The 4D virtual patient: A proof of concept in digital dentistry.

This dental technique article updates the 3-dimensional (3D) virtual patient digital workflow by introducing the space-time information acquired with jaw tracking motion. The direct digital procedure involved scanning the interim prostheses, creating virtual casts, and transferring the digital facebow, virtual articulation, and jaw-tracking motion. All 3D files and records from the intraoral scanner, cone beam computed tomography, extraoral scanner, and jaw tracking motion were superimposed using existing teeth as the connecting link in all data sets and adopting the best-fit alignment. The main advantages of the technique were creating a 4-dimensional virtual patient and standardizing the introduction of clinical space-time information (the fourth dimension) beyond the static condition.

Maxillomandibular relationship and virtual facebow integration in complete-arch intraoral implant scan: A novel clinical technique.

This clinical report introduces a novel clinical technique to create a 3D virtual patient for transferring the edentulous maxillary arch position with maxillomandibular relationship by using a facial scan device and an intraoral scanner and omitting CBCT imaging.

Intraoral scanner-based virtual facebow transferring: A chairside dental technique.

Accurately mounting dental casts on an articulator is an essential step in prosthetic treatments. In digital dentistry, virtual articulator mounting procedures rely on virtual facebow records. However, virtual facebow records usually require devices like face scanners or jaw motion tracking systems that are not commonly available in most dental practices. The present technique report describes a straightforward intraoral scanner-based virtual facebow transfer approach. In this technique, a reference facebow joint support was first scanned and aligned with a virtual articulator. Then, a patient's facebow joint support and bite fork assembly were scanned chairside with an intraoral scanner and aligned with the virtual articulator by matching common features with the reference facebow joint support. After aligning the patient's intraoral scans with the patient's bite fork scan that was already superimposed on the virtual articulator, a virtual mounting process was achieved. Once the corresponding reference facebow joint supports have been generated, this technique can be easily implemented with most facebow systems and be seamlessly integrated into daily clinical practice as only an intraoral scanner and a conventional facebow were required.

Face oriented digital workflow for transferring intraoral and extraoral data of edentulous arch rehabilitated with multiple implants: A clinical technique.

A modified scan body system is described to preserve the occlusal vertical dimension and obtain intraoral and extraoral records to transfer to the dental laboratory technician for a complete arch fixed implant-supported prosthesis. This technique helps to effectively manage the orientation and articulation of the maxillary implants for 3-dimensional smile design.

Prosthetic articulator-based implant rehabilitation virtual patient: A technique bridging implant surgery and reconstructive dentistry.

This technique report describes a fully digital workflow to create a prosthetic articulator-based implant rehabilitation (PAIR) virtual patient for complete-arch or complete-mouth implant rehabilitation. This workflow uses a custom gothic arch tracer during the cone beam computed tomography (CBCT) scan and a 3-dimensional virtual facebow when superimposing data. The PAIR virtual patient possesses reliable centric relation and vertical dimension of occlusion and is compatible with virtual articulators. Computer-aided implant planning and a digital prosthetic design can be seamlessly integrated by using this virtual patient.

Digital fixed complete-arch rehabilitation: From virtual articulator mounting to clinical delivery.

The virtual articulator is a tool that reproduces the relationship between the jaws in a virtual environment. The purpose of this clinical report was to describe a completely digital protocol starting from the virtual articulator mounting to developing static and dynamic occlusion in a complex prosthetic rehabilitation.

Trueness and Precision of Economical Smartphone-Based Virtual Facebow Records.

PURPOSE: To investigate the trueness and precision of virtual facebow records using a smartphone as a three-dimensional (3D) face scanner. MATERIAL AND METHODS: Twenty repeated virtual facebow records were performed on two subjects using a smartphone as a 3D face scanner. For each subject, a virtual facebow was attached to his/her maxillary arch, and face scans were performed using a smartphone with a 3D scan application. The subject's maxillary arch intraoral scan was aligned to the face scan by the virtual facebow fork. This procedure was repeated 10 times for each subject. To investigate if the maxillary scan is located at the right position to the face, these virtual facebow records were superimposed to a cone-beam computed tomography (CBCT) head scan from the same subject by matching the face scan to the 3D face reconstruction from CBCT images. The location of maxillary arch in virtual facebow records was compared with its position in CBCT. The "trueness" of the proposed procedure is defined as the deviation between maxilla arch position in virtual facebow records and the CBCT images. The "precision" is defined as the deviation between each virtual facebow record. The linear deviation at left central incisor (#9), left first molar (#14), and right first molar (#3), as well as angular deviation of occlusal plane were analyzed with descriptive statistics. Differences between two objects were also explored with Mann Whitney U test. RESULTS: The 20 virtual facebow records using the smartphone 3D scanner deviated from the CBCT measurements (trueness) by 1.14 ± 0.40 mm at #9, 1.20 ± 0.50 mm at #14, 1.12 ± 0.51 mm at the #3, and 1.48 ± 0.56° in the occlusal plane. The VFTs deviated from each other by 1.06 ± 0.50 mm at #9, 1.09 ± 0.49 mm at #14, 1.11 ± 0.58 mm at #3, and 0.81 ± 0.58° in the occlusal plane. When all sites combined, the trueness was 1.14 ± 0.40 mm, and the precision was 1.08 ± 0.52 mm. Out of eight measurements, three measurements were significantly different between subjects. Nevertheless, the mean difference was small. CONCLUSIONS: Virtual facebow records made using smartphone-based face scan can capture the maxilla position with high trueness and precision. The deviation can be anticipated as around 1 mm in linear distance and 1° in angulation.

