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Medicina (Kaunas, Lithuania) Mar 2023: Orthodontic tooth movement (OTM) requires bone remodeling resulting from complex processes of aseptic inflammation. Recent studies have confirmed close interaction...
: Orthodontic tooth movement (OTM) requires bone remodeling resulting from complex processes of aseptic inflammation. Recent studies have confirmed close interaction between the immune and skeletal systems. In addition, various orthodontic appliances including fixed systems affect the sublingual microbial composition, and the likelihood of developing inflammatory reactions of the gums is high, especially early in the treatment period. It is known that these systems have both positive and negative effects on the humoral and cellular immune responses. The main aim of the study was to evaluate the influence of self-ligating and conventional brackets on the salivary concentrations of cytokines (IL-6, osteoprotegerin (OPG), TNF-alpha, and IFN-gamma) and cortisol as a marker of stress. : Forty patients were analyzed at baseline (T0) and 2 months (T2) after fixing self-ligating (Ormco Damond Q) and conventional brackets (Ormco Mini Diamond). Salivary cytokine and cortisol concentrations were evaluated by commercial ELISA kits. : Outcomes of our study showed that after two months of treatment with either of these brackets, IFN-gamma and IL-6 levels did not change. However, TNF-alpha decreased with self-ligating brackets (13.36 to 8.32, = 0.002). The self-ligating bracket system also affects OPG concentration and cortisol levels 2 months after orthodontic activation. The level of OPG in the group of self-ligating brackets decreased significantly (8.55 to 2.72, = 0.003). Cortisol concentration was significantly higher in the self-ligation group (25.72 to 48.45, = 0.001) due to the effect of sustained strength movements. : Thus, the use of self-ligating and conventional brackets has a different effect on the concentration of cortisol and cytokines (OPG and TNF-alpha) in saliva 2 months after their fixation. Further longitudinal studies are necessary to explore why OPG levels are decreased in case of self-ligating cases and how OPG levels are related to clinical improvement.
Topics: Humans; Hydrocortisone; Orthodontic Wires; Orthodontic Brackets; Cytokines; Tumor Necrosis Factor-alpha; Interleukin-6
PubMed: 36984567
DOI: 10.3390/medicina59030566 -
Progress in Orthodontics Apr 2023The predictability of incisor movement achieved by clear aligners among Class II division 2 patients is poorly understood. The aim of this retrospective study was to...
BACKGROUND
The predictability of incisor movement achieved by clear aligners among Class II division 2 patients is poorly understood. The aim of this retrospective study was to determine the effectiveness of clear aligners in proclining and intruding upper incisors and its influencing factors.
METHODS
Eligible patients with Class II division 2 malocclusion were included. For clear aligner therapy, three types of incisor movements were designed: proclination, intrusion and labial movement. Pre-treatment and post-treatment dental models were superimposed. The differences between predicted and actual (DPA) tooth movement of incisors were analyzed. Univariate and multivariate linear regression were used to analyze the potential influencing factors.
RESULTS
A total of 51 patients and their 173 upper incisors were included. Actual incisor proclination and intrusion were less than predicted ones (both P < 0.001), while actual labial movement was greater than predicted one (P < 0.001). Predictability of incisor proclination and intrusion was 69.8% and 53.3%, respectively. Multivariate linear regression revealed that DPA of proclination was significantly positively associated with predicted proclination (B = 0.174, P < 0.001), ipsilateral premolar extraction (B = 2.773, P < 0.001) and ipsilateral canine proclination (B = 1.811, P < 0.05), while negatively associated with molar distalization (B = - 2.085, P < 0.05). The DPA of intrusion was significantly positively correlated with predicted intrusion (B = 0.556, P < 0.001) while negatively associated with labial mini-implants (B = - 1.466, P < 0.001). The DPA of labial movement was significantly positively associated with predicted labial movement (B = 0.481, P < 0.001), while negatively correlated with molar distalization (B = - 1.004, P < 0.001), labial mini-implants (B = - 0.738, P < 0.001) and age (B = - 0.486, P < 0.05).
CONCLUSIONS
For Class II division 2 patients, predicted incisor proclination (69.8%) and intrusion (53.3%) are partially achieved with clear aligner therapy. Excessive labial movement (0.7 mm) of incisors may be achieved. Incisor movement is influenced by predicted movement amount, premolar extraction, canine proclination, molar distalization, mini-implants and age.
Topics: Humans; Incisor; Retrospective Studies; Malocclusion, Angle Class II; Tooth Movement Techniques; Orthodontic Appliances, Removable; Multivariate Analysis
PubMed: 37009943
DOI: 10.1186/s40510-023-00463-6 -
Dental Press Journal of Orthodontics 2023This clinical trial was conducted to evaluate the stability and failure rate of surface-treated orthodontic mini-implants and determine whether they differ from those of... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
This clinical trial was conducted to evaluate the stability and failure rate of surface-treated orthodontic mini-implants and determine whether they differ from those of non-surface-treated orthodontic mini-implants.
