Superimposing Intraoral and Facial Digital Scan: A Novel Technique for Accurate Spatial Alignment of Dental Arches
by Marco Valenti1*, Alessandro Valenti, Laura Canale2, Johannes H Schmitz3, Davide Cortellini4
1Private practice in Pordenone, via GB Damiani 5, Italy
2Dental Lab owner in Rimini, via Luigi Tonini 18, Italy
3Private practice in Milan, Galleria Buenos Aires 14, Italy
4Private practice in Riccione, Via Ippolito Nievo 11, Italy
*Corresponding author: Marco Valenti, Private practice in Pordenone, via GB Damiani 5, Italy
Received Date: 26 March, 2024
Accepted Date: 01 April, 2024
Published Date: 03 April, 2024
Citation: Valenti M, Valenti A, Canale L, Schmitz JH, Cortellini D, et al. (2024) Superimposing Intraoral and Facial Digital Scan: A Novel Technique for Accurate Spatial Alignment of Dental Arches. Dent Adv Res 9: 100208. https://doi.org/10.29011/2574-7347.100208
Abstract
A reliable novel technique for superimposing intraoral and face digital scan without using any aligner or scan abutment is presented. This technique involves scanning the perioral area by incorporating parts of the upper dental arch into the perioral tissue scan. Unlike other proposed methods, including the upper dental arch scan in the perioral tissues scan, ensure accurate spatial positioning of intraoral dental arches scans within the facial scan.
Keywords: Alignment point tool, Facial digital scan, Face scanner, Intraoral scan, Superimposing
Introduction
Assessing facial and dental structures is crucial for achieving successful esthetic prosthodontic treatments. A Two-Dimensional (2D) esthetic analysis utilizing facial and dental photographs has been introduced to ensure predictable esthetic outcomes [1-4]. This analysis involves importing full-face photographs taken in a relaxed state, during a wide smile, and smartphone video editing software that supports the smile design for an esthetic treatment plan [5].
Advancements in Three-Dimensional (3D) facial scanning have made it possible to virtually plan a prosthetic design that aligns with the corresponding facial appearance in a 3-D perspective [6]. Through 3D facial scanning, a virtual face can be generated and seamlessly integrated with 3D dental images obtained from digital scans of the teeth [7].
Many different techniques were proposed to superimpose the intraoral scan into a facial scan to create a 3-dimensional virtual patient, using aligner systems or scan abutment [8-10] or simply collecting additional facial scans and perioral scans to collect some skin and dental references merging in superimposition [11,12].
This article presents a novel technique for superimposing facial and intraoral scans, eliminating the need for aligners, scan bodies, or extraoral landmarks. It works well even in patients who do not expose upper incisors smiling. Furthermore, this technique enables precise spatial alignment of intraoral scans within facial scans.
Technique
To simplify the digitalization and superimposing of the facial and intraoral scans to obtain a 3D virtual representation of a patient, the subsequent protocol was performed:









Discussion
In prosthetic treatments involving the esthetic area, the challenge for the dental technician and dentist is to precisely define the interpupillary and midsagittal planes to correctly establish ideal teeth shape concerning the patient’s smile line and lips position (Figure 10). Facial scanning, in comparison to the 2D photography, offers greater accuracy [14], and by incorporating 3D restorations design onto the 3D facial file, it is possible to assess the shapes of the teeth on the x-y-z axis and evaluate their aesthetic outcome before testing it on the patient with interim restorations or resin mock-up. Both facial scanning and its superimposition with intraoral scanning must be accurate to perform these assessments [15].
Figure 10: Positioning inter pupillary, midsagittal, and Camper planes on the facial scan helps the dentist and technician in determining the ideal teeth shape in relation to the patient’s smile line and lips position.
Conversely to a smartphone-specific application that uses a 3D sensor camera [10,12,16] or industrial scanners adapted for medical use [17,18] the advantage of using a static face scanner (Rayface 100,200; Ray Co., Ltd) is that the patient remains still and in 0,5 seconds the scanner scans patient’s face, reducing the risk of inaccurate scans due to movements by the patient, scanner or operator [19,20].
An accurate facial scan [21] is not enough because, due to the distortion all face scanners introduce in the patient’s teeth, it is impossible to superimpose a facial scan to the patient’s dental arches scan. The key to this technique’s success is using a perioral scan that includes lips, nose, forehead, and teeth. The accuracy and time scan of the IOS (TRIOS 3, 4, or 5; 3Shape A/S) [22,23] allow for simple and reliable perioral scanning, avoiding any involuntary patient movements that would affect the accuracy of the perioral scan.
Compared to the technique proposed by Lo Russo, et al. [12] scanning the posterior teeth also allows for the correct sagittal and horizontal alignment of the arches during the superimposition with the facial scan. Furthermore, thanks to the CAD-CAM software program (Dental System; 3 shape A/S) cross-sectional tool, it is possible to assess the accuracy of alignment and correct it by slightly shifting any of the 3 superimposed scans, reducing the risk of mismatching.
Creating a 3-D virtual patient representation could help dentists and dental technicians improve diagnosis, facially driven treatment plans, and prosthetic treatment outcomes. Even if most of the scanners available on the market exhibit accuracy values that are acceptable for clinical application, [24] the 3-D virtual patient accuracy and trueness could be influenced by techniques used and operator skill [25]. The proposed technique simplifies the superimposing procedures to align intraoral scans with facial scans, making the creation of the virtual patient repeatable and reliable without using skin landmarks or scan abutments.
Summary
A technique that allows clinicians and dental technicians to obtain valuable information regarding the relationship between patient smile and patient face is presented. Intraoral, perioral, and facial scans are superimposed easily without any scan abutment, aligner, or skin landmarks, with a CAD software program and an alignment point tool. Furthermore, the spatial alignment of dental arches on facial scan could be more precise than other techniques proposed, thanks to the perioral scan that should include the upper premolar and molar teeth surface and not only incisors.
Declaration
Patient consent
Written informed consent was obtained prior to capturing any face scan or images and published.
Conflict of interest
Authors declare no conflict of interest.
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