# Predictability of ClinCheck in Overbite Correction with Aligners: A Systematic Review
## 1 Introduction  
Clear aligners have become a widely accepted tool for orthodontic tooth movement and are now routinely employed in clinical practice worldwide [1]. Although initially intended for the treatment of mild to moderate orthodontic problems, the increasing aesthetic demand from patients has driven both companies and clinicians to refine the treatment protocols and the quality of aligner therapies, thereby expanding their use for the correction of more complex and less predictable malocclusions [2]. Achieving vertical control of the occlusion remains one of the most demanding aspects of orthodontic treatment, as it includes the complex management of both open bite and deep bite malocclusions. The term \"overbite\" is defined as the superimposition of upper and lower incisal edges in vertical dimension, and it is considered within normal limits when varying by approximately \(\pm 2\) mm [3]. An overbite is classified as deep when it exceeds 30%, while an anterior open bite is defined as a lack of incisal contact between the upper and lower anterior teeth when posterior occlusion is present [4,5]. Both conditions can arise from dental or skeletal origin [6, 7, 8]. The integration of CAD/CAM systems with advanced 3D planning software has enabled orthodontists to digitally simulate tooth movements, customize treatment staging, and select attachments based on case-specific biomechanical requirements, leading to the fabrication of fully customized aligners [9]. Invaslalign (Align Technology, Santa Clara, CA, USA) was the first clear aligner system to incorporate 3D digital technology for orthodontic treatment and it is supported by ClinCheck, the company proprietary software for virtual treatment planning and tooth movement simulation. Since its initial development in 1997, the Invaslalign system has been continuously refined, particularly following the introduction of the SmartTrack material in 2013, which replaced the earlier EX30 and contributed to the progressive optimization of clinical protocols [10, 11, 12, 13, 14]. The correction of deep bite and anterior open bite primarily involves a combination of intrusive and extrusive tooth movements. In deep bite cases, overbite reduction is typically accomplished through a combination of anterior tooth intrusion and/or posterior tooth extrusion. Intrusion can be classified as either absolute or relative, with the latter generally associated with anterior proclination [15]. [PERSON] et al. proposed a biomechanical strategy aimed at generating an inverse Curve of Spee by promoting extrusion of the lower premolars and molars in conjunction with the intrusion of mandibular incisors and canines, thereby effectively mimicking the dental configuration observed in anterior open bite cases. Their study reported an average intrusion of 45.3% of the lower incisors in adults, whereas [PERSON] et al. observed an intrusion rate of 35.3% [12, 16, 17]. Furthermore, they reported an improvement in overbite of 1.5 mm with an average intrusion of the upper incisors of 0.72 mm [18]. A growing clinical approach suggests removing the occlusal coverage on second molars to promote vertical control by enhancing posterior disocclusion. In this context, Align Technology has incorporated bite ramps--elevated structures on the lingual surface of the upper aligner--aimed at minimizing occlusal contact in the posterior region and reducing vertical forces. Despite this innovation, several studies have indicated that the effectiveness of this strategy in correcting deep bite remains limited, even when the G5 protocol is implemented [19, 20]. Conversely, the anterior open bite strategies provided anterior extrusion and/or posterior intrusion. The planning of anterior extrusion may involve either absolute vertical movement or relative extrusion resulting from incisor retraction [21]. [PERSON] et al.