An evaluation of root resorption associated with the use of photobiomodulation during orthodontic treatment with clear aligners: a retrospective cohort pilot study

OBJECTIVES

To evaluate the change in tooth root volume using cone-beam computed tomography (CBCT) in a group of patients treated concurrently with clear aligners and an adjunctive photobiomodulation (PBM) device.

MATERIALS AND METHODS

This retrospective cohort pilot study included the records of 32 consecutively treated clear aligner patients (23 female, 9 male) from the private practice of one orthodontist. The PBM group (n = 16) used the device once per day for 5 minutes per arch and was compared with a matched control group (n = 16). A semiautomated segmentation technique was used to obtain tooth volume of anterior teeth from CBCT imaging prior to (T0) and during or immediately following (T1) orthodontic treatment with clear aligners. The change in root volume between time points was assessed.

RESULTS

There was no statistically significant difference between the pre- and posttreatment root volumes of maxillary and mandibular anterior teeth, regardless of which intervention group the patient belonged to (P > .05). There was also no difference in the mean percentage change in root volume between clear aligner patients in this study who were treated with the PBM device compared with a matched control group (P > .05).

CONCLUSIONS

Clear aligner patients in this study who changed their aligners every 3 to 5 days and used adjunctive photobiomodulation therapy did not experience clinically relevant orthodontically induced external root resorption. Due to the small sample size and measurement error in the root segmentation process, the results should be interpreted with caution.

Systematic review on effects of experimental orthodontic tooth displacement on brain activation assessed by fMRI

BACKGROUND

Orthodontic treatment is often accompanied by discomfort and pain in patients, which are believed to be a result of orthodontic tooth displacement caused by the mechanical forces exerted by the orthodontic appliances on the periodontal tissues. These lead to change blood oxygen level dependent response in related brain regions.

OBJECTIVE

This systematic review aims to assess the impact of experimental orthodontic tooth displacement on alterations in central nervous system activation assessed by tasked based and resting state fMRI.

MATERIALS AND METHODS

A literature search was conducted using online databases, following PRISMA guidelines and the PICO framework. Selected studies utilized magnetic resonance imaging to examine the brain activity changes in healthy participants after the insertion of orthodontic appliances.

RESULTS

The initial database screening resulted in 791 studies. Of these, 234 were duplicates and 547 were deemed irrelevant considering the inclusion and exclusion criteria. Of the ten remaining potential relevant studies, two were excluded during full-text screening. Eight prospective articles were eligible for further analysis. The included studies provided evidence of the intricate interplay between orthodontic treatment, pain perception, and brain function. All of the participants in the included studies employed orthodontic separators in short-term experiments to induce tooth displacement during the early stage of orthodontic treatment. Alterations in brain activation were observed in brain regions, functional connectivity and brain networks, predominantly affecting regions implicated in nociception (thalamus, insula), emotion (insula, frontal areas), and cognition (frontal areas, cerebellum, default mode network).

CONCLUSIONS

The results suggest that orthodontic treatment influences beyond the pain matrix and affects other brain regions including the limbic system. Furthermore, understanding the orthodontically induced brain activation can aid in development of targeted pain management strategies that do not adversely affect orthodontic tooth movement. Due to the moderate to serious risk of bias and the heterogeneity among the included studies, further clinical trials on this subject are recommended.

Three-dimensional volumetric evaluation of root resorption in maxillary anteriors following en-masse retraction with varying force vectors - a randomized control trial

BACKGROUND

Root resorption in orthodontics is associated with direction and magnitude of force application as primary etiological factors. Well-controlled trials that utilize three-dimensional segmentation to detect volumetric changes in tooth structure are required to assess the quantitative nature of root resorption.

OBJECTIVE

To assess the severity of root resorption (RR) during retraction of maxillary anteriors with three different force vectors (with and without skeletal anchorage) via cone-beam computed tomography (CBCT) superimpositions.

TRIAL DESIGN

Three-arm parallel randomized clinical trial (RCT).

MATERIALS AND METHODS

Forty-two (16 males, 26 females) patients, (17-28 years), in permanent dentition with bimaxillary protrusion were randomly allocated to three groups of 14 patients each using block randomization (1:1:1 ratio) and allocation concealment. En-masse anterior retraction post first premolar extractions was carried out with modified force vectors in the three groups based on anchorage type [Molar, Mini-implant and Infrazygomatic crest (IZC) bone screws]. Volumetric root loss and linear dimensional changes were blindly assessed on initial (T0) and final (T1, end of space closure) CBCT scans. Normality distribution of values was done using Shapiro-Wilk's test. ANOVA and Post-hoc Tukey HSD test were done to compare measurements between groups at significance levels (P < .05).

RESULTS

Forty patients were analysed (14, 14, and 12 in three groups). Significant volumetric loss was noted in all groups. Central incisors demonstrated a significant reduction in IZC group (81.5 ± 21.1 mm3 ) compared to conventional (50.1 ± 26.5 mm3 ) and mini-implant groups (76.1 ± 27.6 mm3 ). Canines demonstrated a significant reduction in mini-implant group (108.9 ± 33.9 mm3 ) compared to conventional (68.8 ± 42.5 mm3 ) and IZC groups (103.1 ± 29.1 mm3 ). Regarding linear parameters, central incisors and canines revealed significant root length reduction in both skeletal anchorage groups. Lateral incisors showed no significant changes between groups.

CONCLUSIONS

Intrusive force vectors generated during skeletally anchored retraction can predispose anteriors to an increased risk of resorption. Greater loss of root volume was noted in the centrals and canines when retracted with skeletal anchorage.

LIMITATIONS

Small sample size and variations during CBCT acquisition.

HARMS

Low-dose CBCT scans were taken at T0 and T1 treatment intervals.

Early-stage periodontal ligament compression predicts orthodontically induced root resorption in rats

OBJECTIVES

To determine the effect of orthodontic pressure on periodontal ligament (PDL) compression in rats and assess correlation between PDL compression and orthodontically induced root resorption (OIRR).

MATERIALS AND METHODS

Eight female Wistar rats aged 10 weeks underwent surgery to place 2 mini-screws at the center of the palatal plate. 25 cN coil springs connecting the maxillary first molars and mini-screws were applied bilaterally to generate mesial force. Maxillary first molars were assigned to undergo either bodily or tipping movements. Micro-computed tomography (μCT) scans were taken on days 0, 3, 7, and 14, and histological sections were taken on day 14. OIRR was measured from histological sections, and the corresponding PDL compression ratio was quantified using μCT images.

RESULTS

The PDL was compressed by approximately 76% in tipping movement and 55% in bodily movement after 3 days, and by approximately 47% in bodily and tipping movements after 7 days of orthodontic force application. The extent of OIRR in tipping movement was significantly greater than that in bodily movement. A strong positive correlation between OIRR and PDL compression ratio was observed on day 3; however, no correlation was observed on day 7.

CONCLUSIONS

A strong correlation between PDL compression ratio and OIRR was observed at an early stage after the application of orthodontic force regardless of the tooth movement type (bodily or tipping), implying the importance of early stage PDL compression in the induction of OIRR.

Chroogomphus rutilus Regulates Bone Metabolism to Prevent Periodontal Bone Loss during Orthodontic Tooth Movement in Osteoporotic Rats

Osteoporosis (OP) leads to the acceleration of tooth movement and aggravation of periodontal bone loss during orthodontic treatment. Chroogomphus rutilus (CR) is abundant in nutrients and demonstrates remarkable antioxidant and anti-inflammatory properties. In the present study, the components of CR, including 35.00% total sugar, 0.69% reducing sugar, 14.40% crude protein, 7.30% total ash, 6.10% crude fat, 0.51% total flavonoids, 1.94% total triterpenoids, 0.32% total sterol, 1.30% total saponins, 1.69% total alkaloids, and 1.02% total phenol, were first systematically examined, followed by an investigation into its regulatory effects on bone metabolism in order to mitigate bone loss during orthodontic tooth movement in osteoporotic rats. The results of the imaging tests revealed that CR treatment reduced periodontal bone loss and normalized tooth movement in the OP. In conjunction with analyses of intestinal flora and metabolomics, CR enhances the prevalence of anti-inflammatory genera while reducing the production of inflammatory metabolites. Meanwhile, CR reduced the levels of periodontal inflammatory factors, including TNF-α, IL-1β, and IL-6, by activating Wnt/β-catenin signaling, and promoted periodontal bone formation. These findings imply that CR is a potent supplementary therapy for controlling periodontal bone remodeling in patients with OP undergoing orthodontic treatment.

Effects of Increasing the Orthodontic Forces over Cortical and Trabecular Bone during Periodontal Breakdown-A Finite Elements Analysis

Background and Objectives: Herein we used numerical analysis to study different biomechanical behaviors of mandibular bone subjected to 0.6 N, 1.2 N, and 2.4 N orthodontic loads during 0-8 mm periodontal breakdown using the Tresca failure criterion. Additionally, correlations with earlier FEA reports found potential ischemic and resorptive risks. Materials and Methods: Eighty-one models (nine patients) and 243 simulations (intrusion, extrusion, rotation, tipping, and translation) were analyzed. Results: Intrusion and extrusion displayed after 4 mm bone loss showed extended stress display in the apical and middle third alveolar sockets, showing higher ischemic and resorptive risks for 0.6 N. Rotation, translation, and tipping displayed the highest stress amounts, and cervical-third stress with higher ischemic and resorptive risks after 4 mm loss for 0.6 N. Conclusions: Quantitatively, rotation, translation, and tipping are the most stressful movements. All three applied forces produced similar stress-display areas for all movements and bone levels. The stress doubled for 1.2 N and quadrupled for 2.4 N when compared with 0.6 N. The differences between the three loads consisted of the stress amounts displayed in color-coded areas, while their location and extension remained constant. Since the MHP was exceeded, a reduction in the applied force to under 0.6 N (after 4 mm of bone loss) is recommended for reducing ischemic and resorptive risks. The stress-display pattern correlated with horizontal periodontal-breakdown simulations.

The tooth movement efficiency of different orthodontic thermoplastics for clear aligners: study protocol for a randomized controlled clinical trial

INTRODUCTION

With regard to the esthetics and comfort of orthodontic treatment, the requirement for removable clear aligners (CAs) is increasing. Unlike conventional fixed orthodontic appliances, CAs were made of thermoplastic film by thermoforming on the personalized dental models. The construction of orthodontic thermoplastic is a critical factor for orthodontic tooth movement (OTM). Polyethylene terephthalate glycol-modified (PETG) and thermoplastic polyurethane (TPU) are the most commonly orthodontic thermoplastics; however, the evidence of the differences between different orthodontic thermoplastic are limited to vitro environment and the evidence in vivo environment is not available. Therefore, this trial aims to provide reliable evidence for orthodontists' personalized treatment plans whether the two most commonly used orthodontic thermoplastics of PETG and TPU have differences in the efficiency of OTM.

