and 6880 surgical procedures were done to treat them. Most of these were tibial plateau fractures, although... (Review)
Review
In France, 11,294 proximal tibia fractures occurred in 2018 and 6880 surgical procedures were done to treat them. Most of these were tibial plateau fractures, although fractures can occur in the metaphysis only or in the intercondylar eminence. The proximal tibia's poor vascularization justifies sparing it by doing a percutaneous treatment, setting the stage for bone union. The treatment must be based on rigorous planning with 3D imaging to determine the type of fracture accurately. The goals of treatment are first to realign the lower limb and then to reduce the articular surface, while addressing any associated injuries. Percutaneous reduction is based on ligamentotaxis and the use of spatulas or balloons that spare the vascularization. Surgical navigation and arthroscopy are precious tools for verifying the reduction. There are several options for stabilization, ranging from using polymethylmethacrylate cement for a Schatzker III fracture to applying a cannulated screw or doing MIPPO (Minimal Invasive Percutaneous Plate Osteosynthesis) with an anatomical plate and adjustable locking screws placed under the depression in complex fractures. Percutaneous surgery is not about the size of the incisions; the focus is on sparing the metaphysis and its vascularization to ensure high-quality and long-lasting stability. It appears to yield better functional outcomes than open reduction and internal fixation, not only for Schatzker type I, II and III fractures, but also for complex fractures where open fixation is more damaging and the source of complications.
Topics: Bone Plates; Bone Screws; Fracture Fixation, Internal; France; Humans; Tibial Fractures
PubMed: 33316447
DOI: 10.1016/j.otsr.2020.102753 -
BMC Musculoskeletal Disorders Jan 2022Periarticular hardware placement can be challenging and a source of angst for orthopaedic surgeons due to fear of penetrating the articular surface and causing undue... (Review)
Review
Periarticular hardware placement can be challenging and a source of angst for orthopaedic surgeons due to fear of penetrating the articular surface and causing undue harm to the joint. In recent years, many surgeons have turned to computed tomography (CT) and other intraoperative or postoperative modalities to determine whether hardware is truly extraarticular in areas of complex anatomy. Yet, these adjuncts are expensive, time consuming, and often unnecessary given the advancement in understanding of intraoperative fluoroscopy. We present a review article with the goal of empowering surgeons to leave the operating room, with fluoroscopy alone, assured that all hardware is beneath the articular surface that is being worked on. By understanding a simple concept, surgeons can extrapolate the information in this article to any joint and bony surface in the body. While targeted at both residents and surgeons who may not have completed a trauma fellowship, this review can benefit all orthopaedic surgeons alike.
Topics: Bone Screws; Fluoroscopy; Humans; Tomography, X-Ray Computed
PubMed: 34991568
DOI: 10.1186/s12891-021-04928-9 -
Proceedings of the Institution of... Sep 2022Metal and its alloys have been predominantly used in fracture fixation for centuries, but new materials such as composites and polymers have begun to see clinical use... (Review)
Review
Metal and its alloys have been predominantly used in fracture fixation for centuries, but new materials such as composites and polymers have begun to see clinical use for fracture fixation during the past couple of decades. Along with the emerging of new materials, tribological issues, especially debris, have become a growing concern for fracture fixation plates. This article for the first time systematically reviews the most recent biomechanical research, with a focus on experimental testing, of those plates within ScienceDirect and PubMed databases. Based on the search criteria, a total of 5449 papers were retrieved, which were then further filtered to exclude nonrelevant, duplicate or non-accessible full article papers. In the end, a total of 83 papers were reviewed. In experimental testing plates, screws and simulated bones or cadaver bones are employed to build a fixation construct in order to test the strength and stability of different plate and screw configurations. The test set-up conditions and conclusions are well documented and summarised here, including fracture gap size, types of bones deployed, as well as the applied load, test speed and test ending criteria. However, research on long term plate usage was very limited. It is also discovered that there is very limited experimental research around the tribological behaviour particularly on the debris' generation, collection and characterisation. In addition, there is no identified standard studying debris of fracture fixation plate. Therefore, the authors suggested the generation of a suite of tribological testing standards on fracture fixation plate and screws in the aim to answer key questions around the debris from fracture fixation plate of new materials or new design and ultimately to provide an insight on how to reduce the risks of debris-related osteolysis, inflammation and aseptic loosening.
Topics: Biomechanical Phenomena; Bone Plates; Bone Screws; Cadaver; Fracture Fixation; Fracture Fixation, Internal; Humans; Materials Testing
PubMed: 35920401
DOI: 10.1177/09544119221108540 -
Neurologia Medico-chirurgica Aug 2016Surgical approaches for stabilizing the craniovertebral junction (CVJ) are classified as either anterior or posterior approaches. Among the anterior approaches, the... (Review)
Review
Surgical approaches for stabilizing the craniovertebral junction (CVJ) are classified as either anterior or posterior approaches. Among the anterior approaches, the established method is anterior odontoid screw fixation. Posterior approaches are classified as either atlanto-axial fixation or occipito-cervical (O-C) fixation. Spinal instrumentation using anchor screws and rods has become a popular method for posterior cervical fixation. Because this method achieves greater stability and higher success rates for fusion without the risk of sublaminar wiring, it has become a substitute for previous methods that used bone grafting and wiring. Several types of anchor screws are available, including C1/2 transarticular, C1 lateral mass, C2 pedicle, and translaminar screws. Appropriate anchor screws should be selected according to characteristics such as technical feasibility, safety, and strength. With these stronger anchor screws, shorter fixation has become possible. The present review discusses the current status of surgical interventions for stabilizing the CVJ.
