A review of virtual planning software for guided implant surgery - data import and visualization, drill guide design and manufacturing

Accuracy of Three-Dimensional Computer-Aided Implant Surgical Guides: A Prospective In Vivo Study of the Impact of Template Design

Background: Digital planning and the use of a static surgical guide for implant placement provide predictability and safety for patients and practitioners. The aim of this study was to investigate differences in the accuracy and fit of long and short guides. Methods: In patients with at least one missing tooth, long (supported by the entire dental arch) and short templates (supported by two teeth, mesial and distal) were compared via intraoral scans and the superimposition of the STL files of the initial planning and the actual position in the patient's mouth along the X-, Y- and Z-axes. Furthermore, this study evaluated the conditions (e.g., mouth opening, the implant position) under which fully guided implantation can be realized. Results: The largest deviation was observed in the Z-axis, although this deviation was not as high for the short templates (0.2275 mm) as it was for the long templates (0.4007 mm). With respect to the 3D deviation (dXYZ), the average deviation from the mean value was 0.2953 mm for the short guides and 0.4360 mm for the long guides (p = 0.002). The effect size (Cohen's d) was 0.709, which was between the medium (0.50) and large effect sizes (0.80). The shorter templates showed a smaller deviation from the actual plan by 80%. With a mouth opening ≥50 mm, fully guided surgery can be performed in the molar region. In the premolar region, the lower limit was 32 mm. Conclusions: The 3D accuracy was significantly higher for the shorter template, which could therefore be favored.

Comparison of dynamic navigation systems in dental implantology: a systematic literature review of in vitro studies

Dynamic navigation is an innovative technology in implant surgery that enhances the precision of implant placement through real-time guidance for clinicians. This technology allows on-the-spot adjustments during surgery, reducing the risk of complications and improving implant outcomes. The aim of this systematic review was to assess the accuracy of various dynamic navigation systems in implant placement using in vitro models. A comprehensive literature search was performed across several databases, focusing on studies published between 2016 and 2024 that reported three-dimensional (3D) and angular deviations. Seven in vitro studies were included, analysing five dynamic navigation systems (ImplaNav, Navident, Denacam, X-Guide, and DCARER), with 649 implants evaluated. Results showed mean coronal 3D deviations between 0.46 mm and 1.58 mm, while apical deviations ranged from 0.48 mm to 2.12 mm. Angular deviations varied between 1.01° and 4.24°. Maximum deviations reached up to 4.80 mm for coronal 3D deviation and 10.70° for angular deviation. All systems demonstrated high accuracy within clinically acceptable limits, with X-Guide showing the lowest numerical errors. Factors like tracking technology, calibration methods, and user experience were found to influence accuracy. Overall, dynamic navigation significantly improves implant placement accuracy compared to freehand methods but remains dependent on technical factors.

The Effects of Light Crystal Display 3D Printers, Storage Time and Steam Sterilization on the Dimensional Stability of a Photopolymer Resin for Surgical Guides: An In Vitro Study

BACKGROUND

Implant surgical guides manufactured in-house using 3D printing technology are widely used in clinical practice to translate virtual planning to the operative field.

AIM

The present in vitro study investigated the dimensional changes of 3D surgical guides printed in-house using Shining 3D surgical guide resin (SG01).

MATERIALS AND METHODS

Five test bodies, varying in shape and dimensions, were designed using computer-aided design (CAD) software and manufactured using three different Light Crystal Display (LCD) 3D printers (AccuFab-L4D, Elegoo Mars Pro 3, and Zortrax Inspire). Specific printing and post-processing parameters for the SG01 resin were set to produce 25 test bodies (5 of each shape) from each of the three printers, resulting in a total of 75 samples. The dimensional changes were evaluated using a digital calliper at four different time points: immediately after printing (T0), one month after storage (T1), immediately after sterilization (T2), and one month after sterilization (T3).

RESULTS

All the test bodies showed deviations from the overall CAD reference value of 12.25 mm after printing and post-processing (T0) and following steam sterilization (T2). Similar trends were observed for the effect of storage times at T1 and T3. The AccuFab prints demonstrated a better dimensional stability than the Elegoo and Zortrax samples.

CONCLUSIONS

The LCD 3D printers, sterilization, and storage times influenced the dimensional stability of the test bodies made with SGO1 resin.

Comparative accuracy assessment of analog and virtual wax-up in prosthetic-driven planning and guided implant surgery: A retrospective cohort study

PURPOSE

This retrospective cohort study evaluated the accuracy of analog versus virtual wax-ups in prosthetic-driven planning and guided surgery.

METHODS

There were 73 patients with a single missing posterior tooth who underwent either an analog or virtual wax-up design following a prosthetic-driven concept. Intraoral scans of the final restoration were performed 1 year after completion of the restoration. The accuracy was assessed by comparing the deviation between the final restoration and the wax-up (analog or virtual) of each patient at the prosthetic level. The maximum deviation in six areas (buccal top, buccal mid, buccal bottom, lingual top, lingual mid, and lingual bottom) was recorded. The accuracy was also assessed at the implant level by comparing the deviation between the virtual new implant position, which was redesigned based on the final restoration as the new wax-up, and the planned position. The mean deviations in the coronal, apical, angular, and depth measurements were recorded. A two-tailed independent t-test and a one-way analysis of variance were used.

RESULTS

Statistically significant differences were observed between the buccal (P = 0.03) and lingual tops (P = 0.03) at the prosthetic level. Significant differences were observed in the angular (P < 0.01) and coronal (P = 0.01) deviations at the implant level. There were smaller deviations between the analog wax-ups and final restorations regardless of the prosthetic or implant level.

CONCLUSIONS

Analog wax-ups were preferable to virtual wax-ups for preoperative design in computer-guided implant surgery.

Efficacy of digital templates in edentulous implant placement: a retrospective study

OBJECTIVES

The aim of the present study is to evaluate the accuracy of a digital template on the three-dimensional accuracy of edentulous implantation through a retrospective study to provide more clinical evidence for the use of digital templates in edentulous patient.

