Correct Position Research Articles

High spatial resolution φ-OFDR based on frequency-shift averaging and rotating vector summation

The coherent fading noise hinders the spatial resolution enhancements of phase optical frequency domain reflectometry (φ-OFDR). To mitigate the coherent fading noise, this study introduces frequency-shift averaging and rotating vector summation for strain measurements. The original Rayleigh backscattering signal was first divided into numerous sub-segments in frequency domain by using the frequency-shift averaging, and each sub-signal segment was transferred into vector signal with both intensity and phase information by using the rotating vector summation. Furthermore, a spatial position correction algorithm is incorporated to counteract the degradation of phase coherent, facilitating large-scale strain measurements. After optimizing the sub-frequency range and overlap ratio of the sub-signal in the frequency domain, we experimentally demonstrated that this method achieves strain measurement with a broad strain range of 2000 με, a high spatial resolution of 0.54 mm, and a high precision of 0.87%.

Electric trucks pantograph-catenary interaction condition monitoring method based on semantic segmentation network and linear fitting

Abstract The pantograph-catenary system (PCS) in dual-source electric trucks is crucial for maintaining a stable connection to the power grid, which directly impacts power quality. Ensuring reliable contact between the pantograph and catenary requires accurate detection of the contact point (CPT). However, existing CPT detection methods designed for trains are not well-suited for electric trucks due to differences in structural design. To address this challenge, this paper proposes a novel CPT detection method that integrates semantic segmentation and linear fitting techniques. Firstly, we introduce a lightweight Pantograph and Contact Line Segmentation Network (PCSN), which accurately extracts the regions of the pantograph and contact line. Secondly, a position correction algorithm combined with a least-squares linear fitting technique is employed to detect the CPT of electric trucks. Experimental results demonstrate that the proposed method achieves a detection error within ±5 pixels. In terms of processing speed, it reaches 76.9 FPS on an RTX 3080 GPU, 47.13 FPS on an Intel I9-12900 CPU, and 11.63 FPS on an embedded Jetson TX2 device.

A Rare Case of Neonatal Death Due to a Cranial Vault Fracture Following the Use of Obstetric Vacuum Extractor and Review of Literature.

In the course of childbirth, if complications arise during the expulsion of the fetus, instruments can be employed to facilitate delivery. The vacuum extractor, or ventouse, is considered a relatively safe tool associated with a low rate of complications and mortality. However, it is crucial that the instrument be applied in the correct position and that the pulling force is not excessive to minimize damage to the fetal cranial structures. Fractures of the cranial vault following the application of obstetric vacuum extraction are very rare events.This paper presents a case of perinatal death due to cranial vault fracture and subgaleal hematoma following vacuum extractor application. Only through postmortem examination was it possible to identify incorrect positioning of the ventouse, which was lateralized compared to the recommended position. The misplacement of the device led to an imbalance of forces, causing the cranial vault fracture that led to the infant's demise.A thorough postmortem examination is essential in cases of perinatal death resulting from operative delivery to ascertain the cause of death and reconstruct the dynamics of events during childbirth. In particular, the examination of injuries on the decedent neonate may reveal improper positioning of the instrument.

Study on deviation correction and target positioning of intelligent operation robot for high-voltage switchgear

Study on deviation correction and target positioning of intelligent operation robot for high-voltage switchgear

High-sensitivity and spatial resolution benchtop cone beam XFCT imaging system with pixelated photon counting detectors using enhanced multipixel events correction method

Objective.High atomic number element nanoparticles have shown potential in tumor diagnosis and therapy. X-ray fluorescence computed tomography (XFCT) technology enables quantitative imaging of high atomic number elements by specifically detecting characteristic x-ray signals. The potential for further biomedical applications of XFCT depends on balancing sensitivity, spatial resolution, and imaging speed in existing XFCT imaging systems.Approach.In this study, we utilized a high-energy resolution pixelated photon-counting detector for XFCT imaging. We tackled degradation caused by multi-pixel events in the photon-counting detector through energy and interaction position corrections. Sensitivity and spatial resolution imaging experiments were conducted using PMMA phantoms to validate the effectiveness of the multi-pixel events correction algorithm.Main results.After correction, the system's sensitivity and spatial resolution have both improved. Furthermore, XFCT/CBCT dual-modality imaging of gadolinium nanoparticles within mice subcutaneous tumor was successfully achieved.Significance.These results demonstrate the preclinical research application potential of the XFCT/CBCT dual-modality imaging system in high atomic number nanoparticle-based tumor diagnosis and therapy.