Topics: Atlanto-Axial Joint; Bone Screws; Humans; Joint Instability; Spinal Fusion
PubMed: 27041630
DOI: 10.2176/nmc.ra.2015-0342 -
Scientific Reports Aug 2022Applying the right torque to osteosynthesis screws is important for undisturbed bone healing. This study aimed to compare test-retest and intra-individual reliabilities...
Applying the right torque to osteosynthesis screws is important for undisturbed bone healing. This study aimed to compare test-retest and intra-individual reliabilities of the torque applied to 1.5 mm and 2.0 mm osteosynthesis screws by residents and oral and maxillofacial surgeons (OMF-surgeons), to define the reference torque intervals, and to compare reference torque interval compliances. Five experienced OMF-surgeons and 20 residents, 5 of each 4 residency years, were included. Each participant inserted six 1.5 × 4 mm and six 2.0 × 6 mm screws into a preclinical model at two test moments 2 weeks apart (T1 and T2). Participants were blinded for the applied torque. Descriptive statistics, reference intervals, and intra-class correlation coefficients (ICC) were calculated. The OMF-surgeons complied more to the reference intervals (1.5 mm screws: 95% and 2.0 mm screws: 100%) than the residents (82% and 90%, respectively; P = 0.009 and P = 0.007) with the ICCs ranging between 0.85-0.95 and 0.45-0.97, respectively. The residents' accuracy and reliability were inadequate regarding the 1.5 mm screws but both measures improved at T2 for both screw types compared to T1, indicating a learning effect. Training residents and/or verifying the applied torque by experienced OMF-surgeons remains necessary to achieve high accuracy and reliability, particularly for 1.5 mm screws.
Topics: Bone Screws; Fracture Fixation, Internal; Humans; Oral and Maxillofacial Surgeons; Reproducibility of Results; Torque
PubMed: 36002589
DOI: 10.1038/s41598-022-18687-7 -
Medicinski Glasnik : Official... Feb 2022Aim To describe the technique of the four-corner fusion with two retrograde crossed headless screws in cases of carpal collapse. Methods This technique is a consolidated...
Aim To describe the technique of the four-corner fusion with two retrograde crossed headless screws in cases of carpal collapse. Methods This technique is a consolidated procedure performed in cases of scaphoid non- union advanced collapse (SNAC) type II and III, scapholunate advanced collapse (SLAC) type II and III and in other cases of carpal collapse. Between 2017 and 2019 we treated six male patients (a mean age of 55.0 years) with radiocarpal osteoarthritis. Our technique involves the use of two retrograde crossed headless screws; the first screw was placed distally proximally from the uncinate to the lunate and the second screw from the pyramidal to the capitate, crossed at approximately 90 degrees. Clinical and radiographic two-year follow-up was performed. Before the treatment and during the follow-ups VAS, PRWE and DASH Quick score scales, measured wrist range of motion (WROM) were administered and evaluated. Results In all cases the X-ray consolidation of arthrodesis within five months was noticed; in 50% patients already under 3-month control. No observed signs of mobilization of screws and inflammatory or infectious processes were found. All patients were satisfied (reduction/disappearance of pain). All surgically treated patients resumed normal daily activities. These improvements were confirmed by the results of the evaluation scale and clinical examination. Conclusion This technique, in our opinion, represents a gold standard. Its low costs of the material used (especially comparing to other technique), a low prevalence of complications of materials and fusion in 100% of cases should be also considered.
Topics: Arthrodesis; Bone Screws; Humans; Male; Middle Aged; Range of Motion, Articular; Scaphoid Bone; Wrist Joint
PubMed: 35112563
DOI: 10.17392/1450-21 -
International Journal of Environmental... Nov 2020Different implant-abutment connections have been developed to reduce mechanical and biological failure. The most frequent complications are loss of preload, screw... (Review)
Review
Different implant-abutment connections have been developed to reduce mechanical and biological failure. The most frequent complications are loss of preload, screw loosening, abutment or implant fracture, deformations at the different interfaces, and bacterial microleakage. Aim: To review the evidence indicating whether the implant-abutment connection type is significant regarding the following issues: (1) maintenance of the preload in static and dynamic in vitro studies; (2) assessment of possible deformations at the implant-abutment interfaces, after repeated application of the tightening torque; (3) evaluation of the sealing capability of different implant connections against microleakage. In June 2020, an electronic literature search was performed in Medline, EBSCO host, and PubMed databases. The search was focused on the ability of different implant connections to maintain preload, resist deformation after tightening and retightening, and prevent microleakage. The related titles and abstracts available in English were screened, and the articles that fulfilled the inclusion criteria were selected for full-text reading. The literature search conducted for this review initially resulted in 68 articles, among which 19 articles and 1 systematic review fulfilled the criteria for inclusion. The studies were divided according to the three proposed objectives, with some studies falling into more than one category (maintenance of preload, surface abutment-implant deformation, and resistance to microleakage). Conical abutment appears to result in fewer mechanical complications, such as screw loosening or fractures, and higher torque preservation. After SEM evaluation, damage was observed in the threads of the abutment screws, before and after loading in internal and external connections. Internal hexagon implants and predominantly internal conical (Morse taper) implants showed less microleakage in dynamic loading conditions. We suggest further studies to guarantee excellence in methodological quality.
Topics: Biomechanical Phenomena; Bone Screws; Databases, Factual; Torque
PubMed: 33238476
DOI: 10.3390/ijerph17228685