Creating a virtual patient for completely edentulous computer-aided implant surgery: A dental technique.

A fully digital workflow for generating a virtual patient for completely edentulous computer-aided implant surgery is described. Existing dentures are temporarily relined with a radiopaque dental silicone material, and a cone beam computed tomography scan is made with the relined denture inserted. Then, scans of the relined denture are made with an intraoral scanner. The radiopaque silicone material increases the stability of the dentures and allows the a cone beam computed tomography images and the scans of the dentures to be superimposed to create a virtual patient. This technique may reduce laboratory work steps, clinical chairside time, and treatment costs.

Indirect Digital Workflow for Virtual Cross-Mounting of Fixed Implant-Supported Prostheses to Create a 3D Virtual Patient.

Mounting dental casts in an articulator is an important prerequisite for prosthodontic rehabilitation cases where the design of an accurate static and dynamic occlusion is needed. Virtual mounting can be achieved through the superimposition of various 3D images acquired from the hard and soft tissues of the patient. The purpose of this technical report is to describe a digital cross-mounting technique for patients undergoing implant-supported fixed prosthetic treatment. Through the use of face scanning, intraoral scanning, and cone beam computed tomography, this technique enables creation of a 3D virtual patient with occlusal registration in centric relation. Ultimately, the described methodology allows for the fabrication of definitive full-mouth implant-supported fixed prostheses.

Virtual Articulators and Virtual Mounting Procedures: Where Do We Stand?

A virtual articulator is a computer software tool that is capable of reproducing the relationship between the jaws and simulating jaw movement. It has gradually gained research interest in dentistry over the past decade. In prosthodontics, the virtual articulator should be considered as an additional diagnostic and treatment planning tool to the mechanical articulator, especially in complex cases involving alterations to the vertical dimension of occlusion. Numerous authors have reported on the available digital methodologies used for the assembly of virtual arch models in a virtual articulator, focusing their attention on topics such as the virtual facebow and digital occlusal registration. To correctly simulate jaw movement, the jaw models have to be digitalized and properly mounted on the virtual articulator. The aim of this review was to discuss the current knowledge surrounding the various techniques and methodologies related to virtual mounting in dentistry, and whether virtual articulators will become commonplace in clinical practice in the future. This review also traces the history of the virtual articulator up to its current state and discusses recently developed approaches and workflows for virtual mounting based on current knowledge and technological devices.

Prosthetic Rehabilitation of Edentulous Patients With Implants Based on Facial Profile Assessment: A Case Report.

PURPOSE: To introduce a user-friendly protocol for implant-retained prosthetic rehabilitation of fully edentulous patients based on facial profile and the cephalometric intermaxillary relationship. MATERIALS AND METHODS: The prosthetic rehabilitation of edentulous patients with implants based on facial profile assessment protocol commences with a clinical and cephalometric analysis, followed by a preliminary projection to obtain a harmonious interarch relationship, eventually stabilized by the preplanned prosthesis. The protocol is divided into the following 5 phases: esthetic evaluation; cephalometric-occlusal assessment; surgery; provisionalization; and definitive prosthesis. Evaluation of patient's satisfaction from the treatment provided was performed through a preoperative and postoperative visual analogue scale scores. RESULTS: The patient was granted immediate function and superior esthetics at day 1 of the treatment. These results were re-evaluated on an interval of 18 months and continued to be stable. The overall treatment time was significantly reduced. CONCLUSION: Our recommended protocol gives the clinician a chance to grasp results beyond the offered by traditional protocols by using a wider perspective of rehabilitation, involving the patient's facial profile, thus fulfilling the integration of both occlusal and cephalometric parameters in a unified surgical-prosthetic approach.

A Full-Digital Technique to Mount a Maxillary Arch Scan on a Virtual Articulator.