MATERIALS AND METHODS

This study evaluates the efficacy of a digital surgical template in edentulous jaws, comparing preoperative plans with postoperative outcomes across four metrics: platform, apex, depth, and angular deviations. Utilizing a patient with an edentulous maxilla as a case study, this research employs CBCT for preoperative and postoperative assessments, with deviations analyzed via 3-Shape software. Comparing these deviations with average deviations in lierature.

RESULTS

The average platform deviations at positions 12, 14, 16, 22, 24, 26 were 0.98 ± 0.03 mm, 1.43 ± 0.02 mm, 1.27 ± 0.04 mm, 1.35 ± 0.03 mm, 1.34 ± 0.02 mm, and 1.42 ± 0.03 mm, respectively. The average apex deviations were 1.28 ± 0.02 mm, 1.39 ± 0.03 mm, 1.47 ± 0.04 mm, 1.26 ± 0.04 mm, 1.40 ± 0.04 mm, and 1.48 ± 0.03 mm, respectively, the average angular deviations were 3.50°± 0.08°, 2.87°± 0.07°, 3.49°± 0.06°, 3.36°± 0.10°, 3.41°± 0.13°, and 3.69°± 0.11°, and average depth deviations were 0.29 ± 0.03 mm, 0.26 ± 0.05 mm, 0.59 ± 0.05 mm, 0.28 ± 0.04 mm, 0.47 ± 0.02 mm, 0.53 ± 0.03 mm. Compared with a total mean deviation of 1.2 mm (1.04 mm to 1.44 mm) of platform deviation, 1.4 mm (1.28 mm to 1.58 mm) of apex deviation, angular deviation of 3.5°(3.0° to 3.96°) and depth deviation of 0.2 mm (-0.25 mm to 0.57 mm) reported in literature. While all measured deviations fell within clinically acceptable limits, certain parameters exceeded the benchmarks, suggesting areas for improvement in digital surgical planning and execution.

CONCLUSIONS

This study indicates that while all measured deviations fell within clinically acceptable limits, certain parameters exceeded the benchmarks, suggesting areas for improvement in digital surgical planning and execution. Based on these data, the potential of digital guide plates to fulfill precision requirements in edentulous jaw implantation can be proved, contributing valuable insights into the optimization of implant surgery protocols.

CLINICAL RELEVANCE

Now, the digital template is accepted by many doctors. However, clinical research has not thoroughly verified whether the new digital technology is more accurate than traditional technology. So, this study aims to explore the effect of a whole-process digital template on edentulous implantation and provide more clinical evidence.

Assessment of Accuracy of Linear Alveolar Ridge Measurements with Different Implant Planning Software Programs

Introduction

Virtual implant planning is important before implant surgery for ideal implant size selection and placement. Currently, with technological advancements, there are plethora of virtual implant planning software with DICOM interface (digital imaging and communication in medicine) for the import of CBCT images (cone beam computerized tomographic scan) and with various tools to facilitate linear ridge dimensions. Few available planning software programs are usually associated with high initial cost; however, other programs are available for lesser cost. The literature on accuracy and reliability of these software programs is limited. Hence, our study was done with the aim to compare the reliability of available software systems along with gold standard of ridge mapping using bone caliper.

Methodology

CBCT scans of 10 patients with missing single teeth in maxillary anterior region between the age group of 25 and 45 years were recruited for the study. All CBCT scans of patients were assessed for buccopalatal width and mesiodistal width of planned implant site, using three different implant planning software system, i.e., commercially available Nobel clinician, inbuilt NNT viewer, and open source Blue sky Bio and compared with clinical method of ridge mapping using bone caliper.

Results

The analysis of results obtained in our study showed no statistically significant difference in the mean values for buccopalatal width at points A and B using three different software programs. However, the values obtained from commercial Nobel clinician software were very much like the mean values obtained with the ridge mapping method.

Conclusion

According to our study, measurements obtained from all the three implant planning software system are reliable and can be compared with proven method of clinical ridge assessment using bone caliper.

Feasibility of using two generative AI models for teeth reconstruction

OBJECTIVES

This feasibility study investigates the application of artificial intelligence (AI) models, specifically transformer-based (TM) and diffusion-based (DM) models, for the reconstruction of single and multiple missing teeth.

METHODS

A dataset of 129 digitized models was utilized to create both TM and DM models. Single and multiple missing teeth were artificially generated. Reconstruction accuracy was assessed against ground truth data using Root Mean Square (RMS) and mean absolute error (MAE) across various artificially generated teeth. Paired t-tests were used for analyzing differences between the two models (p < 0.05).

RESULTS

Both TM and DM models demonstrated similar accuracy in the reconstruction of single and multiple missing teeth. The greatest disparity occurred in the reconstruction of all remaining teeth, with the exception of 33 and 43 for both models (RMS TM: 0.37; DM: 0.43). TM exhibited the highest precision in reconstructing tooth 34 (RMS: 0.21), whereas DM demonstrated superior accuracy in reconstructing tooth 21 (RMS: 0.19). Despite there was no significant difference between the models.

CONCLUSIONS

AI-based TM and DM models demonstrate promising results in reconstructing missing teeth, with superior accuracy in single-tooth compared to multiple-tooth edentulous spaces. Despite the need for additional refining and larger datasets, including antagonistic teeth, these models have the potential to streamline and improve the dental restoration processes, potentially leading to cost savings and enhanced clinical outcomes.

SIGNIFICANCE

This study demonstrates the feasibility and potential of transformer- and diffusion-based AI models to accurately reconstruct missing teeth, offering a novel approach that could streamline and enhance the precision of implant planning.

An automatic tracking method to measure the mandibula movement during real time MRI

Mandibular movement is complex and individual due to variations in the temporomandibular joint (TMJ). Consequently, patient-centered dentistry should incorporate patients' specific anatomy and condylar function in treatment planning. Real-time magnetic resonance imaging (rt-MRI) visualizes relevant structures and tracks mandibular movement. However, current assessments rely on qualitative observations or time-consuming manual tracking, lacking reliability. This study developed an automatic tracking algorithm for mandibular movement in rt-MRI using least mean square registration (LMS) and compared it to manual tracking (MT) during mouth opening. Ten participants with skeletal class I underwent rt-MRI (10 frames/s). The same operator tracked the condylar pathway for the two methods, setting 2000 landmarks (2 landmarks x100 frames x10 participants) for MT and 210 landmarks (3 landmarks x7 frames x10 participants) for LMS. Time required, superimposition error, and the distance between tracked condylar pathways were compared between methods. LMS tracking was 76% faster and showed significantly better superimposition (0.0289 ± 0.0058) than MT (0.059 ± 0.0145) (p = 0.002). During one-third of the movement, the pathways tracked by both methods were more than 1 mm and 1° apart. These findings highlight the benefits of automatic condylar movement tracking in rt-MRI, laying the groundwork for more objective and quantitative observation of TMJ function.

