Self-correction of the ectopic eruption of the maxillary first permanent molar and its predictive factors: A systematic review.

BACKGROUND: Ectopic eruption of the maxillary first permanent molar is a local disturbance that affects the development of the occlusion. AIM: To evaluate the occurrence of self-correction of maxillary first permanent molar's ectopic eruption and its predictive factors. DESIGN: Five electronic databases and part of the gray literature were investigated. The risk of bias was assessed using the Newcastle-Ottawa scale and the certainty of evidence using the GRADE tool. RESULTS: Four studies were selected: Three had a low risk of bias, and one, moderate. Evidence with a moderate level of certainty was generated, indicating a possibility of 47%-78% of spontaneous correction up to 7 years of age. Supporting the prognosis, whether reversible or irreversible, there was a positive correlation between the severity of the atypical distal resorption of the second primary molar, a higher magnitude of impaction, a larger eruption angle, and a bilateral occurrence with the irreversibility of the cases. CONCLUSION: Spontaneous correction of the ectopic eruption of the maxillary first permanent molar is feasible and dependent on the severity of predictive factors. Early intervention is mandatory in irreversible cases.

Spontaneous changes in mandibular incisor crowding from mixed to permanent dentition: a systematic review.

INTRODUCTION: Dental crowding is the most prevalent malocclusion in the mixed and permanent detitions and can have a major impact on dentofacial esthetics. However, adjustments to the development and growth of the dentition can potentiate self-correction of dental crowding during childhood. OBJECTIVE: To evaluate the physiological behavior of mandibular incisor crowding in the transition from mixed to permanent dentition. METHODOLOGY: Five electronic databases (PubMed, Scopus, Web of Science, LILACS and LIVIVO) and part of the gray literature (Proquest and Google Scholar) were investigated, based on the eligibility criteria associated with the acronym PECO, until June 2022. The risk of bias was assessed using the ROBINS-E tool and the certainty of evidence, the GRADE tool. RESULTS: Among the 2.663 studies identified, five were selected for qualitative analysis, of which one have a low risk of bias, and four, a moderate risk. A total of 243 patients were evaluated. Evidence with a high level of certainty was generated indicating a tendency for improvement in mandibular incisor crowding from mixed to permanent dentition, with mandibular incisor crowding decreasing from 0.17 to 4.62 mm on average. The mandibular incisor crowding reduction seems to be associated with the amount of initial crowding and spontaneous dental arch dimensional changes that occur in the mixed dentition and culminate in the increase in arch perimeter, leeway space, incisor protrusion and transverse growth of the maxillary and mandibular arch. CONCLUSION: Based on moderate scientific evidence, spontaneous longitudinal changes in dental arch in the transition from the mixed to the permanent dentition demonstrate a spontaneous improvement in mandibular incisor crowding by up to 4.62 mm. These evidence provide a scientific basis for planning only longitudinal follow-up in patients with mild to borderline moderate mandibular incisor crowding in the mixed dentition avoiding overtreatment.

Orthodontic Retainers and the Stability of the Maxillary Arch in Unilateral Cleft lip and Palate Patients: A Systematic Review.

OBJECTIVE: The aim of this systematic review was to elucidate the role of orthodontic retainers on the stability of compensatory orthodontic treatment in patients with unilateral cleft lip and palate. METHODS: Five electronic databases (PubMed, Scopus, Web of Science, LILACS, and LIVIVO) and the grey literature (OpenGrey and Google Scholar) were investigated, according to the population, exposure, comparator, outcomes and Study design eligibility criterion. The risk of bias assessment was determined based on the Risk of Bias In Nonrandomized Studies of Exposure (ROBINS-E) and the level of evidence with the GRADE tool. RESULTS: Three studies were included: two presented moderate risk of bias and one high. A moderate level of evidence revealed a mean value of 0.6 mm of intercanine relapse distance, and great variability between the data, regardless of the use or type of retention or rehabilitation. Relapse in the posterior region showed clinical significance, from -1 to -1.7 mm, especially in individuals who did not use retention, except in patients with symmetrical arches with Hawley retainer, where this value varies from -0.2 ± 0.63 mm. CONCLUSIONS: Orthodontic retainers do not seem essential to prevent relapse at anterior maxillary dimensions after compensatory orthodontic treatment in patients with unilateral cleft lip and palate. Relapse in the posterior region can achieve greater clinical significance, which highlights the need for prolonged use of Hawley retainers and periodic evaluation of the stability of treatment results. Prospective studies with a longer follow-up can improve the certainty of the evidence.

What is the survival rate of deciduous molars in cases with agenesis of premolar successors? A systematic review.