METHODS AND ANALYSIS

This randomized controlled clinical study will recruit 44 orthodontic patients for orthodontic treatment. All the subjects will be randomized into two groups (PETG and TPU, n = 22 for each group). In the first stage (M0 to M1), clear aligners will be made of two orthodontic thermoplastics and move the maxillary first or second premolars 2 mm. In the second stage, patients will take the standard orthodontic treatments. The primary outcome will be the efficiency of clear aligners made of different materials on the digital models. The secondary outcome will be the efficiency of clear aligners made of different materials on the cone-beam computed tomography (CBCT). The efficiency will be calculated through the superimposition of the digital models and CBCT.

DISCUSSION

The results from this trial will serve as evidence for orthodontists and manufacturers and clarify whether the difference in orthodontic thermoplastics significantly impacts the efficiency of OTM.

TRIAL REGISTRATION NUMBER

ChiCTR2300070980. Registered on 27 April 2023. https://www.chictr.org.cn/showproj.html?proj=186253.

Combined orthodontic and prosthodontic treatment in an adolescent patient with traumatically ankylosed incisors: A case report

Symmetric extraction of premolars is a frequently used orthodontic treatment for dental crowding and protrusion. However, when a patient has incisors with ankylosis, the establishment of a treatment protocol often plagues orthodontists. An adolescent patient with a history of incisor trauma sought treatment for dental protrusion and crowding. Upon percussion of his infrapositioned maxillary central incisors, characteristic dull metallic sounds were noted, and a lack of normal mobility of these teeth under the application of external forces was detected. Follow-up radiographs after the trauma showed replacement root resorption of the maxillary central incisors. Based on clinical and radiological findings, ankylosis of the maxillary central incisors was tentatively diagnosed. A combination of orthodontic and prosthodontic treatment options involving extraction of the maxillary central incisors and mandibular first premolars was chosen to resolve the functional and esthetic problems. After treatment, well-aligned dentition, improved smile esthetics, and a more harmonious facial profile were achieved, and these outcomes remained stable during the follow-up period. This case report illustrates a viable treatment strategy for tackling predicaments caused by ankylosed incisors, which is unusual in the literature.

The effect of micro-osteoperforation on the rate of tooth movement during the alignment stage in patients with mandibular crowding: a randomised controlled trial

BACKGROUND

Orthodontic treatment is a long process that requires patient cooperation. Risks of side effects such as caries formation, periodontal problems, and root resorption increases as well as problems in patient cooperation arises with longer treatments. Several different techniques were developed that may shorten the treatment time.

OBJECTIVE

The aim of this study was to evaluate the effectiveness of micro-osteoperforations (MOPs) performed during the alignment stage.

TRIAL DESIGN

Randomized controlled trial.

METHODS

Twenty-eight subjects who had crowding in the mandibular arch were included in the study. The first group (4 boys and 10 girls, mean age = 17.21 ± 3.76 years) was treated with MOP (MOP) and the second group (8 boys and 6 girls, mean age = 15.29 ± 1.77 years) was treated without MOP (control). Cephalometric variables, periodontal parameters, Little irregularity index, alignment duration, patient satisfaction, and ease of operation were evaluated. The level of statistical significance was P ≤ 0.05.

RESULTS

Alignment duration was shorter (P = 0.000) in the MOP group (105.57 ± 18.34 days) compared to control group (135.86 ± 15.12 days). Alleviating of the crowding was more in the MOP group, compared to the control group in all time points. The pain level in the MOP group in the first appointment was higher compared to control group (P = 0.002). There was no significant difference between the groups in cephalometric parameters. Higher increases were found for gingival index (P = 0.008) and bleeding index (P = 0.039) in the control group compared to MOP group at the end of treatment.

LIMITATIONS

The study was a single-centre study.

CONCLUSION

Alignment stage was shortened with MOP application. There was no difference between groups for patient satisfaction and pain level except for the first appointment. No difference was observed between the groups regarding cephalometric values. Clinically insignificant inflammation was observed in periodontal tissues for both groups.

REGISTRATION

This study was registered at the Clinical Trials Registry (ClinicalTrials.gov NCT03652454).

Under pressure-mechanisms and risk factors for orthodontically induced inflammatory root resorption: a systematic review

BACKGROUND

The application of orthodontic forces causes root resorption of variable severity with potentially severe clinical ramifications.

OBJECTIVE

To systematically review reports on the pathophysiological mechanisms of orthodontically induced inflammatory root resorption (OIIRR) and the associated risk factors based on in vitro, experimental, and in vivo studies.

SEARCH METHODS

We undertook an electronic search of four databases and a separate hand-search.

SELECTION CRITERIA

Studies reporting on the effect of orthodontic forces with/without the addition of potential risk factors on OIIRR, including (1) gene expression in in-vitro studies, the incidence root resorption in (2) animal studies, and (3) human studies.

DATA COLLECTION AND ANALYSIS

Potential hits underwent a two-step selection, data extraction, quality assessment, and systematic appraisal performed by duplicate examiners.

RESULTS

One hundred and eighteen articles met the eligibility criteria. Studies varied considerably in methodology, reporting of results, and variable risk of bias judgements.In summary, the variable evidence identified supports the notion that the application of orthodontic forces leads to (1) characteristic alterations of molecular expression profiles in vitro, (2) an increased rate of OIIRR in animal models, as well as (3) in human studies. Importantly, the additional presence of risk factors such as malocclusion, previous trauma, and medications like corticosteroids increased the severity of OIIRR, whilst other factors decreased its severity, including oral contraceptives, baicalin, and high caffeine.

CONCLUSIONS

Based on the systematically reviewed evidence, OIIRR seems to be an inevitable consequence of the application of orthodontic forces-with different risk factors modifying its severity. Our review has identified several molecular mechanisms that can help explain this link between orthodontic forces and OIIRR. Nevertheless, it must be noted that the available eligible literature was in part significantly confounded by bias and was characterized by substantial methodological heterogeneity, suggesting that the results of this systematic review should be interpreted with caution.

REGISTRATION

PROSPERO (CRD42021243431).

Non-surgical adjunctive interventions for accelerating tooth movement in patients undergoing orthodontic treatment

BACKGROUND

Deviation from a normal bite can be defined as malocclusion. Orthodontic treatment takes 20 months on average to correct malocclusion. Accelerating the rate of tooth movement may help to reduce the duration of orthodontic treatment and associated unwanted effects including orthodontically induced inflammatory root resorption (OIIRR), demineralisation and reduced patient motivation and compliance. Several non-surgical adjuncts have been advocated with the aim of accelerating the rate of orthodontic tooth movement (OTM).         OBJECTIVES: To assess the effect of non-surgical adjunctive interventions on the rate of orthodontic tooth movement and the overall duration of treatment.

SEARCH METHODS

An information specialist searched five bibliographic databases up to 6 September 2022 and used additional search methods to identify published, unpublished and ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of people receiving orthodontic treatment using fixed or removable appliances along with non-surgical adjunctive interventions to accelerate tooth movement. We excluded split-mouth studies and studies that involved people who were treated with orthognathic surgery, or who had cleft lip or palate, or other craniofacial syndromes or deformities.

DATA COLLECTION AND ANALYSIS

Two review authors were responsible for study selection, risk of bias assessment and data extraction; they carried out these tasks independently. Disagreements were resolved by discussion amongst the review team to reach consensus.  MAIN RESULTS: We included 23 studies, none of which were rated as low risk of bias overall. We categorised the included studies as testing light vibrational forces or photobiomodulation, the latter including low level laser therapy and light emitting diode. The studies assessed non-surgical interventions added to fixed or removable orthodontic appliances compared to treatment without the adjunct. A total of 1027 participants (children and adults) were recruited with loss to follow-up ranging from 0% to 27% of the original samples.  Certainty of the evidence For all comparisons and outcomes presented below, the certainty of the evidence is low to very low. Light vibrational forces  Eleven studies assessed how applying light vibrational forces (LVF) affected orthodontic tooth movement (OTM). There was no evidence of a difference between the intervention and control groups for duration of orthodontic treatment (MD -0.61 months, 95% confidence interval (CI) -2.44 to 1.22; 2 studies, 77 participants); total number of orthodontic appliance adjustment visits (MD -0.32 visits, 95% CI -1.69 to 1.05; 2 studies, 77 participants); orthodontic tooth movement during the early alignment stage (reduction of lower incisor irregularity (LII)) at 4-6 weeks (MD 0.12 mm, 95% CI -1.77 to 2.01; 3 studies, 144 participants), or 10-16 weeks (MD -0.18 mm, 95% CI -1.20 to 0.83; 4 studies, 175 participants); rate of canine distalisation (MD -0.01 mm/month, 95% CI -0.20 to 0.18; 2 studies, 40 participants); or rate of OTM during en masse space closure (MD 0.10 mm per month, 95% CI -0.08 to 0.29; 2 studies, 81 participants). No evidence of a difference was found between LVF and control groups in rate of OTM when using removable orthodontic aligners. Nor did the studies show evidence of a difference between groups for our secondary outcomes, including patient perception of pain, patient-reported need for analgesics at different stages of treatment and harms or side effects.  Photobiomodulation Ten studies assessed the effect of applying low level laser therapy (LLLT) on rate of OTM. We found that participants in the LLLT group had a statistically significantly shorter length of time for the teeth to align in the early stages of treatment (MD -50 days, 95% CI -58 to -42; 2 studies, 62 participants) and required fewer appointments (-2.3, 95% CI -2.5 to -2.0; 2 studies, 125 participants). There was no evidence of a difference between the LLLT and control groups in OTM when assessed as percentage reduction in LII in the first month of alignment (1.63%, 95% CI -2.60 to 5.86; 2 studies, 56 participants) or in the second month (percentage reduction MD 3.75%, 95% CI -1.74 to 9.24; 2 studies, 56 participants). However, LLLT resulted in an increase in OTM during the space closure stage in the maxillary arch (MD 0.18 mm/month, 95% CI 0.05 to 0.33; 1 study; 65 participants; very low level of certainty) and the mandibular arch (right side MD 0.16 mm/month, 95% CI 0.12 to 0.19; 1 study; 65 participants). In addition, LLLT resulted in an increased  rate of OTM during maxillary canine retraction (MD 0.01 mm/month, 95% CI 0 to 0.02; 1 study, 37 participants). These  findings were not clinically significant. The studies showed no evidence of a difference between groups for our secondary outcomes, including OIIRR, periodontal health and patient perception of pain at early stages of treatment. Two studies assessed the influence of applying light-emitting diode (LED) on OTM. Participants in the LED group required a significantly shorter time to align the mandibular arch compared to the control group (MD -24.50 days, 95% CI -42.45 to -6.55, 1 study, 34 participants). There is no evidence that LED application increased the rate of OTM during maxillary canine retraction (MD 0.01 mm/month, 95% CI 0 to 0.02; P = 0.28; 1 study, 39 participants ). In terms of secondary outcomes, one study assessed patient perception of pain and found no evidence of a difference between groups.   AUTHORS' CONCLUSIONS: The evidence from randomised controlled trials concerning the effectiveness of non-surgical interventions to accelerate orthodontic treatment is of low to very low certainty. It suggests that there is no additional benefit of light vibrational forces or photobiomodulation for reducing the duration of orthodontic treatment. Although there may be a limited benefit from photobiomodulation application for accelerating discrete treatment phases, these results have to be interpreted with caution due to their questionable clinical significance. Further well-designed, rigorous RCTs with longer follow-up periods spanning from start to completion of orthodontic treatment are required to determine whether non-surgical interventions may reduce the duration of orthodontic treatment by a clinically significant amount, with minimal adverse effects.

