Correlation of sex hormone levels with orthodontic tooth movement in the maxilla: a prospective cohort study.

BACKGROUND: Sex hormones secreted during the menstrual cycle and the application of orthodontic forces to teeth can affect the metabolism of periodontal ligaments. This study aimed to determine whether there are any differences in orthodontic tooth displacement during the menstrual cycle and when using hormonal contraceptives and whether the amount of female sex hormones influences the efficiency of tooth displacement. METHODS: A total of 120 women aged between 20 and 30 years with Angle Class II requiring transpalatal arch (TPA) to derotate teeth 16 and 26 were included in this study. The participants were divided into two groups: group A, which included women with regular menstruation, and control group B, which included women taking monophasic combined oral contraceptives. Group A was divided into subgroups according to the moment of TPA activation: menstruation (A1), ovulation phase (A2), and luteal phase (A3) (examination I). On intraoral scans, measurement points were marked on the proximal mesial cusps of teeth 16 and 26, and the intermolar distance (M1) was determined. The change in the position of the measurement points 6 weeks after activation (examination II) made it possible to determine the derotating extent of teeth 16 (O16) and 26 (O26) and the widening of the intermolar distance (M2-M1). In examinations I and II, tooth mobility in the alveoli was assessed using Periotest based on the periotest values (PTV) PTV1 and PTV2, respectively. RESULTS: A significant difference in all parameters was observed among groups A1, A2, and A3 (P < 0.001). Group A3 showed the highest values of parameters O16, O26, and M2-M1, and group A2 showed the lowest values, which did not differ from the control group (P = 0.64). PTV2 and PTV1 were the highest in group A3 and the lowest in groups A1 and B. Intergroup differences were statistically significant (P < 0.001). CONCLUSIONS: With the quantification of changes in tooth mobility in the alveoli during the menstrual cycle in women undergoing orthodontic treatment, it was possible to determine that female sex hormones affect the effectiveness of orthodontic treatment, and the optimal moment for TPA activation is the luteal phase of the menstrual cycle.

The Impact of Progesterone and Estrogen on the Tooth Mobility.

Background and Objectives: Progesterone and estrogen modify the bone metabolism directly related to the periodontium, this study aimed at answering the question whether fluctuations in the levels of these hormones or the use of their synthetic equivalents in modern contraceptives have a significant impact on the natural tooth mobility (TM) in its alveolus. Materials and Methods: Sixty healthy women who had never been pregnant and when interviewed reported either (1) having regular menstruations every 28-30 days or (2) taking oral two-phase two-ingredient hormonal contraceptives formed, respectively, groups M and S in the study. TM evaluated as the Periotest value (PTV) was checked in the menstruation, ovulation, and luteal phases of the menstrual cycle (group M) and on the days corresponding to the moment of the menstrual cycle in group S. Results: Although the PTV-s were within the limits of norm, the canines and the molars were always more stable than the other teeth. In group M, the TM was statistically comparable (p > 0.05) in the menstrual and ovulation phases, thus significantly increased (p < 0.001) in the luteal phase. The TM remained constant (p = 0.758) in all studies in group S. The results demonstrated that the canines and the molars in the luteal phase were significantly more mobile in group M than in group S (p < 0.001), although increased mobility of the teeth in group M affected the canines and the first molars to a significantly lesser degree than the other teeth. Conclusions: However, since women between 20 and 30 years old constitute the majority of ortho-dontic patients, possible determination of the optimum moment of force application in relation to the sex hormones cycle, namely, to its luteal phase, is clinically very promising.

The Use of Microsensors to Assess the Daily Wear Time of Removable Orthodontic Appliances: A Prospective Cohort Study.

Orthodontic treatment with removable appliances is still common in children and adolescents. However, their effectiveness depends primarily on the patients' compliance. Currently, it is possible to check the daily wear time (DWT) of the removable appliances using special microsensors. The aim of this prospective cohort study was to assess the degree of patients' compliance depending on the type of removable appliance used. In total, 167 patients (87 F, 80 M) were enrolled in the study and were treated with block appliances (Klammt, Twin-Block), Schwarz plates, and block appliances in combination with headgear. All patients were followed up for 6 months with the mean daily wear time checked at followup visits using TheraMon® microsensors fitted in the appliances. It has been shown that the type of appliance influences the patients' compliance. The DWT for the Twin Block was significantly longer compared to the DWT for the other appliances. Girls have been shown to wear removable appliances better than boys. It has been proven that the majority of patients do not follow the orthodontist's recommendations, wearing removable appliances for just over half of the recommended time. Microsensors can be used for objective verification of patients' compliance, which allows for a reliable assessment of the effectiveness of treatment with removable appliances.

