Intrusive luxation is a severe form of dental trauma and there is no consensus regarding its management for permanent teeth. A systematic review and meta-analysis was performed to identify the appropriate treatment for teeth with intrusive luxation. The PubMed/MEDLINE, Embase, US Clinical Trials, and ISRCTN Registry electronic databases were used to search for articles in English and unpublished studies without a date limit. Eligible studies evaluated periodontal results (root resorption as the primary outcome; marginal bone defects and/or pulpal changes as secondary outcomes) after spontaneous re-eruption (SRE), orthodontic repositioning (ORP), or surgical repositioning (SRP) for patients with one or more traumatically intruded permanent teeth. Risk ratios with 95% confidence intervals were used to compare treatments. The meta-analysis revealed no significant difference ( P > 0.05) between SRP and SRE for root resorption. For secondary outcomes, SRE was significantly better than SRP and ORP ( P < 0.05). Subgroup analyses showed no significant differences among treatments in teeth with completely formed roots ( P > 0.05) and a better prognosis when SRE was performed in teeth with incompletely formed roots ( P < 0.05). The available evidence does not allow us to conclude on the best treatment for traumatically intruded teeth. More reliable evidence is needed.
Dental trauma is a significant problem that affects approximately 25% of school-age children, and its incidence can exceed those of dental caries and periodontal disease in this population. Moreover, approximately 33% of adults suffer trauma in the permanent dentition.
Intrusive luxation is a severe form of dental trauma, accounting for 0.5–2% of traumas affecting the permanent dentition. Its low incidence makes it difficult to perform research involving a large number of participants, and makes treatment strictly empirical, even at major trauma centres.
Intrusive luxation is defined as the axial dislocation of a tooth in its alveolus. The injury is so severe because the root surface of the intruded tooth remains in intimate contact with the alveolar bone, resulting in the destruction of most fibres of the periodontal ligament and the cementum of the root surface. Vascular compression of the periodontium and pulpal complex causes ischemia. As a result of these characteristics, healing following intrusive luxation is associated with several complications, such as inflammatory and replacement root resorption.
Currently, three treatments are available for intrusive luxation: spontaneous re-eruption, orthodontic repositioning, and surgical repositioning. However, the published evidence provides conflicting prognoses for these three treatment types.
The protocols used by the International Association of Dental Traumatology (IADT) and by the UK National Clinical Guidelines in Paediatric Dentistry were developed based on literature reviews and consensus meetings. In addition, the treatment decision considers the degree of intrusion and the degree of root formation, which are important confounding variables related to the treatment outcome.
In 2014, a systematic review concluded that spontaneous eruption yields the least complications in immature teeth, regardless of the degree of intrusion, and observed no significant differences between active treatments (surgical and orthodontic). These conclusions were based exclusively on the results of the articles included in the review, without statistical analyses. Therefore, a further study including the statistical analysis of primary studies could produce a single estimate result and an overall conclusion, providing the best available evidence to guide the selection of the optimal treatment methods in the future.
A systematic review and meta-analysis of interventional and observational studies—both prospective and retrospective—was thus performed to assess the periodontal effects (inflammatory and/or substitution root resorption) of the three treatments, spontaneous re-eruption, orthodontic repositioning, and surgical repositioning, used to manage patients with one or more permanent teeth that have suffered intrusive luxation.
Materials and methods
This systematic review and meta-analysis was performed in accordance with the criteria established in the PRISMA 2009 guidelines. It is registered in the PROSPERO database (National Institute for Health Research) under registration number CRD42015025334.
The PICO (population, intervention, comparison, and outcomes) method was used to define the research question and to optimize the search strategy : (1) Population: only studies on humans with one or more traumatically intruded permanent teeth were included. (2) Intervention: spontaneous re-eruption, orthodontic repositioning, or surgical repositioning of the intruded tooth/teeth were evaluated. (3) Comparison: comparisons between orthodontic and surgical repositioning, between one of the two types of repositioning and no repositioning, and between the two types of repositioning and no repositioning were evaluated. (4) Outcome: root resorption was the primary outcome evaluated, and marginal bone defects and pulpal changes were the secondary outcomes. All studies that evaluated at least one type of periodontal parameter were included.