The Orientation in Space of the Maxillary Arch: New and Old Devices in the Prosthetic Digital Workflow.

In extensive prosthetic rehabilitations and in those involving the anterior area, a correct 3D spatial position is of fundamental importance for effective communication between the clinician and the dental technician. The aim of this article is to analyze the different methods used to position in space and/or in an articulator the maxillary arch in analog workflows highlighting shortcomings and difficulties in order to understand how to overcome them when employing digital workflows. Traditional mechanical devices, such as anatomical, kinematic, esthetic and postural facebows, have clear indications, but also limitations, especially in cases of skeletal asymmetries. Modern digital tools, including photography, CBCT, facial scanners and jaw recording devices, are here critically analyzed to illustrate the advantages of working in a virtual space. The adoption of digital tools in the prosthetic workflow represents a significant improvement compared to traditional techniques, as it reduces errors and artifacts of registration and transfer of the position of the maxillary arch in the articulator space. This contributes to more predictable esthetic and functional results, with a positive impact for clinicians and technicians, improving clinical-laboratory communication, operational efficiency and overall quality of work. The integration of digital tools into prosthetic workflows represents an important advancement in clinical practice since they reduce human error and facilitate communication between the clinician and the laboratory. When carrying out rehabilitations involving changes in esthetics or occlusal plane orientation, the proper and accurate positioning of the upper arch in space is particularly relevant.

A noncanonical GTPase signaling mechanism controls exit from mitosis in budding yeast

In the budding yeast Saccharomyces cerevisiae, exit from mitosis is coupled to spindle position to ensure successful genome partitioning between mother and daughter cells. This coupling occurs through a GTPase signaling cascade known as the mitotic exit network (MEN). The MEN senses spindle position via a Ras-like GTPase Tem1 which localizes to the spindle pole bodies (SPBs, yeast equivalent of centrosomes) during anaphase and signals to its effector protein kinase Cdc15. How Tem1 couples the status of spindle position to MEN activation is not fully understood. Here, we show that Cdc15 has a relatively weak preference for Tem1GTP and Tem1's nucleotide state does not change upon MEN activation. Instead, we find that Tem1's nucleotide cycle establishes a localization-based concentration difference in the cell where only Tem1GTP is recruited to the SPB, and spindle position regulates the MEN by controlling Tem1 localization to the SPB. SPB localization of Tem1 primarily functions to promote Tem1-Cdc15 interaction for MEN activation by increasing the effective concentration of Tem1. Consistent with this model, we demonstrate that artificially tethering Tem1 to the SPB or concentrating Tem1 in the cytoplasm with genetically encoded multimeric nanoparticles could bypass the requirement of Tem1GTP and correct spindle position for MEN activation. This localization/concentration-based GTPase signaling mechanism for Tem1 differs from the canonical Ras-like GTPase signaling paradigm and is likely relevant to other localization-based signaling scenarios.

Value of projectional imaging relative to cross-sectional imaging to assess catheter tip position in the superior vena cava: Evaluation of reader variability.

The assessment of correct positioning of central venous catheters (CVC) is of major concern to avoid complications.Vascular access associations have established the cavo-atrial junction (CAJ) as the most appropriate CVC tip location. Among the different chest X-ray (CXR) landmarks proposed for assessing tip position relative to the CAJ, only the pericardial reflection lies in the same plane as the vascular structures assessed. Although extensively used, CXR has been criticized for its difficulty in estimating catheter tip location.We aimed to evaluate the observer variability to determine tip positioning on CXR. CT imaging was used as a gold standard for tip identification. 107 CT scans of patients wearing port access catheter devices realized at the XXX University Hospital between January and December 2021 were retrospectively analyzed. Distance from tip to cavo-atrial junction (DCAJ) was measured on topogram projectional imaging (PJ) and axial cross-sectional imaging (CS) by 2 × 2 observers (within and between evaluations). Observational statistics were reported using a paired t-test, repeatability coefficients (RC), and the intraclass correlation coefficient (ICC), and they were displayed comprehensively using Bland-Altman plots. All ICC were >0.9, indicating excellent reliability. The mean difference between observers comparing CS and PJ was 0.13 ± 0.80 cm (P = 0.10) with outer 95% confidence limits of 1.92 cm and -2.17 cm and an RC of 1.79 cm. CXR tip-position reading remains an accurate method for determining CVC localization. However, the assessment variability on CXR is plus or minus 2 cm and should be considered. Chest X-ray (CXR) for the assessment of tip position is subject to intra-individual and inter-individual variation. On CT, the variability is solely linked to determining the cavoatrial junction (CAJ) and represented about 1 cm. On CXR, there is a twofold challenge: the correct determination of the CAJ and the accurate identification of the catheter tip, leading to a greater variability of 2 cm.In clinical practice, while considering the 3 cm anatomical zone around the CAJ acceptable, operators should be aware of the 2 cm variability resulting from CXR assessment. To account for this variability and avoid the risk of positioning the tip beyond 3 cm from the CAJ (theoretically up to plus or minus 5 cm away from the CAJ), operators should reduce the CXR-based acceptable zone to 1 cm around the CAJ. This change may impact up to thirty percent of procedures.