Guided versus freehand single implant placement: A 3-year parallel randomized clinical trial

OBJECTIVES

The present parallel randomized clinical trial aimed to assess, after a 3-year follow-up period, whether the choice of surgical technique-either manual or guided-and of the operator - non-expert operator or skilled - can affect the stability of peri‑implant marginal bone levels in implants placed 1 mm sub-crestal.

MATERIALS AND METHODS

Patients received platform-switched implants (Anyridge, MegaGen Implant Co., Gyeongbuk, South Korea) featuring a 5-degree internal conical connection and supporting single screw-retained fixed crowns. The implants were randomly assigned to be placed through a digitally static guided surgery procedure (Test group - GS) or a freehand surgical technique (Control Group - FH). A non-expert operator (fewer than 20 implants placed in his professional activity) was selected to perform procedures for the GS Group, while a skilled operator (with over 1000 implants placed in his professional activity) was chosen for the FH Group. Marginal bone level (MBL) was measured at prosthesis installation (t0) and at 1 (t1), 2 (t2) and 3 years (t3) of follow-up. Changes in MBL from t0 to t3 were analyzed through periapical radiographs. Moreover, MBL changes at all time points were correlated to different supra-crestal soft tissue heights (STH): less than 3 and ≥ 3 mm, respectively.

RESULTS

60 implants in 18 patients were examined, with 30 implants allocated to the GS group and 30 to the FH group. The difference in MBL change between the two groups was 0.11 ± 0.22 mm, which was not statistically significant (p = 0.61). At the time of prosthetic loading, the mean MBL for implants with STH less than 3 mm was 0.33 mm higher than implants with STH ≥ 3 mm, though this difference was not statistically significant (P = 0.065).

CONCLUSIONS

Digitally static guided implant placement, performed by a non-expert operator, does not limit marginal bone remodeling, when compared to a freehand procedure performed by an experienced operator.

CLINICAL SIGNIFICANCE

After correct and careful planning, early marginal bone levels (MBL) around conical connection, platform-switched implants placed sub-crestally may be stable in time. Digital planning and surgery have the potential to assist non-expert clinicians in achieving implant placements with comparable outcomes to those performed by experts.

A method for assessing guide layout and error on implant accuracy

Functional and esthetic results require accurate implant placement. We aimed to develop a predictive method for assessing guide layout and error on implant accuracy. A mathematical model for position error analysis was constructed based on triangular mesh data. This model examines the relationship between the spatial shifts of multiple surfaces and the spatial shifts of specific points. It involves encasing these surfaces in a cuboid bounding box and expressing them in a local coordinate system. The influence of positioning surface error and layout of surgical guide were researched with a simulation test. The result shows that error in the implant site position is directly related to the error in the guide locating surface under the same layout. When the guide locating surface layout varies, as the length, width, and height of the minimum cuboid envelope increase, the maximum deviation in the implant site position decreases.

Intraoral ultrasonography image registration for evaluation of partial edentulous ridge: A methodology and validation study

OBJECTIVES

Ultrasound (US) reveals details for diagnosing soft- and hard-tissue dimensions around teeth, implants, and the edentulous ridge, not seen in 2D radiographs. Co-registering free-hand US scans with other 3D modalities presents reliability challenges. This study first aims to develop and validate a registration method to longitudinally reproduce US images of the jawbone on a simulator. In addition, it also evaluates the degree of the anatomical match in humans between US images acquired by the proposed registration method and the commonly used freehand acquisitions in comparison to cone beam computed tomography (CBCT) and intra-oral optical scan (IOS), used as references.

METHODS

A previously introduced ultrasound phantom was employed as a CBCT-US hybrid, suitable for training and technique development of US guides in edentulous ridges. After establishing feasibility in the phantom, the methodology was validated in a cohort of 24 human subjects (26 cases). Soft tissues were delineated on US and IOS, and hard tissues on US and CBCT. US accuracy and repeatability from both guided and freehand scans (non-guided) was assessed as the average distance between US and the references.

RESULTS

Guided US images resembled the references more closely than freehand (non-guided) scans. Notably, delineation of soft and hard tissues was significantly more accurate when employing guides. In the phantom, guided scans exhibited an absolute mean deviation of 81.8 µm for gingiva and 90.4 µm for bone, whereas non-guided scans showed deviations of 150.4 µm and 177.2 µm, respectively. Similarly, in vivo, guided US outperformed non-guided US, with gingiva deviations of 125 µm and 196 µm, and bone deviations of 354 µm and 554 µm, respectively.

CONCLUSIONS

By using a registration method, guided US scans improved repeatability and accuracy of mapping hard and soft tissue of the edentulous ridge when compared to non-guided scans.

CLINICAL RELEVANCE

This guided US imaging method could lay the foundation for longitudinal evaluation of tissue behavior and dimensional changes with improved accuracy.

Depth distortion and angular deviation of a fully guided tooth-supported static surgical guide in a partially edentulous patient: A systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the depth distortion and angular deviation of fully-guided tooth-supported static surgical guides (FTSG) in partially edentulous arches compared to partially guided surgical guides or freehand.

