Advertisement
Journal of Prosthetic Dentistry

Creating three-dimensional virtual patients by superimposing intraoral and facial digital scans guided with an aligner system: A dental technique

Open AccessPublished:October 31, 2022DOI:https://doi.org/10.1016/j.prosdent.2022.09.008

      Abstract

      A technique for creating 3-dimensional virtual patients (3DVPs) by superimposing intraoral and facial digital scans guided with a novel aligner system is described. This aligner system supports design modifications to adapt to different facial scanning methods (FSMs) and reduce the impact of FSMs on the accuracy of 3DVPs. Two different designs of the aligner system are described: one for use with less-accurate FSMs and another for use with more-accurate FSMs. These virtual designs are available for download and use.
      Various aligner systems have been developed to guide the superimposition of intraoral and facial digital scans to create 3-dimensional virtual patients (3DVPs). They have been used for different clinical purposes, including obtaining virtual facebow records or performing facially driven digital diagnostic waxing procedures.
      • Solaberrieta E.
      • Garmendia A.
      • Minguez R.
      • Brizuela A.
      • Pradies G.
      Virtual facebow technique.
      • Lam W.Y.H.
      • Hsung R.T.C.
      • Choi W.W.S.
      • Luk H.W.K.
      • Pow E.H.N.
      A 2-part facebow for CAD-CAM dentistry.
      • Sun A.
      • Yang Y.
      • Gao H.
      • Lin W.
      • Chen L.
      • Tan J.
      Integrating facial and intraoral scans for digital esthetic and occlusal design: a technical report.
      • Revilla-León M.
      • Raney L.
      • Piedra-Cascón W.
      • Barrington J.
      • Zandinejad A.
      • Özcan M.
      Digital workflow for an esthetic rehabilitation using a facial and intraoral scanner and an additive manufactured silicone index: a dental technique.
      • Pérez-Giugovaz M.G.
      • Meykadeh Z.
      • Revilla-León M.
      Additively manufactured scan bodies for virtual patient integration: different designs, manufacturing procedures, and clinical protocols.
      • Pérez-Giugovaz M.G.
      • Park S.H.
      • Revilla-León M.
      Three-dimensional virtual representation by superimposing facial and intraoral digital scans with an additively manufactured intraoral scan body.
      • D’Albis G.
      • D’Albis V.
      • Palma M.
      • D’Orazio F.
      • D’Albis G.
      • Cristino G.
      • et al.
      Orientation of digital casts according to the face-bow arbitrary plan.
      • Pérez-Giugovaz M.G.
      • Mosier M.
      • Revilla-León M.
      An additively manufactured intraoral scan body for aiding complete-arch intraoral implant digital scans with guided integration of 3D virtual representation.
      • Lepidi L.
      • Galli M.
      • Grammatica A.
      • Joda T.
      • Wang H.
      • Li J.
      Indirect digital workflow for virtual cross-mounting of fixed implant-supported prostheses to create a 3d virtual patient.
      • Pérez-Giugovaz M.G.
      • Park S.H.
      • Revilla-León M.
      3D Virtual patient representation for guiding a maxillary overdenture fabrication: a dental technique.
      • Granata S.
      • Giberti L.
      • Vigolo P.
      • Stellini E.
      • Di Fiore A.
      Incorporating a facial scanner into the digital workflow: a dental technique.
      Intraoral digital scans are acquired by using intraoral scanners (IOSs), whereas facial digital scans can be acquired by using various facial scanning methods (FSMs). Although most aligner systems can be used to superimpose intraoral digital scans with facial digital scans acquired with any FSM, the accuracy of a 3DVP is greatly influenced by which FSM is used, being more accurate when using more accurate FSMs.
      • Amezua X.
      • Iturrate M.
      • Garikano X.
      • Solaberrieta E.
      Analysis of the influence of the facial scanning method on the transfer accuracy of a maxillary digital scan to a 3D face scan for a virtual facebow technique: an in vitro study.