TRIAL DESIGN
Randomized clinical trial with a split-mouth study design.
SETTING
Department of Orthodontics, SRM Dental College, Chennai.
PARTICIPANTS
Patients who required orthodontic mini-implants for anterior retraction in both arches.
METHODS
Self-drilling, tapered, titanium orthodontic mini-implants with and without surface treatment were placed in each patient following a split-mouth design. The maximum insertion and removal torques were measured for each implant using a digital torque driver. The failure rates were calculated for each type of mini-implant.
RESULTS
The mean maximum insertion torque was 17.9 ± 5.6 Ncm for surface-treated mini-implants and 16.4 ± 9.0 Ncm for non-surface-treated mini-implants. The mean maximum removal torque was 8.1 ± 2.9 Ncm for surface-treated mini-implants and 3.3 ± 1.9 Ncm for non-surface-treated mini-implants. Among the failed implants, 71.4% were non-surface-treated mini-implants and 28.6% were surface-treated mini-implants.
CONCLUSION
The insertion torque and failure rate did not differ significantly between the groups, whereas the removal torque was significantly higher in the surface-treated group. Thus, surface treatment using sandblasting and acid etching may improve the secondary stability of self-drilling orthodontic mini-implants.
TRIAL REGISTRATION
The trial was registered in the Clinical Trials Registry, India (ICMR NIMS). Registration number: CTRI/2019/10/021718.
Topics: Humans; Dental Implants; Survival Rate; Orthodontic Anchorage Procedures; India; Orthodontics; Torque; Orthodontic Appliance Design
PubMed: 37283426
DOI: 10.1590/2177-6709.28.2.e2321345.oar -
Swiss Dental Journal Mar 2023In addition to levelling the teeth in the aesthetically relevant area, the aim of orthodontic treatment is also to achieve a stable periodontal and occlusal situation....
In addition to levelling the teeth in the aesthetically relevant area, the aim of orthodontic treatment is also to achieve a stable periodontal and occlusal situation. It is also desirable to achieve a dental situation that requires little future dental intervention.
Topics: Humans; Dental Care; Orthodontics, Interceptive
PubMed: 36852516
DOI: 10.61872/sdj-2023-03-03 -
The Angle Orthodontist Nov 2022To assess the percentage of dental students interested in orthodontics and likely to apply to orthodontic residency programs, the role of orthodontic-related...
OBJECTIVES
To assess the percentage of dental students interested in orthodontics and likely to apply to orthodontic residency programs, the role of orthodontic-related experiences, and of orthodontic faculty and practitioner role models for student career decision-making.
MATERIALS AND METHODS
This study had a cross-sectional design. A total of 335 students from seven U.S. dental schools responded to an anonymous web-based survey.
RESULTS
35% were much/very much interested in becoming orthodontists and 26% were likely to apply for this specialty training. A total of 80.1% had orthodontic treatment, 58.7% knew an orthodontist in their community, 44% had shadowed an orthodontist, and 10.8% had worked in an orthodontic practice before dental school. Respondents evaluated orthodontic practitioners more positively than orthodontic faculty. They considered practitioners as more compassionate providers than faculty members (5-point scale with 5 = agree strongly: mean = 4.25 vs 3.83; P < .001), making more of a difference in their patients' lives (4.44 vs 4.05; P < .001), and as better role models (4.21 vs 3.94; P < .001) who encouraged students more to pursue orthodontics (4.03 vs 3.65; P < .001). Their interest in becoming an orthodontist and in applying for an orthodontic residency program correlated with educational experiences (r = 0.35; P < .001 / r = 0.34; P < .001) and positive impressions of orthodontic faculty (r = 0.23; P < .001 / r = 0.22; P < .001) and practicing orthodontists (r = 0.29; P < .001 / r = 0.27; P < .001).
CONCLUSIONS
Better understanding of factors motivating dental students to pursue orthodontics is crucial. Orthodontic practitioners and faculty play an important role in this context.
Topics: Humans; Cross-Sectional Studies; Faculty; Internship and Residency; Orthodontics; Students, Dental
PubMed: 36006681
DOI: 10.2319/030822-206.1 -
Progress in Orthodontics Apr 2023The biomechanics generated by the clear aligner (CA) material changes continuously during orthodontic tooth movement, but this factor remains unknown during the...
BACKGROUND
The biomechanics generated by the clear aligner (CA) material changes continuously during orthodontic tooth movement, but this factor remains unknown during the computer-aid design process and the predictability of molars movement is not as expected. Therefore, the purpose of this study was to propose an iterative finite element method to simulate the long-term biomechanical effects of mandibular molar mesialization (MM) in CA therapy under dual-mechanical systems.
