Influence of orthodontic intrusion on pulpal vitality of previously traumatized maxillary permanent incisors

Orthodontic management of traumatic dental injuries in Norway and orthodontists' perceptions of referral routines: A quality assurance survey

BACKGROUND/AIM

Orthodontic treatment of patients with traumatic dental injuries is challenging, with limited evidence of routines and outcomes. The aims of this study were: (i) to describe how orthodontists perceive the information on traumatic dental injuries received by referral from the Public Dental Health Service before orthodontic treatment and (ii) to assess orthodontists' knowledge and working routines in managing traumatic dental injuries.

MATERIALS AND METHODS

Data were obtained through a survey of all practicing orthodontists registered as members of the Norwegian Association of Orthodontists (n = 203).

RESULTS

Eighty-three orthodontists were enrolled, most of whom had received their dental degree (73.0%) and specialist orthodontic training (88.5%) in Norway. They reported examining patients with a history of traumatic dental injury at weekly (34.2%) or monthly (38.0%) basis. In 85.5% of cases, they obtained a history of traumatic dental injury from patients. Half of the respondents (51.3%) favoured two-phase early orthodontic treatment for patients with an overjet ≥6 mm. The observation time and treatment strategy showed considerable discrepancies across traumatic dental injury diagnoses. Most (59.1%) orthodontists considered the information on previous traumatic dental injuries provided by the Public Dental Health Services referral 'inadequate', more commonly in cases of mild (83.5%) than severe (57.5%) traumatic dental injuries.

CONCLUSIONS

Orthodontic management of patients with traumatic dental injuries was characterised by lack of uniformity in both recommended observation time before orthodontic treatment and management strategy. The referral routines by the Public Dental Health Services for patients with traumatic dental injuries were perceived as 'inadequate' in terms of frequency and quality. The results indicate the requirement of standardisation of routines related to orthodontic management of traumatic dental injuries and referral routines by the Public Dental Health Services.

Do orthodontic movements of traumatized teeth induce dental pulp necrosis? A systematic review

INTRODUCTION

Usually, orthodontic movements encompass children and young adult patients, which are more susceptible to the occurrence of traumatic dental injuries. It is necessary to understand whether the effects of orthodontic movements on traumatized teeth could induce pulp necrosis. The aim of this study was to answer the following question: "Do orthodontic movements of traumatized teeth induce dental pulp necrosis?".

MATERIAL AND METHODS

Searches were performed for studies published up to May 11, 2023, in the MEDLINE/PubMed, Cochrane Library, Scopus, SciELO Citation Index, Web of Science, EMBASE, and Grey Literature Report databases, without restriction for language or year of publication. The revised Cochrane risk of bias tools for nonrandomized interventions (ROBINS-I) was used to assess the quality of the included studies. The overall quality of evidence was assessed through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool.

RESULTS

Of 2671 potentially relevant studies, five were included. Four were classified as having a moderate risk of bias and one as a serious risk of bias. It was reported a higher susceptibility to pulp necrosis in teeth subjected to orthodontic movements with history of trauma involving periodontal tissues. Additionally, orthodontic movements of traumatized teeth with total pulp obliteration had an increased risk of pulp necrosis. GRADE analysis presented a moderate certainty of evidence.

CONCLUSIONS

An increased risk for pulp necrosis when traumatized teeth are subjected to orthodontic movements was verified. However, this is based on evaluations performed with subjective tests. Further well-designed studies are necessary to confirm this trend.

CLINICAL RELEVANCE

Clinicians must be aware of the possibility of pulp necrosis. However, endodontic treatment is recommended when verified signs and symptoms of pulp necrosis.

