TRUE INCISOR INTRUSION IN DEEP BITE CORRECTION WITH CLEAR ALIGNERS

Abstract

Background: Deep bite correction with clear aligners may occur through several mechanisms, including true anterior intrusion, relative intrusion, incisor proclination, and posterior dentoalveolar changes (Moshiri et al., 2021; Kravitz et al., 2020). Because these mechanisms differ biomechanically, overbite reduction alone does not necessarily indicate genuine intrusion (Al-Balaa et al., 2021; Yan et al., 2023; Kravitz et al., 2020). Objective: To evaluate the effectiveness and predictability of true incisor intrusion during deep bite correction with clear aligners. Methods: A focused qualitative synthesis was conducted using studies from PubMed, ScienceDirect, and Scopus published in English between January 2020 and February 2026. Eligible studies involved human deep bite treatment with clear aligners and reported intrusion-related outcomes, including true anterior intrusion, mandibular or upper incisor intrusion, or cephalometric/CBCT findings distinguishing intrusion from other bite-opening mechanisms. Case reports, reviews, conference abstracts without full text, in vitro, finite-element, animal, and syndromic/cleft studies were excluded. Results: Seventeen studies were included, though fewer directly quantified true intrusion. Predictability of intrusion was consistently moderate rather than high. Reported accuracy ranged from 45.54% to 53.3% across adult and CBCT-based studies, while mandibular incisor intrusion was more accurate in adolescents than adults (63.5% vs 45.3%) (Kravitz et al., 2024). Findings suggest that clinically observed bite opening often reflects mechanisms other than pure intrusion, particularly proclination and dentoalveolar adaptations. Conclusion: Clear aligners can achieve true incisor intrusion and contribute to deep bite correction, but outcomes are moderately predictable and commonly smaller than digitally planned. Treatment should therefore include realistic expectations, likely refinement, and recognition that improved overbite does not always represent pure bodily intrusion.

Keywords: Clear Aligner; Deep Bite; True Intrusion; Anterior Intrusion; Overbite Correction; Predictability