OBJECTIVES: To systematically review the literature on the survival rate of deciduous molars in cases of agenesis of premolar successors. MATERIALS AND METHODS: Four electronic databases and partial grey literature were searched up to November 2020. The PECOS eligibility criteria included (P) second deciduous molar (E) exposed to agenesis of a premolar successor (O) evaluated by the survival rate in the oral cavity, infraocclusion, and root resorption through (S) observational studies. Risk of bias (RoB) was assessed using the checklists from the Joanna Briggs Institute and the level of evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) tool. RESULTS: Three studies were included: one with low, one with moderate, and one with high RoB. Synthesis methods included the frequency of persistent deciduous second molars during the follow-up. Approximately 82% to 89% remained in the oral cavity after 5 to 13 years. The incidence of root resorption was 11%, and the infraocclusion was 1 mm. The level of evidence was considered low for each outcome. There was considerable RoB regarding the observational studies and a need for clinical and radiographic monitoring of the deciduous molars. CONCLUSIONS: Maintaining a deciduous molar in the oral cavity in patients with agenesis of the premolar successor is a viable clinical choice since 82% to 89% of the retained molars evaluated were in good condition over a follow-up ranging from 5 to 13 years. Infraocclusion and root resorption did not seem to increase considerably. The level of evidence was considered low for each outcome.

Treatment stability with bonded versus vacuum-formed retainers: a systematic review of randomized clinical trials.

BACKGROUND: In orthodontics, the retention phase can be considered challenging and unpredictable. Therefore, evidence obtained from different retention protocols is important to facilitate clinical decision-making. OBJECTIVES: This systematic review aimed to compare the clinical effectiveness of bonded versus vacuum-formed retainers (VFRs) regarding their capacity to maintain treatment stability, periodontal effects, and failure rates. SEARCH METHODS AND ELIGIBILITY CRITERIA: Ten databases comprising published and unpublished literature were systematically searched up to August 2021. Randomized clinical trials (RCTs) comparing both retainers were included. DATA COLLECTION AND ANALYSIS: The risk of bias (RoB) evaluation was performed with the Cochrane Collaboration RoB Tool 2.0. All steps of the screening phase and RoB assessment were performed independently by two reviewers. The Grade of Recommendations, Assessment, Development, and Evaluation (GRADE) was used to evaluate the certainty of the evidence. RESULTS: Initial database search yielded 923 studies. After duplicates removal and full-text assessment, five RCTs remained. Overall, the studies presented Low RoB, except one study judged with 'Some concerns'. Based on the included studies, on a short-term (3-6 months) and long-term (4 years) basis, bonded retainers (BRs) were more effective to maintain treatment stability than VFRs in the lower arch. However, from 12 to 24 months both retainers presented the same efficacy. In the upper arch, the retainers were equally effective. BRs were associated with greater plaque and calculus accumulation than VFRs after 12 months. The retainers' failure rates were similar in the upper arch on the first year of retention; however, after 2 years VFRs showed significantly greater failure rates. Contrarily, BRs presented greater failure rates in the lower arch than VFRs. LIMITATIONS: The findings of the included studies may be influenced by different factors related to the unpredictability of relapse. CONCLUSIONS: Most of the evidence generated in this systematic review derived from a moderate level of certainty. In the lower arch, BRs are more effective than VFRs to maintain treatment stability in the initial 6 months of retention and in the long term. In the upper arch, both retention protocols are equally effective. REGISTRATION: Regist0ration number: PROSPERO CRD42020199392. FUNDING: Coordination for the Improvement of Higher Educational Personnel (CAPES, Process code-001).

Allergies/asthma and root resorption: a systematic review.

BACKGROUND: This review synthesizes the available evidence about the predisposition of individuals with asthma or allergies to orthodontically induced inflammatory root resorption (OIIRR) and possible factors related to root resorption that were investigated in the included studies, such as the type of malocclusion, duration of orthodontic treatment, and tooth units. MATERIAL AND METHODS: Six electronic databases and partial gray literature were searched without date or language restrictions until September 2020. Prospective and retrospective observational cohort and case-control studies were included. The risk of bias (RoB) was assessed using the checklists from the Joanna Briggs Institute and the certainty of the evidence using the GRADE tool. To complement the case-control studies, the odds ratio (OR) of the individuals with allergies/asthma to develop root resorption was calculated. RESULTS: Six studies were included. One study with low RoB, one with moderate, and one with high RoB stated that allergic patients did not report a greater chance of developing OIIRR (OR = 1.17 to 2.10, p = 0.1 to 1), while only one study with low RoB reported that individuals with allergies tend to develop root resorption (OR = 2.4, 95% CI = 1.08-5.37). Three studies with low RoB and one with moderate showed no significant association between asthma and OIIRR (OR = 1.05 to 3.42, p = 0.12 to 0.94). No association was identified between the type of malocclusion and the degree of OIIRR. Uniradicular dental units and a prolonged treatment time seem to be associated with an increased risk of resorption. The certainty of the evidence was considered low for both exposure factors. CONCLUSION: Evidence with a low level of certainty indicates that individuals with allergies or asthma are not more predisposed to OIIRR. Uniradicular teeth and long-term orthodontic treatments are associated with a higher risk of OIIRR. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020188463.