Endodontic-orthodontic interactions: a review and treatment recommendations

The literature is replete with articles describing the many and varied interactions between endodontic treatment and orthodontic tooth movement (OTM), often reporting conflicting views and findings, which creates confusion for clinicians. Original research and review articles have described aspects such as apical root resorption and potential pulpal complications of teeth related to OTM. Some interactions are of relatively minor clinical significance, whilst others may have adverse consequences. A history of dental trauma before or during OTM further complicates the interactions. This review re-assesses the historical literature on endodontic-orthodontic interactions in light of more recent research and presents guidelines for managing clinical situations involving both disciplines. © 2023 Australian Dental Association.

Effect of obesity on tooth movement using an orthodontic device and changes in inflammatory cytokines, periodontal tissues, and orofacial pain

OBJECTIVE

This study aimed to investigate the effect of obesity prospectively on tooth movement via an orthodontic device and changes in inflammatory cytokines, periodontal tissues, and orofacial pain.

SUBJECTS AND METHODS

Prospective design in which data was gathered at baseline T0, 1 hour, 24 hours, and 1 week after the application of fixed orthodontic appliances. The total sample size was 60 participants aged between 12 to 18 years and divided into 2 groups based on the inclusion and exclusion criteria. Anthropometrical estimation was made using a bioimpedance meter. A clinical assessment was performed before the application of fixed appliance bonding (T0) one hour after bonding (T1), after 24 hours (T2), and finally after one week (T3). At T0 little irregularity index was assessed, gingival crevicular fluid (GCF) was collected and periodontal examination including probing depth (PD), gingival bleeding (GB), and the presence or absence of calculus were measured. Orofacial pain was assessed at three levels: 1 hours, 24 hours, and 1 week after application of fixed orthodontics using a visual analog scale. For inter-group comparison, Mann-Whitney and t-tests were used and for interphase, comparison cluster analysis was performed. The level of significance was p<0.05.

RESULTS

The participants in obese groups were significantly higher in terms of weight, BMI, WHR, FM, and BF than in the non-obese group (p<0.05). Obese participants had significantly more PD 4-5 mm (0.64±0.23 mm) and significantly higher BoP than non-obese participants (0.13±0.10 mm). Little's irregularity index at T0 and T3 showed no significant difference among obese and non-obese participants. The inflammatory cytokines level of IL-β was higher in the obese group compared to non-obese groups.

CONCLUSIONS

The intensity of orofacial pain was higher in obese participants after 24 hours along with high levels of IL-β pro-inflammatory cytokines before and during orthodontic treatment. No difference was noted in tooth movement in both obese and non-obese during orthodontic treatment in the first week.

PD-L1, a Potential Immunomodulator Linking Immunology and Orthodontically Induced Inflammatory Root Resorption (OIIRR): Friend or Foe?

Orthodontically induced inflammatory root resorption (OIIRR) is considered an undesired and inevitable complication induced by orthodontic forces. This inflammatory mechanism is regulated by immune cells that precede orthodontic tooth movement (OTM) and can influence the severity of OIIRR. The process of OIIRR is based on an immune response. On some occasions, the immune system attacks the dentition by inflammatory processes during orthodontic treatment. Studies on the involvement of the PD-1/PD-L1 immune checkpoint have demonstrated its role in evading immune responses, aiming to identify possible novel therapeutic approaches for periodontitis. In the field of orthodontics, the important question arises of whether PD-L1 has a role in the development of OIIRR to amplify the amount of resorption. We hypothesize that blocking of the PD-L1 immune checkpoint could be a suitable procedure to reduce the process of OIIRR during orthodontic tooth movement. This review attempts to shed light on the regulation of immune mechanisms and inflammatory responses that could influence the pathogenesis of OIIRR and to acquire knowledge about the role of PD-L1 in the immunomodulation involved in OIIRR. Possible clinical outcomes will be discussed in relation to PD-L1 expression and immunologic changes throughout the resorption process.

Effectiveness of platelet-rich concentrates on the rate of orthodontic tooth movement: a systematic review and meta-analysis

BACKGROUND

Autologous platelet-rich concentrates (PRCs) are recently used as a local biological substance in orthodontics to accelerate the rate of tooth movement.

OBJECTIVES

This systematic review aimed to evaluate the effects of PRCs on the rate of orthodontic tooth movement (OTM).

SEARCH METHODS

Unrestricted search of five electronic databases supplemented by the manual and gray literature search were undertaken in March 2022.

SELECTION CRITERIA

Randomized controlled trials (RCTs) evaluating the effect of PRCs on the rate of OTM with their side effect were included in this systematic review.

DATA COLLECTION AND ANALYSIS

Data items were extracted by two authors using a pre-piloted extraction form. Similar outcomes within a comparable time frame were synthesized in a meta-analysis.

RESULTS

Fourteen studies were deemed eligible for inclusion and seven RCTs were pooled in a meta-analysis. Canine retraction rate was higher in the side of PRCs injection than the control side by 0.28 mm/month (95% CI: 0.16-0.40, I2 = 95.6 per cent, P < 0.001, 345 patients) in the first 4 months after PRCs injection. There was no statistically significant difference between the PRCs side and the control side regarding molar anchorage loss (MAL) (MD = 0.03 mm, 95% CI: -0.18 to 0.24, I2 = 46.3 per cent, P = 0.78, 44 patients), canine rotation (MD = -0.19o, 95% CI: -1.95 to 1.57, I2 = 45.4 per cent, P = 0.96, 48 patients), or en-masse retraction. Likewise, there was no difference between both groups in terms of the duration of de-crowding. The mandibular canine retraction was statistically higher on the PRCs side than on the control side by 0.17 mm/month (P < 0.001, one trial). Regarding root resorption, there was no statistically significant difference between the experimental and control sides within the follow-up time. Mild pain scores were reported by the patients in the first 24 hours after injections.

CONCLUSIONS

Low-level evidence indicates that the effect of PRCs on OTM is minor and clinically insignificant. The findings should be interpreted with caution due to the inherent limitations in the included RCTs.

REGISTRATION

PROSPERO (CRD42022300026).

May alcoholic and non-alcoholic drinks affect the rate of orthodontic tooth movement? A systematic review of animal studies

BACKGROUND

Humans may consume various beverages in everyday life. Previous research has shown that the administration of different substances (medicinal or not) may affect bone turnover and, thus, orthodontic tooth movement. It would be anticipated that the substances contained in beverages could have an impact on tooth movement, as well.

OBJECTIVE

To investigate in a systematic way and appraise the quality of the available evidence from animal studies regarding the impact of various drinks or the main ingredients included in beverages on the rate of orthodontic tooth movement.

SEARCH METHODS

Search without restriction in six databases (including grey literature) and hand searching were performed until March 2022.

SELECTION CRITERIA

We looked for controlled animal studies investigating the effect of drinks, or the main ingredients included in beverages, on the rate of orthodontic tooth movement.

DATA COLLECTION AND ANALYSIS

After study retrieval and selection, relevant data was extracted, and the risk of bias was assessed using the SYRCLE's Risk of Bias Tool. The quality of available evidence was assessed with the Grades of Recommendation, Assessment, Development, and Evaluation.

RESULTS

The initially identified records were finally reduced to nine studies conducted on animals. Carbonated soft drinks were shown to decrease the rate of tooth movement, but alcohol consumption did not have an impact. Exploratory meta-analysis showed that caffeine exhibited an acceleratory effect after 3 weeks of force application. Exploratory meta-regression results indicated that high dosages of caffeine reduced the rate of tooth movement.

CONCLUSIONS

The located animal experiments reported that caffeine accelerates, carbonated drinks decelerate, while alcohol does not affect the rate of orthodontic tooth movement. However, due to various limitations it remains unclear whether caffeine, alcohol, or carbonated drinks finally influence tooth movement in animal studies.

REGISTRATION

Open Science Framework (https://osf.io/jyhbd/).

ALGORITHM OF ORTHODONTIC TREATMENT PATIENTS WITH A BURDENED DRUG ANAMNESIS. DRUGS THAT CAN INHIBIT TOOTH MOVEMENT

According to the literature, more than 60% of orthodontic patients take certain medications and/or nutritional supplements on regular basis. To improve the efficiency and quality of treatment an orthodontic treatment algorithm has been developed for patients taking bisphosphonates, drugs for the treatment of diabetes (except thiazolidinediones and SGLT-2 inhibitors), hypotensive agents, antihistamines, statins, NSAIDs, estrogen-containing drugs, tetracycline, interferon-γ (copyright database IREG deposit certificate No. 2080699). The result of the study showed that 12,6% of patients, who came for consultation and orthodontic treatment, use different drugs on regular basis, with potential ability to slow down tooth movement. ; Algorithm helps orthodontist to make correct treatment plan, select appropriate orthodontic appliance activation regime, choose additional diagnostic procedures and consultations with doctors of other medical specialities according to patient's drug history.