Search strategy to identify studies
The search strategy was developed for PubMed/MEDLINE and revised for other databases. Search terms were related to the types and populations of the studies ( Fig. 1 ). The searches were performed systematically in April 2015 using the online databases Embase and PubMed/MEDLINE. Studies published in English were selected, without restriction on year of publication. The references of pre-selected articles were also reviewed.
Articles that were not available online were obtained using a bibliographic commutation program (Comut; Programa de Comutação Bibliográfica do Instituto Brasileiro de Informação em Ciência e Tecnologia). The US Clinical Trials ( www.clinicaltrials.gov ) and ISRCTN Registry ( www.isrctn.com ) websites were searched for unpublished literature (records of clinical trials) using only the term ‘dental trauma’, because ‘intrusion’ and ‘intrusive luxation’ did not present any results.
Two independent reviewers (LAC and LMC) identified and evaluated the titles and abstracts of the articles. When the information in the title and abstract was insufficient, the entire article was read. The two reviewers met to finalize the article selection. When there was disagreement, a third reviewer (CCCR) decided on the article inclusion. The articles included in this review had to report at least 6 months of follow-up.
Evaluation of study quality
The quality of each study was evaluated on the basis of the risk of bias using the criteria recommended in the Cochrane Handbook for Systematic Reviews of Interventions, version 5.1.0. The following criteria were applied: (1) random sequence generation to form intervention groups; (2) allocation concealment before grouping; (3) blinding of participants and healthcare providers; (4) blinding of the outcome evaluators; (5) incomplete outcome data (i.e., reasons for losses not reported or no corresponding data from the text and tables); (6) selective reporting (i.e., possibility of establishing a connection between diagnosis, treatment, and outcome); and (7) other biases (mainly related to the study design).
Using these criteria, the articles were classified as having a low risk of bias (improbable that bias directly affected the results) if all criteria were followed, as having a moderate risk of bias (bias leaving some doubt about the validity of the results) if one or more criteria were partially followed and judged as having an indeterminate risk of bias, or as having a high risk of bias (bias that severely weakened the reliability of the results) if one or more criteria were not followed.
The studies covered by this research normally followed some type of protocol for choosing the treatment type according to the degree of intrusion and the degree of root formation, which are important confounding variables. Therefore, a second selection was performed, wherein only studies that reported the primary (periodontal) and/or secondary (bone and pulp) outcomes to treatments and/or the diagnosis (degree of intrusion and degree of root formation) were retained. When the pre-selected studies did not meet these criteria, the corresponding authors were e-mailed for additional information. Papers were excluded if the authors did not reply.
Three reviewers (LAC, LMC, CCCR) independently evaluated the quality of the pre-selected studies, and a kappa test was performed to assess the agreement between the reviewers. Disagreements were resolved by discussion until consensus was reached.
Two reviewers (LAC and LMC), who were not blinded to the title of the journal or the authors, extracted the following data from the articles: the collection period, country of study, sample size, sample characteristics, degree of intrusion, degree of root formation, treatments performed, and outcomes. All data were stored in a Microsoft Excel 2007 spreadsheet.
To compare the presence or absence of periodontal and pulpal outcomes after treatment, risk ratios (RR) with 95% confidence intervals (CI) were used; the standard deviation of each group was also analyzed. A meta-analysis was performed only when the comparison of at least three studies was possible.
Values of P < 0.05 were considered significant for all of the analyses performed. A software program was used for the meta-analysis, as well as to produce the forest plots (Review Manager, RevMan version 5.3; The Nordic Cochrane Centre, Copenhagen, Denmark; The Cochrane Collaboration, 2014).
