Evaluation of open bite closure using clear aligners: a retrospective study

Kayla Harris,Chisato Dan,Kenji Ojima,Flavio Uribe,Jinjian Mu,Chia-Ling Kuo,Madhur Upadhyay,Ravindra Nanda,Abdulrahman Alshehri

doi:10.1186/s40510-020-00325-5

Kayla Harris, Chisato Dan + Show 7 more

Open Access

https://doi.org/10.1186/s40510-020-00325-5

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Abstract

ObjectivesTo evaluate the dental and skeletal effects that occur in the correction of anterior open bite with clear aligners.Materials and methodIn this single-center retrospective study, the mechanism of anterior open bite closure using clear aligners (Invisalign, Align Technology, Santa Clara, CA, USA) was evaluated by cephalometric superimposition based on records of patients consecutively treated by a single, experienced Invisalign provider. Inclusion criteria consisted of anterior open bite (overbite < 0.5 mm), adult patients (18+) at the beginning of treatment, consecutive records, and good quality pre- and post-treatment records, where the required landmarks were clearly visible.ResultsA total of 45 patients were included for data analysis with a mean age of 30.73 ± 8.0 years and initial open bite of − 1.21 ± 1.15 mm. During treatment, the upper incisors showed significant (p < 0.05) retraction [U1-SN′(°) = − 10.91 ± 6.95°], [U1-SN′perp(mm) = − 2.57 ± 1.75 mm] and extrusion [U1-SN′(mm) = 1.45 ± 0.89 mm]. The lower incisors also showed significant retraction [IMPA(°) = − 3.73 ± 4.91°), (ΔL1-MP′perp (mm) = − 1.08 ± 1.59] and extrusion (ΔL1-MP′(mm) = 0.53 ± 0.74). Regarding molar position, no significant changes were noted in the anteroposterior position of the upper [ΔU6-SN′perp(mm) = 0.01 ± 1.08 mm] and lower molar [ΔL6-MP′perp(mm) = 0.03 ± 0.87 mm]; however, there was a statistically significant intrusion of the upper [ΔU6-SN′(mm) = − 0.47 ± 0.59 mm] and lower molar [ΔL6-MP′(mm) = − 0.39 ± 0.76 mm].ConclusionOpen bite closure with clear aligners occurred due to a combination of maxillary and mandibular incisor extrusion and maxillary and mandibular molar intrusion, with slight mandibular auto rotation. Significant retraction of maxillary and mandibular incisors was also observed with treatment. Clear aligners are effective in reducing/controlling the vertical dimension in open bite patients.

Highlights

Advances is clear aligner technology have expanded the scope of clear aligners from treatment of simple malocclusions to more complex approaches such as treatment of anterior open bites [1]
A retrospective study evaluating the ability of clear aligners to control the vertical dimension in deep and open bite patients reported that the primary mechanism
The sample size for the open bite group was small, no strong conclusions could be made regarding treatment of open bites [6]. Another retrospective study evaluating 30 adult open bite patients using cephalometric analysis found that the correction of the open bite was primarily occurring by counterclockwise rotation of the mandible resulting from lower molar intrusion [7]

Summary

Introduction

Advances is clear aligner technology have expanded the scope of clear aligners from treatment of simple malocclusions to more complex approaches such as treatment of anterior open bites [1]. The results did not show any significant differences in the treatment outcomes between the groups, suggesting that clear aligners might have the same efficacy at controlling the vertical dimension as fixed appliances with additional auxiliaries, such as TADs in hyperdivergent patients [8]. Based on this limited evidence, additional research is needed to better clarify the mechanism by which aligners are primarily used in open bite correction

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