Necrotic Pulp With Crown Discoloration Associated With Orthodontic Treatment: A Case Report

Orthodontic treatment may have iatrogenic consequences for the pulpal tissue. This study describes the endodontic treatment and internal bleaching that were used to treat a necrotic pulp with internal resorption caused by the dentist. This happened to the pulpal tissue after it had been treated with orthodontics. To prevent such iatrogenic consequences for pulpal tissue during orthodontic treatment, it is essential to maintain frequent radiological follow-ups. Regular radiographic examinations can help identify any potential complications early on, allowing for timely intervention and treatment. Additionally, employing light orthodontic force can help minimize the risk of trauma to the pulpal tissue, reducing the likelihood of necrosis and internal resorption.

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.

Impact of Dental Trauma on Orthodontic Parameters-A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Investigation into the impact of dental trauma on the results of orthodontic treatment is crucial because it can have a major influence on patient care. However, there has not yet been a thorough review or meta-analysis of the available data, which is inconsistent and scant. Therefore, the goal of this systematic review and meta-analysis is to investigate the impact of dental trauma on orthodontic parameters. Search methods and criterion of selection: Major online databases were searched (beginning from the year 2011) for relevant articles using a properly defined search strategy. Analysis protocol: Risk of bias (RoB) and the Cochrane risk of bias tool were utilized for the purposes of bias evaluation within the individual studies and within the review, respectively.

RESULTS

Out of the six clinical trials selected, a significant impact of trauma was observed in individuals in all but one paper. Gender predilection varied across studies and could not be conclusively determined. The follow-up period ranged from two months to two years in the trials. The odds ratio (OR) 0.38 [0.19, 0.77] and the risk ratio (RR) 0.52 [0.32, 0.85] indicated that both the odds as well as the relative risk of experiencing dental trauma were lower in the group with negligible impact compared to the group with noticeable impact. Conclusion and further implications: The findings show that dental trauma significantly affects orthodontic parameters, with lower risk and likelihood of suffering dental trauma in the group with negligible impact than in the group with noticeable impact. However, given the substantial heterogeneity among the studies, it is advised to exercise caution when extrapolating the findings to all populations. Registration and protocol: Registration in the PROSPERO database was carried out before initiating the investigation [CRD42023407218].

Assessment of the Maximum Amount of Orthodontic Force for PDL in Intact and Reduced Periodontium (Part I)

This study examines 0.6 N and 1.2 N as the maximum orthodontic force for periodontal ligament (PDL) at multiple levels of periodontal breakdown, and the relationships with the ischemic, necrotic, and resorptive risks. Additionally, this study evaluates if Tresca failure criteria is more adequate for the PDL study. Eighty-one 3D models (from nine patients; nine models/patients) with the 2nd lower premolar and different degrees of bone loss (0-8 mm) where subjected to intrusion, extrusion, rotation, translation, and tipping movements. Tresca shear stress was assessed individually for each movement and bone loss level. Rotation and translation produced the highest PDL stresses, while intrusion and extrusion determined the lowest. Apical and middle third PDL stresses were lower than the cervical stress. In intact periodontium, the amount of shear stress produced by the two investigated forces was lower than the 16 KPa of the maximum physiological hydrostatic pressure (MHP). In reduced periodontium (1-8 mm tissue loss), the apical amount of PDL shear stress was lower than MHP for both applied forces, while cervically for rotation, translation and tipping movements exceeded 16 KPa. Additionally, 1.2 N could be used in intact periodontium (i.e., without risks) and for the reduced periodontium only in the apical and middle third of PDL up to 8 mm of bone loss. However, for avoiding any resorptive risks, in the cervical third of PDL, the rotation, translation, and tipping movements require less than 0.2-0.4 N of force after 4 mm of loss. Tresca seems to be more adequate for the study of PDL than other criteria.

