[Watch] Clear Aligner Pearl: How To Gain Overjet Without IPR

The faciolingual inclination of the incisors is a key component to a proper occlusion. Lack of crown inclination can decrease overjet, cause anterior hyper occlusion and potentially develop a posterior open bite. In clear aligner treatment, the lack of anterior torque can negatively affect treatment outcomes and become frustrating for orthodontists looking to finish their cases properly.

Many doctors have advocated for resolving overjet issues and developing posterior open bites by performing lower IPR. This solution can be effective with patients presenting with a Bolton discrepancy and tooth size issues. However, this solution is not desired in many cases and may not be enough to improve the occlusion in finishing clear aligner treatment. Therefore, understanding a predictable method to set up clear aligner cases with improved incisor inclination and overjet design can help improve your clinical outcomes.

How to gain upper incisor proclination

We will review today a technique to gain upper incisor proclination and improve a digital setup within CAD software. This series of final tooth positions can help you achieve the necessary incisor inclination and decrease the reliance on lower incisor IPR. In this example, we have a patient in an additional aligner order where insufficient overjet led to heavy anterior occlusion. We aim to gain the necessary overjet using the 3D controls.

First, select the two central incisors along with the crown inclination tool. Then, procline the upper central incisors enough to gain overjet and create a visible space between the lingual surface of the upper incisors and the labial surface of the lower incisor.

This movement will create a discrepancy between the upper central and lateral incisors. If you procline the upper lateral incisors, this movement will not allow you to maintain the increased overjet. Instead, modify lateral incisor positions by adding distal rotation. Select the distal hinge tooth movement tool and rotate the lateral incisors to align the facial surfaces and incisal edges. Notice the increased overjet is maintained.

Notice in these comparisons how the overjet improves because of the central incisor inclination and lateral incisor rotations.