      ,
      • Amezua X.
      • Iturrate M.
      • Garikano X.
      • Solaberrieta E.
      Analysis of the impact of the facial scanning method on the precision of a virtual facebow record technique: an in vivo study.
      Most accurate FSMs, such as stationary facial scanners or professional handheld scanners, however, may be unsuitable for many dental clinics, principally because of their high cost.
      • Petrides G.
      • Clark J.A.R.
      • Low H.
      • Lovell N.
      • Eviston T.J.
      Three-dimensional scanners for soft-tissue facial assessment in clinical practice.
      ,
      • Mai H.N.
      • Lee D.H.
      Accuracy of mobile device–compatible 3d scanners for facial digitization: systematic review and meta-analysis.
      Therefore, alternative FSMs have been proposed, with mobile device-compatible 3D sensor cameras attracting the most interest, principally because of their low cost and ease of use.
      • Mai H.N.
      • Lee D.H.
      Accuracy of mobile device–compatible 3d scanners for facial digitization: systematic review and meta-analysis.
      • Liu J.
      • Zhang C.
      • Cai R.
      • Yao Y.
      • Zhao Z.
      • Liao W.
      Accuracy of 3-dimensional stereophotogrammetry: comparison of the 3dMD and Bellus3D facial scanning systems with one another and with direct anthropometry.
      • Gallardo Y.N.R.
      • Salazar-Gamarra R.
      • Bohner L.
      • De Oliveira J.I.
      • Dib L.L.
      • Sesma N.
      Evaluation of the 3D error of 2 face-scanning systems: an in vitro analysis.
      • D'Ettorre G.
      • Farronato M.
      • Candida E.
      • Quinzi V.
      • Grippaudo C.
      A comparison between stereophotogrammetry and smartphone structured light technology for three-dimensional face scanning.
      • Knoops P.G.M.
      • Beaumont C.A.A.
      • Borghi A.
      • Rodriguez-Florez N.
      • Breakey R.W.F.
      • Rodgers W.
      • et al.
      Comparison of three-dimensional scanner systems for craniomaxillofacial imaging.
      However, improving the accuracy of 3DVPs created with facial digital scans acquired by using these FSMs is important and can be achieved by intervening in the design of the aligners.
      • Revilla-León M.
      • Zandinejad A.
      • Nair M.K.
      • Barmak B.A.
      • Feilzer A.J.
      • Özcan M.
      Accuracy of a patient 3-dimensional virtual representation obtained from the superimposition of facial and intraoral scans guided by extraoral and intraoral scan body systems.
      ,
      • Revilla-León M.
      • Zeitler J.M.
      • Barmak A.B.
      • Kois J.C.
      Accuracy of the 3-dimensional virtual patient representation obtained by using 4 different techniques: an in vitro study.
      For a 3DVP to be accurate, the regions of the aligners involved in the superimpositions should be extensive and contain sufficient shape details because superimpositions are performed by using best-fit algorithms. To avoid superimposition errors, all methods used to scan these regions of the aligners should be able to capture shape details.
      • Li J.
      • Chen Z.
      • Decke A.M.
      • Wang H.L.
      • Joda T.
      • Mendonca G.
      • et al.
      Trueness and precision of economical smartphone-based virtual facebow records.
      In general, FSMs have less ability to capture shape details than IOSs and laboratory scanners, and less-accurate FSMs have even less ability than more accurate ones.
      • D'Ettorre G.
      • Farronato M.
      • Candida E.
      • Quinzi V.
      • Grippaudo C.
      A comparison between stereophotogrammetry and smartphone structured light technology for three-dimensional face scanning.
      ,
      • Knoops P.G.M.
      • Beaumont C.A.A.
      • Borghi A.
      • Rodriguez-Florez N.
      • Breakey R.W.F.
      • Rodgers W.
      • et al.
