Table 2.

Summary of articles included in the systematic review on virtual facebow techniques

Author & Year	Type of Study	Aim	Sample	Study Group	Scan Method/Type	Articulator Type	Anatomical References	Alignment System	Mounting Process	CAD Software Program to Alignment	Conclusion
Kalman, 2016 [28]	Clinical technique	Develop a digital alternative and arbitrary mounting to address the shortcomings of the traditional facebow and provide additional clinical information.	2 separate sets of models poured in Microstone by each clinician technique	Clinician A Timed analog facebow (AF)	Conventional: CounterFit impression material & Quick Bite	N/A	Analog facebow & wax bite registration	Analog facebow & wax bite	Number of occluding teeth checked with 8 μm shim stock.	Mobile technology- application	The efficiency, accuracy, cost, and comfort of the VF provide the clinician with an alternative tool for records and essential technician communication.
				Clinician B Virtual facebow (VF)		Semi-adjustable articulator Whip Mix	Virtual facebow application & record	Face and dentition capture with reference grid and gyroscope
Lam, 2018 [5]	Clinical technique	Present a digital workflow for registering the patient’s horizontal plane in natural head position (NHP) on a virtual articulator.	1 patient	5 attempts of scans were done for the same patient	Stereophotogrammetry (SP) device (3dMDface, 3dMD Inc) used to scan the face. Teeth scanned with intraoral scanner (True definition; 3 M). Another SP scan with virtual facebow in position.	Denar Mark II articulator, Whip Mix	Buccal relationship of maxillary teeth & virtual facebow, 3D facial photograph, full-face cone beam computed tomography (CBCT).	Orientation reference board calibrates a stereophotogrammetry device and a 3D facial photograph of patient in NHP.	Load virtual patient model into Exocad, match THA to condylar element of the virtual articulator.	Exocad; GmBH	Casts mounted with NHP techniques have higher position in the articulator than those mounted with anatomic facebow technique.
Maveli, 2018 [29]	In vitro	Evaluate the coronal and sagittal orientation of the occlusal plane on maxillary casts mounted with an electronic application facebow system onto a semiadjustable arcon articulator.	Sample size: 30, 2 groups	Control group: 15 impressions of maxillary typodont	Polyvinyl siloxane impression material used to take impression of maxillary typodont attached to phantom mannequin head that has anterior landmarks (infraorbital rim & foramina).	Semi- Adjustable arcon Whip Mix Model 3040 Articulator	Frankfort horizontal plane and occlusal plane (OP)	Tablet calibration tool used, casts positioned on the stand with central incisors to a specific line. After alignment, another photograph was made and overlaid with the photograph of the phantom head.	Overlay of photograph of the phantom head aligned to central incisors	MaxAlign LabStand; Whip Mix Corp	MaxAlign system transferred the OP orientation more accurately for the sagittal plane than the coronal plane. Significant variation in coronal OP between test and control group that could have significant esthetic and functional implications. No significant differences were found in the sagittal orientation of the OP.
				Test group: 15 records using MaxAlign system (Whip Mix Corp) digital application on tablet	Tablet was placed on a stand and calibrated, 23 cm away and parallel to phantom head, photograph was taken from the application.
Amezua, 2022 [11]	In vitro	Analyze the influence of the facial scanning method on the accuracy with which a maxillary digital scan is transferred to a 3D face scan in a virtual facebow technique.	2 groups, 21 pairs of maxillary digital scans	Structured white light (SWL) technology (10 scans).	Maxillary digital scan (industrial reference scanner), and 3D face scan	N/A	Maxillary digital scan and standard virtual patient	Virtual facebow transfer (VFT) by intraoral transfer element (IOTE) kept in during face scans, removed, scanned with the impression material inside it, and another face scan without IOTE placed.	N/A	Geomagic Studio 2013, closest point algorithm/iterative closest point (ICP)	The accuracy with which a maxillary scan is transferred to a 3D face scan in a virtual facebow technique is strongly influenced by the facial scanner. Inaccuracies have been introduced when transferring a maxillary digital scan to a 3D face scan. Significant differences among trueness values when using different facial scanning methods with a very large effect size. Trueness of 0.138 mm and precision of 0.022 mm obtained by using SWL compared to trueness of 0.416 mm and precision of 0.095 mm was acquired from SFM scanning method.