Innovative Application of Diathermy in Orthodontics: A Case Report

Introduction: Several strategies have been proposed in the literature to accelerate tooth movement, many of which are invasive and have numerous side effects, such as surgical techniques (corticotomy and piezocision technique). This research investigates to what extent diathermy can accelerate the orthodontic alignment phase. Materials and Methods: A patient with lower teeth crowding index of the same magnitude was selected. The orthodontic treatment with Nickel–Titanium (NiTi) thermal arc 0.015 in the lower arch was performed, associated with a weekly application of diathermy using the intraoral handpiece. The total duration of treatment was three weeks. During each session, an intraoral transducer was employed to stimulate the hard and soft tissues of the left dental hemiarch, which was also orthodontically aligned like the right one. Results: Comparing the tooth movements of four elements of the two hemiarchies, it was found that, overall, the two teeth examined on the treated side underwent a more significant number of changes than on the untreated side, although not by a significant amount. Conclusions: The use of diathermy, according to the authors, is a non-invasive approach that may speed up the orthodontic alignment phase and reduce treatment duration, resulting in a lower risk of caries, gingival recessions, root resorptions, and patient compliance improvement, without side effects. Further studies and an adequate sample size will be needed to confirm the findings.

Lithium reduces orthodontically induced root resorption by suppressing cell death, hyalinization, and odontoclast formation in rats

OBJECTIVES

To examine whether lithium suppresses orthodontically induced root resorption (OIRR) via two mechanisms (prevention of hyalinization in periodontal tissue and suppression of odontoclasts) and to investigate the changes in the periodontal tissue and alveolar bone, focusing on the appearance of cell death, hyalinization, and odontoclasts.

MATERIALS AND METHODS

The maxillary first molars of 10-week-old male Wistar rats were moved mesially by a closed-coil spring for 14 days. Lithium chloride (LiCl; 0.64 mM/kg) or saline (control) was administered intraperitoneally daily. Tooth movements were measured using micro-computed tomography. Appearances of cell death, hyalinization, and odontoclasts were evaluated by histological analysis.

RESULTS

OIRR observed on day 14 in the control group was suppressed strongly by LiCl administration. Apoptotic cells observed on day 1 in the compression area were gradually diminished on days 2 and 3 and transformed to hyalinization tissue in the control group. LiCl administration remarkably suppressed this cell death and subsequent hyalinization. Also, the appearance of odontoclasts in the compression area observed on day 7 was significantly suppressed by LiCl administration. Accordingly, these degenerative processes to OIRR were suppressed substantially by LiCl treatment.

CONCLUSIONS

Lithium reduces OIRR through the suppression of periodontal ligament cell death, hyalinization, and odontoclast formation.

Root resorption associated with maxillary buccal segment intrusion using variable force magnitudes

OBJECTIVES

To compare the root resorption resulting from miniscrew-supported maxillary posterior dentoalveolar intrusion using two different force magnitudes.

MATERIALS AND METHODS

Adult patients with skeletal open bite, indicated for maxillary posterior dentoalveolar intrusion, were recruited and randomly assigned to the comparison or intervention groups. The comparison group involved applying 200 g of intrusive force per segment, which measured 20 g per root, while this force was 400 g per segment in the intervention group, measuring 40 g per root.

RESULTS

Twenty participants were included in the final analysis after 2 patients dropped out, 1 in each group, to end up with 10 subjects (200 roots) per group. There was statistically significant root resorption of 0.84 ± 0.96 mm and 0.93 ± 1.00 mm in the comparison and the intervention groups, respectively. However, there was no statistically significant difference between the groups.

CONCLUSIONS

Root resorption inevitably took place in association with orthodontic intrusion. However, increasing the magnitude of the intrusive force did not increase the amount of root resorption, either statistically or clinically.

Assessment of salivary stress and pain biomarkers and their relation to self-reported pain intensity during orthodontic tooth movement: a longitudinal and prospective study

PURPOSE

The aim of this prospective study was to evaluate the relationship between pain intensity and concentrations of salivary pain and stress biomarkers during orthodontic tooth movement.

METHODS

Eighteen patients (8 males, 10 females; mean age 14.57 ± 2.39 years) who needed orthodontic treatment with maxillary premolar extraction and segmental canine distalization participated in this study. Baseline samples were collected (T1), and orthodontic attachments were placed to maxillary first molars, second premolars, and canines. Then extractions were performed. After 1‑month follow-up, canine distalization started with a segmental wire (T2). Concentrations of salivary α‑amylase (sAA), cortisol, secretory immunoglobulin A (sIgA) and chromogranin A (CgA) were examined at T1, T2, and on days 4 (T3), 7 (T4), 14 (T5), and 30 (T6) after starting retraction. Participants also scored their pain on a visual analogue scale (VAS). Pain catastrophizing behavior and dental anxiety levels of the participants were evaluated by the Pain Catastrophizing Scale (PCS) and Corah's Dental Anxiety Scale (C-DAS), respectively. Repeated measure ANOVA, Mann-Whitney U test and Spearman's rank correlation coefficient analysis were used for statistical evaluations (p < 0.05).

RESULTS

The maximum values for sAA were seen at T1. Males had higher sAA levels than females with statistical differences at T1, T3, and T4. No significant differences for cortisol, sIgA, and CgA concentrations were observed. The highest mean VAS score was recorded at T3. No correlations were detected between any salivary biomarkers, VAS, C‑DAS, and PCS scores.

CONCLUSIONS

The stress of starting orthodontic treatment increased sAA levels more than the pain that was experienced during orthodontic tooth movement. Being male was a predictor of higher sAA concentrations. Orthodontic tooth movement did not cause significant alterations in salivary pain and stress biomarkers.

Varied temporal expression patterns of trigeminal TRPA1 and TRPV1 and the neuropeptide CGRP during orthodontic force-induced pain

OBJECTIVE

The aim of this study was to quantify the temporal changes in inflammation and TRPA1, TRPV1 and CGRP expression in the trigeminal ganglion during force-induced orthodontic pain.

DESIGN

Orthodontic force was applied to both maxillary first molars in 8-week-old Wistar rats for 12 h, 24 h, 3 d or 7 d. The rat grimace scale (RGS) score and duration of face grooming were used to measure orthodontic pain. Western blotting was performed to assess TRPA1, TRPV1 and CGRP expression in trigeminal ganglia. NF-кB levels and colocalization of TRPA1, TRPV1 and CGRP were evaluated by immunofluorescent staining.

RESULTS

Application of continuous force significantly increased pain behaviours at 1 and 3 d. NF-кB significantly increased in periodontal ligament at 12 h until 3 d. TRPV1 was significantly elevated within 1 d; TRPA1 significantly increased from 1-3 d; CGRP expression significantly increased from 12 h to 3 d. The TRPV1/TRPA1 expression ratio was highest at 12 h; the TRPA1/TRPV1 ratio peaked at 3 d. The percentages of trigeminal neurons co-expressing TRPA1/TRPV1, TRPA1/CGRP, and TRPV1/CGRP significantly increased by 12 h and peaked at 24 h. CGRP expression had a stronger positive correlation with TRPV1 than TRPA1.

CONCLUSIONS

Inflammation induced by application of orthodontic force sensitizes trigeminal TRPV1 and TRPA1; TRPV1 is primarily activated as an early response, whereas TRPA1 is activated as a late response. Activation of both nociceptors results in CGRP release. Thus, blocking both TRPV1 and TRPA1 may represent a primary therapeutic target for relief of orthodontic pain.

N/OFQ modulates orofacial pain induced by tooth movement through CGRP-dependent pathways

BACKGROUND

Nociceptin/orphanin FQ (N/OFQ) has been revealed to play bidirectional roles in orofacial pain modulation. Calcitonin gene-related peptide (CGRP) is a well-known pro-nociceptive molecule that participates in the modulation of orofacial pain. We aimed to determine the effects of N/OFQ on the modulation of orofacial pain and on the release of CGRP.

METHODS

Orofacial pain model was established by ligating springs between incisors and molars in rats for the simulation of tooth movement. The expression level of N/OFQ was determined and pain level was scored in response to orofacial pain. Both agonist and antagonist of N/OFQ receptor were administered to examine their effects on pain and the expression of CGRP in trigeminal ganglia (TG). Moreover, gene therapy based on the overexpression of N/OFQ was delivered to validate the modulatory role of N/OFQ on pain and CGRP expression.

RESULTS

Tooth movement elicited orofacial pain and an elevation in N/OFQ expression. N/OFQ exacerbated orofacial pain and upregulated CGRP expression in TG, while UFP-101 alleviated pain and downregulated CGRP expression. N/OFQ-based gene therapy was successful in overexpressing N/OFQ in TG, which resulted in pain exacerbation and elevation of CGRP expression in TG.

CONCLUSIONS

N/OFQ exacerbated orofacial pain possibly through upregulating CGRP.

Expansion treatment using Invisalign®: Periodontal health status and maxillary buccal bone changes. A clinical and tomographic evaluation

The aim of this study was to evaluate changes in periodontal status and maxillary buccal bone by considering clinical and tomographic parameters during the first year of orthodontic expansion with Invisalign® aligners. Upper first (1PM) and upper second (2PM) premolars of 19 patients with orthodontic expansion requirement treated with Invisalign® aligners were evaluated. Plaque index (PI), gingival index (GI), probing pocket depth (PPD), clinical attachment level (CAL) and cone beam tomographic (CBCT) records were collected at 76 sites before starting treatment (T0) and at 12 months (T1). Bone height was measured from cementoenamel junction (CEJ) to the crest cortical bone (CC). Bone thickness was measured at two levels: 4 mm (CEJ+4) and 6 mm (CEJ+6) apical to the CEJ. A descriptive analysis was made of the variations of bone thickness and height in a series of cases. The average expansion was 1.93 mm for 1PM and 167 mm for 2PM. Arithmetic mean of distance CEJ-CC in 1PM was 3.05 mm at T0, and remained at 3.05 mm at T1. Arithmetic mean of distance CEJ-CC in 2PM was 2.06 mm at T0 and 2.31 at T1. Post-expansion, most of the analyzed sites (86%) exhibited a bone thickness of ≥0.5 mm. The greatest variations between T0 and T1 were observed at the level of 1PM CEJ+ 4 and 2PM CEJ+ 6. The minimal changes in the clinical records (GI, PI, PPD and CAL) between T0 and T1 were compatible with the maintenance of gingivalperiodontal health. Invisalign® for expansion movements did not produce substantial changes in the evaluated periodontal clinical parameters or in the bone measurements. Removable appliances reduce plaque retentive factors and favor adequate oral hygiene.