      Comparison of three-dimensional scanner systems for craniomaxillofacial imaging.
      ,
      • Li J.
      • Chen Z.
      • Decke A.M.
      • Wang H.L.
      • Joda T.
      • Mendonca G.
      • et al.
      Trueness and precision of economical smartphone-based virtual facebow records.
      This article describes a technique for creating 3DVPs by superimposing intraoral and facial digital scans guided by a novel aligner system that supports design modifications to adapt to different FSMs in order to reduce the impact of FSMs on the accuracy of 3DVPs. Two designs of the aligner system are described: one for use with less-accurate FSMs (Fig. 1), such as some mobile device-compatible 3D sensor cameras, composed of aligners with fewer shape details in regions that are scanned by using FSMs (Fig. 1A, 1C) (Supplemental File 1, available online), and another for use with more-accurate FSMs (Fig. 2), such as some professional handheld scanners composed of aligners with more shape details in the regions that are scanned by using FSMs (Fig. 2A, 2C) (Supplemental File 2, available online). As the technique is the same with both designs of the aligner system, the use of only 1 is described.
      Figure thumbnail gr1
      Figure 1Virtual designs of aligners for less-accurate facial scanning methods. A, Frontal view of virtual design of buccal aligner. B, Posterior view of virtual design of buccal aligner. C, Virtual designs of forehead aligners.
      Figure thumbnail gr2
      Figure 2Virtual designs of aligners for more-accurate facial scanning methods. A, Frontal view of virtual design of buccal aligner. B, Posterior view of virtual design of buccal aligner. C, Virtual designs of forehead aligners.
      Figure thumbnail gr3
      Figure 3Additively manufactured aligners. A, Additively manufactured buccal aligner. B, Additively manufactured forehead aligners.
      Figure thumbnail gr4
      Figure 4Additively manufactured tray of buccal aligner.
      Figure thumbnail gr5
      Figure 5Additively manufactured buccal aligner and its tray assembled.
      Figure thumbnail gr7
      Figure 7Facial digital scans. A, Reference facial digital scan. B, Definitive facial digital scan at rest.
      Figure thumbnail gr8
      Figure 8Digital scan of back of buccal aligner.
      Figure thumbnail gr9
      Figure 9Superimposition of intraoral and facial digital scans. A, Superimposition of digital scan of back of buccal aligner with maxillary digital scan. B, Superimposition of virtual design of buccal aligner with digital scan of back of buccal aligner. C, Superimposition of reference facial digital scan with virtual design of buccal aligner. D, Superimposition of definitive facial digital scan with reference facial digital scan. E, Three-dimensional virtual patient created by superimposing intraoral and facial digital scans. Blue indicates regions selected for superimposition with best-fit algorithm.

      Technique

      • 1.
        Manufacture the virtual designs of the aligners—1 copy of the virtual design of the buccal aligner (Supplemental File 1A, available online), 1 copy of the virtual design of the central forehead aligner (Supplemental File 1B, available online), and 2 copies of the virtual design of the lateral forehead aligner (Supplemental File 1C, available online)—in an opaque material that meets biocompatibility requirements
        International Organization for Standardization
        ISO-10993-1. Biological evaluation of medical devices - Part 1: evaluation and testing within a risk management process.
        ,
        Food and Drug Administration
        FDA-2013-D-0350. Use of International Standard ISO 10993-1, “Biological evaluation of medical devices - Part 1: evaluation and testing within a risk management process”: guidance for Industry and Food and Drug Administration staff.
        (VisiJet M2R-WT; 3D Systems, Inc) with an additive manufacturing (AM) machine (ProJet MJP 2500 Plus; 3D Systems, Inc) according to the manufacturer’s protocol (Fig. 3).
      • 2.
        Manufacture the virtual design of the tray of the buccal aligner (Supplemental File 3, available online) in a material that meets biocompatibility requirements
        International Organization for Standardization
        ISO-10993-1. Biological evaluation of medical devices - Part 1: evaluation and testing within a risk management process.
