ORAL HEALTH EVIDENCE-BASED PRACTICE PROGRAM
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Title Effectiveness of Clear Aligners at Controlling Minor Anterior Intrusions is Comparable to Straight Wire Orthodontics
Clinical Question For patients desiring minor esthetic improvements, are clear aligners time and cost effective alternatives to fixed orthodontic appliances at correcting minor anterior misalignments?
Clinical Bottom Line Clear aligner therapy may be considered for minor esthetic improvements to maxillary and mandibular incisors for non-growing patients. Cost benefit over fixed orthodontic appliances will vary between general dentists and specialists as well as by region.
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 25412265Rossini/2015Total of 480 patients who had received clear aligners in 11 different studiesSystematic review of randomized and nonrandomized trials
Key resultsEffectiveness of clear aligners at controlling minor anterior intrusions is comparable to straight wire orthodontics appliances, though not effective for anterior extrusion movements. Average intrusion attempted measured 0.72 mm with the highest accuracy in maxillary central incisors at 45% and 40% for mandibular intrusion accuracy. Average extrusion measured 0.56 mm with maxillary and mandibular central incisors accuracies of 18% and 25%, respectively, thus appearing to be a challenging movement to control. The systematic review noted marginal ridge alignments to be similar for clear aligners and fixed orthodontic appliances in one retrospective study, noting an Orthodontics Objective Grading System (OGS) score of -4.5 for braces, and -4.9 for the clear aligner therapy; the same study also found comparable results between braces and clear aligners for root angulation (braces: -2.85, clear aligners: -3.56) and interproximal contacts (braces: -0.65, clear aligners: -0.77). Additionally, in one randomized clinical trial, 78% showed an improvement in Peer Assessment Rating (PAR) score in anterior alignment and 62% for a centerline improvement. Thus, the clear aligners appear effective in proximal alignment in both aligning the marginal ridges and correcting interproximal contacts of anterior teeth. In one prospective study, rotational accuracy was 55% for maxillary central incisors, 52% for mandibular lateral incisors, 32% for maxillary canines, 29% for mandibular canines. Incisal rotation appears controlled, but caution must be had for consideration of canine rotation. This is because rotations of more than 15 degrees resulted in 19% accuracy for maxillary canines (SD:14.1%, P < .05).
Evidence Search (("review"[Publication Type] OR "review literature as topic"[MeSH Terms] OR "systematic review"[All Fields]) AND ("orthodontics"[MeSH Terms] OR "orthodontics"[All Fields])) AND (clear[All Fields] AND aligners[All Fields])
Comments on
The Evidence
This was a systematic review of two randomized clinical trials, four non-randomized retrospective studies, and five non-randomized prospective studies. These eleven studies were selected out of a systematic search of peer-reviewed medical literature from 2000-2014. The quality of the analysis revealed that the most common sources of bias were the design of the studies, the lack of control groups, the sample size, and improper blinding procedures. Among the selected studies, the methodological quality of six studies was moderate. There were not enough studies investigating the same anterior outcome. Additional data will be needed to improve the clinical evidence.
Applicability Results of the systematic review apply to a specific patient population. Patients desiring minor esthetic movement for maxillary and mandibular central and lateral incisors may consider clear aligner therapy if limited to controlling anterior intrusions. Canines should be evaluated for the desired degree of rotation as therapy accuracy is greatly reduced beyond 15 degrees of rotation. As for time, there has yet to be peer-reviewed publications noting the amount of time to treatment and time frames for particular cases of complexity. Cost benefit studies have yet to be published as well. However, the cost may be dependent on varying treatment modalities such as whether treatment is planned by a general dentist or dental specialist as well as regional to local variations of cost.
Specialty/Discipline (General Dentistry) (Orthodontics)
Keywords Clear aligner therapy; Invisalign; Invisible orthodontics; Orthodontics
ID# 3033
Date of submission: 03/12/2016spacer
E-mail poonj@livemail.uthscsa.edu
Author Jason Poon
Co-author(s)
Co-author(s) e-mail
Faculty mentor/Co-author Thomas W. Oates, DMD, PhD
Faculty mentor/Co-author e-mail OATES@uthscsa.edu
Basic Science Rationale
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