				Structure-from-motion (SFM) technology (10 scans). 27 digital photographs of the mannequin’s face at different positions and angles. Photos uploaded to digital image-processing & 3D data-generation software program (Agisoft).
Li, 2022 [30]	Clinical technique	To investigate the trueness and precision of virtual facebow records using a smartphone as a 3D face scanner.	2 subjects	10 repeated virtual facebow records for each subject	Intraoral scan of maxillary arch (TRIOS), 3D facial scan with smartphone application (Hege 3D scanner).	Not mentioned	3 points: mesh spheres with diameter of 0.5 mm added to mesial buccal cusps of the left #14, right #3, and the mesial incisor angle of #9.	Facebow fork placed, and scan taken with it	N/A	Blender, version 2.8 and DentalCAD software (Exocad 2.2)	Virtual records made using smart-phone scans can capture maxilla position with high trueness and precision. Deviation anticipated to be around 1 mm in linear distance and 1º in angulation.
Inoue, 2024 [4]	Pilot clinical study	To determine differences in measurements among casts mounted virtually by using the average values of the Bonwill triangle and the Balkwill angle, casts mounted by using facebow records, and casts mounted from 3D facial scans.	10 participants (3 men, 7 women) with complete maxillary and mandibular dentitions	Facebow preservation group (FPG)	Intraoral scans, 3D printed models, face bow record (Artex Rotofix; Amann Girrbach AG), desktop scanner (Freedom HD; Degree of Freedom Inc) used to preserve the mounting	Semi-adjustable arcon articulator- (Artex CR; Amann Girrbach AG)	Right & left external auditory meatus, point at 42 mm inferior to nasal locator of the facebow	Facebow (Artex Rotofix; Amann Girrbach)	All mounted with same maxillomandibular relationship	ExodCAD; exocad GmbH, distances were measured from mesiobuccal tip of mandibular first molar to center of left condyle with incisal pin at 0 mm, 3 mm, and 5 mm.	1.Accuracies of FPG & FSG were comparable without statistical differences 2.AMG produced lower accuracy than FPG & FSG; however, increase in vertical dimension up to 5 mm was not significantly different 3.Use of 3D facial scanner to virtually mount dental casts provides a suitable option for the restorative dentist -Both anterior and posterior condylar measurements between the FPG & AMG were found to be sig different, while comparisons between the FPG & FSG were found not sig different. -All changes in vertical dimension were found not to be sig different with respect to both anterior & posterior measurements.
				Average mounting group (AMG)	Intraoral digital scans mounted virtually with Bonwill triangle and Balkwill angle concepts		Incisal edge of mandibular central incisor (anterior reference) and mesiobuccal cusp tips of mandibular first molars (posterior reference)	Average values of Bonwill triangle & Balkwill angle
				Facial scan group (FSG)	Casts digitized and superimposed on facial scans using a target system		Bergstrom point, glabella, and orbitale	Target facebow fork system with a facial scanner used to superimpose facial scans with STL files
Revilla-León, 2024 [26] (a)	In vitro	Compare the accuracy of the maxillary cast transfer into the virtual semi-adjustable articulator by using analog and digital methods.	3 groups n=10	Conventional facebow (CNV)	Reference scan; Industrial scanner (Gom ATOS Q3D 12 M). Study group: Max typodont; T170;Medit), Digitized facebow record	Panadent PCH Articulator, exocad GmbH	Reference glasses 3.0; Kois Center +Kois dentofacial analyzer system + LazrTrak	Reference platform (Kois adjustable platform) (DentalCAD)	Digitized facebow superimposed with the virtual reference Kois table (Kois Platform; exocad GmbH)	Dental CAD Software, v3.1 Rijeka, exocad GmbH	P group demonstrated best trueness & precision values. The maxillary cast transfer accuracy ranged from 137 ±44 μm to 453 ±176 μm among techniques. Midline evaluation a no trueness & precision. Significant posterior right anterior, posterior left, and overall trueness discrepancies among the groups. P group obtained best posterior R & L and overall precision and trueness. P & FS groups demonstrated best anterior trueness but no anterior precision discrepancies were found.