METHODS
Three groups including CA alone, CA with a button, and CA with a modified lever arm (MLA) were created. Material properties of CA were obtained by in vitro mechanical experiments. MM was conducted by the rebound force exerted by CA material and the mesial elastic force (2N, 30° to the occlusal plane) applied to the auxiliary devices. Stress intensity and distribution on periodontal ligament (PDL), attachment, button and MLA, and displacement of the second molar (M2) during the iterations were recorded.
RESULTS
There was a significant difference between the initial and cumulative long-term displacement. Specifically, compared to the beginning, the maximum stress of PDL decreased by 90% on average in the intermediate and final steps. The aligner was the main mechanical system at first, and then, the additional system exerted by the button and MLA dominated gradually. The stress of attachments and auxiliary devices is mainly concentrated on their interfaces with the tooth. Additionally, MLA provided a distal tipping and extrusive moment, which was the only group that manifested a total mesial displacement of the root.
CONCLUSIONS
The innovatively designed MLA was more effective in reducing undesigned mesial tipping and rotation of M2 than the traditional button and CA alone, which provided a therapeutic method for MM. The proposed iterative method simulated tooth movement by considering the mechanical characteristic of CA and its long-term mechanical force changes, which will facilitate better movement prediction and minimize the failure rate.
Topics: Humans; Finite Element Analysis; Tooth; Molar; Periodontal Ligament; Biomechanical Phenomena; Tooth Movement Techniques; Orthodontic Appliances, Removable; Stress, Mechanical
PubMed: 37032410
DOI: 10.1186/s40510-023-00462-7 -
Dental Press Journal of Orthodontics Sep 2019It is undeniable that extra-alveolar mini-implants anchorage has revolutionized Orthodontics. Correspondingly, the proper understanding of mini-implants biomechanics...
It is undeniable that extra-alveolar mini-implants anchorage has revolutionized Orthodontics. Correspondingly, the proper understanding of mini-implants biomechanics allowed to broaden the range of dental movements as never seen before in clinical practice. However, in order to produce better treatments, especially regarding the effects in occlusal plane, it is important to be aware of the numerous possibilities of applying force systems based on skeletal anchorage. Thus, this paper aims to address, by means of clinical cases, the application of biomechanics concepts that are extremely relevant to the proper employment of extra-alveolar mini-implants.
Topics: Dental Implants; Orthodontic Anchorage Procedures; Orthodontics
PubMed: 31508712
DOI: 10.1590/2177-6709.24.4.093-109.sar -
American Journal of Orthodontics and... Sep 2023This 2-arm parallel study aimed to compare and evaluate the efficiency of Hanks Herbst (HH) and Twin-block (TB) functional appliances in treating adolescents with Class... (Randomized Controlled Trial)
Randomized Controlled Trial
INTRODUCTION
This 2-arm parallel study aimed to compare and evaluate the efficiency of Hanks Herbst (HH) and Twin-block (TB) functional appliances in treating adolescents with Class II malocclusion.
METHODS
A parallel-group randomized controlled trial was undertaken in a single United Kingdom hospital. Eighty participants were recruited and randomized in a 1:1 ratio to receive either the HH or TB appliance. Eligibility criteria included children aged 10-14 years with an overjet of ≥7 mm without dental anomalies. The primary outcome was the time (in months) required to reduce overjet to normal limits (<4 mm). Secondary outcomes included treatment failure rates, complications and their impact on oral health-related quality of life (OHRQOL). Randomization was accomplished using electronic software with allocation concealed using sequentially numbered, opaque, and sealed envelopes. Blinding was only applicable for outcome assessment. Data were analyzed using descriptive statistics and regression analyses to detect between-group differences, including Cox regression for time to treatment success.
RESULTS
HH was significantly faster than TB in reducing the overjet to within normal limits (95% confidence interval [CI], -3.00 to -0.03; P = 0.046). Mean overjet reduction was more efficient with the HH than the TB appliance (ß = 1.3; 95% CI, 0.04-2.40; P = 0.04). Fifteen (37.5%) of the participants in the TB group and 7 (17.5%) in the HH group failed to complete the treatment (hazard ratio = 0.54; 95% CI, 0.32-0.91, P = 0.02). However, TB was associated with fewer routine (incidence rate ratio = 0.81; 95% CI, 0.7-0.9; P = 0.004) and emergency (incidence rate ratio = 0.1; 95% CI, 0.1-0.3; P = 0.001) visits. Chairside time was greater with the HH (ß = 2.7; 95% CI, 1.8-3.6, P = 0.001). Participants in both groups experienced complications with similar frequency. A greater deterioration in OHRQOL was found during treatment with the TB.