Botulinum toxin A alleviates orofacial nociception induced by orthodontic tooth movement through nociceptin/orphanin-FQ pathway in rats

OBJECTIVES

To investigate the effect and mechanism of botulinum neurotoxin type A (BoNT/A) in the modulation of orofacial nociception induced by orthodontic tooth movement in rats.

METHODS

An orofacial nociception model was established in male Sprague-Dawley rats by ligating closed-coil springs between incisors and ipsilateral molars. There were two group sets of animals. For the first group set, 120 rats were randomly divided into four groups: no-force group (n = 30), force + saline group (n = 30), force + low dose BoNT/A group (1U/6 μL, n = 30), and force + high dose BoNT/A group (1U/6 μL, n = 30). BoNT/A and saline were injected into periodontal ligament to explore the nociceptive effect of BoNT/A. Ipsilateral trigeminal ganglia (TG) were harvested for detecting the expression levels of nociceptin/orphanin-FQ (N/OFQ). For the second group set, 36 rats were randomly divided into three force groups: BoNT/A + saline group (n = 12), BoNT/A + UFP-101 group (n = 12), and saline + UFP-101 group (n = 12). A potent N/OFQ receptor (NOP) antagonist (UFP-101) was used to examine the role of N/OFQ in BoNT/A-induced antinociception. Tooth-movement nociception level of all groups was evaluated by bite force and rat grimace scale (RGS) at baseline, day 1, day 3, day 5, day 7, day 14.

RESULTS

The behavioral assessments showed the orofacial nociception level in the force + low dose BoNT/A group and force + high dose BoNT/A group were lower than that in the force + saline group. No significant difference was observed in orofacial nociception among no-force group, force + low dose and force + high dose group. The expression levels of N/OFQ in TG were elevated from day 1 and maintained a high level, presenting in descending order among the force + high dose, force + low dose, force + saline and no-force group, respectively. The nociception level of the BoNT/A + UFP-101 group was higher than that of the BoNT/A + saline group. No significant difference was observed between the BoNT/A + UFP-101 group and the saline + UFP-101 group.

CONCLUSIONS

BoNT/A can exert an antinociceptive effect on orofacial nociception induced by tooth movement by stimulating the expression of N/OFQ in TG.

The effect of alveolar decortication on orthodontically induced root resorption

OBJECTIVE

To determine the effect of alveolar decortication on orthodontically induced root resorption.

MATERIALS AND METHODS

A total of 24 male Wistar rats (14 week old) were used. The rats were randomly divided into one of the following three groups: group 1 (control group), orthodontic tooth movement (OTM) for 2 weeks; group 2, OTM for 2 weeks + two alveolar decortications (2AD); group 3, OTM for 2 weeks + four alveolar decortications (4AD). The first molar was moved mesially for 2 weeks. Micro computed tomography was used to analyze root volume. In addition, histological sections were stained with Tartrate Resistant Acid Phosphatase (TRAP) to quantify the osteoclast number.

RESULTS

The buccal root volume in OTM + 4AD group was decreased by 8.92% and 6.11% when compared with the OTM-only group and OTM + 2AD group, respectively. Similarly, the other four root volumes in the OTM + 4AD group was decreased by 8.99% and 5.24% when compared with the OTM-only group and OTM + 2AD group, respectively. There was a decrease in buccal root density in the OTM + 4AD group by 4.66% and 3.56% when compared with the OTM-only group and the OTM + 2AD group, respectively. In addition, there was an increase in the number of osteoclasts by 195.73% and 98.74% in OTM + 4AD group in comparison with the OTM and OTM + 2AD group.

CONCLUSIONS

The amount of orthodontically induced root resorption was positively correlated with the extent of surgical injury used to accelerate orthodontic tooth movement.

Effectiveness of supplemental vibrational force in reducing pain associated with orthodontic treatment: a systematic review

OBJECTIVE

The aim of this review was to systematically appraise the current evidence of utilizing vibration to reduce orthodontic pain.

METHOD AND MATERIALS

A comprehensive search was performed in ten databases. Only randomized controlled trials (RCTs) with patients receiving orthodontic treatment accompanied by vibrational force application were included. Risk of bias was assessed using the Cochrane tool. The lack of reasonable homogeneity across studies prevented the quantitative synthesis of the data.

RESULTS

Fifteen RCTs were included. Three out of four RCTs revealed lower pain levels in at least one time-point when aligners were enhanced by vibration. Three out of 11 RCTs found that vibration accompanying fixed appliances was effective in reducing orthodontic pain. All studies had different methodologic shortcomings including: performance bias due to lack of participants' blinding; inappropriate sample size calculation; nonuniform demographic characteristics of participants; high potential of retrospective documentation of pain perception; and attrition bias.

CONCLUSION

It is difficult to answer the question of whether vibration alleviates orthodontic pain or not, especially with the multiple existing shortcomings. More precise research is needed. It is recommended to focus on comparing different vibrational variables in an attempt to find the optimal values that might contribute to pain reduction, including: vibrational frequency; magnitude; and number and duration of sessions per day. Based on the concept of stimulation-induced analgesia, it is suggested that future research highlights the number of vibration sessions/day.

Bone dehiscence formation during orthodontic tooth movement through atrophic alveolar ridges

OBJECTIVES

To test the null hypothesis that there is no difference in bone dehiscence formation before and after orthodontic tooth movement through an atrophic alveolar ridge.

MATERIAL AND METHODS

This longitudinal retrospective study evaluated pretreatment and posttreatment cone-beam computed tomography imaging of 15 adult patients. Twenty-five teeth were moved through the atrophic alveolar bone, whereas 25 teeth not subjected to translational movement were considered controls. The distances between the cementoenamel junction and the alveolar bone crest were assessed at the mesial, distal, buccal, and lingual surfaces of all of these teeth. Data were compared using the Wilcoxon test. The Spearman correlation test and multivariate linear regression analysis were also performed.

RESULTS

In general, crestal bone height was reduced around 0.5 mm in all groups in every direction. Median buccal dehiscence increased significantly (+2.25 mm) (P < .05) in teeth moved through the atrophic ridge. Control teeth also had buccal crest loss (+0.83 mm), but this was not statistically different from that of the experimental teeth. Lingual dehiscence increased significantly for the experimental (+0.17 mm) and control (+0.65 mm) groups. Mesial bone height decreased more in the control group (-0.44mm) than in the experimental group (-0.14mm). There was moderate correlation between amount of tooth movement and alveolar bone loss.

CONCLUSIONS

The null hypothesis was rejected as dehiscence increased after tooth movement through an atrophic alveolar ridge, mainly in the buccal plate.

Evaluation of the effects of photobiomodulation on orthodontic movement of molar verticalization with mini-implant: A randomized double-blind protocol study

INTRODUCTION

Loss of a dental element can generate several repercussions in the stomatognathic system. According to the latest survey by the Ministry of Health, in 2010, Brazilian adults had, on average, 7 missing teeth. This loss may lead to movement of the adjacent teeth and the antagonist, which would make prosthetic rehabilitation harder to do. Anchoring systems, such as mini-implants, have been increasingly used as a treatment option because they act with heavy but controlled forces and without side effects. Recent studies have shown that photobiomodulation (PBM) can accelerate orthodontic movement in molar intrusion. The objective of this study will be to evaluate the effect of PBM on the acceleration of the orthodontic movement of molar verticalization and its effect on pain and inflammation of the periodontal tissues. PATIENT CONCERNS:: the concerns assessments will be done over the study using anamnesis interviews and specific questionnaire.

DIAGNOSIS

verticalization will be evaluated by clinical and radiographic analysis.

INTERVENTIONS

Thirty four healthy patients aged 30 to 60 years, who need to recover the prosthetic space for oral rehabilitation after loss of the posterior inferior dental elements and inclination of the adjacent element, will be randomly divided into 2 groups: G1 (control group) - verticalization by mini-implant + PBM simulation (placebo); G2 (experimental group) - verticalization by mini-implant + PBM. The movements will occur with the aid of mini-implants and elastomeric chains ligatures. The PBM will occur with diode laser application, 808 nm, 100 mW, receiving 1J per point, 10 seconds, 10 points (5 per buccal and 5 per lingual) and radiant exposure of 25 J/cm. The orthodontic forces of verticalization (corresponding to any exchange of elastomeric ligation) will be applied every 30 days and the PBM will be applied immediately, 3 and 7 days of each month, for a period of 3 months. The crevicular gingival fluid (CGF) will be collected on the 1st, 3rd, and 7th days after the first activation, and then on the 3rd day of the following 2 months.

OUTCOMES

Interleukins IL1β, IL-6, IL-8, IL-10, and TNF-α will be analyzed by ELISA. Panoramic radiography will be performed at baseline and 90 afterwards to ascertain the amount (in degrees) of verticalization. To evaluate the pain, the Visual Analog Scale (VAS) will be used in all the consultations, and to evaluate the quality of life, the Oral Health Impact Profile (OHIP-14) questionnaire will be applied. Analgesics will be given and the quantity of drugs will be counted. If the data are normal, they will be submitted to Student t test. The data will be presented as means ± SD and the value of p will be defined as <0.05.

DISCUSSION

This protocol will determine the effectiveness of photobiomoduation regarding the orthodontic movement of molar verticalization.

ETHICS AND DISSEMINATION

This protocol received approval from the Human Research Ethics Committee of Universidade Nove de Julho (certificate number: 3 533 219). The data will be published in a peer-reviewed periodical.

Evaluation of the use of photobiomodulation following the placement of elastomeric separators: Protocol for a randomized controlled clinical trial

BACKGROUND

Pain stemming from the placement of elastomeric separators and the exchanging of wires and accessories is the greatest reason for abandoning orthodontic treatment. Indeed, discomfort related to treatment exerts a negative impact on quality of life due to the difficulty chewing and biting. This paper proposes a study to evaluate the analgesic effects of photomiobodulation (PBM) on individuals undergoing orthodontic treatment.

METHODS

The sample will be composed of 72 individuals who receiving elastomeric separators on the mesial and distal faces of the maxillary first molars. The patients will be randomly allocated to 2 groups: an experimental group irradiated with low-level laser and a sham group submitted to simulated laser irradiation. Upon the placement of the separators, the experimental group will receive a single application of PBM on the mesial and distal cervical portion and apical third of the molars. Perceived pain will be analyzed after one hour using the visual analog scale in both groups. Samples will be taken of the gingival crevice with absorbent paper for 30 seconds for the analysis of cytokines using ELISA and the results of the 2 groups will be compared. The patients will sign a statement of informed consent. Statistical analysis will be performed with the Student's t test and analysis of variance (ANOVA).

