Risk Factors Associated With Orthodontic Root Resorption and its Treatment Methods

ABSTRACT

Orthodontic-related root resorption affects dental health. The aim of the present study was to review the research conducted on the risk factors associated with orthodontic-related root resorption and its treatment methods. This is a review on scientific databases PubMed, Google Scholar, and Web of Science. Available data were extracted from the studies, and they were reviewed for quality and methodology. Between 2021 and 2024, 16,531 records were identified. Based on the search keywords, 398 studies were remined from screened records, and finally, 24 records were included. Factors such as the intensity and duration of orthodontic forces, tooth root characteristics (including root length and shape), age, history of dental trauma, and genetics may increase the risk of root resorption.

INTRODUCTION

Orthodontic-related root resorption is a problem that affects dental health, particularly in maxillary anterior teeth, leading to reduced root length and weakened tooth stability.[1] Despite having no clinical symptoms, in severe and advanced cases, it leads to loss of tooth function.[2]

Several factors play a role in its occurrence, including the intensity and duration of orthodontic forces applied,[3] anatomical features of the tooth root[4] and genetic factors,[5] imaging studies using cone beam computed tomography (CBCT) have shown that it is possible to detect this condition early and assess the extent of root resorption at different stages of orthodontic treatment.[6]

Given the importance of this issue, this study provides a review of research conducted on the risk factors associated with root resorption caused by orthodontic treatment and its treatment methods. The aim of this study was to synthesize the available scientific evidence to better understand the underlying mechanisms of root resorption and to provide effective strategies to reduce its detrimental effects.

METHODS

Study type

This is a review that assessed and identified the risk factors for root resorption caused by orthodontics and some of its treatment methods.

Inclusion Criteria: Articles published between 2021 and 2024 that examined root resorption caused by orthodontic treatment and evaluated risk factors such as anatomical features of teeth, duration of treatment, intensity of orthodontic forces, genetic factors, and use of imaging methods. Exclusion Criteria: Articles that lacked precision or comprehensive results or were based on unreliable hospital or experimental samples.

Data collection

Articles were extracted from reputable scientific databases PubMed, Google Scholar, and Web of Science. The search was conducted based on keywords such as “external root resorption,” “orthodontic treatment,” “risk factors,” and “root resorption treatment.”

The available data were extracted from cross-sectional, clinical trials and observational studies.

RESULTS

Between 2021 and 2024, 16,531 records were identified. Based on the search keywords, 398 studies were remined from records screened, and finally, based on Figure 1, 24 records were included in the study.

Figure 1.

PRISMA Flowchart for selecting of the literature related to this review

Most studies have focused on adolescent and adult patients, although some studies have focused on children or specific groups such as African-American orthodontics. Most studies had small sample sizes. In terms of study type, most studies were cross-sectional, and most used advanced imaging tools such as CBCT.

DISCUSSION

In general, orthodontic root resorption is directly influenced by factors such as the anatomical characteristics of the teeth, the intensity and duration of orthodontic forces, and genetics. The results showed that teeth with thinner or severely curved roots are more susceptible to root resorption. In addition, long-term treatment and the use of severe orthodontic forces increase the risk of root resorption.

In the review of treatment methods, the use of advanced imaging techniques such as CBCT has been able to effectively help in the early detection of root resorption. In addition, the use of photo-biomodulation as an auxiliary method has had a positive effect in reducing the incidence of root resorption during orthodontic treatment.

A study[7] that external apical root resorption (EARR) may occur due to repeated impacts or increased mechanical stresses on the teeth during exercise. Factors such as previous dental trauma, previous dental treatments, and mechanical stimuli including orthodontic forces increase the risk of root resorption, especially in sensitive teeth.[8,9] Various studies[3,4,10,11,12,13,14] identified factors such as the intensity and duration of orthodontic forces, patient age, history of dental trauma, type of tooth movement, and anatomical features of teeth (such as root length and shape) as factors affecting the occurrence of root resorption. In addition, long-term treatments and the use of high forces, especially in patients with shorter roots, increase the likelihood of EARR.[1,3,10,15,16,17]

A study[18] emphasizes that the position, orientation, and proximity of impacted supernumerary teeth to the roots of adjacent teeth are the most important risk factors for root resorption. Pereira et al.[19] showed that root resorption is commonly observed in endodontically treated teeth, especially in cases where treatment was delayed or the wrong treatment method was used. Various factors such as the duration of treatment, the severity of previous infections, the type and quality of root filling materials, and treatment techniques affect the occurrence of root resorption.

In addition, on the one hand, inflammation can help accelerate tooth movement and improve the speed of healing, but on the other hand, severe and prolonged inflammation can lead to apical root resorption and other dental problems. Therefore, the use of anti-inflammatory treatments and careful monitoring can help reduce the complications caused by inflammation.[20]

Gene polymorphisms related to bone remodeling, duration of orthodontic treatment, and intensity of applied forces were key factors in predicting the rate of root resorption.[4,9,11] IL1RN and P2RX7 gene polymorphisms have also been shown to be effective in the incidence of apical root resorption after orthodontic treatment.[5] A study by Rossi et al.[21] showed that the use of photo-biomodulation may help reduce the rate of root resorption, but further research is still needed to confirm these results.

CONCLUSION

It is concluded that EARR during orthodontic treatment, especially in teeth with specific anatomical features, can increase the risk of root resorption under the influence of factors such as the intensity and duration of orthodontic forces, tooth root characteristics (including root length and shape), patient age, history of dental trauma, and genetics. In addition, evidence suggests that the use of advanced imaging methods such as CBCT can help in the accurate identification and assessment of root resorption. Orthodontic treatment should be individually tailored to apply forces in a controlled manner and prevent the occurrence of root resorption. In addition, the combination of close clinical monitoring with the use of new therapeutic methods such as photo-biomodulation can be effective in reducing the complications of root resorption.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.