        ,
        Food and Drug Administration
        FDA-2013-D-0350. Use of International Standard ISO 10993-1, “Biological evaluation of medical devices - Part 1: evaluation and testing within a risk management process”: guidance for Industry and Food and Drug Administration staff.
        (Surgical Guide Resin; Formlabs, Inc) with an AM machine (Form 3B; Formlabs, Inc) according to the manufacturer’s protocol (Fig. 4).
      • 3.
        Assemble the buccal aligner and its tray by inserting the tip of the tray into the hole of the buccal aligner (press them together until they are firmly attached) (Fig. 5).
      • 4.
        Acquire the patient’s maxillary, mandibular, and occlusal digital scans by using an IOS (TRIOS 3; 3Shape A/S) as per the manufacturer’s protocol (Fig. 6).
      • 5.
        Acquire the patient’s facial digital scans by using an FSM such as a smartphone with an integrated 3D sensor camera (iPhone 12 Pro; Apple, Inc) controlled with a mobile application (Heges 3D Scanner; Marek Simonik) as per the manufacturer’s protocol (Fig. 7). First, acquire a reference facial digital scan with the additively manufactured aligners placed on the corresponding areas of the patient’s face (Fig. 7A): the forehead aligners on the forehead area (the central one in the center and the lateral ones on the sides close to the temporal line of the frontal bone), fixed to the head by a headband (Elastic tape; William Prym Holding GmbH), and the buccal aligner over the buccal area, fixed to the maxillary arch with high- and low-viscosity polyvinyl siloxane impression material (VPS Hydro; Henry Schein, Inc) loaded onto its tray. Place the forehead aligners first and, before placing the buccal aligner, instruct patients to avoid moving their eyebrows until all facial digital scans have been acquired. Check that the forehead aligners do not move in the absence of eyebrow movement (otherwise, correct their placement). After acquiring the reference facial digital scan, obtain at least 1 definitive facial digital scan with the buccal aligner removed (carefully, without separating it from its tray) and the forehead aligners in place in a specific facial expression such as at rest (Fig. 7B).
      • 6.
        Acquire the digital scan of the back of the buccal aligner with the IOS (Fig. 8).
      • 7.
        Superimpose intraoral and facial digital scans to create a 3DVP (Fig. 9). For that, import all previous digital scans to a dental computer-aided design software program (exocad; exocad GmbH) and perform the following steps: first, superimpose the digital scan of the back of the buccal aligner with the maxillary digital scan (Fig. 9A); second, superimpose the virtual design of the buccal aligner with the digital scan of the back of the buccal aligner (Fig. 9B); third, superimpose the reference facial digital scan with the virtual design of the buccal aligner (Fig. 9C); fourth, superimpose the definitive facial digital scan with the reference facial digital scan (Fig. 9D); and, finally, if necessary, superimpose the mandibular and occlusal digital scans with the maxillary digital scan. Perform all superimpositions by using a best-fit algorithm after selecting the regions of the digital scans to be superimposed (Fig. 9).

      Discussion

      A technique to create 3DVPs by superimposing intraoral and facial digital scans guided with a novel aligner system is described. The aligner system is composed of 4 reusable aligners: 3 forehead aligners and 1 buccal aligner, with a removable and disposable tray (a removable and disposable tray is used to enable the use of both standard and custom trays without the need to remanufacture the buccal aligner as was required with most previously developed aligners of this type). The aligners, as well as the tray of the buccal aligner, can be additively manufactured, taking into account that they should meet or exceed the biocompatibility requirements established for medical devices in contact with intact skin surfaces and, in the case of the buccal aligner and its tray, also with intact mucosal membrane surfaces, the duration of contact being long term for aligners and limited for the tray of the buccal aligner.
      International Organization for Standardization
      ISO-10993-1. Biological evaluation of medical devices - Part 1: evaluation and testing within a risk management process.