NIpple Position to Pinpoint Localization of Chest Drain Insertion in FEmale Trauma Patients: The NIPPLE-Trial—A Landmark Study

Background: The insertion of chest drains (CD) in trauma patients is a lifesaving, albeit high-risk intervention. Safe insertion of CD in settings where aids like ultrasound are not available relies on a landmark technique defining the so-called triangle of safety. The inferior margin of this triangle is identified by nipple height, which is thought to correspond to the fifth intercostal space (ICS). Training manikins are modeled after a lean male body and oftentimes insinuating jokes fuel uncertainty about the height of the nipple as a reliable landmark in female trauma patients. This study aims to prove that the nipple can be considered a safe landmark for CD insertion in women: even if larger breasts follow the force of gravity, it should not act towards the direction of the feet, but to the sides of the thorax in a flat-lying trauma patient. Methods: An online questionnaire was designed and distributed amongst female surgeons. Epidemiological data (age, nr of pregnancies, history of breastfeeding) was collected. Height, weight, and body mass index (BMI) were reported. Chest circumference and underbust girth were self-measured. The nipple position in relation to the ICS was measured by the women while lying in a supine position. Results: 237 female surgeons completed the questionnaire. Nine questionnaires were excluded due to incomplete data sets. 20 women were excluded due to previous breast surgery. Thus, 208 participants (or 416 nipples) were included in analysis. In supine position, both nipples were located in the 5th (±0.8) intercostal space. Age, BMI, height, weight, and status post-pregnancy had no significant impact on nipple position. Interestingly, a history of breastfeeding correlated with lower nipple position. Conclusions: The nipple is a safe landmark for identifying the correct insertion position of chest drains in supine-lying female trauma patients.

Research on underwater target signal orientation estimation based on smoothness priors approach

Purpose This paper aims to address the challenges in hydroacoustic signal detection, signal distortion and target localization caused by baseline drift. The authors propose a combined algorithm that integrates short-time Fourier transform (STFT) detection, smoothness priors approach (SPA), attitude calibration and direction of arrival (DOA) estimation for micro-electro-mechanical system vector hydrophones. Design/methodology/approach Initially, STFT method screens target signals with baseline drift in low signal-to-noise ratio environments, facilitating easier subsequent processing. Next, SPA is applied to the screened target signal, effectively removing the baseline drift, and combined with filtering to improve the signal-to-noise ratio. Then, vector channel amplitudes are corrected using attitude correction with 2D compass data. Finally, the absolute target azimuth is estimated using the minimum variance distortion-free response beamformer. Findings Simulation and experimental results demonstrate that the SPA outperforms high-pass filtering in removing baseline drift and is comparable to the effectiveness of variational mode decomposition, with significantly shorter processing times, making it more suitable for real-time applications. The detection performance of the STFT method is superior to instantaneous correlation detection and sample entropy methods. The final DOA estimation achieves an accuracy within 2°, enabling precise target azimuth estimation. Originality/value To the best of the authors’ knowledge, this study is the first to apply SPA to baseline drift removal in hydroacoustic signals, significantly enhancing the efficiency and accuracy of signal processing. It demonstrates the method’s outstanding performance in the field of underwater signal processing. In addition, it confirms the reliability and feasibility of STFT for signal detection in the presence of baseline drift.

