Space Closure Research Articles

Compatible structure in ideal Cech closure spaces

In Al-Omari et al., Touch points in ideal Cech closure spaces, Mathematica, 64 (2022), (C, f, I) is a Cech closure space with an ideal I. For a subset H of C, there is introducet the set of Cech touch points of H with respect to f and I. Several characterizations of these sets will be discussed in this paper. Moreover, we investigate the notion of f-compatibility with an ideal I and obtain several characterizations of this type of compatibility.

The Role of Astrocytes in Migraine with Cortical Spreading Depression: Protagonists or Bystanders? A Narrative Review.

Cortical spreading depression (CSD) is a slow wave of cortical depolarization closely associated with migraines with an aura. Previously, it was thought that CSD depolarization was mainly driven by neurons, with characteristic changes in neuronal swelling and increased extracellular potassium (K+) and glutamate. However, the role of astrocytes, a member of the neurovascular unit, in migraine with CSD has recently received increasing attention. In the early stages of CSD, astrocytes provide neurons with energy support and clear K+ and glutamate from synaptic gaps. However, in the late stages of CSD, astrocytes release large amounts of lactic acid to exacerbate hypoxia when the energy demand exceeds the astrocytes' compensatory capacity. Astrocyte endfoot swelling is a characteristic of CSD, and neurons are not similarly altered. It is primarily due to K+ influx and abnormally active calcium (Ca2+) signaling. Aquaporin 4 (AQP-4) only mediates K+ influx and has little role as an aquaporin. Astrocytes endfoot swelling causes perivascular space closure, slowing the glymphatic system flow and exacerbating neuroinflammation, leading to persistent CSD. Astrocytes are double-edged swords in migraine with CSD and may be potential targets for CSD interventions.

Comparison of Amount of Space Closure During En- Masse Retraction of Maxillary Anterior Teeth Using Three Accelerated Orthodontic Treatment Techniques- Micro Osteo-Perforation, Photo Bio-Modulation and Peizocision : A Retrospective Study

AIM: The study aimed at comparing the amount of space closure using peizocision (PZ) and micro- osteoperforation (MOP) and low-level laser therapy (LLLT). Materials and methods: A retrospective study consisted of 3 groups, sample number of minimum 8 patients per group were estimated using statistical model called an Analysis of Variance, or ANOVA model. Three sets of data were collected. Which included patients who were treated with upper first premolar extraction for en- masse retraction of maxillary anterior teeth using NiTi closed coil spring with regional acceleratory procedures. The data collected was divided into 3 groups, GROUP 1- micro osteo perforations (n=8), GROUP 2- photo bio modulation (n=8), GROUP 3- peizocision (n=8).sing digital Vernier calipers, a direct approach was used to measure all the stone casts obtained before canine retraction (T0) and after the retraction was completed after three months (T1). The statistical analysis was performed on the data acquired about the amount of space closure of en-masse retraction of maxillary anteriors in the PZ, LLLT, and MOP groups. Results: Compared to MOP (2.60mm) and LLLT (2.44mm), the PZ group had a greater mean amount of space closure (5.06mm). In conclusion, the quantity of space closure in piezocision was significantly higher than that in MOP and LLLT, although there was no statistically significant difference between the two. It is imperative that treatment duration be shortened. Finding the most effective and practical method to speed up tooth movement using the biomechanical mechanisms that are currently in place is therefore necessary

NF-κB Decoy Oligodeoxynucleotide-Loaded Poly Lactic-co-glycolic Acid Nanospheres Facilitate Socket Healing in Orthodontic Tooth Movement.