      ,
      Food and Drug Administration
      FDA-2013-D-0350. Use of International Standard ISO 10993-1, “Biological evaluation of medical devices - Part 1: evaluation and testing within a risk management process”: guidance for Industry and Food and Drug Administration staff.
      The aligners should be sterilized before reuse by following the instructions of the manufacturer of the material used to manufacture them.
      An innovation of the aligner system is that it supports design modifications to adapt to different FSMs in order to reduce the impact of FSMs on the accuracy of 3DVPs. Almost all previously developed aligner systems propose a single design for all FSMs
      • Solaberrieta E.
      • Garmendia A.
      • Minguez R.
      • Brizuela A.
      • Pradies G.
      Virtual facebow technique.
      • Lam W.Y.H.
      • Hsung R.T.C.
      • Choi W.W.S.
      • Luk H.W.K.
      • Pow E.H.N.
      A 2-part facebow for CAD-CAM dentistry.
      • Sun A.
      • Yang Y.
      • Gao H.
      • Lin W.
      • Chen L.
      • Tan J.
      Integrating facial and intraoral scans for digital esthetic and occlusal design: a technical report.
      • Revilla-León M.
      • Raney L.
      • Piedra-Cascón W.
      • Barrington J.
      • Zandinejad A.
      • Özcan M.
      Digital workflow for an esthetic rehabilitation using a facial and intraoral scanner and an additive manufactured silicone index: a dental technique.
      • Pérez-Giugovaz M.G.
      • Meykadeh Z.
      • Revilla-León M.
      Additively manufactured scan bodies for virtual patient integration: different designs, manufacturing procedures, and clinical protocols.
      • Pérez-Giugovaz M.G.
      • Park S.H.
      • Revilla-León M.
      Three-dimensional virtual representation by superimposing facial and intraoral digital scans with an additively manufactured intraoral scan body.
      • D’Albis G.
      • D’Albis V.
      • Palma M.
      • D’Orazio F.
      • D’Albis G.
      • Cristino G.
      • et al.
      Orientation of digital casts according to the face-bow arbitrary plan.
      • Pérez-Giugovaz M.G.
      • Mosier M.
      • Revilla-León M.
      An additively manufactured intraoral scan body for aiding complete-arch intraoral implant digital scans with guided integration of 3D virtual representation.
      • Lepidi L.
      • Galli M.
      • Grammatica A.
      • Joda T.
      • Wang H.
      • Li J.
      Indirect digital workflow for virtual cross-mounting of fixed implant-supported prostheses to create a 3d virtual patient.
      • Pérez-Giugovaz M.G.
      • Park S.H.
      • Revilla-León M.
      3D Virtual patient representation for guiding a maxillary overdenture fabrication: a dental technique.
      • Granata S.
      • Giberti L.
      • Vigolo P.
      • Stellini E.
      • Di Fiore A.
      Incorporating a facial scanner into the digital workflow: a dental technique.
      without taking into account that not all FSMs have the same ability to capture shape details and that not capturing shape details of the aligner regions involved in the superimpositions may lead to errors that affect the accuracy of the resulting 3DVPs.
      • Li J.
      • Chen Z.
      • Decke A.M.
      • Wang H.L.
      • Joda T.
      • Mendonca G.
      • et al.
      Trueness and precision of economical smartphone-based virtual facebow records.
      That is why 2 different aligner system designs are described: one for use with more-accurate FSMs with a greater ability to capture shape details and another for use with less-accurate FSMs with less ability to capture shape details (this design should only be used with FSMs that cannot capture the shape details of the first design). The buccal aligner is a further innovation of the aligner system. The regions involved in the superimpositions are notably more extensive than those of most previously developed aligners of this type,
      • Solaberrieta E.
      • Garmendia A.
      • Minguez R.
      • Brizuela A.
      • Pradies G.