Assessment of the reliability of measurements taken on digital orthodontic models obtained from scans of plaster models in laboratory scanners. A systematic review and meta-analysis.

BACKGROUND: In recent years, digital models have become increasingly popular among orthodontists, both for clinical and scientific purposes. It is, therefore, crucial to appropriately investigate their reliability. To this date, however, there has been no scientific, statistical investigation of their reliability as compared to the traditional gold standard-plaster models in the form of a meta-analysis. OBJECTIVES: To evaluate the reliability and reproducibility of measurements taken on digital orthodontic models obtained from scanning plaster models in laboratory scanners compared to measurements taken directly on plaster models. SEARCH METHODS: Multiple electronic databases (PubMed, Scopus, Web of Science, Google Scholar and Cochrane Central Register of Controlled Trials) were searched for articles with no year or language limitations. SELECTION CRITERIA: The included original papers should have dealt with the accuracy and repeatability of the measurements conducted on plaster and digital models derived from laboratory scanners. In order to provide an adequate statistical analysis, the studies should have provided sufficient data, that is the difference of means (MDs) with standard deviations (SDs) for analysed measurements. DATA COLLECTION AND ANALYSIS: In total, 25 types of non-standardised measurements were found in the evaluated studies. The quantitative analysis included papers that compared at least one of the parameters: upper/lower intermolar width, upper/lower intercanine width, overjet and overbite and provided standard deviation of the mean differences between measurements obtained on plaster and digital models from a laboratory scanner. RESULTS: GRADE and QUADAS tools were used to assess the quality of evidence, and they revealed substantial heterogeneity. Random-effects meta-analysis revealed no statistically significant differences for analysed measurements. Four of the analysed papers reported differences that may be considered clinically significant. CONCLUSIONS: No statistical significance between the direct measurements on plaster models and the digital ones taken from laboratory scanners could be identified by means of random-effects meta-analysis. REGISTRATION: The systematic review was registered in the PROSPERO database (ID CRD42020215411).

Evidence-based selection of orthodontic miniscrews, increasing their success rate in the mandibular buccal shelf. A randomized, prospective clinical trial.

BACKGROUND: Skeletal anchorage has made it possible to perform complex orthodontic tooth movements that are difficult or even impossible to achieve with conventional orthodontic treatment. Mandibular buccal shelf miniscrews, used for distalization, play a particularly important role in treatment of Class III malocclusion. Unfortunately, stability of the miniscrews placed in the mandible is still considered at higher risk of failure compared to other intraoral locations. The aim of our study was to determine the influence of the miniscrew size on their long-term stability, occurrence of oral mucosa inflammation and pain lasting over 48 h after implantation. METHODS: 184 Absoanchor® miniscrews (Dentos, South Korea) in two sizes: SH2018-10 (length 10 mm, ø 1.8-2.0 mm) and SH1514-08 (length 8 mm, ø 1.4-1.5 mm) were inserted in the mandibular buccal shelf in 92 Caucasians aged 20-50 years, diagnosed with Class III malocclusion that required en-masse distalization of the mandibular dentition. Data was statistically analyzed with the level of significance set at p = .05. RESULTS: 91.3% of the SH2018-10 and 75% of the SH1514-08 miniscrews were stable, and this difference was statistically significant (p < .05). Inflammation of the oral mucosa was noticed around both types of miniscrews and affected 50% of the SH2018-10 and 26.09% of the SH1514-08 group (p < .05). Pain lasting longer than 48 h after implantation was related to 60.87% and 20.65% of the SH2018-10 and the SH1514-08 miniscrews (p < .05), respectively. Inflammation associated with larger SH2018-10 miniscrews did not affect their stability (p > .05), contrary to the SH1514-08 ones (p < .05). When inflammation was present, the overall success rate declined to 64.29%, from 94.74% noted for TADs without inflammation. According to the log-rank test, smaller TADs failed significantly sooner than the larger ones (p = .002). CONCLUSION: Larger SH2018-10 miniscrews are the anchorage of choice for the mandibular buccal shelf, despite triggering inflammation and long-lasting pain significantly more often than the smaller ones. Therefore, this issue should be discussed with every patient prior to miniscrew use. Trial registration ID: ClinicalTrials.gov Identifier: NCT05280678 Date of Registration: 15/03/2022. Retrospectively registered.

Clinical and economic impact of a one-year treatment with omalizumab in patients with severe allergic asthma within a drug programme in Poland.