MATERIAL AND METHODS

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in the Open Science Framework (OSF). The formulated population, intervention, comparison, and outcome (PICO) question was: "In partially edentulous arches, what are the depth distortion and angular deviation of FTSG compared to partially guided surgical guides or freehand?" The search strategy involved four main electronic databases, and an additional manual search was completed in November 2023 by following an established search strategy. Initial inclusion was based on titles and abstracts, followed by a detailed review of selected studies, and clinical studies that evaluated the angular deviations or depth distortion in FTSG in partial arches, compared to partially guided surgical guides or freehand, were included. In FTSG, two surgical approaches were compared: open flap and flapless techniques, and two digital methods were assessed for surgical guide design with fiducial markers or dental surfaces. A qualitative analysis for clinical studies was used to assess the risk of bias. The certainty of the evidence was assessed according to the grading of recommendations, assessment, development, and evaluations (GRADE) system. In addition, a single-arm meta-analysis of proportion was performed to evaluate the angular deviation of freehand and FTSG.

RESULTS

Ten studies, published between 2018 and 2023, met the eligibility criteria. Among them, 10 studies reported angular deviations ranging from -0.32° to 4.96° for FTSG. Regarding FTSG surgical approaches, seven studies examined the open flap technique for FTSG, reporting mean angular deviations ranging from 2.03° to 4.23°, and four studies evaluated flapless FTSG, reporting angular deviations ranging from -0.32° to 3.38°. Six studies assessed the freehand surgical approach, reporting angular deviations ranging from 1.40° to 7.36°. The mean depth distortion ranged between 0.19 mm to 2.05 mm for open flap FTSG, and between 0.15 mm to 0.45 mm for flapless FTSG. For partially guided surgical guides, two studies reported angular deviations ranging from 0.59° to 3.44°. Seven studies were eligible for meta-analysis, focusing on the FTSG in open flap technique, with high heterogeneity (I2 (95%CI) = 92.3% (88.7%-96.4%)). In contrast, heterogeneity was low in studies comparing freehand versus FTSG in open flap techniques (I2 (95%CI) = 21.3% (0.0%-67.8%)), favoring the FTSG surgical approach.

CONCLUSION

In partially edentulous arches, FTSG systems exhibited less angular deviation than freehand and partially guided surgical guides. Flapless surgical approaches were associated with reduced angular deviation and depth distortion, suggesting a potential preference for the FTSG method in these procedures.

Autoclaving-induced dimensional changes of three-dimensional printed surgical guides: An in vitro study

OBJECTIVES

Surgical guides are frequently used for dental implant placement. The aim of this study was to evaluate the impact of the 3D printing process itself and subsequent steam autoclaving on the dimensional stability of five different resin/printer combinations (RPCs).

MATERIALS AND METHODS

Fifty identical surgical guides (10 per group) were produced consisting of five RPCs. Half of the guides (5 per group) were steam autoclaved with cycle 1 (121°C, 1 bar, 20.5 min) and the other half with cycle 2 (134°C, 2 bar, 5.5 min). All guides were scanned with a structured-light (SL) 3D scanner before (T0) and after (T1) autoclaving. Linear measurements along the x-, y-, and z-axes were performed at landmarks on the original STL file and on SL scans at T0 and T1, respectively. Wilcoxon signed-rank test, Kruskal-Wallis test, and linear mixed-effects models were performed, depending on the analysis.

RESULTS

Three-dimensional printing was associated with significant dimensional alterations for all RPCs. Steam autoclaving using cycle 1 was associated with significant shrinkage in x- (1 RPC), y- (2 RPCs), and z-direction (2 RPCs), while cycle 2 was also associated with shrinkage in x- (2 RPCs), y- (1 RPC), and z-direction (1 RPC). One resin did not present any dimensional changes independently of the cycle.

CONCLUSIONS

The majority of the guides presented minor but significant shrinkage due to 3D printing itself and both steam autoclaving cycles, the extent varied between different RPCs. Whether these changes compromise implant placement accuracy remains to be investigated.

Accuracy of Implant Size Prediction Based on Edentulous Ridge Dimension on Cone-beam Computed Tomography - A Retrospective Study

Introduction

Cone-beam computed tomography (CBCT) is the recommended imaging modality for implant planning. It is important to evaluate the accuracy of CBCT-based implant size prediction. This study aims to correlate projected implant sizes from CBCT alveolar ridge measurements with the actual sizes of placed implants, to determine the accuracy of the prediction.

Materials and Methods

CBCTs taken for implant placement were included. The heights and widths of edentulous ridges were measured with Anatomage in vivo dental three-dimensional software, and actual implant size data were retrieved from treatment notes. Central incisor, canine, first premolar and first molar locations were analysed. One-way analysis of variance (ANOVA) was run to determine the average sizes for edentulous ridges and implants and Pearson correlation was conducted to determine the accuracy of CBCT-based implant size prediction.

Results

Of 544 cases analysed, the average implant diameter was 4.17 mm (standard deviation [SD] =0.38) and the length was 10.05 mm (SD =1.17). Alveolar width and height were 3.74 mm and 4.31 mm larger than the implant diameters and lengths, respectively providing approximately 1.5-2 mm of extra space on either side of the implant in relation to adjacent anatomical structures. Implants placed at mandibular canine and first molar and maxillary first premolar demonstrated significant correlations with the sizes of the edentulous ridges (P < 0.05).

Discussion

CBCT-based alveolar ridge measurements have been demonstrated as reliable parameters to predict implant sizes. However, its accuracy may be limited by the factors such as edentulous ridge morphology and proximity to vital anatomic landmarks.

Cone-wedge anchored surgical templates for stackable metal guide: a novel technique

OBJECTIVE

To address the instability in implant surgical guides, this technique proposes an alternative anchoring mechanism in the stackable metal surgical guides utilizing cone-wedge anchors for improved stability.

METHODS

Postoperative implant position superimposed onto the preoperatively planned design using Mimics Medical 21.0 and Materialise Magics 24.0 to assess 3D coronal implant deviation, 3D apical implant deviation, and implant angular deviation.

RESULTS

Postoperative cone-beam computed tomography (CBCT) revealed a high level of precision in the implant placement, with an average 0.97 mm deviation at implant coronal region, 1.56 mm at implant apexes, and 2.95° angular deviation.

CONCLUSION

This technique introduces a novel cone-wedge anchoring mechanism to enhance the stability of stackable metal surgical guide templates, addressing inherent instability issues. The utilization of this approach significantly improves the accuracy of implant placement procedures.