Orthodontic space closure following tooth extraction is often hindered by alveolar bone deficiency. This study investigates the therapeutic use of nuclear factor-kappa B (NF-κB) decoy oligodeoxynucleotides loaded with polylactic-co-glycolic acid nanospheres (PLGA-NfDs) to mitigate alveolar bone loss during orthodontic tooth movement (OTM) following the bilateral extraction of maxillary first molars in a controlled experiment involving forty rats of OTM model with ethics approved. The decreased tendency of the OTM distance and inclination angle with increased bone volume and improved trabecular bone structure indicated minimized alveolar bone destruction. Reverse transcription-quantitative polymerase chain reaction and histomorphometric analysis demonstrated the suppression of inflammation and bone resorption by downregulating the expression of tartrate-resistant acid phosphatase, tumor necrosis factor-α, interleukin-1β, cathepsin K, NF-κB p65, and receptor activator of NF-κB ligand while provoking periodontal regeneration by upregulating the expression of alkaline phosphatase, transforming growth factor-β1, osteopontin, and fibroblast growth factor-2. Importantly, relative gene expression over the maxillary second molar compression side in proximity to the alveolus highlighted the pharmacological effect of intra-socket PLGA-NfD administration, as evidenced by elevated osteocalcin expression, indicative of enhanced osteocytogenesis. These findings emphasize that locally administered PLGA-NfD serves as an effective inflammatory suppressor and yields periodontal regenerative responses following tooth extraction.

Esthetic outcomes in orthodontics through digital customization with a lingual appliance system.

Contemporary fixed orthodontic appliances are shifting from non-customized pre-adjusted appliances to custom-designed and printed appliances with novel digital setup systems. We are one step closer to precision dentistry and orthodontics using personalized mechanics and custom appliances. However, despite the evidential enhancement and other improvements to fixed appliances, tooth movement is still limited to five degrees of freedom. Opening or closing spaces still requires manually placing elastomeric chains or coil springs. In this article, we aimed to demonstrate how advancements in CAD/CAM technology, reverse engineering, and digital customization are helping orthodontics constantly evolve, enabling treatment with enhanced esthetics and minimal compliance. The clinical system (InBrace®, Irvine, CA) described in this article uses a patient-specific, digitally designed multiloop NITI wire that delivers friction-free, light, and continuous forces and activates automatically whenever the malocclusion deviates from the digital setup. Through digital customization, InBrace allows for automated tooth movement in all six degrees of freedom, including space opening or closure, via programmed non-sliding mechanics. Precision orthodontics and personalized treatment have been significant developments in orthodontics recently. This article focuses on how a technologically advanced lingual appliance system could achieve targeted cosmetic results methodically via automation and personalization.

Negotiation of Calcified Canals.

The gradual formation of hard tissue along the root canal walls is a natural process associated with aging, typically progressing slowly over time. In reaction to tooth wear, operative procedures, vital pulp treatments, or regenerative endodontic procedures, hard tissue may also accumulate within the pulp canal space at a slow rate. In certain cases, such as dental trauma, autotransplantation, or orthodontic treatment, this deposition of hard tissue can accelerate unexpectedly, resulting in rapid narrowing or complete closure of the root canal space. This situation is called calcific metamorphosis (CM), root canal calcification, or pulp canal obliteration (PCO). Performing conventional endodontic therapy on severely calcified canals presents significant challenges and increases the risk of procedural accidents. Calcified canals introduce such complexity that dedicated negotiation concepts and specially designed instruments have been developed to deal with the challenge. This article seeks to review the existing methods for effectively navigating calcified canals and to introduce the buckling resistance activation test (BRAT) technique.

In vitro comparison of force losses over time of orthodontic nickel-titanium closed springs, elastomeric chains, and active tie-backs

OBJECTIVE: This study aims to compare the force losses of nickel-titanium closed springs, elastomeric chains, and active tie-backs over time in an in vitro environment containing artificial saliva. MATERIALS AND METHODS: In the study, elastomeric chains, nickel-titanium closed springs, and active tie-backs from 3 different brands were divided into 9 groups. The percentages of force loss in the samples over time were compared in the in vitro environment containing artificial saliva. Force values were measured and recorded at initial activation, 1st hour, 24th hour, 7th day, 21st day, and 28th day. Statistical analysis of the data were performed with Kolmogorov-Smirnov, Kruskal Wallis, Mann-Whitney U, and Wilcoxon tests. The significance value was considered as p<0.05. RESULTS: The highest and lowest forces at the initial activation hour were measured in elastomeric chains and nickel-titanium closed springs, respectively (p<0.05). There was no significant difference between elastomeric chains, nickel-titanium closed springs, and active tie-backs in the measurements performed at the 24th hour (p>0.05). Although significant force losses were measured in all groups on the 28th day, active tie-backs lost significantly less force than elastomeric chains, regardless of brand. On the 28th day, the lowest and highest forces were measured in elastomeric chains and nickel-titanium closed springs, respectively (p<0.05). CONCLUSIONS: Among the orthodontic space closure mechanics, nickel-titanium closed springs were the most stable; however, active tie-backs produced a more stable force than elastomeric chains, so the type of force element used was the main indicator of the force loss level.