A Vision-Guided Robotic System for Safe Dental Implant Surgery

Background: Recent advancements in dental implantology have significantly improved outcomes, with success rates of 90–95% over a 10-year period. Key improvements include enhanced preplanning processes, such as precise implant positioning, model selection, and optimal insertion depth. However, challenges remain, particularly in achieving correct spatial positioning and alignment of implants for optimal occlusion. These challenges are pronounced in patients with reduced bone substance or complex anthropometric features, where even minor misalignments can result in complications or defects. Methods: This paper introduces a vision-guided robotic system designed to improve spatial positioning accuracy during dental implant surgery. The system incorporates advanced force-feedback control to regulate the pressure applied to bone, minimizing the risk of bone damage. A preoperative CBCT scan, combined with real-time images from a robot-mounted camera, guides implant positioning. A personalized marker holder guide, developed from the initial CBCT scan, is used for patient–robot calibration. The robot-mounted camera provides continuous visual feedback of the oral cavity during surgery, enabling precise registration of the patient with the robotic system. Results: Initial experiments were conducted on a 3D-printed mandible using a personalized marker holder. Following successful patient–robot registration, the robotic system autonomously performed implant drilling. To evaluate the accuracy of the robotic-assisted procedure, further tests were conducted on 40 identical molds, followed by measurements of implant positioning. The results demonstrated improved positioning accuracy compared to the manual procedure. Conclusions: The vision-guided robotic system significantly enhances the spatial accuracy of dental implants compared to traditional manual methods. By integrating advanced force-feedback control and real-time visual guidance, the system addresses key challenges in implant positioning, particularly for patients with complex anatomical structures. These findings suggest that robotic-assisted implant surgery could offer a safer and more precise alternative to manual procedures, reducing the risk of implant misalignment and associated complications.

Machine learning-based screening for outpatients with dementia using drawing features from the clock drawing test.

Background and Objectives: In geriatrics and dementia care, early diagnosis is crucial. We developed a dementia screening model using drawing features from clock drawing tests (CDT) and investigated the features contributing to the discrimination of dementia and its screening performance. Methods: This study included 129 older adults attending a dementia outpatient clinic. We obtained information on the diagnosis of dementia and CDT data from medical records and quantified 12 types of drawing features according to the Freedman scoring system. Based on the dementia diagnosis information, participants were assigned to two groups: 58 in the dementia diagnosis group and 71 in the non-diagnosis group. Using Boruta, an iterative feature selection algorithm, and a support vector machine, a machine learning method, we analyzed the drawing features contributing to dementia discrimination and evaluated discrimination performance. Results: Five types of drawing features were selected as contributors to discrimination, including "numbers in the correct position," "minute target number indicated," and "hand in correct proportion." These features exhibited a discriminating sensitivity of 0.74 ± 0.16 and specificity of 0.74 ± 0.18 for detecting dementia. Conclusion: This study demonstrated a method for identifying individuals likely to be diagnosed with dementia among patients attending a dementia outpatient clinic using drawing features. The knowledge of drawing features contributing to dementia differentiation may assist healthcare practitioners in clinical reasoning and provide novel insights for clinical practice. In the future, we plan to develop a primary screening for dementia based on machine learning using CDT.

Adaptive probe position correction for automated complex weld inspection based on structural signal monitoring

ABSTRACT To ensure comprehensive coverage of welds, multi-axis motions are necessary for the probe during the automatic detection of complex welds. Guaranteeing the effectiveness of ultrasonic data during this process is crucial for ensuring detection accuracy and reliability. Taking tubular Y-joints as an example, this paper presents an adaptive probe posture correction method based on structural signal monitoring: (1) The structural and acoustic model of tubular Y-joints is established to select and predict the target structural signal. (2) Feature extraction and signal tracking algorithms are developed to achieve real-time monitoring of signals. (3) A posture correction method is proposed based on signal characteristics: time-domain characteristics correspond to position adjustments, while amplitudes correspond to orientation corrections. Building upon this, a feedback mechanism for probe posture is established. The effectiveness of the developed method is verified through underwater automatic detection experiments of tubular Y-joints. Results demonstrate that, with the assistance of the probe posture correction method, the coverage of the effective area increases to more than 95%, and embedded defects are fully detected through a single scan. In conclusion, the adaptive probe posture correction method based on structural signal monitoring presents a promising approach for the automatic ultrasonic examination of complex welds.

Orthodontic management of severe inversely impacted maxillary central incisors: a case series.