A 10-year follow-up study on clinical outcomes of dental implant rehabilitation using surgical guide

Objectives

The surgical guide is a static computer-assisted device used for implant surgery planning and guidance. By taking an impression and referring to the patients' three-dimensional computed tomography scan of the desired implant site, a surgical guide can be created. During surgery, the surgical guide aids in achieving the designed implant placement position and direction. We examined and evaluated the long-term clinical outcomes of implant surgery using surgical guides.

Materials and Methods

This study investigated a total of 15 patients with 32 implants that were placed using surgical guides from 2009 to 2011 with a mean follow-up period extended beyond 10 years. Patient demographics and implant survival rates were recorded. We analyzed marginal bone loss (MBL) by assessing the radiographs acquired at installation, three months after installation, and one month, one, two, and five years after prosthesis delivery.

Results

The mean patient age was 57.33 years at implant placement. Of the 32 implants, five implants were placed in the anterior region and 27 implants were in the posterior region. Six implants failed and three of them were replaced, resulting in an 81.25% survival rate. The mean follow-up period was 10 years and nine months. Mean MBL compared to post-installation was significantly higher than at three months after installation, and one month, one, two, and five years after prosthesis delivery. Mean MBL at three months after installation, and one month, one year, and two years were significantly higher compared to the previous visit (P<0.05). However, MBL at five years after prosthesis delivery did not differ significantly compared to at two years.

Conclusion

In this study, implant rehabilitation assisted by surgical guides exhibited favorable survival rates. With the limitation of the sample amount in this study, further research and more samples are required to evaluate the long-term clinical effectiveness of surgical guides.

Mechanical shock test simulation analysis of butterfly valves developed for the naval defense industry and evaluation of real test and production data

The main purpose of this study is to investigate the mechanical shock behavior and develop the shock resistance of widely preferred butterfly valves for navy defense industries by handling the real test results with computer aided design and simulation programs. The 2D and 3D drawings were realized by using solid modeling and design programs. Mechanical analyzes to determine the mechanical strength of the specimens were carried out with the finite element analysis method by using structural simulation program. Mechanical shock test simulations were carried out by with shock response spectrum analysis. Solidification, filling-time-temperature analyzes, and simulation studies of inner stresses caused by micro and macro shrinkages were performed by using the casting simulation program. Comparisons of virtual tests simulated in computer environment with real tests were done in shock test setup. Products made of bronze were preferred due to the high corrosion resistance and the desire to be a useful research article that can respond to common applications in the defense industry. Virtual shock test simulation and real shock tests were performed according to the MIL STD 810 standard. The shock test results observations showed that by revising the design with a safety factor of 18% on the specimen, it was ensured that the product could pass the mechanical shock test even at an acceleration of 4000 m/s2. Then material become safe to use. With the use of a three-way feeder in the production of the reinforced design the difference in net weight from 19% has been reduced to 12%, while the production time has been improved by 22%.

A comprehensive review and update on the current state of computer-assisted rehabilitation in implant dentistry

AIM

This paper provides a comprehensive review of the established concepts and newer developments related to computer-assisted implant rehabilitation.

METHODS

Two independent researchers searched the English literature published to 31st December 2023 in the PubMed/Medline database for primary and secondary research and related publications on computer-assisted implant planning, computer-assisted implant placement and computer-assisted implant restoration.

RESULTS

A total of 58,923 papers were identified, 198 relevant papers were read in full text and 110 studies were finally included. Computer-assisted implant rehabilitation was found to result in more precise implant positioning than freehand placement. Advantages include reduced trauma and surgery time; disadvantages include reduced primary implant stability and higher cost.

CONCLUSION

Computer-assisted surgery is particularly indicated in cases of critical anatomy, but may encounter limitations in terms of cost, restricted mouth opening, visibility and adjustment of the surgical guides and the need for prior familiarisation with the procedure. Nonetheless, this surgical technique reduces the post-implant placement complication rate.

A literature review on prosthetically designed guided implant placement and the factors influencing dental implant success

This is an extensive review of the literature on prosthetically designed implant planning with particular regard to the factors influencing dental implant success. Electronic searches on PubMed and the Cochrane Central Register of Controlled Trials and manual searches were performed. The author selected the studies according to the inclusion and exclusion criteria. Meta-analysis of implant placement accuracy and a qualitative review of potential influencing factors were performed.This literature review will explore prosthetically designed implant placement and its influence on dental implant success. By examining the factors that impact implant outcomes, this review aims to provide clinicians with a comprehensive understanding of the key considerations and best practices in achieving successful implant placements. Ultimately, this knowledge can contribute to enhancing patient care and the long-term success of dental implant treatments.

The use of virtual reality and augmented reality in oral and maxillofacial surgery: A narrative review

OBJECTIVE

The purpose of this article is to review the current uses of virtual reality (VR) and augmented reality (AR) in oral and maxillofacial surgery. We discuss the use of VR/AR in educational training, surgical planning, advances in hardware and software, and the implementation of VR/AR in this field.

STUDY DESIGN

A retrospective comprehensive review search of PubMed, Web of Science, Embase, and Cochrane Library was conducted. The search resulted in finding 313 English articles in the last 10 years.

RESULTS

A total of 38 articles were selected after a meticulous review of the aims, objectives, and methodology by 2 independent reviewers.

CONCLUSIONS

Virtual reality/AR technology offers significant potential in various aspects, including student education, resident evaluation, surgical planning, and overall surgical implementation. However, its widespread adoption in practice is hindered by factors such as the need for further research, cost concerns, unfamiliarity among current educators, and the necessity for technological improvement. Furthermore, residency programs hold a unique position to influence the future of oral and maxillofacial surgery. As VR/AR has demonstrated substantial benefits in resident education and other applications, residency programs have much to gain by integrating these emerging technologies into their curricula.