Mounting casts accurately on an articulator is a prerequisite for the treatment planning/execution of complex dental cases that require occlusal rehabilitation. A full digital approach to transfer the position of maxillary dentition to a virtual articulator, by using intraoral scans and cone beam computed tomography (CBCT) files is presented. This technique offers reduced chairside time and the flexibility of choosing the orientation plane. It can be used in orthognathic surgeries, complex interdisciplinary treatments requiring a CBCT scan with a large field of view, or treatments that already have the head CT or CBCT scans from previous diagnosis/treatment.

Novel complete-arch pillar system (CAPS) to register implant position and maxillomandibular relationship in one single visit.

OBJECTIVES: This article presents a novel complete-arch pillar system (CAPS) to register implant position and maxillomandibular relationship in one single visit for implant-supported fixed complete dental prostheses (IFCDPs). MATERIAL AND METHODS: The novel system presents a 3-unit toolset comprising intraoral scan bodies (ISBs), lateral pillar attachments (LPAs) and occlusal pillar attachments (OPAs). A 2-stage single visit workflow by an intraoral scanner (Trios 5) was introduced. The first stage "Screw-Scan-Done" was used to describe complete-arch intraoral implant scanning using LPAs. The second stage "Screw-Occlude-Done" involved virtual occlusal recording using OPAs. Two patients with one single edentulous arch were selected for this study. In the first patient, 6 bone level implants (Bone Level Tapered, Straumann) were placed in the edentulous maxilla at positions 12, 14, 16, 22, 24 and 26. In the second patient, 4 bone level implants (NobelActive CC, Nobel Biocare) were placed in the edentulous mandible at positions 32, 35, 42 and 45. A CAD-CAM procedure was initiated with the acquired IOS data to fabricate an interim IFCDP at the same day. Periapical radiographs were obtained of the implant-prosthetic connection of the definitive IFCDPs to verify the passive fit. Metrology software (Geomagic Qualify, 3D Systems - Matlab, Mathworks) was used to assess the implant analogs position in the 3D-printed casts used for fabricating the definitive IFCDPs. A quantitative occlusal relationship analysis was performed with IOS. RESULTS: Radiographic examination revealed no gaps at implant-prosthetic connection of the definitive IFCDPs. The 3D-printed casts showed an overall average distance deviation within the clinically acceptable range of errors of 150 µm. Quantitative occlusal relationship analysis with IOS showed well-distributed contacts. CONCLUSION: Within the limitations of this study, the following conclusions can be drawn: (1) A 3-unit toolset with ISBs, LPAs and OPAs allows to register the implant position and maxillomandibular relationship in one single visit; (2) the 2-stage clinical workflow with the CAPS system facilitates the IOS data acquisition for fabrication of an interim IFCDP at the same day; (3) a passive fit was demonstrated for the interim and the definitive IFCDPs. CLINICAL SIGNIFICANCE: The CAPS system can help clinicians to register the implant position and the maxillomandibular relationship in one single visit for the fabrication of an IFCDP.

Investigation of the precision of a novel jaw tracking system in recording mandibular movements: A preliminary clinical study.

OBJECTIVES: This preliminary study aimed to clinically assess the precision of a novel optical jaw tracking system (JTS) in registering mandibular movements (MMs) of protrusion and mediotrusion. METHODS: Twenty healthy participants underwent recordings using Cyclops JTS (Itaka Way Med) for functional MMs of protrusion and laterotrusion by two trained clinicians. Each subject performed five registrations at different times according to a standardized pattern within one-month period. The angulations of protrusive and mediotrusive functional paths within the first 2 mm from the maximal intercuspal position (MIP) were calculated for each trace, using a data software for angle measurements. Descriptive statistics were used to assess the repeatability of the recordings for each participant and MM. Additionally, inferential statistics were carried out on standard deviation values obtained (α=0.05). RESULTS: The overall precision for all the patients was 7.07±3.37° for the protrusion angle, 5.24±2.24° for right laterotrusion and 5.14±3.06° for left laterotrusion angles. The protrusion angle ranged from 3.08° to 13.57°, while the right and left laterotrusion ranged from 1.82° to 9.42° and from 1.58° to 10.59°, respectively. No statistically significant differences were observed between different functional MM types and gender (p > 0.05). CONCLUSIONS: Recordings functional MMs of mediotrusion and protrusion using Cyclops JTS showed consistent repeatability, regardless of gender and functional MM type. The results revealed non-negligible variations that may be due to the patients' abilities to precisely reproduce jaw movements or to the operator's ability to consistently connect the kinesiograph. CLINICAL SIGNIFICANCE: Capturing functional MMs digitally and importing the data into dental CAD software is essential for virtual waxing in prosthetic rehabilitations to design a functionalized adapted occlusion. Establishing the repeatability of MM recordings by a JTS is a crucial step in better understanding this novel JTS in the market. This process could facilitate the interpretation of cusp angles, aid in CAD dynamic technical modeling, and enhance clinical data communication between clinicians and technicians in a modern workflow.