DISCUSSION

The expectation is that the patients in the irradiated group will have a lower perception of pain and lower quantity of cytokines compared to those in the sham group. The purpose of the study is to establish an effective method for PBM with the use of low-level infrared laser (Ga-Al-As with a wavelength of 808 nm and output power of 100 mW) for reductions in pain and inflammatory cytokines related to orthodontic treatment.

TRIAL REGISTRATION

This protocol was registered in ClinicalTrial.gov, under number NCT03939988. It was first posted and last updated in May 6, 2019.

Correlation between pain and hyalinization during tooth movement induced by different types of force

OBJECTIVES

To evaluate the correlation between pain and tissue reactions during induced tooth movement (ITM).

MATERIALS AND METHODS

Forty-two male Wistar rats (Rattus norvegicus; ∼90 days of age, 300 g) were used. The animals were divided into seven groups of six rats each: one control group and six experimental groups subjected to ITM by continuous force (CF) or interrupted continuous force (ICF) for 1, 3, and 5 days. Hyalinization of the periodontal ligament (PL) and occurrence of pain were observed. Animal behavior (walking, climbing, immobile posture, resting/sleeping, and directed face grooming) and the presence of chemical mediators associated with nociception, cyclooxygenase-2 (COX-2), and interleukin-1 beta (IL-1β) in the PL were analyzed.

RESULTS

There was a moderate positive correlation between hyalinization and the presence of COX-2 (r_s = 0.404; P < .05) and IL-1β (r_s = 0.429; P < .05). There was a moderate negative correlation between hyalinization and exploratory behaviors (walking, r = -0.586, P < .01; climbing, r = -0.573, P < .01), and a moderate positive correlation between hyalinization and resting/sleeping (r = 0.467; P < .01).

CONCLUSIONS

The results suggest a correlation between pain and undesirable tissue reactions in ITM.

A randomized, single-blind, placebo-controlled trial to evaluate the effectiveness of verbal behavior modification and acetaminophen on orthodontic pain

OBJECTIVES

To evaluate the effectiveness of verbal behavior modification, acetaminophen, and the combined effectiveness of verbal behavior modification along with acetaminophen on orthodontic pain.

MATERIALS AND METHODS

One hundred and forty orthodontic fixed appliance patients were randomly assigned to four groups. Group A was administered acetaminophen, group B was given verbal behavior modification, group C was administered acetaminophen as well as verbal behavior modification, and group D was placebo-controlled. A visual analog scale was used to assess pain intensity after 1 week of separator placement.

RESULTS

Group A had less mean pain intensity when compared to group B at 6 hours (P < .001) and at 1 (P < .001) and 2 (P = .002) days. Group C patients encountered less mean pain intensity when compared to group B patients at 6 hours (P < .001) and at 1 (P < .001), 2 (P < .001), and 4 (P = .001) days. There was a statistically significant difference between groups A and C (group C experienced less pain intensity) after 6 hours (P = .004) and at day 4 (P = .009) after separator placement.

CONCLUSIONS

Acetaminophen is the main agent of orthodontic pain reduction after separator placement, with verbal behavior serving as an adjunct to it.

Effect of continuous versus intermittent orthodontic forces on root resorption: A microcomputed tomography study

OBJECTIVES:

To compare the extent of root resorption and the amount of tooth movement between continuous orthodontic force and intermittent orthodontic force that was activated in a similar way to a 4-week orthodontic adjustment period.

MATERIALS AND METHODS:

Twenty-five patients who required the extraction of upper first premolars were recruited in this study. A buccally directed continuous force of 150 g was applied to the upper first premolar on one side for 15 weeks. A buccally directed intermittent force (28 days on, 7 days off) of the same magnitude was applied to the contralateral first premolar. The teeth were extracted at the end of the experimental period and processed for volumetric evaluations of resorption craters. The degree of tooth movement and rotation were measured on the study models.

RESULTS:

Continuous force application displayed significantly higher root resorption volume than the intermittent force application ( P < .05), particularly on the buccal and lingual surfaces (P < .05) and the middle third of the root ( P < .01). There was more tipping and rotational movement in the continuous force group.

CONCLUSIONS:

In a 4-week orthodontic adjustment period, intermittent force significantly reduced the amount of root resorption compared with continuous force. Although there was less degree of tooth movement with intermittent force, unwanted rotational movement was avoided. This is crucial in patients who are predisposed to orthodontically induced inflammatory root resorption, and the use of this intermittent regimen should be considered.

Apical root displacement is a critical risk factor for apical root resorption after orthodontic treatment

OBJECTIVES:

To identify risk factors for apical root resorption (ARR) of maxillary and mandibular incisors using mathematical quantification of apical root displacement (ARD) and multiple linear mixed-effects modeling.

MATERIALS AND METHODS:

Periapical radiographs of maxillary and mandibular incisors and lateral cephalograms of 135 adults were taken before and after orthodontic treatment. ARR was measured on the periapical radiographs, and movement of central incisors was evaluated on the superimposed pre- and posttreatment lateral cephalograms. ARD was mathematically calculated from pretreatment tooth length, inclination change, and movement of the incisal edge. Linear mixed-effects model analysis was performed to identify risk factors for ARR, and standardized coefficients (SCs) were calculated to investigate the relative contribution of the risk factors to ARR.

RESULTS:

Vertical ARD showed the highest SCs for both maxillary and mandibular incisors. Horizontal ARD showed the second highest SC for mandibular incisors but was not significantly correlated with the ARR of maxillary incisors. When horizontal and vertical ARDs were included in the mixed-effects model, the use of self-ligating brackets was significantly correlated with increased ARR of mandibular incisors.

CONCLUSIONS:

ARD is a critical factor for ARR after orthodontic treatment. Careful monitoring of ARR is recommended for patients requiring significant ARD of incisors.

There is no pulp necrosis or calcific metamorphosis of pulp induced by orthodontic treatment: biological basis

To biologically explain why the orthodontic treatment does not induce pulp necrosis and calcific metamorphosis of the pulp, this paper presents explanations based on pulp physiology, microscopy and pathology, and especially the cell and tissue phenomena that characterize the induced tooth movement. The final reflections are as follows: 1) the orthodontic movement does not induce pulp necrosis or calcific metamorphosis of the pulp; 2) there is no literature or experimental and clinical models to demonstrate or minimally evidence pulp alterations induced by orthodontic movement; 3) when pulp necrosis or calcific metamorphosis of the pulp is diagnosed during orthodontic treatment or soon after removal of orthodontic appliances, its etiology should be assigned to concussion dental trauma, rather than to orthodontic treatment; 4) the two pulp disorders that cause tooth discoloration in apparently healthy teeth are the aseptic pulp necrosis and calcific metamorphosis of the pulp, both only induced by dental trauma; 5) the concussion dental trauma still requires many clinical and laboratory studies with pertinent experimental models, to increasingly explain its effects on the periodontal and pulp tissues.

Initial arch wires used in orthodontic treatment with fixed appliances

BACKGROUND

Initial arch wires are the first arch wires to be inserted into the fixed appliance at the beginning of orthodontic treatment and are used mainly for the alignment of teeth by correcting crowding and rotations. With a number of different types of orthodontic arch wires available for initial tooth alignment, it is important to understand which wire is most efficient, as well as which wires cause least amount of root resorption and pain during the initial aligning stage of treatment. This is an update of the review entitledInitial arch wires for alignment of crooked teeth with fixed orthodontic braces, which was first published in 2010.

OBJECTIVES

To assess the effects of initial arch wires for the alignment of teeth with fixed orthodontic braces, in terms of the rate of tooth alignment, amount of root resorption accompanying tooth movement, and intensity of pain experienced by patients during the initial alignment stage of treatment.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 5 October 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 9), MEDLINE Ovid (1946 to 5 October 2017), and Embase Ovid (1980 to 5 October 2017. The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of initial arch wires to align teeth with fixed orthodontic braces. We included only studies involving participants with upper or lower, or both, full arch fixed orthodontic appliances.

DATA COLLECTION AND ANALYSIS

Two review authors were responsible for study selection, 'Risk of bias' assessment and data extraction. We resolved disagreements by discussion between the review authors. We contacted corresponding authors of included studies to obtain missing information. We assessed the quality of the evidence for each comparison and outcome as high, moderate, low or very low, according to GRADE criteria.

MAIN RESULTS

For this update, we found three new RCTs (228 participants), bringing the total to 12 RCTs with 799 participants. We judged three studies to be at high risk of bias, and three to be at low risk of bias; six were unclear. None of the studies reported the adverse outcome of root resorption. The review assessed six comparisons.1. Multistrand stainless steel versus superelastic nickel-titanium (NiTi) arch wires. There were five studies in this group and it was appropriate to undertake a meta-analysis of two of them. There is insufficient evidence from these studies to determine whether there is a difference in rate of alignment between multistrand stainless steel and superelastic NiTi arch wires (mean difference (MD) -7.5 mm per month, 95% confidence interval (CI) -26.27 to 11.27; 1 study, 48 participants; low-quality evidence). The findings for pain at day 1 as measured on a 100 mm visual analogue scale suggested that there was no meaningful difference between the interventions (MD -2.68 mm, 95% CI -6.75 to 1.38; 2 studies, 127 participants; moderate-quality evidence).2. Multistrand stainless steel versus thermoelastic NiTi arch wires. There were two studies in this group, but it was not appropriate to undertake a meta-analysis of the data. There is insufficient evidence from the studies to determine whether there is a difference in rate of alignment between multistrand stainless steel and thermoelastic NiTi arch wires (low-quality evidence). Pain was not measured.3. Conventional NiTi versus superelastic NiTi arch wires. There were three studies in this group, but it was not appropriate to undertake a meta-analysis of the data. There is insufficient evidence from these studies to determine whether there is any difference between conventional and superelastic NiTi arch wires with regard to either alignment or pain (low- to very low-quality evidence).4. Conventional NiTi versus thermoelastic NiTi arch wires. There were two studies in this group, but it was not appropriate to undertake a meta-analysis of the data. There is insufficient evidence from these studies to determine whether there is a difference in alignment between conventional and thermoelastic NiTi arch wires (low-quality evidence). Pain was not measured.5. Single-strand superelastic NiTi versus coaxial superelastic NiTi arch wires. There was only one study (24 participants) in this group. There is moderate-quality evidence that coaxial superelastic NiTi can produce greater tooth movement over 12 weeks (MD -6.76 mm, 95% CI -7.98 to -5.55). Pain was not measured.6. Superelastic NiTi versus thermoelastic NiTi arch wires. There were three studies in this group, but it was not appropriate to undertake a meta-analysis of the data. There is insufficient evidence from these studies to determine whether there is a difference in alignment or pain between superelastic and thermoelastic NiTi arch wires (low-quality evidence).