      Virtual facebow technique.
      • Lam W.Y.H.
      • Hsung R.T.C.
      • Choi W.W.S.
      • Luk H.W.K.
      • Pow E.H.N.
      A 2-part facebow for CAD-CAM dentistry.
      • Sun A.
      • Yang Y.
      • Gao H.
      • Lin W.
      • Chen L.
      • Tan J.
      Integrating facial and intraoral scans for digital esthetic and occlusal design: a technical report.
      • Revilla-León M.
      • Raney L.
      • Piedra-Cascón W.
      • Barrington J.
      • Zandinejad A.
      • Özcan M.
      Digital workflow for an esthetic rehabilitation using a facial and intraoral scanner and an additive manufactured silicone index: a dental technique.
      • Pérez-Giugovaz M.G.
      • Meykadeh Z.
      • Revilla-León M.
      Additively manufactured scan bodies for virtual patient integration: different designs, manufacturing procedures, and clinical protocols.
      • Pérez-Giugovaz M.G.
      • Park S.H.
      • Revilla-León M.
      Three-dimensional virtual representation by superimposing facial and intraoral digital scans with an additively manufactured intraoral scan body.
      • D’Albis G.
      • D’Albis V.
      • Palma M.
      • D’Orazio F.
      • D’Albis G.
      • Cristino G.
      • et al.
      Orientation of digital casts according to the face-bow arbitrary plan.
      • Pérez-Giugovaz M.G.
      • Mosier M.
      • Revilla-León M.
      An additively manufactured intraoral scan body for aiding complete-arch intraoral implant digital scans with guided integration of 3D virtual representation.
      • Lepidi L.
      • Galli M.
      • Grammatica A.
      • Joda T.
      • Wang H.
      • Li J.
      Indirect digital workflow for virtual cross-mounting of fixed implant-supported prostheses to create a 3d virtual patient.
      • Pérez-Giugovaz M.G.
      • Park S.H.
      • Revilla-León M.
      3D Virtual patient representation for guiding a maxillary overdenture fabrication: a dental technique.
      • Granata S.
      • Giberti L.
      • Vigolo P.
      • Stellini E.
      • Di Fiore A.
      Incorporating a facial scanner into the digital workflow: a dental technique.
      which favors the accuracy of the superimpositions, and therefore that of the resulting 3DVPs. Even so, there is no need for a laboratory scanner to obtain its digital scan after acquiring the reference facial digital scan because only the digital scan of its back is necessary (Fig. 8); this can be obtained by using an IOS. In addition, the regions of the buccal aligner that are scanned by using FSMs (Figs. 1A, 2A) do not coincide with those scanned by using IOSs (Figs. 1B, 2B), which enables the independent adaptation of the shape details of those regions. Thus, the difference between the 2 described aligner system designs is only in the shape details of the aligner regions that are scanned by using FSMs (Figs. 1A, 1C, 2A, 2C), whereas the shape details of the regions scanned by using IOSs are similar (Figs. 1B, 2B) as all IOSs have a similar ability to capture shape details.
      Limitations of the novel aligner system include that its buccal aligner should be manufactured accurately, as its virtual design is involved in the superimpositions (Fig. 9B, 9C), and therefore, manufacturing errors may lead to superimposition errors that affect the accuracy of the resulting 3DVPs. However, if this is not possible, it could be manufactured less accurately, and its digital scan acquired with a laboratory scanner could substitute the virtual design in the superimpositions. To avoid the need for an AM machine with high accuracy or the presence of a laboratory scanner in the clinic, reusable buccal aligners could be manufactured externally, and the disposable trays and reusable forehead aligners could be manufactured in-house on a more accessible AM machine.
      Virtual designs of the novel aligner system can be downloaded and used by the dental community. However, studies are needed to assess the accuracy of 3DVPs created with this technique, to optimize the aligner system, and to develop new designs for different FSMs.