Automation in Dentistry with Mechanical Drills and Lasers for Implant Osteotomy: A Narrative-Scoping Review

The popularity of implants is increasing with the aging population requiring oral-dental rehabilitation. There are several critical steps in the implant workflow, including case selection, implant design, surgical procedure, biological tissue responses, and functional restoration. Among these steps, surgical osteotomy procedures are a crucial determinant of clinical success. This brief review was aimed at outlining the current state of the field in automation-assisted implant surgical osteotomy technologies. A broad search of the literature was performed to identify current literature. The results are outlined in three broad categories: semi-automated static (image-guided) or dynamic (navigation-assisted) systems, and fully-automated robotic systems. As well as the current mechanical rotary approaches, the literature supporting the use of lasers in further refinement of these approaches is reviewed. The advantages and limitations of adopting autonomous technologies in practical clinical dental practices are discussed. In summary, advances in clinical technologies enable improved precision and efficacious clinical outcomes with implant dentistry. Hard-tissue lasers offer further advancements in precision, improved biological responses, and favorable clinical outcomes that require further investigation.

Accuracy Comparison between Robot-Assisted Dental Implant Placement and Static/Dynamic Computer-Assisted Implant Surgery: A Systematic Review and Meta-Analysis of In Vitro Studies

Background and Objectives: The present systematic review and meta-analysis undertake a comparison of studies that examine the accuracy of robot-assisted dental implant placement in relation to static computer-assisted implant surgery (SCAIS), dynamic computer-assisted implant surgery (DCAIS), and freehand procedures. This study aims to provide a comprehensive understanding of the precision of robot-assisted dental implant placement and its comparative efficacy in relation to other placement techniques. Methods: The guidelines recommended by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were used to organize and compose this review. Four electronic databases (PubMed, Web of Science, Scopus, and Cochrane) were systematically searched for pertinent articles. Articles were selected following the inclusion and exclusion criteria. Qualitative and quantitative analyses of the selected articles were performed. Results: The initial electronic search resulted in 1087 hits. Based on the inclusion and exclusion criteria, five articles were selected for qualitative analysis, out of which three were considered for quantitative analysis. Three parameters were considered for accuracy evaluation (angular, coronal, and apical deviation). The mean angular deviation was -1.22 degrees (95% CI, -1.06--1.39), the mean coronal deviation was -0.15 mm (95% CI, -0.24--0.07), and the mean apical deviation was -0.19 mm (95% CI, -0.27--0.10). Conclusions: The robotic implant system was found to have significantly lower angular deviations and insignificantly lower coronal and apical deviations compared to DCAIS. Within the limitations of this review, it can be concluded that robot-assisted implant placement in resin models permits higher accuracy compared to DCAIS and SCAIS systems. However, due to the limited number of comparative studies with high heterogeneity, the findings of this review should be interpreted with caution. Further research is necessary to confirm the clinical application of robotics in implant surgery.

Integrating a mouth opening assessment of virtual patients to prevent intraoperative challenges during treatment

Template-guided implant surgery in the posterior region or zygomatic implant surgery using dynamic navigation systems is often hindered if a patient has limited mouth opening. To overcome the problem, the authors have proposed a novel digital protocol that integrates the use of a facial scan for the assessment of the maximal mouth opening of a virtual patient to assist in preoperative planning, thereby minimizing the likelihood of intraoperative obstruction of the surgical site. The proposed method is cost effective and can be easily used in clinical practice.

[Forensic dentistry for identity verification. A survey at the state police level]

BACKGROUND

In Germany, the identification of unknown dead persons is the responsibility of the police. According to INTERPOL standards, primary (e.g., DNA, fingerprints, and teeth) and secondary (e.g., tattoos) characteristics are examined. Forensic dentistry is already used internationally as an efficient method. In this study, the approach of state police in Germany was analyzed. The methods used for identification, the role of forensic dentistry, the cooperation with dentists, and possible optimization approaches are investigated.

METHODS

By means of a digital questionnaire, police officers competent in all federal states for the discovery of unknown dead bodies were asked about identification methods and specifically about the use of forensic dentistry.

RESULTS

Eighty-five officers from at least 11 federal states participated in the survey. The procedure turned out to be department specific. In 72.6% of the cases, different characteristics are combined in the identification process, most frequently DNA with dental status (37.1%). DNA analysis is used most frequently. Of the respondents, 62.9% agreed that dental identification is used "often." The percentage of identifications using dental status is estimated to be 1.6-8.1%. For forensic dentistry, 19.4% have a fixed point of contact. A digital platform to contact dentists was estimated to be helpful by 56.5%.

DISCUSSION

Forensic dentistry is currently still lagging behind DNA analysis, which could change through increasing digitalization if, for example, ante-mortem data are more reliably available and platforms for interdisciplinary exchange are created.

Comparative Analysis between 3D-Printed Models Designed with Generic and Dental-Specific Software

With the great demand in the market for new dental software, the need has been seen to carry out a precision study for applications in digital dentistry, for which there is no comparative study, and there is a general ignorance regarding their applications. The purpose of this study was to investigate the accuracy differences between digital impressions obtained using generic G-CAD (general CAD) and D-CAD (CAD dental) software. Today, there is a difference between the design software used in dentistry and these in common use. Thus, it is necessary to make a comparison of precision software for specific and generic dental use. We hypothesized that there is no significant difference between the software for specific and general dental use.

METHODS

A typodont was digitized with an intraoral scanner and the models obtained were exported in STL format to four different softwares (Autodesk MeshMixer 3.5, Exocad Dental, Blender for dental, and InLAB). The STL files obtained by each software were materialized using a 3D printer. The printed models were scanned and exported in STL files, with which six pairs of groups were formed. The groups were compared using analysis software (3D Geomagic Control X) by superimposing them in the initial alignment order and using the best fit method.

RESULTS

There were no significant differences between the four analyzed software types; however, group 4, composed of the combination of D-CAD (Blender-InLAB), obtained the highest average (-0.0324 SD = 0.0456), with a higher accuracy compared to the group with the lowest average (group 5, composed of the combination of the Meshmixer and Blender models), a generic software and a specific software (0.1024 SD = 0.0819).

CONCLUSION

Although no evidence of significant difference was found regarding the accuracy of 3D models produced by G-CAD and D-CAD, combinations of groups where specific dental design software was present showed higher accuracy (precision and trueness). The comparison of the 3D graphics obtained with the superimposition of the digital meshes of the printed models performed with the help of the analysis software using the best fit method, replicating the same five reference points for the six groups formed, evidenced a greater tolerance in the groups using D-CAD.