AUTHORS' CONCLUSIONS

Moderate-quality evidence shows that arch wires of coaxial superelastic nickel-titanium (NiTi) can produce greater tooth movement over 12 weeks than arch wires made of single-strand superelastic NiTi. Moderate-quality evidence also suggests there may be no difference in pain at day 1 between multistrand stainless steel arch wires and superelastic NiTi arch wires. Other than these findings, there is insufficient evidence to determine whether any particular arch wire material is superior to any other in terms of alignment rate, time to alignment, pain and root resorption.

Evaluation of maxillary buccal alveolar bone before and after orthodontic alignment without extractions: A cone beam computed tomographic study

OBJECTIVES:

To assess the changes in the maxillary buccal alveolar bone during alignment without extractions. Secondarily, to evaluate the changes in arch dimensions and buccolingual inclinations of teeth and to identify risk factors for bone loss.

MATERIALS AND METHODS:

Twenty-two adolescents with crowded permanent dentitions were treated without extractions with Damon 3MX brackets. Cone beam computed tomographic scans were taken before treatment (T0) and after alignment (T1). Bone thickness (BT) and height from the cementoenamel junction to the alveolar crest (BH) were evaluated at the maxillary central incisors, second premolars, and buccal roots of first molars. Changes in all variables from T0 to T1 were assessed. Correlations between bone changes and initial bone thickness, initial arch widths, initial crowding, amount of expansion, amount of tipping, and amount of molar rotation were calculated.

RESULTS:

BT decreased and BH increased significantly for the incisors and mesiobuccal root of the first molars. Arch dimensions generally increased together with tipping. Bone loss was correlated with crowding and amount of expansion in the premolar region. Initially thinner BT was correlated with greater apical migration of bone for the incisors.

CONCLUSIONS:

Nonextraction alignment with self-ligating brackets led to arch expansion associated with tipping of teeth. Expansion related to alignment resulted in horizontal and vertical bone loss at the incisors and mesiobuccal root of the first molars. Thinner BTs and more severe crowding before treatment increased the risk for buccal bone loss.

Comparison of orthodontic tooth movement between adolescents and adults based on implant superimposition

OBJECTIVE

We compared tooth movement under maximum anchorage control with mini-screw implants in growing and non-growing patients.

METHODS

In total, 15 adolescent (G1) and 19 adult (G2) patients with prognathic profiles were selected. All patients underwent first premolar extraction treatment with mini-screw implants for maximum anchorage control. Cone-beam computed tomography (CBCT) data were obtained immediately after implant placement (T1) and at the end of anterior tooth retraction (T2). Tooth movement and root length changes of the maxillary first molar, canine, and incisors were evaluated with three-dimensional models constructed using CBCT data obtained before and after orthodontic retraction through the superimposition of stable implants.

RESULTS

Distal movement of the molar crown was observed in G2, but mesial movement was observed in G1. Mesial tipping of the first molar (1.82 ± 6.76°) was seen in G1 and distal tipping (4.44 ± 3.77°) was observed in G2. For the canines, mesial crown tipping (0.33 ± 4.99°) was noted in G1 and distal crown tipping (8.00 ± 5.57°) was observed in G2. In adults, the lingual inclinations of the lateral and central incisors were 11.91 ± 7.01° and 11.47 ± 6.70°, with 0.99 ± 1.22 mm and 1.08 ± 1.20 mm root retraction, respectively. In adolescents, the torque changes were smaller (lateral incisors, 8.25 ± 10.15°; central incisors, 9.82 ± 8.97°) and the root retractions were 0.31 ± 1.81 mm and 0.77 ± 1.59 mm, respectively. Less shortening of the central incisor roots occurred in adolescents than in adults.

CONCLUSIONS

Tooth movements, such as anchor molar angular change, the canine tipping pattern, and the amount of incisor retraction, differed between adolescents and adults treated using the same anchorage with mini-screw implants, bracket prescription, and en masse retraction method. Anchorage strength of the first molars, canine movement patterns, and incisor retraction ranges are not determined by the anchorage device alone; growth and alveolar limitations also play roles.

Effects of loxoprofen on the apical root resorption during orthodontic tooth movement in rats

Studies have revealed that severe apical root resorption during tooth movement is caused by the noninfective inflammatory reaction of apical root tissues. We hypothesized that loxoprofen can suppress apical root resorption during tooth movement. Cyclic tensile force (CTF) of 10 kPa was applied to the human pulp cells for 48 hours by the Flexcell Strain Unit. Loxoprofen (10 and 100 μM) was added to the culture cells, and expression of cyclooxygenase (COX)-1, COX-2, interleukin (IL)-1β, receptor activator of nuclear factor kappa-B ligand (RANKL), tumor necrosis factor (TNF)-α, and macrophage colony-stimulating factor (M-CSF) were examined. To determine the effects of loxoprofen sodium on apical root reabsorption during tooth movement, the upper first molars of 7-week-old rats were subjected to mesial movement by 10g force for 30 days with or without the oral administration of loxoprofen. Gene expression and protein concentration of COX-1, COX-2, IL-1β, TNF-α, RANKL and M-CSF were significantly higher in the CTF group than in the control group. However, these levels were decreased by loxoprofen administration. After orthodontic tooth movement, the expression of IL-1β, TNF-α, RANKL and M-CSF decreased in the loxoprofen group than in the control group by immunohistochemical staining. In comparison to control group, less number of odontoclasts and a decrease in the amount of apical root resorption was observed in the loxoprofen group. Many osteoclasts became visible on the pressure side of the alveolar bone in the both groups, and the amount of tooth movement did not show a significant difference. These findings demonstrate that severe apical root resorption may be suppressed by loxoprofen administration, without a disturbance of tooth movement.

External apical root resorption diagnosis by using FII human dentine fraction and salivary IGg

BACKGROUND

External apical root resorption as a consequence of orthodontic treatment is an inflammatory pathological process that results in permanent loss of tooth structure from the root apex.

OBJECTIVES

This study aimed to investigate the diagnostic potential of human dentine fractions and salivary IgG in external apical root resorption.

PATIENTS AND METHODS

Saliva samples were collected from 10 patients before (T0) and after 3 (T3), 6 (T6) and 12 (T12) months of orthodontic treatment. The total dentinal extract, obtained from human third molars, was fractioned by gel filtration chromatography in three fractions denominated FI, FII and FIII. The root resorption analysis of the upper central incisors was performed by digital image subtraction method. Reactivity of salivary IgG to antigenic fractions of dentine was determined by enzyme-linked immunosorbent assay (Elisa).

RESULTS

Regardless of treatment, FI dentin fraction with high MM (<300kDa) was the one that presented highest reactivity with salivary IgG. However, it was found higher salivary IgG reactivity for FII (69 to 45 kilodalton [kDa]) as compared to FIII (<45kDa) at (T6) and (T12), (P<0.05), the same periods in that the root resorptions were detected.

CONCLUSION

Our results suggest that FII human dentine fraction and salivary IgG have potential to be used in diagnosis and monitoring of external apical root resorption. The development of a practical and accessible biochemical test using saliva and FII dentine fraction may help in the prevention of severe root resorption.

Lithium chloride reduces orthodontically induced root resorption and affects tooth root movement in rats

OBJECTIVE

To investigate the influence of lithium chloride (LiCl) on orthodontic tooth movement (OTM), orthodontically induced root resorption (OIRR), and bone morphometry.

MATERIALS AND METHODS

Ten-week-old female Sprague Dawley rats (n = 32) were divided into four groups based on the concentration of LiCl administered daily per kilogram body weight: 0 (control group), 0.32, 0.64, and 1.28 mM/kg body weight. The maxillary left first molars were moved mesially by a 10 cN coil spring for 14 days. Micro-computed tomography, scanning electron microscope, and scanning laser microscope images were taken to measure the amount of OTM, the volume of OIRR, and bone morphometry.

RESULTS

OIRR clearly decreased depending on the amount of LiCl administered, although OTM moderately decreased. The tooth inclined mesially and the root apex moved distally in the control and 0.32 mM groups. On the other hand, the tooth inclination angle became smaller and the root apex moved mesially in the 0.64 and 1.28 mM groups. In bone morphometry, the cortical bone mineral content and bone volume increased because of LiCl administration, and the trabecular bone measurements decreased. OIRR negatively correlated to the cortical bone measurements, and the amount of OTM significantly correlated to the cortical bone morphometry.

CONCLUSIONS

In rats, LiCl reduced OIRR, which induced mesial movement of the tooth root apex. OIRR positively correlated to cortical bone morphometry.

Comparative evaluation of treatment effects between two fixed functional appliances for correction of Class II malocclusion: A single-center, randomized controlled trial

OBJECTIVE

The objective of this study was to evaluate and compare the effects of PowerScope and Forsus in the treatment of Class II division 1 malocclusion.

MATERIALS AND METHODS

This was a 2-arm parallel, double-blind, randomized, controlled trial. A total of 28 Class II division 1 malocclusion patients indicated for treatment with fixed functional appliances were randomized and equally divided (n = 14) among PowerScope (American Orthodontics, Sheboygan, Wis; mean age 14.11 ± 1.3 years) and Forsus (3M Unitek Corp, Monrovia, Calif; mean age 15.5 ± 1.1 years) groups. Skeletal and dentoalveolar effects of PowerScope and Forsus were compared. The secondary outcomes were evaluation of patient comfort and operator convenience. Randomization was accomplished with a 1:1 allocation ratio, and concealment was achieved by sealed opaque envelopes. The participants and data collectors were all blinded to study group allocation. Data were analyzed for 26 patients, 13 in each group, as one patient from each group discontinued treatment. Statistical comparisons were carried out using Student's t-tests and chi square tests ( P ≤ .05).

RESULTS

A significantly greater mesial mandibular movement and improvement in sagittal skeletal relation were found in the Forsus patients ( P ≤ .05). The forward movement of the mandibular molar and incisors were greater in the PowerScope patients (2.3 mm and 2.80 mm) than in the Forsus patients (1.9 mm and 2.38 mm).