      Summary

      A technique for creating 3DVPs by superimposing intraoral and facial digital scans guided with a novel aligner system is described. The aligner system supports design modifications to adapt to different FSMs in order to reduce the impact of FSMs on the accuracy of 3DVPs. Two designs of the aligner system are described: one for use with less-accurate FSMs and another for use with more-accurate FSMs. Their virtual designs are available for download and use.

      Acknowledgments

      The authors thank the University of the Basque Country UPV/EHU for providing DEHI research laboratory (www.ehu.eus/dehi), Corus Dental Institute SL for their support and assistance, 3DZ SpA for providing their additive manufacturing machines, and exocad GmbH for providing their software.

      References

        • Solaberrieta E.
        • Garmendia A.
        • Minguez R.
        • Brizuela A.
        • Pradies G.
        Virtual facebow technique.
        J Prosthet Dent. 2015; 114: 751-755
        • Lam W.Y.H.
        • Hsung R.T.C.
        • Choi W.W.S.
        • Luk H.W.K.
        • Pow E.H.N.
        A 2-part facebow for CAD-CAM dentistry.
        J Prosthet Dent. 2016; 116: 843-847
        • Sun A.
        • Yang Y.
        • Gao H.
        • Lin W.
        • Chen L.
        • Tan J.
        Integrating facial and intraoral scans for digital esthetic and occlusal design: a technical report.
        J Prosthodont. 2021; 30: 729-733
        • Revilla-León M.
        • Raney L.
        • Piedra-Cascón W.
        • Barrington J.
        • Zandinejad A.
        • Özcan M.
        Digital workflow for an esthetic rehabilitation using a facial and intraoral scanner and an additive manufactured silicone index: a dental technique.
        J Prosthet Dent. 2020; 123: 564-570
        • Pérez-Giugovaz M.G.
        • Meykadeh Z.
        • Revilla-León M.
        Additively manufactured scan bodies for virtual patient integration: different designs, manufacturing procedures, and clinical protocols.
        J Prosthodont. 2022; 31: 23-29
        • Pérez-Giugovaz M.G.
        • Park S.H.
        • Revilla-León M.
        Three-dimensional virtual representation by superimposing facial and intraoral digital scans with an additively manufactured intraoral scan body.
        J Prosthet Dent. 2021; 126: 459-463
        • D’Albis G.
        • D’Albis V.
        • Palma M.
        • D’Orazio F.
        • D’Albis G.
        • Cristino G.
        • et al.
        Orientation of digital casts according to the face-bow arbitrary plan.
        Clin Dent Rev. 2021; 5: 13
        • Pérez-Giugovaz M.G.
        • Mosier M.
        • Revilla-León M.
        An additively manufactured intraoral scan body for aiding complete-arch intraoral implant digital scans with guided integration of 3D virtual representation.
        J Prosthet Dent. 2022; 127: 38-43
        • Lepidi L.
        • Galli M.
        • Grammatica A.
        • Joda T.
        • Wang H.
        • Li J.
        Indirect digital workflow for virtual cross-mounting of fixed implant-supported prostheses to create a 3d virtual patient.
        J Prosthodont. 2021; 30: 177-182
        • Pérez-Giugovaz M.G.
        • Park S.H.
        • Revilla-León M.
        3D Virtual patient representation for guiding a maxillary overdenture fabrication: a dental technique.
        J Prosthodont. 2021; 30: 636-641
        • Granata S.
        • Giberti L.
        • Vigolo P.
        • Stellini E.
        • Di Fiore A.
        Incorporating a facial scanner into the digital workflow: a dental technique.
        J Prosthet Dent. 2020; 123: 781-785
        • Amezua X.
        • Iturrate M.
        • Garikano X.
        • Solaberrieta E.
        Analysis of the influence of the facial scanning method on the transfer accuracy of a maxillary digital scan to a 3D face scan for a virtual facebow technique: an in vitro study.
