Integration of intraoral digital scans with a 3D facial scan for anterior tooth rehabilitation

Comparison of the accuracy (trueness and precision) of virtual dentofacial patients digitized by three different methods based on 3D facial and dental images

STATEMENT OF PROBLEM

The accuracy of virtual dentofacial patients has been explored, but the accuracy of virtual patients established by using a straightforward and reliable method and the accuracy of different virtual patients are unclear.

PURPOSE

The purpose of this clinical study was to compare the accuracy of virtual dentofacial patients digitized by using registered-block impression, exposed anterior teeth, and cone beam computed tomography (CBCT) reconstruction methods based on 3-dimensional (3D) facial and dental images.

MATERIAL AND METHODS

From the 15 selected participants who needed CBCT scanning, 3 kinds of virtual dentofacial patients were established by using 3 registration methods based on digital dental casts: 3D facial images, CBCT data, and registered-block impression. Compared with actual measurement, 25 linear distances of all virtual dentofacial patients were selected and measured by using a software program, and 3 separate measurements were calculated by the same person. The 1-way analysis of variance (ANOVA) was used to compare the deviations among 3 kinds of virtual dentofacial patients (trueness) and the deviations within groups (precision). The 1-sample t test was used to compare the difference between the deviation and the ideal error of 0.00 (α=.05).

RESULTS

Compared with the actual measurement, the trueness of the average deviations for registered-block impression (1.02 ±1.24 mm) was better than that of exposed anterior teeth (2.35 ±1.71 mm) and CBCT reconstruction (2.86 ±1.61 mm). The precision of the average deviations for registered-block impression (1.29 ±1.43 mm) was better than that of exposed anterior teeth (2.00 ±1.72 mm) and CBCT reconstruction (2.12 ±1.94 mm). Significant differences in trueness and precision were found among the 3 groups of virtual dentofacial patients (P<.01). Significant differences among the deviations of all linear distances and the ideal error of 0.00 were observed for all groups of virtual dentofacial patients (P<.05).

CONCLUSIONS

The accuracy of registered-block impression was better than that of the exposed anterior teeth and CBCT reconstruction. The accuracy of exposed anterior teeth was lower than that of the other methods but could satisfy the requirements of clinical diagnostics and scientific methods. The accuracy of CBCT reconstruction was poor and could only be used for special situations that permitted low accuracy.

Fabrication of digital complete dentures guided by facial scanning with a device for recording the maxillomandibular relation: A dental technique

This article describes a technique for the fabrication of digital complete dentures guided by facial scanning using an innovative device for maxillomandibular relation records. For this, a device was designed and 3-dimensionally (3D) printed to assist in the maxillomandibular record stage. Digital files of the diagnostic casts, jaw relation record, and facial images were superimposed, and the complete denture was virtually planned. Subsequently, trial complete dentures were 3D printed, and a functional and esthetic clinical tooth evaluation was conducted. Then, definitive impressions were made, and definitive complete dentures were obtained. The method of recording the maxillomandibular relation associated with facial scanning in a digital workflow for manufacturing the dentures in a 3-appointment protocol provided better predictability of patient care and reduced clinical and laboratory time than with the conventional denture technique.

CAD-CAM natural restorations-Reproducing nature using a digital workflow

OBJECTIVES

Natural restorations combine digital workflow and shell technique to create CAD/CAM restorations with the form and texture of natural teeth. This case report describes an interdisciplinary digital workflow combined with CAD/CAM natural restorations to achieve the naturalness of an anterior rehabilitation.

CLINICAL CONSIDERATIONS

A 38-year-old patient attended to the office with esthetic issues. An interdisciplinary treatment plan was conducted, which included periodontal surgery to recreate the gingival contour, associated with bleaching and manufacturing CAD/CAM ceramic veneers to return an optimal teeth surface texture and shape.

CONCLUSIONS

The design and manufacturing of CAD/CAM natural restorations using a digital workflow allowed a predictable result and overcame the limitations of conventional shell technique.

CLINICAL SIGNIFICANCE

Conventional shell technique is used to create restorations with the form and texture of natural teeth. This article presents a combination of the conventional shell technique with a digital workflow, facilitating the design and manufacturing of CAD/CAM natural restorations.

Four-dimensional digital design to prediction of the real-time functional rehabilitation in the esthetic zone

Recent developments in digital technology and materials have improved the accuracy and efficiency of tracking and recording mandibular motion, with various methods being described. The present article describes a digital workflow with complete and accurate 3-dimensional spatial trajectories of mandibular motion to direct the design of lingual restorations. The workflow allowed the lingual curvature of the restoration to conform with the distinctive trajectory of mandibular protrusion.