				Digital photograph (P group)	10 digital photographs (jpeg) with a DSLR D780, Marcolens 105 mm, and maxillary scan		Photographs with levelled Kois reference glasses	Rescaled photograph, maxillary scan positioned on Kois reference table & aligned with photo
				Facial scanning with a 3D extraoral scan body (FS)	Facial scan (Instarisa 3.0 Facial Scanner) with extraoral scan body in place on mannequin; exported as PLY, without scan body, mannequin scanned with laboratory scanner (Gom ATOS Q3D 12 M),		Facial scan with a 3D extraoral scan body with grid	Digitized extraoral scan body with Kois reference table
Revilla-León, 2024 (b) [31]	In vitro	Compare the accuracy of maxillary cast transfer into the virtual semi-adjustable articulator by using an analog and digital standardized photography technique	2 groups	Conventional facebow (CNV)	Laboratory scanner (T710; Medit) scan of maxillary dentate cast with a magnet, mannequin positioned in a tripod, reference scan of the assembled mannequin obtained with facial scanner	Panadent PCH Articulator; exocad GmbH	CNV group: Kois disposable tray in the facebow of the dentofacial analyzer system (Kois, Panadent), facebow acquired, digitized with same laboratory scanner	Digitized facebow superimposed with virtual reference Kois table of semi-adjustable by using disposable index as common information	N/A	DentalCAD, v.3.1 Rijeka; Exocad GmbH	Facebow record methods impacted trueness and precision of maxillary cast transfer into virtual semi-adjustable articulator. Photo group obtained better trueness in midline transfer compared to CNV. CNV obtained better trueness in anterior, posterior right & left, overall discrepancy compared to P group. P group obtained better precision in midline, posterior right & left, anterior and overall discrepancy of maxillary cast transfer compared to CNV. Overall discrepancy measured in CNV group was 0.620 ± 0.396 mm, in P group was 1.282 ± 0.118 mm. Sig trueness differences found in midline, anterior, posterior right, posterior left, and overall discrepancy between CNV & P groups.
							P group: 10 digital photos with levelled Kois reference glasses	Photographs rescaled, aligned with maxillary scan
Villanueva et al. 2025 [27]	Clinical dental technique	describes a digital technique for virtual mounting in a semi-adjustable articulator by integrating CBCT and intraoral and facial scans	Single patient	intraoral scans of the maxillary and mandibular arches + CBCT + facial scan	maxillary intraoral scan (reference scan) CBCT Facial scan		1. Mesiobuccal cusps of the bilateral first molars and the distoincisal angles of the maxillary lateral incisors as craniofacial reference points to establish a stable 4-point registration (align CBCT to intraoral scan) 2. Reference points on the cusp tips of both maxillary canines and the midpoint of the central incisors (align face scan to intraoral scan)	best-fit algorithm to refine the superimposition coincides at the defined reference points and along the occlusal plane ensuring symmetry with the facial midline and interpupillary line	aligning the Frankfort horizontal plane with the articulator reference plane using digital semi-adjustable articulator (BioArt A7 Plus)	Exocad; GmBH	By eliminating analog transfers, it improves accuracy, reduces variability, and enhances communication among specialists
Kim, 2025 [32]	In vivo	Compare accuracy of a novel virtual facebow transfer (VM) technique based on CBCT with that of conventional mounting (CM) technique using a facebow.	5 repeated mountings for with each technique for 15 participants	Conventional mounting technique	CBCT, preliminary impressions à Casts, one cast was digitalizedà STL	Hanau Modular Articulator System, WhipMix Corp scanned with 5 cube shaped markers with an industrial scanner as the reference articulator (RA-STL).	Anatomical Frankfort horizontal plane, infraorbital notch.	For CM group (Hanau Springbow; WhipMix Corp)	Mounted conventionally with facebow, then with cast on articulator, industrial scanner scan it all; TEMPLATE	Geomagic Control X v2018.0.1; 3D Systems	Significant differences found between 2 groups, VM more precise technique. Position of maxillary right central incisor indicated VM casts were positioned ahead of CM casts. Occlusal plane angle tended to be steeper in CM casts than VM casts. Mean distance between target points was significantly greater in the CM group than VM. Standard deviation between target points was sig greater in CM group than VM.
				Virtual facebow transfer technique			References from the skull: Bilateral porions, condyle, external acoustic meatuses, orbit, midline, sagittal suture, & spine	For VM group: CBCT, STL files of their skulls were obtained	Superimposing the scans with the CBCT.