CONCLUSIONS
Treatment with HH resulted in more efficient and predictable overjet reduction than TB. More treatment discontinuation and greater deterioration in OHRQOL were observed with the TB. However, HH was associated with more routine and emergency visits.
REGISTRATION
ISRCTN11717011.
PROTOCOL
The protocol was not published before trial commencement.
FUNDING
No specific external or internal funding was provided. Treatment for participants was provided as part of routine orthodontic treatment in the hospital.
Topics: Adolescent; Child; Humans; Quality of Life; Orthodontic Appliances, Functional; Orthodontics, Corrective; Malocclusion, Angle Class II; Overbite; Treatment Outcome
PubMed: 37409988
DOI: 10.1016/j.ajodo.2023.06.002 -
Head & Face Medicine Dec 2023The fundamental part of every successful orthodontic treatment is the detailed treatment planning including a precise determination of the virtual treatment objective...
BACKGROUND
The fundamental part of every successful orthodontic treatment is the detailed treatment planning including a precise determination of the virtual treatment objective (VTO) while considering the biological and anatomical limits. The aim of this study is to investigate and to compare the feasibility of the established reference values before and after orthodontic treatment and to determine the usefulness of this parameters as guidance for the sagittal anterior, sagittal posterior and transverse biological boundaries.
MATERIALS AND METHODS
Thirty-two patients aged 9 to 18 years (12 male and 20 female) with all permanent teeth present were randomly selected for orthodontic treatment with fixed multibracket appliance regardless of the potential malocclusion. The parameters 6-PTV, 1-NB [mm] and the WALA ridge were set for the identification of the transverse, sagittal anterior and sagittal posterior tooth position. The measurements were carried out at the beginning (T0) and at the end (T1) of the orthodontic treatment. They were set in relation with their individual threshold values (G). After the results of the measurements were conducted using the software OnyxCeph3TM (version 3.2.185 (505), Image Instruments GmbH, Chemnitz, DE), they were statistically calculated in the software RStudio (2022.12.0 Build 353 © 2009-2022 Posit Software PBC).
RESULTS
Among the 32 patients, the mean pre- and post-treatment changes measured through the three parameters in relation to the individual reference values were statistically significant (p < 0.01). The mean values for 6-PTV, 1-NB and the WALA ridge amounted 15.37 mm, 2.56 mm and 4.23 mm at the beginning of the treatment, while after the treatment the measured values amounted 20.31 mm, 2.4 mm and 5.55 mm. These measurements combined with the statistical analysis of the changes of WALA ridge (T0, T1) confirmed that the teeth have been successfully uprighted and aligned. Furthermore, the maxillary first molars have been moved slightly mesially, as proven by the changes in 6-PTV, without certainty as to whether bodily movement or mesial tipping took place. Additionally, the lower incisors have been protruded, slightly exceeding the individual threshold values.
CONCLUSION
The parameters investigated provide a suitable assessment tool for recording the limits of the sagittal posterior, the sagittal anterior and the transverse dimension.
Topics: Humans; Male; Female; Retrospective Studies; Malocclusion; Molar; Incisor; Tooth Movement Techniques; Orthodontic Appliance Design; Cephalometry
PubMed: 38098121
DOI: 10.1186/s13005-023-00399-6 -
International Journal of Molecular... Sep 2022During orthodontic tooth movement, mechanically induced remodeling occurs in the alveolar bone due to the action of orthodontic forces. The number of factors identified... (Review)
Review
During orthodontic tooth movement, mechanically induced remodeling occurs in the alveolar bone due to the action of orthodontic forces. The number of factors identified to be involved in mechanically induced bone remodeling is growing steadily. With the uncovering of the functions of neuronal guidance molecules (NGMs) for skeletal development as well as for bone homeostasis, NGMs are now also among the potentially significant factors for the regulation of bone remodeling during orthodontic tooth movement. This narrative review attempts to summarize the functions of NGMs in bone homeostasis and provides insight into the currently sparse literature on the functions of these molecules during orthodontic tooth movement. Presently, four families of NGMs are known: Netrins, Slits, Semaphorins, ephrins and Eph receptors. A search of electronic databases revealed roles in bone homeostasis for representatives from all four NGM families. Functions during orthodontic tooth movement, however, were only identified for Semaphorins, ephrins and Eph receptors. For these, crucial prerequisites for participation in the regulation of orthodontically induced bone remodeling, such as expression in cells of the periodontal ligament and in the alveolar bone, as well as mechanical inducibility, were shown, which suggests that the importance of NGMs in orthodontic tooth movement may be underappreciated to date and further research might be warranted.
Topics: Axon Guidance; Bone Remodeling; Ephrins; Periodontal Ligament; Receptors, Eph Family; Semaphorins; Tooth Movement Techniques
PubMed: 36077474
DOI: 10.3390/ijms231710077