Creative biomechanics for complex cases

Orthodontic biomechanics play a crucial role in achieving successful outcomes, especially in complex cases requiring precise control of tooth movements. This article explores force system analysis based on the moments and forces around the center of resistance and emphasizes traditional and contemporary approaches in orthodontic biomechanics, focusing on key tooth movements such as bite opening, space closure, retraction, protraction, intrusion, and extrusion.In complex borderline cases involving nonsurgical treatment, this article addresses the significance of total arch distalization for maximum retraction, total arch intrusion for vertical control, total arch extrusion for enhancing maxillary incisor display, lever arm mechanics for achieving incisor torque control, and total arch protraction for improving the maxillary incisor show.Patient-specific factors, efficient biomechanics, and a comprehensive understanding of the limitations of treatment modalities are emphasized in pursuit of optimal orthodontic outcomes.

Situated belonging as everyday practice in a semi-public Youth Living Room for undocumented young city dwellers

ABSTRACT This article discusses how everyday practices in a day shelter for undocumented youth interfere with binary narratives of belonging versus non-belonging. Tapping into scholarship on a home in the face of displacement and marginalization, this article draws on ethnographic fieldwork in the so-called ‘Youth Living Room’ in Amsterdam. Caught up in migration management, the undocumented young people present here experience structural exclusion and are cut off from welfare arrangements in the Netherlands. But while their precarious situation was reinforced even further under COVID-19 measures, in the Youth Living Room, undocumented youths engaged in mundane practices that incited feelings of belonging. In the absence of a house and faced with the closure of public space, the Youth Living Room as a semi-public place accommodated ‘homemaking practices’. These homemaking practices, I argue, attest to the complexities of belonging and rather suggest alternative orderings to a dichotomized politics of belonging; this paper shows that homemaking practices in this semi-public shelter alert us to the inherent situatedness of being at home in society. Situated belonging then challenges our political imagination to ask what collective practices of homemaking we want to engage in.

Nonsurgical synergistic full-arch vertical intrusion treatment of bimaxillary protruded hyperdivergent skeletal Class II malocclusion using aligners.

A bone-borne full-arch vertical control strategy using miniscrews was deployed with aligners to treat a case of skeletal hyperdivergent Class II malocclusion with bimaxillary protrusion. Miniscrews were inserted in the posterior buccal and palatal regions and the anterior buccal region of the maxilla to distribute vertical intrusive force through the upper arch by anchoring vertical elastics from the miniscrews to the aligners. Synergetic lower anterior intrusion was completed using bilateral posterior miniscrews to counteract the extrusive force generated. Substantial full upper arch and lower anterior vertical intrusion was achieved. In conjunction with en masse anterior-posterior retraction, synergetic posterior and anterior vertical intrusion facilitated counterclockwise rotation of the mandible, creating significant esthetic improvement. Anterior vertical elastics also provided flaring of the anterior teeth, reducing the side effect of lingual tipping from en masse retraction, while successfully controlling overbite and incisor torque during space closure. The bone-borne full-arch vertical intrusion strategy can work well with aligners to address hyperdivergent skeletal Class II malocclusion with bimaxillary protrusion.

