Title : A digital workflow integrating intraoral and facial scanning for 3D monitoring of dentofacial changes in class II malocclusion
Abstract:
The pursuit of optimal orthodontic outcomes extends beyond achieving functional occlusion to encompass the enhancement of facial aesthetics, a core concern for patients. Conventional assessment methods, reliant on two-dimensional photography, lateral cephalograms, and clinical evaluation, frequently fall short in their ability to visualize and, more importantly, precisely quantify the dynamic three-dimensional relationship between tooth movement and the resulting soft-tissue adaptations. This limitation poses a challenge in treatment planning, monitoring, and patient communication. The emergence of digital technologies, particularly the integration of IntraOral Scanners (IOS) and three-Dimensional Facial Scanners (3DFS), offers a transformative solution. This case report details the clinical application and outcomes of a novel, integrated digital workflow designed to monitor dentofacial changes comprehensively in a patient presenting with a Class II division 1 malocclusion.
A single patient undergoing treatment with the Smartee clear aligners system, supplemented by a Transpalatal Arch for enhanced anchorage and torque control, was enrolled. Digital records were acquired at two time points: Pre-treatment (T0) and after six months of active treatment (T1). The scanning protocol was meticulously standardized. Facial scans were captured using the MetiSmile structured-light scanner with the patient in a natural head position. To encapsulate a range of soft-tissue states, three distinct facial expressions were recorded sequentially: A resting pose with lips in gentle contact, a posed natural smile, and a retracted pose using cheek retractors to fully expose the dentition. Immediately following, a complete arch intraoral scan was obtained using the Medit T100 scanner to ensure consistency in jaw position.
The core of the workflow lay in the fusion and analysis of these multi-source data sets. Initial co-registration of the three facial scans with the intraoral scan was performed using proprietary AI-based software. These pre-aligned files were then imported into Consulface software, where automated facial landmark detection and anatomical plane alignment functions were employed to register the 3D facial models from T0 and T1. For final, high-precision superimposition, the data was exported to Geomagic Wrap 2021. The models were aligned based on stable, untreated cranial regions—specifically the forehead and nasion—ensuring that observed changes were attributable to treatment effects rather than registration artifact.
A comprehensive deviation analysis was conducted, generating a color-coded 3D heat map that provided an intuitive visual comparison between T0 and T1 states. Quantitative assessments were performed using defined parameters. Sagittal profile analysis evaluated the relationship of the lips to the Esthetic line (E-line) and the position of soft-tissue pogonion. Transverse analysis compared changes in maxillary arch width to corresponding changes in facial soft-tissue width. Results after six months demonstrated measurable improvements: upper and lower lip prominence to the E-line decreased by 1.16 mm and 1.52 mm, respectively, indicating a favorable profile retraction. The maxillary arch width increased by 1.67 mm, which correlated with a 3.57 mm increase in facial width at the level of the maxillary arches, illustrating the direct impact of skeletal expansion on the overlying soft-tissue envelope. Overbite was reduced from 3.3 mm to 2.2 mm.
In conclusion, this report successfully demonstrates a feasible and precise digital monitoring workflow that synergizes intraoral and facial scanning. The protocol moves beyond traditional 2D assessment by providing an integrated 3D environment where hard- and soft-tissue changes can be visualized simultaneously and quantified objectively. This enhances clinical decision-making, allows for mid-treatment progress evaluation with unprecedented detail, and serves as a powerful tool for patient education and communication. The workflow establishes a reproducible framework for 3D orthodontic documentation and shows significant promise for broader clinical and research applications, warranting further validation with larger cohort studies.
