External root resorption with the self-ligating Damon system-a retrospective study

Effects of premolar extraction and orthodontic treatment in adolescents - a retrospective cephalometric study

OBJECTIVES

To evaluate the cephalometric effects of premolar extraction on skeletal and dental parameters, and on the soft tissues, in patients subsequently treated with fixed appliances. Prevalence and severity of external apical root resorption due to premolar extraction were also examined.

MATERIALS AND METHODS

The dental records of 79 patients treated with fixed appliances were retrieved (groups: extraction, n = 19; non-extraction, n = 60). Pre- and post-treatment statuses of skeletal, dentoalveolar, and soft tissue variables were analyzed on lateral cephalograms to determine change. Periapical radiographs of the maxillary incisors were assessed for external apical root resorption using the Levander & Malmgren index. The t-test, Mann-Whitney U test, chi-squared test, and Kruskal-Wallis test were used to analyze the data. Significance was set at p < .05.

RESULTS

Changes in the protrusion and proclination of the incisors and in lip position were significantly different between the groups. Prevalence of external apical root resorption in the two groups was similar.

CONCLUSIONS

Our findings suggest that extraction therapy affects dentoalveolar traits but not jaw position, nor the risk of root resorption, in patients treated with fixed appliances.

The influence of bracket torque on external apical root resorption in bimaxillary protrusion patients: a retrospective study

Background

To evaluate the difference in root resorption between standard torque self-ligating brackets and high torque self-ligating brackets in bimaxillary protrusion patients after orthodontic treatment.

Methods

Pre-treatment and post-treatment Cone beam computed tomography (CBCT) of 32 patients (16 treated with the high torque DamonQ 0.022″ bracket and 16 with the 0.022″ standard torque self-ligating bracket) were selected. The first premolars were extracted from all patients before treatment. After mini-screw implants were inserted into the buccal region between the second premolar and first molar, 150 g of force was applied to retract the upper and lower anterior teeth to close the extraction space on each side. CBCT images of all patients were taken before and after treatment. Three-dimensional reconstruction of the maxillary central incisor, lateral incisor and canine was conducted with Mimics 20.0 software. The volumes of the roots were calculated using Gomagics Studio 12.0 software. The differences between the pre-treatment and post-treatment root volumes were statistically evaluated with a paired-samples t-test.

Results

There was no statistically significant difference in root resorption degree between the two kinds of torque brackets. The patient’s degree of root resorption in the high torque self-ligating group was greater than that in the standard torque group.

Conclusions

There was no significant difference in root external apical resorption between the high torque self-ligating brackets and the standard torque self-ligating brackets in bimaxillary protrusion patients.

Orthodontically Induced External Apical Root Resorption in Class II Malocclusion

Orthodontic-induced external apical root resorption is one of the idiopathic phenomena as an effect, with force generated through mechanotherapy as the cause and the biological tissues with their diversified variations as witness. It is also classified as iatrogenic as a result of indeterminate application of orthodontic forces with subconscious appreciation of the existing underlying conditions. Numerous factors were identified to relate to this irreversible pathologic condition, but none were proven scientifically. Genetics and salivary markers have proved the reliability with time, but the application became insignificant limiting mostly to the research field. Different assessment methods were also identified to clinically diagnose it both subjectively and objectively. Mostly, it is identified through routine radiographic stage records like orthopantomogram or certain prediction radiographs for root resorption probability assessment like in this case. This case report discusses one such encounter which was experienced after stage 1 and 2 mechanics involving quite a few teeth. Considering the biotype of the individual and tooth morphology, the ongoing treatment was terminated and recovery measures were briefed to uplift the self-esteem of the individual. Furthermore, the prognosis is compromised to be very poor with unpredictability to any other treatment modalities.

Concentration of dentin sialoprotein at the initial stage of orthodontic treatment using self-ligating and conventional preadjusted brackets: A pilot study

OBJECTIVES:

This study evaluated differences in concentration of dentin sialoprotein (DSP) in gingival crevicular fluid (GCF) relating to orthodontically induced inflammatory root resorption (OIIRR) at the initial stage of orthodontic treatment using self-ligating and conventional preadjusted brackets.

MATERIALS AND METHODS:

Eighteen patients were assigned to three groups of equal size. Two experimental groups received non-extraction orthodontic treatment using passive self-ligating or conventional preadjusted bracket. The control group included patients without orthodontic treatment. GCF was collected from five proximal sites of maxillary anterior teeth at subsequent intervals: immediately prior to orthodontic treatment (T0), and at three and 12 weeks after initiation of treatment (T1 and T2). DSP concentration was evaluated by enzyme-linked immunoabsorbent assay and the differences in DSP levels were analyzed between and within groups.