Evaluation of Trabecular Changes Using Fractal Analysis After Orthodontic Treatment for Congenital Maxillary Lateral Incisor Missing with Space Opening and Closure Methods

Aim: The aim of the study was to compare the trabecular changes in alveolar bone structure after the treatment of congenital maxillary lateral incisor missing (CMLIM) with space-opening and -closure methods by fractal dimension (FD) analysis. Material and Methods: The study included 48 patients and three groups were formed: control (Group 1), space-opening (Group 2), and space-closure groups (Group 3). FD analysis was performed on panoramic images taken before (T0) and after (T1) treatment in the area of interest of trabecular alveolar bone determined in the distal apical region of the maxillary central incisor. For inter-group comparisons, the Kruskal-Wallis test was employed, while the Wilcoxon test was utilized for intra-group comparisons. The statistical significance was determined as p0.05). In Group 2, a significant decrease in FD values was observed during the T1 period compared to T0, whereas Group 3 showed a significant increase (p

Evaluation of the aesthetics and clinical findings in patients with missing maxillary lateral incisors treated with a 10-year interval.

The most common treatment approaches for patients missing maxillary lateral incisors are implant replacement (IT) and orthodontic space closure (SC). Treatment techniques change and improve over time, and it is of interest to know if improvements differ between the methods. To compare the aesthetic outcome and other clinical findings in patients with one or two missing maxillary lateral incisors who were treated with a 10-year difference in time, with either orthodontic space closure or implant replacement. A total of 88 patients were included in the study. Forty-four patients treated between 2011 and 2018 were included as the latter cohort (LC). The LC was compared to the early cohort (EC; n = 44), treated between 2001 and 2008. A total of 132 teeth was analysed: 62 teeth in the EC (28 teeth in IT cases and 34 teeth in SC cases) and 70 teeth in the LC (34 teeth in IT cases and 36 teeth in SC cases). Long-term clinical and aesthetic outcomes were evaluated. An improvement over time was found in crown length, BoP, papilla, the inclination of incisors, and overall appearance in IT cases and in crown colour and overbite in SC cases. A deterioration over time was found in crown length and BoP among the SC cases. Among the IT cases, an improvement in outcomes was noted over time. When comparing SC cases the colour of the crown and overbite had improved, while crown length and BoP had deteriorated over time.

Investigation of the Mesiodistal Angulations of Maxillary Canines and Central Incisors for Missing Bilateral Maxillary Lateral Incisor.

(1) Background: A missing bilateral maxillary lateral incisor (MBMLI) causes aesthetic and functional problems and a multidisciplinary approach is required for treatment. This study aimed to compare the changes in the mesiodistal axial angulations of the maxillary canines and central incisors with orthodontic treatment of MBMLI. (2) Methods: A total of 56 patients with MBMLI were included in the study, and three groups were formed: the control group (Group 1, n = 20) with untreated ideal occlusion and the space opening (Group 2, n = 20) and space closure (Group 3, n = 16) groups as treated study groups. The mesiodistal angulations between the long axes of the maxillary right canine (tooth no 13), right central incisor (tooth no 11), left central incisor (tooth no 21) and maxillary left canine (tooth no 23), and the bicondylar plane, were measured on the panoramic radiographs taken pre (T0) and post treatment (T1). p < 0.05 was accepted for statistical significance. (3) Results: At T0, while there was no significant difference between the mesiodistal angulations of the right-left maxillary canines and central incisors in all groups (p > 0.05), the mesiodistal angulations of the canines in the Group 1 were significantly higher than the study groups (p < 0.05). With treatment, while the mesiodistal angulation of the canines increased in Group 2, it decreased in Group 3 (p < 0.05). On the other hand, the mesiodistal angulation of the central incisors decreased in Group 2 and did not change in Group 3 (p > 0.05). At T1, the mesiodistal angulation of the canines was found to be lower in Group 3 than in Groups 1 and 2, while the angulation of the central incisors was found to be lower in Group 2 compared to Group 1 (p < 0.05). (4) Conclusions: In the orthodontic treatment of MBMLIs, changes in the mesiodistal angulations of the maxillary canine and central incisors should be taken into account for satisfactory outcomes. It was concluded that there should be a tendency to select the space closure method in which normal mesiodistal angulations are obtained in maxillary central incisors for aesthetics and planned incisor position, and also at a low cost.

Space Closure with Different Appointment Intervals: A Split-mouth Randomized Controlled Trial.