Rehabilitation with implant-supported overdentures in preteens patients with ectodermal dysplasia: A cohort study.

INTRODUCTION: Hypohidrotic ectodermal dysplasia (HED) patients suffering of oligo-anodontia require early dental treatment to improve oral functions and reduce social impairment. The aim of this study was to evaluate the skeletal growth, implant and prosthetic survival rate, success, and complications after the rehabilitation with a maxillary denture and an implant-supported overdenture provided by a sliding bar in case of severe hypodontia/anodontia related to HED. MATERIALS AND METHODS: This retrospective cohort study began in 2009. Nine patients over 7 years old with HED and associated oligo-anodontia who presented at the University of Bologna for dental treatment were included in the study. They were first treated with conventional dentures and then with a maxillary denture and an implant-supported overdenture with a sliding bar connected to two implants placed in the anterior mandible. The subjects treated were followed for 3-12 years. In each case, orthopanoramic and lateral cephalometric radiographic exam were taken before implant placement and annually after prosthetic load. Vertical and transverse dimensions of the mandible in the symphysis area at implant sites were taken on the lateral cephalometric radiography at the time of implant placement and after 5 years from the prosthetic loading to assess the presence or absence of an anterior mandibular growth. Biologic and mechanical complications were also recorded at every visit. RESULTS: A mandibular vertical growth under the implant apex, at the implant neck, and a sagittal growth of the symphysis after 5 years from the prosthetic loading were observed and measured. Implant and prosthetic success and survival rates were 100% after 8.1 years (mean) follow-up period. No complications were reported except in one patient, where the repositioning of a retentive cap on the counter bar in the superstructure was necessary after 3 years from the prosthetic loading. CONCLUSIONS: The present study suggests that the growth of the mandible near implant sites continues even after their positioning. Implants can be successfully placed and provide support for prosthetic rehabilitation in preteens patients with HED.

Preliminary clinical study of the accuracy of a digital axiographic recording system for the assessment of sagittal condylar inclination.

OBJECTIVES: The aim of this study was to clinically evaluate the accuracy of a digital axiographic recording system in tracing the sagittal condylar inclination. METHODS: An axiographic examination that records the sagittal condylar path during protrusive/retrusive movement was performed on ten patients. Each subject was registered five different times by two different systems: 1) the Cadiax Gamma Diagnostic 4 computerized system as the control; 2) the Zebris Jaw Motion Analyser+  Optic System as the tested digital axiographic recording system. The records obtained allow to calculate the kinematic terminal transverse horizontal axis and the sagittal condylar inclination (SCI) at 3 and 5 mm along the pro-retrusive path. A linear mixed model was used to analyze if there was a statistically significant difference between the two systems. RESULTS: The mean left SCI value recorded by Zebris system were 49.81 ± 10.64° at 3 mm, 48.10 ± 11.04° at 5 mm, while the values recorded by Gamma system were 55.16° at 3 mm, 52.18° at 5 mm. The mean right SCI value recorded by Zebris system were 54.53 ± 10.26° at 3 mm, 51.85 ± 8.55° at 5 mm, while the values recorded by Gamma system were 49.68° at 3 mm, 48.23° at 5 mm. Linear mixed model showed no significant statistical difference between the two systems. CONCLUSIONS: Based on preliminary results, the Zebris Jaw Motion Analyzer+ Optic System demonstrates comparable accuracy to the Cadiax Gamma Diagnostic 4 when measuring sagittal condylar inclination. CLINICAL SIGNIFICANCE: The digital axiographic recording system enables to evaluate sagittal condylar inclination and to adjust virtual articulators in a digital workflow.

A novel digital technique for maintaining maxillomandibular relations in fixed prosthetic rehabilitations.

INTRODUCTION: In fixed prosthetic rehabilitations, the restorations must be designed and fabricated in a proper maxillomandibular relationship, with correct vertical dimensions of occlusion (VDO) and centric relation (CR). This short communication introduces a novel digital technique that allows to obtain the maxillomandibular record and transfer it throughout the treatment procedure. METHODS: The protocol consisted of the following steps: 1. scan-jig planning and production; 2. maxillomandibular record prior to tooth preparation; 3. sequential tooth preparation and post-operative data recording through a cut-out and re-scan protocol; 4. control of the pre- and post-operative alignment of the scans in the correct VDO and CR, design and delivery of the definitive restorations. RESULTS: There was no clinical difference in the spatial positions of the virtual models and the relationships between the arches throughout every step of the treatment. CONCLUSION: The main advantages of this technique are that it allows to maintain the therapeutic maxillomandibular relationship after its clinical evaluation, to reduce chair time and to avoid inaccuracies determined by multiple bite registrations.