        J Prosthet Dent. 12 March 2021; ([Epub ahead of print])https://doi.org/10.1016/j.prosdent.2021.02.007
        • Amezua X.
        • Iturrate M.
        • Garikano X.
        • Solaberrieta E.
        Analysis of the impact of the facial scanning method on the precision of a virtual facebow record technique: an in vivo study.
        J Prosthet Dent. 13 December 2021; ([Epub ahead of print])https://doi.org/10.1016/j.prosdent.2021.10.025
        • Petrides G.
        • Clark J.A.R.
        • Low H.
        • Lovell N.
        • Eviston T.J.
        Three-dimensional scanners for soft-tissue facial assessment in clinical practice.
        J Plast Reconstr Aesthetic Surg. 2021; 74: 605-614
        • Mai H.N.
        • Lee D.H.
        Accuracy of mobile device–compatible 3d scanners for facial digitization: systematic review and meta-analysis.
        J Med Internet Res. 2020; 22: e22228
        • Liu J.
        • Zhang C.
        • Cai R.
        • Yao Y.
        • Zhao Z.
        • Liao W.
        Accuracy of 3-dimensional stereophotogrammetry: comparison of the 3dMD and Bellus3D facial scanning systems with one another and with direct anthropometry.
        Am J Orthod Dentofac Orthop. 2021; 160: 862-871
        • Gallardo Y.N.R.
        • Salazar-Gamarra R.
        • Bohner L.
        • De Oliveira J.I.
        • Dib L.L.
        • Sesma N.
        Evaluation of the 3D error of 2 face-scanning systems: an in vitro analysis.
        J Prosthet Dent. 3 August 2021; ([Epub ahead of print])https://doi.org/10.1016/j.prosdent.2021.06.049
        • D'Ettorre G.
        • Farronato M.
        • Candida E.
        • Quinzi V.
        • Grippaudo C.
        A comparison between stereophotogrammetry and smartphone structured light technology for three-dimensional face scanning.
        Angle Orthod. 2022; 92: 358-363
        • Knoops P.G.M.
        • Beaumont C.A.A.
        • Borghi A.
        • Rodriguez-Florez N.
        • Breakey R.W.F.
        • Rodgers W.
        • et al.
        Comparison of three-dimensional scanner systems for craniomaxillofacial imaging.
        J Plast Reconstr Aesthet Surg. 2017; 70: 441-449
        • Revilla-León M.
        • Zandinejad A.
        • Nair M.K.
        • Barmak B.A.
        • Feilzer A.J.
        • Özcan M.
        Accuracy of a patient 3-dimensional virtual representation obtained from the superimposition of facial and intraoral scans guided by extraoral and intraoral scan body systems.
        J Prosthet Dent. 7 April 2021; ([Epub ahead of print])https://doi.org/10.1016/j.prosdent.2021.02.023
        • Revilla-León M.
        • Zeitler J.M.
        • Barmak A.B.
        • Kois J.C.
        Accuracy of the 3-dimensional virtual patient representation obtained by using 4 different techniques: an in vitro study.
        J Prosthet Dent. 27 June 2022; ([Epub ahead of print])https://doi.org/10.1016/j.prosdent.2022.05.016
        • Li J.
        • Chen Z.
        • Decke A.M.
        • Wang H.L.
        • Joda T.
        • Mendonca G.
        • et al.
        Trueness and precision of economical smartphone-based virtual facebow records.
        J Prosthodont. 2022; 31: 22-29
        • International Organization for Standardization
        ISO-10993-1. Biological evaluation of medical devices - Part 1: evaluation and testing within a risk management process.
        ISO, Geneva2018
        • Food and Drug Administration
        FDA-2013-D-0350. Use of International Standard ISO 10993-1, “Biological evaluation of medical devices - Part 1: evaluation and testing within a risk management process”: guidance for Industry and Food and Drug Administration staff.
        FDA, Silver Spring2020