Is Orthodontic Treatment an Etiologic Factor for Altered Passive Eruption? A Clinical Study and Systematic Review

Abstract

This research aims to investigate the relationship between orthodontic treatment (OT) and altered passive eruption (APE). Materials and Methods: A case–control study was carried out among the dentistry students at Jazan University. A total of 21 students were recruited for the case group and 20 others for the control group. Variables were measured on the maxillary incisor teeth. They included an image analysis of the teeth width-to-height (W/H) ratio, a cone beam computed tomography (CBCT) analysis of buccal bone thickness (BCT), and the distance from the cementoenamel junction (CEJ) to the bone crest (BC) (CEJ–BC). In addition, a systematic review was performed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Prominent literature databases, including Medline/PubMed, the Cochrane Library, Embase, Scopus, Saudi Digital Library, and Google Scholar, were searched for articles published before November 2022 on two main concepts (APE and orthodontics). Quality of evidence was assessed using the Newcastle–Ottawa scale (NOS), and the certainty of evidence was assessed using the grading of recommendations assessment development and evaluation (GRADE) approach. Results: A total of 164 teeth were evaluated. No statistical differences were observed in the W/H ratio and BCT between the two groups. A significant increase in the CEJ–BC distance in the right and left maxillary lateral incisors was observed for people who had undergone OT (p ≤ 0.002 and 0.001, respectively). In the systematic review, two articles were included for qualitative synthesis. One of the included studies showed an increase in the post-orthodontics clinical crown length of the maxillary anterior teeth. Another study reported no difference in the prevalence of APE between orthodontically treated and untreated people. Conclusion: This research concludes that OT might not be an etiological factor for APE. However, more clinical and radiological studies must be conducted to arrive at decisive conclusions.