Digital to Analog Facially Generated Interchangeable Facebow Transfer: Capturing a Standardized Reference Position

Abstract

Although the evolution of digital technology continues to improve patient data acquisition, the ability to both standardize the recording of the maxillary occlusal plane and capture the necessary dynamic data for dento‐facial analysis remains elusive. This article describes step‐by‐step techniques to position the maxilla on an articulator using the natural head position and a facial reference system (Kois Facial Reference Glasses) for both analog and digital workflows. A photographic technique will be presented that captures the natural head position and allows the clinician to align a 2D reference photograph with the maxillary intraoral digital scan and the virtual articulator. Using this reference photograph, the clinician can record and communicate to the technician the maxillary arch position in relationship with the facial references, as well as transfer the additively manufactured casts in the same facial orientation for mounting and analysis either virtually or on an analog articulator.

Four-Dimensional Superimposition Techniques to Compose Dental Dynamic Virtual Patients: A Systematic Review

“…Thirteen studies obtained positional relationships to help simulate jaw movements on the VA. First, the facial reference system helped to locate the natural head position (NHP), a reliable plane to align the skull and VA hinge axis [ 22 , 30 ]. The common VF techniques involve transferring the maxillary dentition to the FS, guided by an Intraoral transfer element (IOTE) (i.e., facebow fork) or a scan body, and to the FS without an IOTE/scan body [ 19 , 22 , 24 , 32 , 33 , 37 , 40 , 42 ].…”

“…Special VF transfers the relationship by anatomical points/marker planes, reducing the errors by omitting the traditional facebow transfer [ 36 ]. The FS can be replaced by photographs [ 30 , 41 ]/CBCT [ 27 , 28 ]; however, the accuracy was not calculated. Once VF transfer is completed, VA systems are available for jaw motion simulation.…”

“…One study [ 36 ] combined bones from CBCT with mandibular position from VA and VF and dentition in CRO/MICP from IOS to simulate a patient. Six studies [ 22 , 30 , 37 , 40 , 41 ] described methods to create models with faces from FS [ 22 , 23 , 37 , 40 ]/2D photograph [ 30 , 41 ], dentition models from IOS [ 22 , 23 , 30 , 41 ]/DS [ 37 ], and mandibular position using VF and VA. Kois et al [ 30 ] used the “Align Mesh” tool to align data. The Alignment of the casts, scan body, facial scan, or alignment of the facebow forks was based on points [ 22 , 41 ].…”

An Indirect Digital Technique to Transfer 3D Printed Casts to a Mechanical Articulator With Individual Sagittal Condylar Inclination Settings Using CBCT and Intraoral Scans

“…In this technique, only a single CBCT scan is used to achieve the virtual mounting procedure. In cases where patients’ facial information is needed, a 2‐dimensional (2D) facial picture or 3D facial scan acquired with the patient in the natural head position (NHP) could also be superimposed on the CBCT scan and intraoral scan to guide the virtual mounting and preoperative treatment planning procedures 29,30 …”

“…In cases where patients' facial information is needed, a 2-dimensional (2D) facial picture or 3D facial scan acquired with the patient in the natural head position (NHP) could also be superimposed on the CBCT scan and intraoral scan to guide the virtual mounting and preoperative treatment planning procedures. 29,30 This technique records the MIP of the maxillomandibular arches during the CBCT scan and intraoral scan. In cases where the centric relation (CR) or treatment position is required, additional devices like gothic arch tracer, leaf gauge, or Lucia jig are first needed to fix the mandibular arch into the desired position.…”