Histological changes in pulp-dentin complex in tooth subjected to traumatic occlusion and subluxation

Background

This study evaluated the influence of traumatic occlusion in the dentin-pulp complex a molar teeth submitted to subluxation.

Material and methods

Ninety Wistar rats were divided into groups Naïve (N), Subluxation (S) and Subluxation with traumatic occlusion (STO) and submitted to histological analysis after 7 and 21 days. A quantitative analysis was submitted to one-way ANOVA and Tukey's post-hoc test, and Chi-square and Bonferronís post-hoc test.

Results

S and STO showed a significant increase in blood vessels area (p < 0.0005), amorphous fundamental substance (p < 0.0005) and reactionary dentin formation (p < 0.0005), as well as a decrease in the nuclear profile (p < 0.0005), odontoblast layer (p = 0.013 and p < 0.0005) by day 7 when compared with N. These changes normalized by day 21, except for the reactionary dentin (p < 0.0005) in both S and STO groups. Interestingly, the STO group exhibited significant changes in the increase of pulp calcification (p < 0.0005), presence of tubules with nuclei (p < 0.0005), and inflammatory infiltrate (p < 0.0005), as well reduction of nuclear profile (p < 0.0005), odontoblast layer (p < 0.0005) compared with N and S at day 21.

Conclusions

STO impaired the defence response and decreased pulp regeneration capacity by increasing the inflammatory infiltrate and pulp calcification, and decreasing the nucleated cell number in the odontoblast layer and central pulp.

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.

Comparison of Tooth Color and Enamel and Dentinal Thickness between Orthodontically Treated and Untreated Individuals

This study compared tooth color and enamel and dentinal thickness between orthodontically treated and untreated individuals. (1) Methods: A matched case-control study was conducted. The sample included 26 patients who had received orthodontic treatment and 31 matched controls. The color assessment was performed subjectively using the VITA 3D-Master (VM) shade guide and objectively using the VITA Easyshade (VE) spectrophotometer. Differences in L*, a*, and b* (lightness, red/green, and blue/yellow) were calculated. The color change was evaluated using ΔE*ab and the whiteness index (WID). Tooth structure thickness (labiolingual, labial enamel, and labial dentin) was evaluated using cone-beam computerized tomography. The correlations between overall tooth color and tooth structure thickness were evaluated. (2) Results: A total of 228 teeth were evaluated. Color assessment using VM showed significant differences between orthodontically treated and untreated teeth (p < 0.001), while VE revealed no significant differences. Both groups showed no difference in tooth enamel and dentinal thickness. Significant differences in tooth color (p < 0.05) were observed between genders. Both VM and VE showed weak to moderate correlations with tooth color and enamel and dentinal thickness (p < 0.05). (3) Conclusions: Orthodontic treatment may demonstrate visually perceptible but acceptable and clinically undetectable tooth color alteration.

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.

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.

Incisal Interference Correction after Severe Extrusive Luxation Trauma during Orthodontic Treatment

This case report presents the treatment of a 12-year-old boy who suffered serious dental trauma, accompanied with buccal alveolar socket wall fractures, during orthodontic treatment. The maxillary right lateral incisor and canine were severely extruded and laterally luxated to the palatal side, resulting in an anterior crossbite and creating an incisal interference that prevented the jaws from closing in normal occlusion. During emergency treatment, the dentist attempted manual repositioning, but both severely extruded teeth were found to be immobile. One day after trauma, orthodontic repositioning was started using full fixed appliances with light 0.012″ nickel–titanium round wires, and this occlusal interference was corrected within 3 weeks. In the various internationally recognized treatment guidelines, the options for orthodontic repositioning for dental luxation trauma are only marginally described. Internationally accepted dental treatment guidelines may include immediate orthodontic repositioning after trauma as a treatment option in the management of dental extrusive and lateral luxation trauma.

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.

Incidence of pulp sensibility loss of anterior teeth after paramedian insertion of orthodontic mini-implants in the anterior maxilla

BACKGROUND

The aim of this retrospective investigation was to evaluate the incidence of loss to pulp sensibility testing (PST) of maxillary front teeth after paramedian (3 to 5 mm away from the suture) orthodontic mini-implant (OMI) insertion in the anterior palate.

METHODS

A total of 284 patients (102 males, 182 females; mean age was 14.4 years (±8.8) years at time of OMI-Insertion) with a total of 568 OMIs (1.7 mm diameter, length 8 mm) were retrospectively investigated. A binomial regression analysis was performed to explore covariates, such as age, gender, inclination of upper central incisors, dentition status and insertion position of OMIs that could have contributed to loss of sensibility. Statistical significance was set at p < 0.05.

