Abstract

Aligner Treatment in Patients with Dento-Skeletal Asymmetries

by Rapa Silvia

Inter-arch asymmetries, particularly Class II subdivision cases, represent a significant proportion of malocclusions encountered in orthodontic practice. These conditions can exhibit various clinical patterns that are well described in the literature and serve as the starting point for our analysis. Using this classification as a reference, we extend the same diagnostic and therapeutic framework to other asymmetric cases with different characteristics, maintaining a similar logical approach. From a diagnostic standpoint, it is essential to assess the relative contribution of the dentoalveolar versus skeletal components of the asymmetry, in order to determine both the feasibility and direction of potential orthodontic treatment. Dentoalveolar asymmetries require a quadrant-based evaluation, aimed at identifying whether the primary discrepancy lies in the lower arch (Type 1 subdivision), the upper arch (Type 2), or both (Type 1/2). Identifying the site of the dentoalveolar asymmetry is a prerequisite for an accurate digital planning and represents a key step in defining treatment vectors and the consequent biomechanical sequence with aligners. When a skeletal component is also present, even if mild, the orthodontic approach becomes more complex, as the orthodontist has to compensate for the skeletal discrepancy through dental movements only. Conversely, when the skeletal discrepancy is more severe and the patient’s aesthetic expectations are significant, a combined orthodontic-surgical approach is indicated. In such cases, it is essential to distinguish the dentoalveolar component—whose correction should be managed by the orthodontist—from the skeletal component, which should be addressed by the surgeon. A novel clinical method will be presented to assist in this crucial diagnostic differentiation, based on precise orientation of the face and arches relative to the patient’s mid-sagittal plane. In asymmetric cases, aligners offer an elective treatment modality due to their ability to closely follow the digital treatment plan—whose precision is critical in managing these complex malocclusions.

Learning Objectives

After this lecture, you will be able to distinguish the mandibular and/or maxillary components of the dentoalveolar asymmetry as the basis for accurate orthodontic treatment planning.
After this lecture, you will be able to differentiate the dentoalveolar component of the asymmetry from the skeletal component in orthodontic-surgical cases.
After this lecture, you will be able to understand the potential and the limitations of aligner therapy in the management of asymmetries.