BACKGROUND: Allergic asthma is the most prevalent phenotype of severe asthma where treatment with omalizumab (OMB) has been proven to be particularly beneficial. In Poland, OMB therapy is available and reimbursed within a drug programme where strict inclusion and exclusion criteria are defined. The objective of this study was to present a descriptive analysis regarding the trends in outcomes (clinical, quality of life, costs) among a cohort of patients who satisfy inclusion criteria for the initiation of OMB treatment and who successfully responded to OMB according to a set of objective criteria. METHODS: A retrospective analysis of data collected during the 52 weeks of OMB treatment was carried out. The study population was adolescents and adults with severe allergic asthma that was uncontrolled despite a combination of high-dose inhaled corticosteroids (ICS)/long-acting beta-agonists (LABA) and/or other controllers (leukotriene receptor antagonists (LTRA), sustained-release theophylline, and short- or long-acting muscarinic antagonists (SAMA/LAMA), who were the first to finish the one-year treatment. A clinical and cost analysis for patients included in the programme was conducted comparing the one-year pre-treatment period to the one-year treatment period outcomes. RESULTS: Data of 85 patients who completed the first year of therapy were reviewed and analysed. Add-on OMB treatment resulted in a median decrease in exacerbation rate of 66% relative to the baseline and a reduction in oral steroid (OCS) dose by an average of 7.7 mg. At the end of the 52 weeks of therapy the changes in the quality of life questionnaire (AQLQ) and the asthma control questionnaire (ACQ) scores were 1.86 and 1.45 points, respectively. The mean cost of asthma treatment increased by an average of 15,979 EUR per patient per year (baseline period - 802 EUR/patient/year; OMB treatment - 16,781 EUR/patient/year). The cost to avoid one exacerbation was 17721 EUR. CONCLUSION: The clinical outcomes for the observed subset of patients were highly improved. At the same time, costs of the treatment increased, mainly due to the high OMB costs. Other costs associated with a lower number of hospitalizations and ED and office visits and a reduction in OCS dose decreased. These descriptive data can be used for further investigation in defining patients who benefit the most from OMB treatment in clinical practice.

Evaluating the accuracy of one-piece and three-piece 3D-printed indirect bonding transfer trays: An in vitro study.

BACKGROUND: Recent developments in computer-aided design/computer-aided manufacturing (CAD/CAM) and 3D printing have enabled the fabrication of digital indirect bonding (IDB) transfer trays. These modern products require thorough investigation. OBJECTIVES: The aim of the study was to determine the accuracy of one-piece and three-piece IDB transfer trays in vitro. MATERIAL AND METHODS: An initial dental scan (IDS) of a randomly selected patient with digitally positioned brackets served as the master scan (MS) for designing 16 IDB transfer trays of each type. They were 3D printed and used for bonding 448 brackets to the models. Subsequently, the models were scanned with a TRIOS® 3 Intraoral Scanner (3Shape A/S, Copenhagen, Denmark), producing actual scans (ASs). The accuracy of bracket positioning was measured digitally on both MSs and ASs. The measurements were compared to the Objective Grading System for dental casts provided by the American Board of Orthodontics (ABO). RESULTS: The 2 types of IDB transfer trays showed comparable accuracy. All linear errors were within the clinically acceptable range, whereas the angular measurements demonstrated significant variability, resulting in clinically unacceptable transfer errors that ranged from 3.3% to 90.3%. CONCLUSIONS: The study results cannot be unconditionally extrapolated to other types of IDB transfer trays due to the diversity of their properties and features. The study evaluated the in vitro accuracy of IDB transfer trays. The revealed number of errors may be even higher in vivo due to limitations in visibility, salivary flow, interference from the tongue, and difficulties in achieving a proper fit of the IDB transfer tray to the teeth.

The Hydrostatic Pressure Distribution in the Periodontal Ligament and the Risk of Root Resorption-A Finite Element Method (FEM) Study on the Nonlinear Innovative Model.

Excessive orthodontic force can induce inflammatory tooth root resorption due to sustained high stresses within the periodontal ligament (PDL). This study aimed to analyze the PDL pressures during upper incisor retraction using the en masse method with TISAD. The finite element method (FEM) ensured consistent conditions across cases. The models included bone geometry, adjacent teeth, PDL, and orthodontic hardware, analyzed with LS-Dyna. The pressure ranged from 0.37 to 2.5 kPa across the dental arch, with the central incisors bearing 55% of the load. The pressure distribution remained consistent regardless of the force or hook height. The critical pressure (4.7 kPa) was exceeded at 600-650 g force, with notable pressure (3.88 kPa) on the palatal root wall of the right central incisor. Utilizing 0.017 × 0.025 SS archwires in MBT 0.018 brackets provided good torque control and reduced the root resorption risk when forces of 180-200 g per side were applied, maintaining light to moderate stress. Triple forces may initiate resorption, highlighting the importance of nonlinear finite element analysis (FEA) for accurate oral cavity simulations.