RESULTS

Loss of response to PST was encountered during retention in 3 out of 284 patients and the respective OMIs had been placed at height of the second rugae (R-2). Affected teeth were a right canine, a left lateral and a left central incisor. Subsequent root canal treatment was successful. Results of the binomial regression analysis revealed that the covariate insertion position (R-2) of OMIs (p = 0.008) had statistically significant influence on loss of response to PST.

CONCLUSIONS

(1) Although there was no radiographic evidence for direct root injury, the proximity of the implants to the anterior teeth was nevertheless statistically related to loss of PST. (2) In all cases of PST loss OMIs were inserted at the second rugae. Therefore OMIs should be placed either more posteriorly, at the third rugae or in the median plane. (3). Loss of PST was not increased for patients with palatal OMI (0.18%) compared to samples without OMI (0.25%).

[Vitality loss: influence of orthodontic process]

Vitality loss is an unusual event that can occur before, during or after an orthodontic treatment. It can lead to loss of sensitivity, color change or necrosis of the pulp tissue. Before starting the orthodontic treatment, we have to identify the tooth's risk (injured tooth, included occlusal trauma...). Knowing that, if an endodontic treatment has to be done, it is better to do it before starting orthodontic forces. Lamps do not provide problems except high intensity halogen ones. RPE on children, Le Fort I and mandibular osteotomies, corticotomies, genioplasties are responsible of a transitory ischemia without reaching a pathogen level. Mini-screws or mini-plates may be iatrogenic, if they impact the root. The repair options depend on the delay before removing the miniscrew and the nature of injured tissue.

Influence of orthodontic forces on human dental pulp: a systematic review

AIM

The aim of the present study was to systematically review the influence of orthodontic force on human dental pulp.

METHODS AND RESULTS

The addressed focused question was "Do orthodontic forces affect the human dental pulp?" which was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a specific question was constructed according to the PICO (Participants, Interventions, Control, Outcomes) principle. Databases were explored from 1952 up to and including August 2014 using different combinations of the following keywords: "orthodontic force"; "dental pulp"; "reaction" and "tooth movement". Literature reviews, letters to the editor, commentaries and case-reports were excluded. Thirty studies were included. Six studies assessed the effect of orthodontic forces on pulpal blood flow and 20 studies investigated the pulpal cellular responses to orthodontic forces. In 4 studies, pulpal responses to orthodontic forces were compared between previously traumatized- and non-traumatized teeth.

CONCLUSIONS

There is insufficient scientific validation regarding the association between orthodontic forces and human dental pulp. However, a history of dental trauma maybe considered a risk factor for loss of pulp vitality during orthodontic treatment.

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.

Radicular maturity level of primary teeth and its association with trauma sequelae

AIM

This study aimed to investigate the influence of the radicular maturity level of primary teeth on the sequelae of traumatic dental injury (TDI).

MATERIALS AND METHODS

A longitudinal retrospective study that collected data from dental records and radiographs of patients with TDI in one or both maxillary primary central incisors was conducted. Sequelae such as crown discoloration, pulp canal obliteration (PCO) and inflammatory root resorption (IRR) were evaluated during a 12- to 18-month follow-up period after the trauma.

RESULTS

Of the 132 patients included in the study, 103 (78%) had luxations and 29 (22%) had dental fractures. At the initial postinjury examination, 12 teeth (9.1%) were found to have immature roots, 107 (81.1%) had closed apexes and 13 (9.8%) had visible root resorption. Inflammatory root resorption occurred mostly in traumatized teeth that presented with physiological root resorption at the moment of trauma (P = 0.004). The frequency of PCO was higher in teeth with a closed apex at the moment of the injury (P = 0.026). There was also an association between the type of injury and the occurrence of crown discoloration (P = 0.008) as well as between the type of injury and the development of PCO (P = 0.001).

CONCLUSIONS

The occurrence of TDI sequelae can be determined by the type of injury as well as by the radicular maturity level of the primary teeth at the moment of injury.

Low-level laser therapy effects in traumatized permanent teeth with extrusive luxation in an orthodontic patient

The aim of this case report was to present and evaluate the effect of low-level laser therapy on traumatized permanent teeth with extrusive luxation in an orthodontic patient. The treatment and follow-up evaluation of two orally luxated maxillary permanent central incisors in a 19-year-old man is described. Detailed anamnesis was taken, and extraoral, intraoral, radiographic examinations and electrical and thermal pulpal tests were performed to determine the type of the luxation and the further treatment protocol. Teeth were splinted with composite resin, and antibiotic therapy was prescribed. Low-level laser therapy was applied for 25 sessions. No root canal treatment was applied to the teeth. Continuation of the orthodontic treatment was restarted after 6 months. No sign of clinical or radiographic pathology was detected after 2 years from the end of the treatment. Teeth were identified healthy and sound without any root canal intervention. Treatments with low-level laser applications may be evaluated as noninvasive alternative treatment options in comparison with endodontic treatment for teeth with extrusive luxation more than 2 mm, especially for those who have orthodontic treatment needs.