Invisalign ClinCheck can predict open gingival embrasures in adult extraction cases: a pilot study

Abstract

Objectives: To evaluate the accuracy of Invisalign ClinCheck in predicting open gingival embrasures (OGEs) and to identify predictors of OGEs in adult extraction cases.

Materials and methods: Fifty-seven adult patients treated with Invisalign and four first premolar extractions were included in this retrospective study. OGEs were measured in maxillary and mandibular anterior regions using posttreatment intraoral photographs (actual OGEs) and the final step from the first treatment plan in ClinCheck (predicted OGEs). Prediction performance indicators including precision, sensitivity, specificity, false positive rate, false negative rate, and accuracy were evaluated at each tooth site. Predictors of OGEs (age, crowding, crown morphology, tooth movement, tooth site, treatment duration, and attachment design) were analyzed using binary logistic regression.

Results: Incidence of actual OGEs was like that of the ClinCheck predicted OGEs in the maxillary and mandibular anterior regions. The predictability of ClinCheck was satisfactory in both the maxilla and mandible, with accuracy rates of 94.0% and 86.0%, respectively. The most accurate prediction was for the maxillary central incisors, achieving a precision of 100% and an accuracy of 96.6%. The most significant predictors of OGEs included patient age at initial consultation, anterior crowding, tooth crown morphology, and type of tooth movement.

Conclusions: Invisalign ClinCheck predicted OGEs in adult patients treated with four premolar extractions. The accuracy of the prediction was satisfactory, 94% in the maxilla and 86% in the mandible, demonstrating great potential for clinical application.

Keywords: Clear aligners; ClinCheck; Extraction; Invisalign; Open gingival embrasures.

Figure 1.

Flow diagram of the participant screening process.

Figure 2.

Classification of the severity of OGEs. Line (a) represents a tangent line passing through the highest gingival curvature of the crown; line (c) is parallel to line (a) and passes through the most cervical contact point; line (b) bisects the distance between lines (a) and (c).

Figure 3.

Measurement of tooth crown morphology. The crown was equally divided into three parts in the crown-root direction. The crown length (CL) refers to the distance from the gingival curvature to the middle of the incisal edge (or cusps of canines). The crown width (CW) refers to the width at the junction between the cervical 1/3 and middle 1/3 of the crown.

Figure 4.

Measurement of tooth movement. U1-SN and IMPA represent inclination of maxillary and mandibular incisors, respectively. The displacement of the upper and lower incisors, both vertically and horizontally, was quantified parallel to the SN line and perpendicular to the mandibular plane, respectively.

Figure 5.

Example of the actual and ClinCheck predicted OGEs.

Figure 6.

Pyramid chart of the actual and ClinCheck predicted OGEs.

Figure 7.

Confusion matrix of the actual and ClinCheck predicted OGE scores at different tooth sites.