Applications of CAD/CAM Technology for Craniofacial Implants Placement and Manufacturing of Auricular Prostheses-Systematic Review

This systematic review was aimed at gathering the clinical and technical applications of CAD/CAM technology for craniofacial implant placement and processing of auricular prostheses based on clinical cases. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, an electronic data search was performed. Human clinical studies utilizing digital planning, designing, and printing systems for craniofacial implant placement and processing of auricular prostheses for prosthetic rehabilitation of auricular defects were included. Following a data search, a total of 36 clinical human studies were included, which were digitally planned and executed through various virtual software to rehabilitate auricular defects. Preoperative data were collected mainly through computed tomography scans (CT scans) (55 cases); meanwhile, the most common laser scanners were the 3dMDface System (3dMD LLC, Atlanta, Georgia, USA) (6 cases) and the 3 Shape scanner (3 Shape, Copenhagen, Denmark) (6 cases). The most common digital design software are Mimics Software (Mimics Innovation Suite, Materialize, Leuven, Belgium) (18 cases), Freeform software (Freeform, NC, USA) (13 cases), and 3 Shape software (3 Shape, Copenhagen, Denmark) (12 cases). Surgical templates were designed and utilized in 35 cases to place 88 craniofacial implants in auricular defect areas. The most common craniofacial implants were Vistafix craniofacial implants (Entific Medical Systems, Goteborg, Sweden) in 22 cases. A surgical navigation system was used to place 20 craniofacial implants in the mastoid bone. Digital applications of CAD/CAM technology include, but are not limited to, study models, mirrored replicas of intact ears, molds, retentive attachments, customized implants, substructures, and silicone prostheses. The included studies demonstrated a predictable clinical outcome, reduced the patient's visits, and completed the prosthetic rehabilitation in reasonable time and at reasonable cost. However, equipment costs and trained technical staff were highlighted as possible limitations to the use of CAD/CAM systems.

Prosthetically guided oral implant surgery. A retrospective cohort study evaluating the 5-year surgical outcome

Purpose

This study primarily evaluated the 5-year implant survival and success rate of prosthetically guided inserted implants. The secondary aim was to evaluate the impact of clinical variables on the development of mucositis, peri-implant bone resorption, peri-implantitis, as well as early and late implant failure.

Materials and methods

An observational retrospective single-centre study was conducted on patients who were treated with dental implants in the department of oral and plastic maxillofacial surgery of the military hospital of Ulm University between 2008 and 2010. In all patients, computer-assisted 3D planning after wax-up of the prosthetic restoration and template-guided surgery with titanium implants were performed. Bone augmentation procedures were performed primarily if needed. Intraoperative and postoperative complications as well as technical and mechanical complications after prosthesis loading were evaluated. In a 5-year clinical and radiological follow-up, implant success and implant survival were assessed using descriptive statistics. A multivariable regression analysis evaluated the potential impact of augmentation procedures, wound healing complications, smoking, history of periodontitis, and preoperative API (approximal plaque index) and SBI (sulcus bleeding index) values on peri-implant mucositis, peri-implant bone resorption, peri-implantitis, as well as early and late implant failure.

Results

In this study, 466 implants in 283 patients were considered for inclusion, and sufficient data were obtained for analysis from 368 (78.9%) implants in 229 (80.9%) patients. An overall implant survival rate of 98.1% (n=361/368) at the 5-year follow-up was revealed. According to the success criteria of the study, the 5-year success rate was 97.04% (n=263/271). An early implant failure of 1.07% (n=5/466) was recorded. 48.2% of the implants were affected by peri-implant mucositis (n=122/253), while peri-implant bone resorption was detected in 21.7% of the radiologically examined implants (n=59/271). Fifteen cases of peri-implantitis (5.5%) were detected. Peri-implant bone resorption increased significantly after bone augmentation procedures (p=0.028). Wound healing complications after implantation significantly increased the prevalence of late implant failure in the maxilla (p<0.001). Peri-implant bone resorption and peri-implantitis were significantly more prevalent in smokers (p=0.022/p=0.043). Implants in patients with API>20% presented significantly higher rates of peri-implant mucositis (p=0.042). Wound healing complications after augmentation, history of periodontitis, and SBI>20% had no significant impact on the study parameters.

Conclusions

The study confirms the reliability of prosthetically guided implant surgery, showing a high implant survival and success rate in a 5-year follow-up. Intraoperative complications and technical or mechanical complications after prosthesis loading remain within acceptable clinical limits. The rate of peri-implant mucositis, peri-implant bone resorption, and peri-implantitis was within the current literature range. Optimizing periodontal health and reducing smoking would improve the outcome. Further studies need to clarify the clinical indications and investigate the long-term surgical outcome of this treatment concept.

Application of orthodontics combined with porcelain laminate veneers in the aesthetic restoration and flora regulation of anterior teeth

To evaluate the effectiveness of orthodontics in combination with porcelain laminate veneers (PLV) in the aesthetic restoration and flora regulation of anterior teeth. A retrospective analysis of 336 patients who underwent aesthetic restoration of anterior teeth in our hospital from April 2019 to September 2022 was performed and divided into a control group (n = 168) and an observation group (n = 168) according to the restorative modality. The restorative modality in the control group was conventional restorative remediation, while the restorative modality in the observation group was orthodontic combined with PLV treatment. To evaluate the excellent rate of aesthetic restoration of anterior teeth in the 2 groups, and compare the color, shape, degree of translucency, edge aesthetic score, complications and satisfaction rate of restoration of anterior teeth in the 2 groups before and after restoration. The observation group had a significantly higher rate of excellent aesthetic restorations (95.23%) compared to the control group (80.95%) (P < .001). The scores of anterior tooth color, morphology, degree of translucency and marginal aesthetics were improved in both groups after restoration compared to before restoration, and the scores were significantly higher in the observation group (P < .05). After restoration, the subgingival Digestive streptococcus, Campylobacter and Propionibacterium increased in both groups, but the number of bacterial strains was significantly less in the observation group (P < .05). Compared with the total complication rate in the control group (16.66%), the total complication rate in the observation group (2.38%) was significantly lower (P < .001). Compared with the control group (85.71%), the observation group had a significantly higher restoration satisfaction rate of 97.61%, with a statistically significant difference (P < .001). The application of orthodontics combined with PLV in the aesthetic restoration of anterior teeth has a significant clinical effect, which is conducive to improving the aesthetic restoration and satisfaction rate of anterior teeth, reducing the subgingival microbial imbalance and decreasing the incidence of complications.