Abnormal positioning and dislocation of the central incisor can disturb tooth eruption. Generally, inversely impacted maxillary central incisors do not erupt naturally. Performing traction and applied extrusion of an inversely impacted maxillary central incisor with a high inclination angle of the crown is challenging. This study aimed to examine the possibility of orthodontic treatment for severely inversely impacted maxillary central incisors in a series of case studies. The inclination angle of the tooth crown, curvature of the tooth root, and length of the formed tooth root were measured using radiography. The teeth were then fenestrated and traction was applied using a lingual arch appliance with elastics. The average crown axis inclination was 113°, the degree of root curvature was 97.3°, and the root formation was 36.1%. Although the crown axis inclination and root curvature were severe, all the incisors were aligned in the correct position as vital teeth through surgical and orthodontic treatments. Traction should be performed in the early period of incisor development when root formation is not progressing, regardless of the tooth angle.

Exemption from serving a sentence with probation for pregnant women and women with children under the age of seven as a means of probation: specific problems of application practice

The article highlights certain problems of the judicial practice of applying the institution of exemption from serving a sentence with probation for pregnant women and women with children under the age of seven as a means of probation. It was established that, unlike the general rule on exemption from serving a sentence with probation (Article 75 of the CC of Ukraine), the provisions of Article 79 of the CC of Ukraine are mainly focused not on the possibility of correcting a person without isolating him from society, but first, on ensuring the interests of the child. Courts adhere to the same position when, releasing those specified in part 1 of Article 79 of the CC of Ukraine, persons from serving a sentence with probation, do not motivate the possibility of correction of the specified category without isolation from society. It was found that in many cases the courts also do not consider the interests of the child when deciding provided for in Article 79 of the CC of Ukraine. Based on the analysis of law enforcement practice, the author concluded that courts follow the trend of “automatic” appointment of the institute under investigation, given the fact that the guilty party is pregnant or has a dependent child under the age of seven. The correctness of the legal position of the Supreme Court is emphasized, according to which the “automatic” application by the courts of the norm of Article 79 of the CC of Ukraine on the basis of the offender belonging to the category of persons provided for by the specified norm, is inadmissible, since its application must be preceded by an assessment of the person of the offender, the possibility of her correction without isolation from society and ensuring the interests of the child. It has been established that by fixing the provisions regarding the probationary period, which is set for those released from serving a probationary sentence under Article 79 of the CC of Ukraine, the legislator did not specify its minimum duration, constructing the relevant norm in such a way that it could be individualized depending on the age of the convicted child. At the same time, the courts in their decisions do not always indicate the specific age of the child, which makes it impossible not only to correctly determine the time limits of the examination period, but also to apply the investigated institute in general. The author found that some courts incorrectly apply the norm of part 1 of Article 79 of the CC of Ukraine regarding the determination of the probationary period, as they establish a probationary period that exceeds the time during which a woman can be dismissed from work in connection with pregnancy, childbirth and before the child reaches the age of seven. It was concluded that the correct practice of applying the provisions of Article 79 of the CC of Ukraine, means of probation are not only the determination of the state of pregnancy or the presence of a minor child in the convicted person and the determination of the probation period until the latter reaches the age of seven, but also taking into account the circumstances of the committed criminal offense, the guilty party and the interests of the child.

Emerging Thrombotic Disorders Associated with Virus-Based Innovative Therapies: From VITT to AAV Gene Therapy-Related Thrombotic Microangiopathy.

Gene therapy is a promising therapeutic approach for treating life-threatening disorders. Despite the clinical improvements observed with gene therapy, immune responses either innate or adaptive against the vector used for gene delivery, can affect treatment efficacy and lead to adverse reactions. Thrombotic microangiopathy (TMA) is a thrombosis with thrombocytopenia syndrome (TTS) characterized by microangiopathic hemolytic anemia, thrombocytopenia, and small vessel occlusion known to be elicited by several drugs, that has been recently reported as an adverse event of adeno-associated virus (AAV)-based gene therapy. TMA encompasses a heterogenous group of disorders, its classification and underlining mechanisms are still uncertain, and still lacks validated biomarkers. The identification of predictors of TMA, such as vector dose and patient characteristics, is a pressing need to recognize patients at risk before and after AAV-based gene therapy administration. This review aims to explore the literature on TMA associated with AAV-based gene therapy in the larger context of TMA (i.e., hemolytic-uremic syndrome, thrombotic thrombocytopenic purpura, and other drug-related TMAs). Considering the wide attention recently gained by another TTS associated with a non-gene therapy viral platform (adenovirus, AV COVID-19 vaccine), namely vaccine-induced immune thrombocytopenia and thrombosis (VITT), AAV gene therapy-related TMA mechanisms will be discussed and differentiated from those of VITT to avoid recency bias and favor a correct positioning of these two recently emerged syndromes within the heterogenous group of drug-related TTS. Finally, the review will discuss strategies for enhancing the safety and optimize the management of AAV-based gene therapy that is emerging as an efficacious therapeutic option for disparate, severe, and often orphan conditions.