Assessment of the Maximum Amount of Orthodontic Force for Dental Pulp and Apical Neuro-Vascular Bundle in Intact and Reduced Periodontium on Bicuspids (Part II)

This study examines 0.6 N-4.8 N as the maximum orthodontic force to be applied to dental pulp and apical NVB on intact and 1-8 mm reduced periodontal-ligament (PDL), in connection with movement and ischemic, necrotic and resorptive risk. In addition, it examines whether the Tresca finite-element-analysis (FEA) criterion is more adequate for the examination of dental pulp and its apical NVB. Eighty-one (nine patients, with nine models for each patient) anatomically correct models of the periodontium, with the second lower-premolar reconstructed with its apical NVB and dental pulp were assembled, based on X-ray CBCT (cone-beam-computed-tomography) examinations and subjected to 0.6 N, 1.2 N, 2.4 N and 4.8 N of intrusion, extrusion, translation, rotation, and tipping. The Tresca failure criterion was applied, and the shear stress was assessed. Forces of 0.6 N, 1.2 N, and 2.4 N had negligible effects on apical NVB and dental pulp up to 8 mm of periodontal breakdown. A force of 4.8 N was safely applied to apical NVB on the intact periodontium only. Rotation and tipping seemed to be the most invasive movements for the apical NVB. For the dental pulp, only the translation and rotation movements seemed to display a particular risk of ischemia, necrosis, and internal orthodontic-resorption for both coronal (0-8 mm of loss) and radicular pulp (4-8 mm of loss), despite the amount of stress being lower than the MHP. The Tresca failure criterion seems more suitable than other criteria for apical NVB and dental pulp.

Assessment of the Best FEA Failure Criteria (Part II): Investigation of the Biomechanical Behavior of Dental Pulp and Apical-Neuro-Vascular Bundle in Intact and Reduced Periodontium

The aim of this study was to biomechanically assess the behavior of apical neuro-vascular bundles (NVB) and dental pulp employing Tresca, Von Mises, Pressure, S1 and S3 failure criterions in a gradual periodontal breakdown under orthodontic movements. Additionally, it was to assess the accuracy of failure criteria, correlation with the maximum hydrostatic pressure (MHP), and the amount of force safe for reduced periodontium. Based on cone-beam computed tomography, 81 3D models of the second lower premolar were subjected to 0.5 N of intrusion, extrusion, rotation, tipping, and translation. A Finite Elements Analysis (FEA) was performed. In intact and reduced periodontium apical NVB, stress (predominant in all criteria) was significantly higher than dental pulp stress, but lower than MHP. VM and Tresca displayed identical results, with added pulpal stress in translation and rotation. S1, S3 and Pressure showed stress in the apical NVB area. 0.5 N seems safe up to 8 mm periodontal breakdown. A clear difference between failure criteria for dental pulp and apical NVB cannot be proved based only on the correlation quantitative results-MHP. Tresca and VM (adequate for ductile materials) showed equivalent results with the lowest amounts of stress. The employed failure criteria must be selected based on the type of material to be analyzed.

Do orthodontic tooth movements induce pulp necrosis? A systematic review

BACKGROUND

Orthodontic tooth movements are performed by applying forces on teeth, which may cause alterations within the dental pulp. Previously published systematic reviews on the subject only included a small number of studies that assessed pulp status through reliable diagnostic methods. Since then, new evidence has been published, and a further systematic review on the subject is necessary.

OBJECTIVES

To evaluate whether there is scientific evidence to support the possibility that orthodontic tooth movements could induce pulp necrosis.

METHODS

A systematic search of articles published until June 2020 was performed using MeSH and free terms in the PubMed, Cochrane Library, LILACS, SciELO, Web of Science, EMBASE, Open Grey and Grey Literature databases. Randomized clinical trials (RCTs), nonrandomized clinical trials (nRCTs) and longitudinal (prospective or retrospective) studies that evaluated the pulp status of teeth subjected to orthodontic movements using laser Doppler flowmetry or pulse oximetry were included. The revised Cochrane risk of bias tools for randomized trials (RoB 2) and nonrandomized interventions (ROBINS-I) were used to assess the quality of the included studies. Relevant findings were summarized and evaluated. The overall quality of evidence was assessed through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool.