Canine retraction has been successful with various force systems and retraction techniques. The appointment interval for force reactivation in canine retraction along the archwire is 4-8 weeks. The aim was to evaluate the effect of different reactivation intervals on the rate of space closure. This split-mouth randomized clinical trial recruited 38 patients indicated for the first premolar extraction. Monthly digital models were acquired for 6 months. The first premolars were extracted, and temporary anchorage devices were placed for maximum anchorage control. The canines were retracted using elastomeric chains which were replaced every 2, 4, 6, or 8 weeks. The monthly rate of canine retraction was measured. The time to space closure was calculated. The secondary outcome was the mesial drift of the first molars. The Kaplan-Meier survival analysis and the Friedman test evaluated and compared the groups. There was no significant difference between the monthly canine retraction rate or the first molar mesial drift between the groups. The mean time to space closure was 5.74 months in the 2-week reactivation group, which was statistically less than the other groups. The 2-week reactivation interval may reduce time to space closure. Direct anchorage control with miniscrews limited anchorage loss significantly.

Evaluation of Efficacy of MV Loop for En masse Anterior Retraction as Compared to Opus and Snail Loop Using Finite Element Method and Clinical Intervention: A Research Protocol

Abstract Background: In orthodontics, space closure after extraction is crucial. Frictionless mechanics in preadjusted “edgewise appliance” treatment in orthodontics are better alternatives to friction mechanics. The major benefit is dissipation of force, a high M: F ratio and a low load-deflection rate which is not there in friction mechanics. The retraction loops are Snail loop, Opus loop, K Sir loop, L loop etc. which are used as force system in frictionless mechanics. Objectives: To evaluate and compare the efficacy of Multiple Variability (MV) loop for qualitative and quantitative en masse anterior retraction as compared to Opus and Snail loop. Materials and Methods: The study will be carried out in the Department of Orthodontics and Dentofacial Orthopaedics, Sharad Pawar Dental College, Sawangi (M), Wardha with the technical assistance from NIT Engineering College, Pune. MV loop, Opus loop and Snail loop will be fabricated in “0.019 × 0.025, 0.017 × 0.025 inch Titanium Molybdenum alloy (TMA) and 0.017 × 0.025 inch Stainless Steel (SS) wire” with 1 and 2 mm preactivation bends will be analysed on Finite element method (FEM) Software. Then clinical trials will be carried out based on qualitative and quantitative assessment of records for evaluation of MV loop, opus loop and Snail loop. Expected Results: The FEM analysis and clinical trials will predict the perfect design of loop with adequate preactivation bends. Mainly on data access layer (DHAL) analysis MV loop showed 10:1 Moment to Force (M:F). Similar results are expected on FEM analysis and clinical trials. MV loop will show superior results as compared to Opus and Snail loop. Conclusion: Loop mechanics provide efficient intrusion and retraction in extraction cases. A loop to be effective and efficient needs to clinically as well as mechanically evaluated. MV loop was fabricated to fulfill all the requirements of loop. Clinical evaluation of loop will provide complete effectiveness of loop.

Impact of irregular appointment interval on Orthodontic treatment amid COVID-19 Pandemic- A Cross sectional Observational Study.

Introduction: The COVID-19 pandemic situation has affected all professions including orthodontics. The present study proposed determination of impact of irregular appointments on Orthodontic treatment amid COVID-19 pandemic. Materials and Methods: The cross-sectional observational study design enrolled 134 patients over period of 2 weeks were recorded such as treatment start date, total number of appointments scheduled and frequency of missed appointments after 24 March 2020, Stage of Orthodontic treatment on or before 24 March 2020 i.e., Alignment &amp; levelling b) Space closure c) Finishing and Detailing d) Retention. Results: The distribution of malocclusion based on Angle Molar criteria showed prevalence of 53.73 % Class I, 37.32 % Class II and 8.95% Class III. The malocclusions were treated predominantly by extraction in 57.46 % and non-extraction in 42.44 % patients. The total treatment duration revealed that more than 51 % patients’ treatment lasted beyond 24 months but finished before 36 months. Similarly, 35.82 % patients’ treatment duration was less than 12 months. It was found that more than 47 % were in Stage I, 28.36 % were in stage II, 18.66 % in stage III and lastly 5.97 % were in stage IV. Conclusion: Orthodontic emergencies and un-schedule appointments had prevalence of Class I, followed by Class II and Class III with extraction treatment therapy. Majority patients treated with fixed mechanotherapy followed by Clear aligners and Retainers. More than half of the patients had increased treatment duration due to irregular follow up. Keywords: COVID-19, Corona Virus Disease, Orthodontic Appointment, Orthodontic Appliances.