Risk of bias in the studies
The fixed-effects model was used when there was no statistically significant difference and the random-effects model when there was a statistically significant difference, i.e., a high level of heterogeneity, between trials (this was considered significant at P < 0.1). Heterogeneity was assessed using the Q method ( χ 2 ), and the value of I 2 was calculated. The statistical value of I 2 was used to analyze heterogeneity, where I 2 of 50–75% indicated moderate heterogeneity and I 2 above 75% indicated significant heterogeneity.
To analyze the sensitivity of the tests employed, a subgroup analysis to identify any potential causes of heterogeneity was performed. Specifically, subgroup analyses based on the degree of root formation and the degree of intrusion were performed.
The electronic search yielded 294 unique titles. After evaluating all of the titles and abstracts, and reading 17 full articles, seven studies were eligible on the basis of the inclusion criteria. No unpublished study met the eligibility criteria.
A search of the references revealed 16 additional studies of interest that had not been identified in the original search. After searching for and reading the full-texts of these articles, three of them were eligible for inclusion in this review. Finally, a total of 10 articles met the inclusion criteria and were included ( Fig. 2 ).
The 10 eligible articles were assessed for their individual quality and risk of bias. After this step, two articles were excluded. The reasons for exclusion are presented in Table 1 .
|Studies excluded||Reasons for exclusion|
|Andreasen and Pedersen, 1985||It was not possible to establish a relationship between the outcome and levels of root formation and intrusion, or between the outcome and treatment|
|Tsilingaridis et al., 2012||It was possible to establish a relationship between the diagnosis and treatment, but not between these and the outcomes|
The risk of bias did not influence the exclusion of the articles, but it did affect the interpretation of the data obtained. The kappa test for agreement among the reviewers was 0.84 (95% CI 0.63–1.0).
Characteristics of selected articles
Initially, only five of the 10 eligible articles were included in this review, as they presented data on the correlations between the treatments and outcomes. The corresponding authors of the remaining studies were contacted by e-mail for additional information, and three authors responded. With the additional data provided, these three studies were included in the review, yielding eight articles that appropriately addressed the research questions.
The studies included in this review reported 6 months to 5 years of follow-up. The outcomes presented in these studies are reported without establishing relationships with the follow-up period shown.
Table 2 presents the key information from these eight selected articles. Only one study included cases from two centres, and only one study reported financing using outside funds.
|Study||Country||n||Age (years), mean (range), or mean ± SD||Follow-up||Antibiotics||Local disinfection||Post-surgical splint|
|Kinirons and Sutcliffe, 1991||Northern Ireland||29||9.55 (7–12)||2 years total||NR||NR||Removable splint 4–7 days|
|Ebeleseder et al., 2000||Austria||58||11.1 ± 5.21 (medium-term)
11.7 ± 4.25 (short-term)
|Medium-term group: mean 40 months
Short-term group: mean 9 months
|Cephalosporin, penicillin, or erythromycin for 8 days||Chlorhexidine mouth rinse 3 times daily for 2 weeks||Held in place with thread and resin for 3–4 weeks|