RESULTS

Initial screening of databases resulted in 353 studies. In total, 285 studies were excluded because they were duplicates. Of 68 eligible papers, fourteen met the inclusion criteria and were selected for full-text reading. Two studies were excluded due to the methods used to evaluate pulp status. Twelve studies (five RCTs, one nRCT and six prospective) were included. Four RCTs were classified as having an unclear risk of bias and one as having a high risk of bias. The nRCT was classified as having a low risk of bias. Two prospective studies were classified as having a moderate risk of bias and four as having a serious risk of bias. The GRADE analysis demonstrated a low to very low quality of evidence.

DISCUSSION

Significant limitations regarding the randomization processes within the included RCTs and a lack of control of confounders on most nonrandomized and longitudinal studies were verified.

CONCLUSIONS

This systematic review indicates that orthodontic movements do not induce loss of pulp vitality with low to very low certainty of evidence.

In Vivo Biological Evaluation of Orthodontically Moved Incisors after Replantation

Background and Objectives: There is still considerable controversy regarding the possibility of submitting replanted teeth to orthodontic movement (OM). The purpose of the present study was to evaluate the tissue response after orthodontic movement on replanted teeth. Materials and Methods: Sixty Wistar rats were randomly assigned to four groups (n = 15): G1, replantation without OM after 30 days; G2, replantation with OM after 30 days; G3, replantation without OM after 60 days, and G4, replantation with OM after 60 days. The maxillary left central incisors were extracted and the teeth were stored in milk media. After 30 min, the teeth were replanted and fixed with non-rigid immobilization. All specimens were observed after 30 and 60 days of replantation and then subdivided into two subgroups (with OM or without OM). The animals were euthanized after seven days of the OM started, and the maxillary bone blocks were processed for histological evaluation. Results: The histological results showed periodontal ligament repair in both periods studied without OM; however, ankylosis and root resorption was seen in all orthodontically moved teeth. Conclusions: The orthodontic movement did not favor tissue response in all replanted teeth, regardless of the experimental periods.

Orthodontic treatment recommendation and expected adverse reactions in patients with a history of dental trauma: A survey among general dentists, paediatric dentists, and orthodontic specialists

BACKGROUND

Trauma-induced adverse reactions may trigger complications when moving teeth orthodontically.

AIM

The purpose of this study was to evaluate the knowledge of dental practitioners about this topic.

DESIGN

A questionnaire survey was organized among general dentists, paediatric dentists, and orthodontists in Flanders (Belgium). Three clinical cases describing trauma-induced tooth damage (tooth ankylosis, apical root resorption, and pulp/root canal obliteration) were presented, followed by a set of questions.

RESULTS

The questionnaire was completed by 121 general dentists (GD), 47 paediatric dentists (PD), and 99 orthodontic specialists (OS). In the case with ankylosis, impossibility to move the tooth orthodontically was reported as most frequent adverse reaction (82.8% of GD, 95.7% of PD, and 100.0% of OS) (P < .001). In the situation of apical root resorption, the most frequently reported adverse event was progressive apical root resorption (78.9%, 85.7%, and 88.8% respectively; P = .265). Most frequently mentioned adverse reaction in the case with pulp and root canal obliteration was tooth discoloration (64.1%, 57.1%, and 78.3%; P = .055), followed by apical root resorption (57.4%, 56.8%, and 68.7%; P = .283). Orthodontic treatment recommendation differed among specific clinical situations but also among groups of dental practitioners.

CONCLUSIONS

Important knowledge gaps exist regarding the orthodontic managment of traumatized teeth. This topic requires more attention in undergraduate training, specialist training, and continuing education.

Knowledge of orthodontic treatment approach of traumatized teeth by a group of Belgian general dentists, pediatric dentists, and orthodontists

BACKGROUND/AIM

Traumatized teeth are more susceptible to complications during orthodontic tooth movement. The aim of this study was to explore current practices among Belgian dental practitioners regarding orthodontic treatment of children with a history of dental trauma.