Three-dimensional morphometric analysis of facial units in virtual smiling facial images with different smile expressions

PURPOSE

Accuracy of image matching between resting and smiling facial models is affected by the stability of the reference surfaces. This study aimed to investigate the morphometric variations in subdivided facial units during resting, posed and spontaneous smiling.

MATERIALS AND METHODS

The posed and spontaneous smiling faces of 33 adults were digitized and registered to the resting faces. The morphological changes of subdivided facial units at the forehead (upper and lower central, upper and lower lateral, and temple), nasal (dorsum, tip, lateral wall, and alar lobules), and chin (central and lateral) regions were assessed by measuring the 3D mesh deviations between the smiling and resting facial models. The one-way analysis of variance, Duncan post hoc tests, and Student's t-test were used to determine the differences among the groups (α = .05).

RESULTS

The smallest morphometric changes were observed at the upper and central forehead and nasal dorsum; meanwhile, the largest deviation was found at the nasal alar lobules in both the posed and spontaneous smiles (P < .001). The spontaneous smile generally resulted in larger facial unit changes than the posed smile, and significant difference was observed at the alar lobules, central chin, and lateral chin units (P < .001).

CONCLUSION

The upper and central forehead and nasal dorsum are reliable areas for image matching between resting and smiling 3D facial images. The central chin area can be considered an additional reference area for posed smiles; however, special cautions should be taken when selecting this area as references for spontaneous smiles.

Efficacy confirmation of Scutellaria baicalensis Georgi in the treatment of periodontitis via topical administration and active ingredients screening

ETHNOPHARMACOLOGICAL RELEVANCE

Periodontal disease is a complex inflammatory disease that seriously affects peoples' lives. Scutellaria radix (SR) is traditionally used as a folk medicine to clear away heat and dampness, purge fire and detoxification. Although it has been extensively used as a medicinal plant to treat a variety of inflammatory illnesses, the efficacy and active ingredient for topical administration in the treatment of periodontitis is unknown.

AIM OF STUDY

The aim of this study was to screen and validate the active ingredients in SR for the prevention and treatment of periodontitis.

MATERIALS AND METHODS

A ligature-induced periodontitis in rats was used to investigate the efficacy of topical administration of SR for the treatment of periodontitis, and the active fraction was screened after separation of the aqueous extract of SR into fractions of different polarities using a lipopolysaccharide (LPS)-induced cell model. Chromatographic fingerprints were established for 18 batches of SR by high performance liquid chromatography. The potential active components were screened using spectral effect relationship analysis and the target cell extraction method.

RESULTS

SR has good efficacy in the topical treatment of periodontitis, according to animal experiments. Five active ingredients were screened out and their anti-inflammatory activity was confirmed in vitro.

CONCLUSION

The main active compounds in the treatment of periodontitis via topical administration of SR were found and this provides an experimental basis for further studies on the pharmacodynamic material basis of SR, as well as reference for the comprehensive evaluation of SR quality and the development of substitute resources.

Comparison of the accuracy of different handheld-type scanners in three-dimensional facial image recognition

PURPOSE

Handheld-type scanners are widely used in clinical practice. This study examined the accuracy of handheld-type scanners using plaster statues to assess their performance in facial recognition.

METHODS

Twelve 4-mm zirconia balls as measuring points were attached to the facial portions of three types of plaster statue. Six digital facial images of each plaster statue were obtained using one of the following five handheld-type scanners: Artec Eva, Artec Spider, Bellus 3D FaceApp, SNAP, and Vectra H1. Four-millimeter spherical objects were manually placed at the measurement points on the scanned data generated using computer-aided design software and coordinate positions were measured using a contact-type high-resolution three-dimensional measurement device. Consequently, the discrepancy between the distance measured using the contact-type device and that measured using the handheld-type scanner was calculated. The scanning time, processing time, and deviation of the distance between the measuring points were analyzed using two-way analysis of variance and t-test with Bonferroni correction.

RESULTS

The scanning and processing times ranged from 15.2 to 42.2 s and 20.7 to 234.2 s, respectively. Overall, 97% of all measured distances by Spider were within ±1.00% deviation; 79%, Vectra; 73%, Eva; 70%, Bellus; and 42%, SNAP.

CONCLUSIONS

The performance of handheld-type scanners using plaster statues varied among the different scanners. The scanning time of Eva and the processing time of Bellus were significantly shorter than those of other scanners. Furthermore, Spider exhibited the best accuracy, followed by Eva, Vectra, Bellus, and SNAP.