Some new open sets in bipolar N-neutrosophic supra topological spaces

The primary focus of this work is to develop the concept of bipolar N-neutrosophic supra topological spaces. Also, extended some concepts such as closure and interior operators of N-neutrosophic supra topological spaces to Bipolar N-neutrosophic supra topological spaces. The properties and relationship between weak forms of bipolar N-neutrosophic supra topological open sets are also established. Further, suggested several separations amongst bipolar N-neutrosophic supra sets. Some distance between bipolar N-neutrosophic sets is introduced and an efficient approachfor group multi-criteria decision making based on bipolar N-neutrosophic sets is proposed.

Predictability of Orthodontic Space Closure Using Invisalign Clear Aligners: A Retrospective Study.

Introduction Clear aligners have demonstrated success in achieving complex tooth movements. However, orthodontists have faced challenges related to the predictability of clear aligners. This retrospective study aimed to assess the predictability of ClinCheck® accuracy in space closure before and after Invisalign® treatment and to identify factors associated with the need for refinement. Methods Patient records from one private clinic in Makkah, Saudi Arabia, were analyzed, and a sample of 55 adult patients who had spacing and underwent Invisalign treatment were included. Data on demographic and orthodontic variables were collected, and a chi-square test was conducted to examine the association between the requirement for refinement and demographic as well as clinical/orthodontic factors. Furthermore, the initial and final space measurements were compared using paired t-tests across various demographic and clinical/orthodontic variables. Results After completing the treatment, 70.9% (N=39) of the cases did not require any orthodontic refinement. The mean final space measurement was higher for males compared to females (0.7 mm and 0.4 mm, respectively), individuals who received treatment in the upper compared to lower arch (0.5 and 0.4 mm, respectively), those with moderate compared to mild spacing (0.5 and 0.1 mm, respectively), and those with class III compared to class I Angle classification (0.9 and 0.3 mm, respectively). Additionally, patients with severe spacing had a significantly higher probability of requiring refinement compared to patients with mild spacing (adjusted odds ratio = 20.9; p < 0.05). Conclusion The study emphasizes the significance of careful patient selection and treatment planning, suggesting that orthodontists should consider overcorrecting in space closure when using clear aligners, especially in cases with more significant spacing.

Neighbourhood Walkability and Physical Activity during the COVID-19 Pandemic.

This study investigated whether living in a walkable neighbourhood could mitigate the adverse effects of the lockdown and closure of public open spaces during the COVID-19 pandemic on physical activity among adults in Bangkok, Thailand. We conducted a telephone survey with 579 respondents and collected information on their physical activity, access to green open spaces, neighbourhood walkability, and socioeconomic characteristics during the pandemic. Our study indicates that living in a walkable neighbourhood is associated with a higher likelihood of engaging in sufficient physical activity during the pandemic. Furthermore, we confirm the influence of socioeconomic factors and health behaviours on physical activity levels, aligning with previous research. Notably, our study highlights the significant association between access to green open spaces during lockdown and increased physical activity. These results underscore the importance of promoting walkable neighbourhoods and ensuring accessible green spaces to enhance physical activity and improve health outcomes during and beyond the pandemic.

Bilateral transposed and impacted upper canines: case report

The aim of the study was to report, through a clinical case, the treatment of bilaterally impacted upper canines. A 9-year-old patient presented with prolonged retention of deciduous canines. Radiographic analysis revealed bilateral and horizontally impacted canines. After extraction of the deciduous teeth and access to the impacted canines, a transpalatal bar associated with a cantilever was used for traction without compromising neighboring teeth. Due to the location and complexity of the case, the upper canines underwent transposition with the first premolars. The lower arch was aligned and exhibited diastemas, which were treated with elastomeric chains and bull loops for space closure. The treatment goals were achieved with excellence in aesthetics, function, and healthy periodontal conditions