|Andreasen et al., 2006||Denmark||140||8 ± 11.41
6–11, n = 73
12–17, n = 30
18–67, n = 37
|≥1 year||1 g penicillin immediately and 500 mg 4 times daily for 4 days||NR||Rigid, semi-rigid, or flexible for 6–8 weeks|
|Wigen et al., 2008||Norway||51||6–11, 45 teeth
12–17, 6 teeth
|Mean 4 years, range 1–12 years||Penicillin prescribed to 15 patients (from table) and nine patients (from text)||0.1% chlorhexidine mouth rinse 2× daily||Held in place with wire and resin for 2–6 weeks|
|Moreira Neto et al., 2009||Brazil||15||8.9 (7–14.8)||Minimum 6 months, mean 26.6 months||NR||NR||NR|
|Stewart et al., 2009||Ireland||55||9.3 ± 1.99||2.3 ± 1.6 years||21 patients, posology NR||NR||NR|
|Al-Badri et al., 2002||Northern Ireland and North East England||61||9.3 ± 1.94||Mean 2.9 years||NR||NR||NR|
|Humphrey et al., 2003||Canada||31||9.3 ± 2.7||Minimum 6 months, mean 26.6 months||Penicillin (50 mg/kg) prescribed to all patients for 7 days||0.1% chlorhexidine gluconate mouth rinse||Passive non-rigid splint of 0.014 or 0.016 inch stainless steel orthodontic wire|
|Study||Losses||Treatment time||Degree of intrusion||Classification of root development||Treatment||Correlation possible|
|Kinirons and Sutcliffe, 1991||9 teeth: 6 SRE, 3 SRP||SRE: NR
SRP: >24 h, 9 teeth; <24 h, 10 teeth
|<4 mm: 14 teeth
≥5 mm: 15 teeth
|Root canal and apex features||SRE: 10 teeth
SRP: 19 teeth
|Ebeleseder et al., 2000||2 teeth in medium-term and 1 tooth in short-term follow-up; due to epithelial invagination (1), longitudinal fracture (1), a new trauma (1)||Emergency||1–2 mm: 12 teeth
3–4 mm: 15 teeth
5–mm: 14 teeth
>9 mm: 16 teeth
NR: 1 tooth
|Root, root canal, and apex features||SRE: 9 teeth
SRP: 48 teeth
ORP: 1 tooth
|Outcome/degree of intrusion; outcome/degree of root formation; outcome/treatment|
|Andreasen et al., 2006||28 teeth: by root resorption (17), spontaneous root fracture after endodontic treatment (4), due to poor prognosis (7)||≤24 h: 58 teeth
≥24 h: 11 teeth
SRE: 38 teeth
NR: 33 teeth
|1–3 mm: 30 teeth
4–5 mm: 54 teeth
6–7 mm: 24 teeth
8–9 mm: 18 teeth
10–16 mm: 14 teeth
|Root and apex features||SRE: 38 teeth
ORP: 29 teeth
SRP: 73 teeth
|Degree of intrusion/treatment/outcome; degree of root formation/treatment/outcome|
|Wigen et al., 2008||7 teeth: due to ankylosis (2), immature teeth with necrotic pulp (4), extracted for orthodontic reasons (1)||NR||Incisor almost invisible: 21 teeth
>2 mm: 22 teeth
<2 mm: 8 teeth
|Root and apex features||SRE: 37 teeth
ORP: 7 teeth
SRP: 7 teeth
|Outcome/degree of intrusion; outcome/degree of root formation;
|Moreira Neto et al., 2009||2 teeth: due to inflammatory root resorption (1), replacement root resorption (1)||NR||All >6 mm||Nolla’s classification||SRE: 5 teeth
SRP: 10 teeth
|Degree of intrusion/degree of root formation/treatment/outcome|
|Stewart et al., 2009||5 teeth: 1 tooth SRE, with incomplete apex; 4 teeth ORP with incomplete apex||NR||<3 mm: 4 teeth
3–6 mm: 10 teeth
>6 mm: 11 teeth
NR: 30 teeth
|Root and apex features||SRE: 19 teeth
ORP: 22 teeth
SRP: 14 teeth
|Degree of root formation/treatment/outcome|
|Al-Badri et al., 2002||13 teeth: submitted treatment NR||NR||0–2 mm: 7 teeth
3–5 mm: 27 teeth
>5 mm: 27 teeth
|According to apex features||SRP: 35 teeth
NSRP: 26 teeth
|Degree of root formation/treatment/outcome|
|Humphrey et al., 2003||5 teeth: reasons NR||NR||<3 mm: 8 teeth
3–6 mm: 12 teeth
>6 mm: 11 teeth
|Root and apex features||SRE: 11 teeth
ORP: 6 teeth
SRP: 14 teeth
|Degree of intrusion/degree of root formation/treatment/outcome|