Is Apical Root Resorption Greater When Using Clear Aligners as Compared to Conventional Fixed Appliances in Adult Patients Following Orthodontic Treatment? A literature Review

Abstract

Background: Apical root resorption has been identified as a potential risk/adverse effect of conventional orthodontic treatment, however, with changing dental demand and increasing patient preference for clear aligners therapy, the availability of evidence-based information on its incidence/severity following treatment with either clear aligners or fixed appliance is of relevance to clinical practice in providing guidance on orthodontic treatment risk to patients and therefore contributing to the process of obtaining valid informed consent. Objectives: The aim of this study is to undertake a literature review to establish whether apical root resorption following orthodontic treatment is greater in adult patients treated with clear aligners as compared to conventional fixed appliances, to analyse and appraise the data, to make appropriate recommendations relevant to orthodontic practice and is widely referenced by orthodontists. Search Methods: A systematic literature search of three databases (Medline, Embase, Web of science), Google scholar and a hand search of relevant journals was done. Selection Criteria: Primary research studies high in the hierarchy of evidence that investigated/compared apical root resorption following extraction/non-extraction based orthodontic treatment with fixed appliance or clear aligners in adult patients equal to or greater than 18 years between January 2010 and December 2021 were selected for this systematic review. Data Collection and Analysis: Studies were accessed, duplicates eliminated, data extracted with the use of a customized data extraction form, and quality assessed using a critical appraisals skills programme tool. Results: A total of 67 studies were identified, and after the elimination of duplicates and quality assessment, six studies were selected for review. The Cochrane Rob 2 bias tool was used to assess the risk of bias of the selected studies. Apical root resorption prevalence/severity was measured using two different radiographic methods: 3-Dimesional (CBCT-scan) and 2-Dimensional (panoramic/periapical radiographs). Conclusions: The majority of the studies showed that the severity/prevalence of apical root resorption is less in clear aligners compared to fixed appliance treated patients, however, they are characterized by different baseline malocclusion/treatment duration/modalities, study design flaw, inconsistency in outcome measurement/calculation. Due to these limitations, it is difficult to arrive at a conclusion and make recommendations applicable to everyday clinical practice. The clinician should take into consideration factors that increase the risk of apical root resorption such as genetic predisposition, treatment duration, force application (types and location), types of tooth movement, initial malocclusion and extraction/ non-extraction-based treatment in deciding on the orthodontic treatment option and gaining patient consent.Limitations: The current evidence has a number of limitations including the lack of robust prospective studies on apical root resorption, different methods of outcome measurement and calculation, different baseline malocclusions, the evaluation of apical root resorption in only one treatment modality and short treatment duration which may influence the validity of the study conclusions. A meta-analysis could not be performed due to the heterogeneous outcome recording methods. Further research is recommended