RESULTS:

There were no significant differences in DSP levels within both experimental groups and the control group during T0-T1-T2 (P ≥ 0.05). A significant difference of DSP concentration was found between the conventional preadjusted bracket and the control group at T2 (P = 0.038). However, it was thought to be clinically insignificant.

CONCLUSION:

The study showed no significant difference in DSP concentration at the initial stage of orthodontic treatment with either self-ligating or conventional preadjusted bracket.

A tool for assessment of risk of bias in studies of adverse effects of orthodontic treatment applied in a systematic review on external root resorption

BACKGROUND AND AIMS

Systematic reviews (SRs) are considered to provide reliable estimates, but flaws in designs, methods of monitoring effects, and outcomes have the potential to bias results. There are several tools for assessing risk of bias (RoB), most of them designed for SRs of beneficial effects. To our knowledge, there is no tool that is adapted specifically to assess RoB in studies of adverse effects associated with orthodontic treatment. To address this, the aim of this study was first to introduce a tool for assessment of RoB in studies of adverse effects associated with orthodontic treatment and, second, to apply it in an SR of external root resorption (ERR) associated with orthodontic treatment with fixed appliance.

MATERIALS AND METHODS

The approach with domains supported by signalling questions was used for the tool. Domains and signalling questions were tailored to the review questions of the SR of studies of ERR after orthodontic treatment using periapical radiography or cone beam computed tomography. Duplicate study selection, data extraction, and RoB assessment using the tool, followed by meta-analyses, were performed.

RESULTS

Using the tool for the assessment of RoB identified shortcomings and report deficiencies of primary studies concerning the presentation of orthodontic treatment, identification of ERR, and analysis of outcomes. RoB assessment resulted in 12 of 32 studies read in full text being included. Reported severe ERR varied across studies between 2 and 14 per cent for all incisors and 10 and 29 per cent for maxillary incisors. Results of ERR related to patients' age and sex, orthodontic diagnosis, and treatment were contradictory. Quality of evidence evaluated by GRADE was low due to study limitations, imprecision, and inconsistency of study results.

CONCLUSIONS

As the tool and its application highlight important issues to consider when planning, conducting, and reporting research, the tool may have a valuable role for quality enhancement of future studies of outcomes of orthodontic treatment. The tool may also serve for authors when planning SRs. Our SR identified a need for studies that use rigorous methodology and transparent reporting.

REGISTRATION

PROSPERO (ID = CRD42018084725).

Highly variable rate of orthodontic tooth movement measured by a novel 3D method correlates with gingival inflammation

Objectives

Individual orthodontic treatment duration is hard to predict. Individual biological factors are amongst factors influencing individual rate of orthodontically induced tooth movement (OTM). The study aim is to determine the rate of OTM by a novel 3D method and investigate parameters that may predict the rate of tooth movement.

Materials and methods

In this prospective cohort study, rate of OTM was determined from 90 three-dimensional intra-oral scans in 15 patients (aged 12–15) undergoing orthodontic treatment. For each patient, intra-oral scans were taken every week for up to 6 weeks (T0–T5). The teeth were segmented from the scans and the scans were superimposed on the palatal rugae. The rate of OTM was calculated for each tooth. Other parameters were gingival inflammation, contact-point displacement and the biological markers, matrix metalloproteinases (MMP), MMP-9 and MMP-2 in gingival crevicular fluid (GCF).

Results

Our study showed a high variation in the rate of OTM, varying from 0.15 to 1.24 mm/week. Teeth in the anterior segment tended to move more compared with the posterior segment. The contact point displacement and gingival inflammation varied greatly amongst the patients. The MMPs measured did not correlate with tooth movement. However, the gingival inflammation index showed a significant correlation with OTM. Future studies should include other biological markers related to bone-remodeling.

Conclusion

This novel and efficient 3D method is suitable for measuring OTM and showed large individual variation in rate of OTM.

Clinical relevance

Patients show different rates of OTM. The rate of OTM in an individual patient can provide guidance in timing of follow-up appointments.

[Therapeutic effect analysis of skeletal class Ⅲ malocclusion treatment by transmission straight wire technique]

OBJECTIVE

This study aimed to investigate the therapeutic effects and advantages of skeletal class Ⅲ malocclusion treatment by transmission straight wire technique.