Additively Manufactured Scan Bodies for Virtual Patient Integration: Different Designs, Manufacturing Procedures, and Clinical Protocols

Additively manufactured intraoral scan bodies can be used to guide the alignment of a patient's digital file information, including facial and intraoral digital scans both with and without a cone beam computed tomography scan, and to obtain a 3D virtual patient's representation. The present manuscript reviews the different intraoral scan body designs, procedures involved in additive manufacturing, clinical protocols for fabricating an additively manufactured scan body, performing a patient's digital data collection, and completing the alignment techniques.

Effects of Artificial Extraoral Markers on Accuracy of Three-Dimensional Dentofacial Image Integration: Smartphone Face Scan versus Stereophotogrammetry

Recently, three-dimensional (3D) facial scanning has been gaining popularity in personalized dentistry. Integration of the digital dental model into the 3D facial image allows for a treatment plan to be made in accordance with the patients’ individual needs. The aim of this study was to evaluate the effects of extraoral markers on the accuracy of digital dentofacial integrations. Facial models were generated using smartphone and stereophotogrammetry. Dental models were generated with and without extraoral markers and were registered to the facial models by matching the teeth or markers (n = 10 in each condition; total = 40). Accuracy of the image integration was measured in terms of general 3D position, occlusal plane, and dental midline deviations. The Mann−Whitney U test and two-way analysis of variance were used to compare results among face-scanning systems and matching methods (α = 0.05). As result, the accuracy of dentofacial registration was significantly affected by the use of artificial markers and different face-scanning systems (p < 0.001). The deviations were smallest in stereophotogrammetry with the marker-based matching and highest in smartphone face scans with the tooth-based matching. In comparison between the two face-scanning systems, the stereophotogrammetry generally produced smaller discrepancies than smartphones.

The Digital Clone: Intraoral Scanning, Face Scans and Cone Beam Computed Tomography Integration for Diagnosis and Treatment Planning

The purpose of this article is to synthesize different technologies that are available for the creation of a virtual patient, "the digital clone" because the data can be used for diagnosis as well as treatment planning. The role of facial scans, 3-dimensional intraoral scans as well as the cone beam computed tomography in the creation of a digital clone is discussed in detail. A step-by-step guide is created for the reader for integration of the intraoral scan data with the cone beam computed tomography Dicom data to create a digital clone.

Esthetic treatment planning with digital animation of the smile dynamics: A technique to create a 4-dimensional virtual patient

A method is presented for obtaining a virtual 4-dimensional patient that replicates the intended esthetic treatment. The process involves facial and intraoral scanning to acquire records and software manipulation to enable a virtual waxing of the smile. Once the digital design is complete, patient information can be merged to generate an animated video of the projected rehabilitation, displaying movement and smile dynamics. This strategy provides a noninvasive and reliable diagnostic tool for predicting clinical outcomes.

The Effect of Perioral Scan and Artificial Skin Markers on the Accuracy of Virtual Dentofacial Integration: Stereophotogrammetry Versus Smartphone Three-Dimensional Face-Scanning

This study evaluated the effects of different matching methods on the accuracy of dentofacial integration in stereophotogrammetry and smartphone face-scanning systems. The integration was done (N = 30) with different matching areas (n = 10), including teeth image only (TO), perioral area without markers (PN) and with markers (PM). The positional accuracy of the integrated models was assessed by measuring the midline linear deviations and incisal line canting between the experimental groups and laser scanner-based reference standards. Kruskal–Wallis and Mann–Whitney U tests were used for statistical analyses (α = 0.05). The PM method exhibited the smallest linear deviations in both systems; while the highest deviations were found in the TO in stereophotogrammetry; and in PN in smartphone. For the incisal line canting; the canting degree was the lowest in the PM method; followed by that in the TO and the PN in both systems. Although stereophotogrammetry generally exhibited higher accuracy than the smartphone; the two systems demonstrated no significant difference when the perioral areas were used for matching. The use of perioral scans with markers enables accurate dentofacial image integration; however; cautions should be given on the accuracy of the perioral image obtained without the use of markers.

Integrating intraoral, perioral, and facial scans into the design of digital dentures

Digital technologies offer the opportunity to integrate facial scans into the design of digital dentures and provide a beneficial 3D preview and simulation of the tooth arrangement for both treatment planning and communication. The presented technique describes a procedure of merging and aligning the intraoral scans of edentulous arches, the scans of the perioral area, and the scan of the nose made by using an intraoral scanner, as well as facial scans made by using a mobile phone. Thus, a digital patient can be obtained and used to optimize individual tooth arrangement during the design of the digital denture.