Evaluation of root resorption following orthodontic intrusion: a systematic review and meta-analysis.

BACKGROUND/OBJECTIVE: To quantify the expected amount of orthodontically induced root resorption (OIRR) after orthodontic intrusion and assess the treatment-related factors. SEARCH METHODS AND ELIGIBILITY CRITERIA: Six electronic databases and partial grey literature were searched without limitations regarding language or publication year until April 2020. Randomized clinical trials and non-randomized prospective and retrospective studies evaluating root resorption after orthodontic intrusion were included. DATA COLLECTION AND ANALYSIS: Risk of bias (RoB) assessment was performed with the Cochrane Collaboration's RoB Tool 2.0 and ROBINS-I tool for the randomized and non-randomized studies, respectively. The data were combined into two random-effects meta-analyses estimating OIRR following orthodontic intrusion. One evaluated OIRR in the anterior region, while the other assessed OIRR in the posterior region. Sub-group analyses regarding the type of mechanics applied, duration of intrusion, amount of force, and sensitivity analysis of the study design and imaging examinations were also performed. The certainty of the evidence was assessed through the Grade of Recommendation, Assessment, Development, and Evaluation (GRADE) approach. RESULTS: The qualitative analysis included 14 studies; however, the meta-analysis was performed with 7 records. The random-effects model assumes that 0.72 mm [95% confidence interval (CI): 0.16 to 1.28] and 0.41 mm (95% CI: -0.24 to 1.07) of OIRR should be expected in the incisors and the molars, respectively. Sub-group analyses showed that the assessed treatment-related factors presented minimum impact in OIRR after orthodontic intrusion. The GRADE resulted in moderate and low certainty regarding the meta-analysis. LIMITATIONS: The major limitation of the present meta-analysis is that OIRR can be affected by several factors, some of which are assessed in this review. CONCLUSIONS: Orthodontic intrusion, evaluated as an isolated mechanic, caused less than 1 mm of OIRR, which is within the acceptable limits for clinical implication. Treatment-related factors did not show a significant influence on OIRR. REGISTRATION: This review was registered in PROSPERO, protocol number CRD42018098495.

Effects of micro-osteoperforations performed with Propel system on tooth movement, pain/quality of life, anchorage loss, and root resorption: a systematic review and meta-analysis.

BACKGROUND: The aim of this systematic review was to evaluate the effect of micro-osteoperforations (MOPs) performed with Propel and other mini-screws on the rate of tooth movement, pain/discomfort, periodontal health, anchorage loss, and root resorption in patients undergoing orthodontic retraction compared to a control group. MATERIALS AND METHODS: PubMed, Cochrane, Web of Science, LILACS, Google Scholar, Scopus, and OpenGrey were searched without restriction. A manual search was also carried out. Only randomized clinical trials (RCT) were included. The risk of bias (RoB) was assessed using RoB 2.0 and the certainty of evidence through the GRADE tool. RESULTS: Among the twelve RCTs reviewed, five used the Propel system. Overall, the RoB was classified as low (4), moderate (5), and high (3). Two RCTs with moderate and one with a low RoB using the Propel system reported mild increases on rate of tooth movement associated with MOPs. One RCT with a moderate and another with high RoB did not find a significant effect of Propel on orthodontic movement. Regarding tooth movement, a subgroup meta-analysis found no differences between control and Propel movement (95% CI = - 0.01 to 0.75) or other mini-screws (- 0.02 to 0.31) related to rate of tooth movement per month. There was no effect of MOPs on root resorption, periodontal health, anchorage loss, and a mild effect on pain and oral health related to quality of life regardless of mini-screw type. The level of certainty was graded as low for the rate of tooth movement and pain/discomfort, as moderate for anchorage loss, and high for root resorption. CONCLUSION: A low certainty of evidence supports that MOPs performed with Propel seem to have no significant effect on the rate of tooth movement. Moreover, this intervention does not seem to cause an increase in root resorption, periodontal heath, pain/discomfort, or anchorage loss. Thus, the Propel system does not appear to produce different results from those observed for other mini-screws.