METHODS

Ninety-seven patients who received treatment for skeletal class Ⅲ malocclusion at the Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2012 to January 2017 were selected for this retrospective study. All these patients refused surgery. They were divided into two groups in accordance with the type of skeletal malocclusion: mild-to-moderate skeletal malocclusion group (-4°≤ANB <0°) and severe skeletal malocclusion group (-8°≤ANB<-4°). Each of the two groups was divided further into two small groups in accordance with the technique used: T group (transmission straight wire technique) and M group (MBT technique).

RESULTS

The crossbite of all 59 patients in the mild-to-moderate skeletal malocclusion group was successfully treated. The molars were classified as classⅠrelationship, and the facial profile improved. Significant differences were found in the values of U1/SN angle, L1/MP angle, and Lip-Diff between the T and M groups before and after the treatment (P<0.05). The extent of incisor root resorption was lighter in the T group than in the M group (P<0.05). In the severe skeletal malocclusion group, the crossbite of all 38 patients was cured or partially cured. Fourteen patients showed severe lower anterior teeth inclination (five in the T group and nine in the M group), and the profiles did not significantly improve. Significant differences were observed in the values of U1-NA value, U1/SN angle, L1-NB value, L1/MP angle, LLP, and Lip-Diff between the T and M groups before and after the treatment (P<0.05). The extent of incisor root resorption was lighter in the T group than in the M group (P<0.05).

CONCLUSIONS

Relative to the MBT technique, the transmission straight wire technique has great advantages in improving facial profile, reducing the compensatory inclination of the upper and lower anterior teeth, and reducing the risk of root resorption in the treatment of skeletal class Ⅲ malocclusion.

Evaluation of root length following treatment with clear aligners and two different fixed orthodontic appliances. A pilot study

OBJECTIVES:

The purpose of this pilot study was to evaluate the root lengths of upper incisors as an indication of the degree of orthodontically-induced apical root resorption following treatment with Smart Track® aligners and compare it with two different fixed orthodontic appliances – regular and Damon brackets – using cone-beam computerized tomography (CBCT).

MATERIALS AND METHODS:

The sample comprised 33 patients with class I malocclusion and 4–6 mm crowding divided in 3 groups; Group I: 11 patients treated with Smart Track® aligners, group II: 11 patients treated with Damon brackets, and group III: 11 patients with regular brackets. Maxillary incisors teeth lengths were assessed using Dolphin imaging software before and after treatment. All data were analyzed using analysis of variance and t-test.

RESULTS:

All groups showed statistically significant root resorption, 0–1.4 mm for clear aligners, 0.1–2.3 mm for Damon, and 0–2.5 mm for regular brackets group. However, cases treated with fixed appliance in general showed significantly higher resorption than those treated with Smart Track® aligners (P < 0.05).

CONCLUSION:

Orthodontically-induced root resorption, as evaluated by root length, is an inevitable drawback with different orthodontic techniques. However, the use of Smart Track® aligners showed less root resorption relative to regular fixed appliances.

Retrospective Analysis of Different Bracket Systems used in the Treatment of Patients with Anterior Crowding: A Longitudinal Comparative Study

INTRODUCTION

New design of brackets have been introduced in the field of orthodontics in the recent past, and one of such advancement is the self-ligating brackets. These brackets are said to have less friction, with a shorter period of treatment. Better patient acceptance and good treatment results are some of the other advantages offered by self-ligating brackets. Hence, we comparatively evaluated root resorption of anterior teeth by self-ligating and conventional preadjusted brackets in cases of severe anterior crowding in class I patients.

MATERIALS AND METHODS

The present study was carried out at the department of orthodontics in a dental institution and included 140 patients that presented with the chief complaint of Angle class I malocclusion with crowding of more than 6 mm in the anterior tooth region. Two groups were formed with 70 patients in each group. In one group self-ligating brackets were used, while in other group conventional brackets were used. Malmgren's method was sued for evaluating the root resorption score ranging from 0 to 4. All the results were analyzed by the Statistical Package for the Social Sciences software. Chi-square test, nonpaired t-test, and paired t-test were used to evaluate the level of significance.

RESULTS

The mean age of the patients in groups I and II was 13.92 and 13.81 years respectively. While comparing age of the patients and time duration of the treatment, no significant results were obtained. While comparing the root resorptions at various time intervals in groups I and II patients, significant results were obtained. While comparing the root resorptions in between groups I and II patients, no statistically significant results were obtained (p-value > 0.05).

CONCLUSION

Statistically similar amount of resorption is seen in patients in both the groups either on self-ligating brackets or on conventional preadjusted brackets during treatment of Angle class I patients with severe anterior crowding.

CLINICAL SIGNIFICANCE

In treating anterior crowding patients with Angle class I patients, choice of brackets has no effect on the amount of root resorption.