ACCESS: ACtive Catheterization for EndovaScular TreatmentS-A First-in-Human, Single-Center, Nonrandomized, Open Clinical Study of the G60 Active Device for Endovascular Neurointerventions.

The catheterization of supra-aortic vessels during neuroendovascular interventions may be challenging in the setting of complex aortic arch anatomy. Evaluation of a new mechatronic controllable directional device in conjunction with different sheath and guide catheters to ease the cannulation of the supra-aortic vessels was conducted in the setting of a first-in-human clinical study. The evaluation assessment included access to the aortic arch, the technical success of the device in terms of time to target vessel, target vessel catheterization, adverse events, and clinical outcome. Ten subjects were enrolled at 1 site for treatment. Successful access, target vessel catheterization, and correct positioning of the catheter into the target vessel with the G60 device were achieved for all 10 procedures (7 from femoral access, 3 from radial access). One procedural complication, unrelated to the G60 device, was recorded during the investigation. The G60 is a polyvalent active device that facilitates guide catheter navigation in neuroendovascular interventions.

Considerations for the Management of Early Complications in Bone Regeneration: A Case Report

This case report evaluates the possible reasons for early complications after guided bone regeneration, as well as options for their management. A thorough evaluation prior to surgery will help determine appropriate planning. Each clinician should be aware of the goals and possible limitations of the treatment to be performed to ensure optimal patient care. The management of the membrane, early exposure and contamination with a second bone augmentation surgery provided a sufficient amount of bone to place a dental implant in a correct three-dimensional position. CPD/Clinical Relevance: The correct approach for the management of the complications for regenerative bone therapy is highlighted.

Hole position correction method for robotic drilling based on single reference hole and local surface features

Hole position correction method for robotic drilling based on single reference hole and local surface features

Survey - Based Study For Common Retention Practices Among Orthodontists In North Macedonia

Background: Orthodontic therapy always ends with retention to prevent the return of the final occlusal outcome and to maintain the teeth in the correct position after the end of orthodontic therapy. This research aimed to survey retention practices, factors affecting retention protocol and differences regarding retention among orthodontists in North Macedonia. Material and methods: 150 questionnaire copies were distributed by mail or personally to orthodontics in North Macedonia. The survey included 24 single or multiple-answer questions, about retention system, frequently used fixed and removable retainers in certain malocclusions, the duration of the retention period, retainer supervision, instructions for patients, and the need for retention guidelines in order to determine habits and knowledge, and reasons for choosing a particular retention regime. Results : Out of 150 questionnaires, 93 were appropriately filled out and returned, so response rate was 62%. 90% give oral information about retention, only 25% informed their patients both oral and written. The most preferred retainer in maxilla (54%) was vacuum-formed appliance, than removable acrylic plate appliance (41%) and only 9% bonded retainer. In mandible, mostly used are VFR (45%), then acrylic plate appliance (29%), bonded retainers (20%). Dual retention was used more in upper jaw. The retention period was 4 to 5 years or lifelong; the choice of retention device in 77% depended on malocclusion. The reason for the choice of VFR are availability (50,5%), quality (36,56%), low-cost (33,3%). Protocol was influenced by clinical experience (75%), knowledge from residency (58%), courses (56%) and from colleagues (40%). 83% made changes in retention protocol in past years, in appliance time (20%) or in retention period (19%). 95,7% of the surveyed orthodontists believe that general guidelines for retention are needed. Conclusions: The most preferred retainers in North Macedonia were vacuum-formed appliance, than removable acrylic plate appliance and at least bonded retainer. Combination of fixed and removable appliance in mandible were used less than in upper jaw. Reason for choosing was malocclusion. Retention protocols are influenced mostly by the clinical experience. Common retention guidelines are required for most orthodontists.