Bone Remodeling of Maxilla after Retraction of Incisors during Orthodontic Treatment with Extraction of Premolars Based on CBCT Study: A Systematic Review.

Background: Incisor retraction is often a crucial phase in ongoing orthodontic treatment, with significant implications for alveolar remodeling mechanisms. There are two prevailing theories which seek to explain this. According to the first, teeth move with the bone, while according to the second, teeth move within the bone. This systematic review seeks to assess morphometric changes in the maxillary alveolar process resulting from incisor retraction following premolar extraction and to evaluate the potential for bone remodeling associated with orthodontic movement. Methods: The study was conducted following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The following electronic databases were searched: PubMed, Google Scholar, Web of Science EMBASE and the Cochrane Central Register of Controlled Trials. The databases were searched using the following keywords: "Bone remodeling and retraction of incisors", "Alveolar bone and incisor retraction", "Bone thickness and incisor retraction", and "Bone changes and orthodontic treatment". Search filters were utilized to identify relevant papers and articles written in English and published during the last 10 years. Based on the information provided in their abstracts, papers and articles were selected according to the following criteria: randomized clinical trials (RCTs), controlled clinical prospective trials (CCTs), and retrospective studies. Articles unrelated to the study's scope or failing to meet inclusion criteria were excluded. These generally comprised individual case reports, case series reports, literature reviews, experimental studies, studies with limited data (including conference abstracts and journal writings), studies involving an unrepresentative group of patients (less than 10 patients), studies concerning patients with syndromes, and animal experiments. The remaining articles which were deemed relevant underwent comprehensive reference review and such journals as the American Journal of Orthodontics, Dentofacial Orthopedics, International Orthodontics, Journal of Clinical Orthodontics, and Angle Orthodontist were manually searched. Results: Seven articles meeting the inclusion criteria articles were selected for final evaluation, with a total of 284 participants, including 233 women and 51 men. During the analysis of the results included in the publications, a lack of homogeneity was observed, rendering a reliable statistical analysis and heterogeneity assessment unobtainable. Noteworthy disparities in methodologies and measurements posed a risk of drawing inappropriate conclusions. Consequently, emphasis was placed on qualitative analysis, emphasizing the need for standardization in future studies of a similar nature, to enable valid and comparable analyses. Conclusions: The research findings incorporated in this review demonstrate that significant bone loss occurs because of incisor retraction, which diminishes distance between the bone surface and the root surface on the palatal aspect. The magnitude of this change may vary, contingent upon both the extent of incisor displacement and alterations in their inclination, thereby affecting the positioning of the root tips. This change is significantly higher in adults than in growing adolescents. The rationale behind this assertion lies in the widely recognized phenomenon of declining cellular activity with advancing age. The decrease in the speed and intensity of cellular changes may explain the diminished capacity for remodeling as patient age increases. There is ongoing discourse regarding alterations in the volume of bone on the labial aspect of the alveolar process. Further research is necessary to measure whether bone remodeling during orthodontic movement is contingent upon other factors, such as the speed and biomechanics of retraction, the level of applied orthodontic force, and the patient age.

Are Currently Selected Laboratory Animals Useful in the Research of How Female Hormones Influence Orthodontic Biomechanics?

Animal testing was and remains the only method of introducing a certain treatment and medical procedure on humans. On the other hand, animals have their rights resulting from applicable legal acts, including Directive 2010/63/EU and, indirectly, the World Medical Association International Code of Medical Ethics (Helsinki Declaration, 1975, amended 2000). Thus, the question arises whether the credibility of the results of hormonal and orthodontic tests obtained so far and their usefulness for the human population is scientifically justified and worth sacrificing laboratory animals for. Especially that, according to statistical data, about 50% of laboratory animals are euthanized at the conclusion of the experiments. The aim of this article was to determine whether animal experiments are scientifically or morally justified in bringing significant evidence in studies that may validate the influence of changes in the concentration of female hormones secreted by the ovaries in various phases of the menstrual cycle in young patients on the duration of an increased tooth movement rate in orthodontic treatment. Papers reporting the results of the original research into female hormones, either natural or exogeneous ones, likely to alternate the orthodontic tooth movement rate were critically evaluated in terms of animal selection. Thorough analysis supported by veterinary knowledge proved that none of the publications enabled an extrapolation of the results to humans. The evaluation of the relation between the rate of tooth movement upon loading with orthodontic forces and hormones either secreted during the menstrual cycle of women or released from the contraceptives already present in the market, does not require sacrificing laboratory animals.