CONCLUSIONS

Both PowerScope and Forsus are effective in correcting Class II malocclusion. The percentage of dentoalveolar effects in correcting Class II malocclusion is more for PowerScope when compared with Forsus. Patient comfort was the same with both appliances. This trial was registered.

Risk factors associated with open gingival embrasures after orthodontic treatment

OBJECTIVES

To investigate the incidence of and contributing factors to open gingival embrasures between the central incisors after orthodontic treatment.

MATERIALS AND METHODS

One hundred posttreatment patients (29 men and 71 women; mean age, 24.7 years) were divided retrospectively into occurrence and nonoccurrence groups based on intraoral photographs. Based on the severity, the occurrence group was further divided into mild, moderate, and severe groups. Parameters from periapical radiographs, superimposed lateral cephalograms, and study models were compared between the occurrence and the nonoccurrence groups by using independent t-tests and were also analyzed on the basis of severity via analysis of variance. Logistic regression analysis was performed to identify the contributing factors to open gingival embrasures.

RESULTS

The incidence of open gingival embrasures between the central incisors was 22% and 36% in the maxilla and the mandible, respectively. Lingual movement of the incisors, distance from the contact point to the alveolar crest after treatment, antero-posterior overlap of the two central incisors before treatment in the maxilla, and distance from the contact point to the alveolar crest after treatment in the mandible were significantly associated with the occurrence of open gingival embrasures ( P < .05). In the mandible, the amount of intrusion was significantly related to severity ( P < .05).

CONCLUSIONS

The incidence of open gingival embrasures following orthodontic tooth movement is high. Therefore, attention should be paid to the contributing factors to prevent or reduce the occurrence of open gingival embrasures.

Evaluation of maxillary central incisors on the noncleft and cleft sides in patients with unilateral cleft lip and palate-Part 2: Relationship between root resorption, horizontal tooth movement, and quantity of grafted autogenous bone

OBJECTIVE

To evaluate the relationship between external apical root resorption (EARR) of the maxillary central incisors (U1), horizontal orthodontic tooth movement, and quantity of grafted bone in subjects with unilateral cleft lip and palate (UCLP) over an average duration of 8 years.

MATERIALS AND METHODS

Thirty subjects with UCLP were evaluated for EARR of U1 after edgewise treatment (T2). The teeth were classified as having no EARR, moderate EARR (combined into "no/moderate" EARR), or severe EARR. Frontal cephalometric radiographs acquired at eruption of U1 (T0), less than 6 months before secondary alveolar bone grafting (T1), and T2 were evaluated to determine the horizontal inclination (U1-axis angle) and distance of the root apex from the median line (U1-root-VL distance). On the cleft side, the quantities of grafted bone at less than 12 months postsecondary bone grafting and at T2 were evaluated using the alveolar bone graft (ABG) scale.

RESULTS

Cleft-adjacent teeth exhibited more severe EARR than did teeth on the noncleft side. The cleft side exhibited greater changes in U1-axis angle and U1-root-VL distance between T0 and T2 than did the noncleft side. On the cleft side, the ABG score at T2 in the severe EARR group was significantly lower than that in the no/moderate EARR group. These measurements were correlated with EARR grade.

CONCLUSIONS

Cleft-adjacent U1 exhibited more severe EARR than did the U1 on the noncleft side, which might be associated with orthodontic treatment-induced changes in horizontal inclination and root apex movement. On the cleft side, severity of EARR may be correlated with the success of ABG.

Gingival crevicular fluid bone turnover biomarkers: How postmenopausal women respond to orthodontic activation

INTRODUCTION

Bone turnover associated with orthodontic tooth movement is evidenced by increased bone turnover markers in gingival crevicular fluid (GCF). Postmenopausal women have an increased concentration of serum bone turnover markers. The filtrate of this serum makes up GCF, but little is known of the bone turnover around teeth in this cohort. The objective of this investigation was to compare the GCF bone turnover markers in premenopausal vs postmenopausal women receiving orthodontic treatment at baseline and at orthodontic activation.

METHODS

Twenty-eight women were enrolled in the study and separated into 2 groups: premenopausal (16) and postmenopausal (12). Bone turnover was evaluated by GCF at baseline and 24 hours after orthodontic appliance activation. GCF concentrations of RANKL and OPN were measured using ELISA. Baseline and change in concentrations were compared between groups.

RESULTS

Baseline RANKL and OPN were significantly different between the premenopausal and postmenopausal groups (P <0.05). Both markers increased significantly from baseline to 24 hours after orthodontic appliance activation in both groups (P <0.05). However, the response to orthodontic activation was not significantly different between groups.

CONCLUSIONS

Although postmenopausal women have a different bone turnover profile at baseline than do their premenopausal counterparts, there is no difference in their response to orthodontic activation. This confers a level of security associated with orthodontic activation. Future studies are warranted to construct biomarker curves throughout orthodontic therapy.

Peridental bone changes after orthodontic tooth movement with fixed appliances: A cone-beam computed tomographic study

OBJECTIVE

To quantify treatment-related changes in peridental bone height and thickness in orthodontic patients.

MATERIALS AND METHODS

Cone-beam computed tomographs (CBCTs) of 43 patients (24 female, 19 male; mean age: 25 years, 5 months) who underwent orthodontic treatment with multibracket appliances for at least 1 year were chosen for retrospective evaluation. Dehiscence depth and changes in bone width and tooth inclination were determined for 954 teeth.

RESULTS

There was a significant decrease in peridental bone height (dehiscence; -0.82 ± 1.47 mm) and bone thickness (-0.56 ± 0.7 and -0.69 ± 0.9 mm at 5 mm and 10 mm apical to the CEJ, respectively) during treatment (P < .001). A significantly greater dehiscence depth with increased vertical bone loss occurred in patients older than 30 years. In patients <30 years old, approximately 20% of the teeth showed defect depths >2 mm before treatment. In 90% of these patients, at least one tooth was affected. The maxillary canines and all mandibular teeth showed a higher risk for vestibular bone loss. Treatment changes in tooth inclination were correlated with horizontal bone loss.

CONCLUSIONS

Based on these results, it seems reasonable to recommend that peridental bone in orthodontic patients older than 30 be evaluated on a routine basis due to the risk of increased vertical bone loss. Ninety percent of patients younger than 30 showed reduced bone height (dehiscence) of the periodontium of at least one tooth.

Salivary leptin levels in normal weight and overweight individuals and their correlation with orthodontic tooth movement

OBJECTIVES

To assess and compare the concentration of leptin in saliva between normal weight and overweight individuals and to evaluate the rate of orthodontic tooth movement.

MATERIALS AND METHODS

Thirty female subjects were divided into two groups: I (normal weight) and II (overweight group) based on their body mass index. All subjects underwent fixed appliance therapy requiring upper first premolar extraction and distal movement of the canine. Distal force was applied to the maxillary right canine using active lacebacks. Salivary samples were collected just before force application (T₀), 1 hour (T₁), and 1 month (T₂) after force application. The rate of tooth movement was evaluated over 3 months and was measured on study models.

RESULTS

At all three time intervals, mean leptin concentration was greater in overweight individuals than normal weight individuals. In both groups at T₁, the mean leptin concentration was found to increase significantly compared with the baseline value (T₀), but at T₂, the leptin concentration declined to values lesser than the baseline values (T₀).

CONCLUSIONS

Overweight individuals had greater salivary leptin concentration. There was a positive correlation between salivary leptin concentration and rate of tooth movement in both normal and overweight individuals. The rate of tooth movement is decreased in overweight individuals as compared with normal weight individuals.

Influence of Periodontal Biotype on Root Surface Exposure During Orthodontic Treatment: A Preliminary Study

The aim of this study was to investigate the role of periodontal biotype in the development of gingival recession in patients who have undergone orthodontic treatment. A total of 60 mandibular incisors were analyzed. The qualitative assessment of periodontal biotype was performed with the use of a new biotype probe. A strong correlation was found between thin biotype and proinclination in terms of recession depth and keratinized tissue width. Patients with thin periodontal biotype are more prone to gingival margin instability, irrespective of the type of orthodontic movements. Thin periodontal biotype and proinclination orthodontic movement were related to loss of keratinized tissue width.

Corticotomy-Accelerated Orthodontics: A Comprehensive Review and Update

Of all the modalities reported to decrease orthodontic treatment time, corticotomy-accelerated orthodontics (CAO) is the only evidence-based approach. The aim of this article is to critically review the available evidence and to summarize the pros and cons of CAO. Articles published in the last 15 years related to CAO were screened and critically assessed. Based on the literature, CAO results in acceleration of the orthodontic treatment rate as much as three times on average, in addition to many benefits not commonly recognized by the profession or reported in the literature. CAO is effective and safe for shortening the orthodontic treatment time, as well as for enhancing interdisciplinary outcomes beyond what conventional treatment alone is able to yield. More investigations are needed to validate and verify, as well as understand, the long-term implications to treatment from both a periodontal and orthodontic outcome standpoint.

Root length and alveolar bone level of impacted canines and adjacent teeth after orthodontic traction: a long-term evaluation

OBJECTIVE

The aim of this retrospective study was to evaluate the long-term effects of orthodontic traction on root length and alveolar bone level in impacted canines and adjacent teeth.

MATERIAL AND METHODS

Sample consisted of 16 patients (nine males and seven females), mean initial age 11 years and 8 months presenting with unilaterally maxillary impacted canines, palatally displaced, treated with the same surgical and orthodontic approach. Teeth from the impacted-canine side were assigned as Group I (GI), and contralateral teeth as control, Group II (GII). The mean age of patients at the end of orthodontic treatment was 14 years and 2 months and the mean post-treatment time was 5 years and 11 months. Both contralateral erupted maxillary canines and adjacent teeth served as control. Root length and alveolar bone level (buccal and palatal) were evaluated on cone-beam computed tomography (CBCT) images. The comparison of root length and alveolar bone level changes between groups were assessed by applying paired t-test, at a significance level of 5% (p<0.05).

RESULTS

There were no statistically significant differences in root length and buccal and palatal bone levels of canines and adjacent teeth among groups.

CONCLUSIONS

Impacted canine treatment by closed-eruption technique associated with canine crown perforation, has a minimal effect on root length and buccal and palatal alveolar bone level in both canine and adjacent teeth, demonstrating that this treatment protocol has a good long-term prognosis.