MATERIAL AND METHODS

A questionnaire survey was organized among general dentists, pediatric dentists, and orthodontists in Flanders (Belgium). Questionnaires were distributed at the occasions of annual meetings or symposia. They consisted of questions regarding exposure to dental trauma and orthodontic treatment approach for patients with a dental trauma history.

RESULTS

The questionnaire was completed by 121 general dentists, 47 pediatric dentists, and 99 orthodontists. A history of dental trauma influenced referral for orthodontic treatment by general dentists and pediatric dentists moderately (median VAS scores of 5 and 6, respectively, on a scale of 0 (not at all) to 10 (utmost)), indicating uncertainty and doubt. Additional checkups during tooth movement were usually not organized by general dentists in 33.6% and by pediatric dentists in 19.1% of cases (P = 0.006). One-third of the orthodontists (33.3%) experienced tooth loss linked to orthodontic movement of a tooth with dental trauma history in at least one patient. Only a minority of the practitioners knew of the existence of specific guidelines (7.6%, 15.6% and 22.7%, respectively, of general dentists, pediatric dentists, and orthodontists) (P = 0.007). The Dental Trauma Guide was the guideline mentioned most frequently, although this tool does not contain recommendations regarding orthodontic treatment after trauma.

CONCLUSION

In the group of Belgian general dental, pediatric and orthodontists surveyed, there was uncertainty regarding the orthodontic management of patients with a history of dental trauma especially among general practitioners. Further educational training is recommended.

The Effect of Orthodontic Forces on Tooth Response to Electric Pulp Test

Introduction:

The current study investigated the pulp response to electric pulp testing (EPT), before, upon initiation and one month after the start of orthodontic tooth movement.

Methods and Materials:

A total of 402 anterior teeth from 39 patients (mean age of 16.8±2.7 years) were examined in this non-controlled prospective study. The aligning forces were administered using initial NiTi archwires ligated on fixed appliances by using the MBT straight wire technique. The electrical stimulation was provided by the EPT. The EPT readings were recorded at three time points: before bonding (EPT₀), immediately upon initiation (EPT₁) and 1 month post-treatment (EPT₂). The data were statistically analyzed by the ANOVA and Bonferroni tests (P<0.05).

Results:

Prior to bonding of the orthodontic brackets, the mean EPT value for all the experimental teeth was 3.42 EPT units. Upon initiation, the mean value of EPT₁ for each tooth increased to 7.62 units. One month later, the mean EPT₂ values dropped to 6.27 units. At this time point, 64 teeth (16%) of the experimental teeth failed to respond. The differences among EPT values at different time points were significant. There was no association between the EPT values and the location or the type of teeth.

Conclusion:

The physiological changes in the pulp affect the nerve fibers in the early stages of the orthodontic force application. As a result, thresholds to electrical stimulation would increase and the EPT may not initiate a response. Therefore results obtained by electrical pulp testing should be interpreted accordingly.

Nonsurgical management of an extensive endodontic lesion in an orthodontic patient by calcium-enriched mixture apical plug

Periapical lesion is a general term used to describe the periapical inflammatory process that occurs in response to the invasion of micro-organisms in the root canal system as well as inflamed vital pulp. This phenomenon necessitates endodontic intervention and if the necrosis has occurred prior to tooth maturation, wide patency of the apical foramen requires some treatment modalities such as apexification or apical plug. Orthodontic treatment, on the other hand, is cautiously done for previously traumatized teeth due to increased risk for necrosis of the compromised tooth. This article tends to review the successful treatment process with calcium-enriched mixture (CEM) cement apical plug for an immature previously traumatized incisor tooth with an extensive periapical lesion, which was under orthodontic treatment as well.

Orthodontic procedures after trauma

This review considers oral trauma and its relationship to orthodontics with respect to prevention and primary, secondary, and tertiary care. The level of evidence is not high in regard to this topic, but recommendable approaches to trauma at each stage are discussed on the basis of available literature and published guidelines. Simplified biomechanics are presented to aid treatment.