Comparison of Dental Implant Placement Accuracy Using a Static Surgical Guide, a Virtual Guide and a Manual Placement Method - An In-Vitro Study

Introduction

The use of a surgical guide during pre-operative planning significantly increases the efficiency and safety of dental implantation. However, the current widespread use of static navigation has led to a decrease in accuracy. Dynamic navigation, on the other hand, can be an alternative. This study compared the accuracy of dental implant placement on jaw models using static navigation, a virtual guide and the manual placement method.

Materials and Methods

Nine patients with favourable conditions were selected, and three-dimensional full-body jaw models were set up. Group I had 21 implants placed using static navigation, Group II had 21 implants placed using dynamic navigation and Group III had 21 implants placed using the 'free hand' method. Placement accuracy was calculated by the deviation between the planned implant position and the actual position obtained from post-operative cone-beam computed tomography and model scanning.

Results

The deviation from the planned implant position was 0.4° in Group I and 0.5° in Group II. The 'free hand' method yielded the worst result, with a statistically significant difference between Groups I and II. However, implantation using dynamic navigation showed a lower variance of deviation, with the majority of implants having a deviation ≤0.5 mm (86% compared to 67% in the static navigation group).

Discussion

The accuracy of implant positioning using a virtual guide with dynamic imaging was comparable to static navigation and surpassed the accuracy obtained using the 'free hand' technique. This study highlights the potential of dynamic navigation control in dental implantology and warrants further clinical research to improve this system.

Accuracy of Microimplant Placement Using a 3D Guide Plate for Orthodontic Anchorage

This study aimed to design a three-dimensional (3D) guide plate using computer-aided design and a 3D printing system for precise implantation of microimplants for orthodontic treatment and investigate the accuracy and feasibility of a 3D guide plate in clinical practice. A total of 30 microimplants were placed in 15 patients in the Department of Stomatology, Affiliated Hospital of Jiangnan University. Before surgery, DICOM data from cone-beam computed tomography (CBCT) scans and STereoLithography data from the 3D model scan were imported to 3Shape Dental System. Data fitting and matching were performed, and 3D guide plates were designed primarily focusing on the thickness of guide plates, amount of concave compensation, and dimensions of the ring. Assist implantation method was used to place the microimplants, and postoperative CBCT images were used to evaluate the position and implantation angle. The feasibility of placing microimplants and precise implantation guided by the 3D guide plate. CBCT data before and after the placement of microimplants were compared. Regarding the secure positioning of microimplants based on CBCT data, 26 implants were categorized as Grade i, four as Grade ii, and none as Grade iii. No loosening of microimplants 1 and 3 months after surgery was reported. The implantation of microimplants is more accurate under the guidance of a 3D guide plate. This technology can achieve accurate implant positioning, thus ensuring safety, stability, and improved success rates after implantation.

Accuracy Analysis of Computer-Assisted and Guided Dental Implantology by Comparing 3D Planning Data and Actual Implant Placement in a Mandibular Training Model: A Monocentric Comparison between Dental Students and Trained Implantologists

The aim of this study was to investigate how precisely implantation can be realized by participants on a phantom head according to preliminary planning. Of particular interest here was the influence of participants' previous knowledge and surgical experience on the precision of the implant placement. The placed implants were scanned using an intraoral scanner, saved as STL files, and superimposed with the 3D-planned implant placement. Deviations from the planning were indicated in millimeters and degrees. We were able to show that on average, the deviations from computer-assisted 3D planning were less than 1 mm for implantologists, and the students also did not deviate more than 1.78 mm on average from 3D planning. This study shows that guided implantology provides predictable and reproducible results in dental implantology. Incorrect positioning, injuries to anatomical structures, and implant positions that cannot be prosthetically restored can thus be avoided.

Exploring the Intersection of Artificial Intelligence and Clinical Healthcare: A Multidisciplinary Review

Artificial intelligence (AI) plays a more and more important role in our everyday life due to the advantages that it brings when used, such as 24/7 availability, a very low percentage of errors, ability to provide real time insights, or performing a fast analysis. AI is increasingly being used in clinical medical and dental healthcare analyses, with valuable applications, which include disease diagnosis, risk assessment, treatment planning, and drug discovery. This paper presents a narrative literature review of AI use in healthcare from a multi-disciplinary perspective, specifically in the cardiology, allergology, endocrinology, and dental fields. The paper highlights data from recent research and development efforts in AI for healthcare, as well as challenges and limitations associated with AI implementation, such as data privacy and security considerations, along with ethical and legal concerns. The regulation of responsible design, development, and use of AI in healthcare is still in early stages due to the rapid evolution of the field. However, it is our duty to carefully consider the ethical implications of implementing AI and to respond appropriately. With the potential to reshape healthcare delivery and enhance patient outcomes, AI systems continue to reveal their capabilities.

Automatic registration of dental CT and 3D scanned model using deep split jaw and surface curvature

BACKGROUND AND OBJECTIVES

In the medical field, various image registration applications have been studied. In dentistry, the registration of computed tomography (CT) volume data and 3D optically scanned models is essential for various clinical applications, including orthognathic surgery, implant surgical planning, and augmented reality. Our purpose was to present a fully automatic registration method of dental CT data and 3D scanned models.

METHODS

We use a 2D convolutional neural network to regress a curve splitting the maxilla (i.e., upper jaw) and mandible (i.e., lower jaw) and the points specifying the front and back ends of the crown from the CT data. Using this regressed information, we extract the point cloud and vertices corresponding to the tooth crown from the CT and scanned data, respectively. We introduce a novel metric, called curvature variance of neighbor (CVN), to discriminate between highly fluctuating and smoothly varying regions of the tooth crown. The registration based on CVN enables more accurate fine registration while reducing the effects of metal artifacts. Moreover, the proposed method does not require any preprocessing such as extracting the iso-surface for the tooth crown from the CT data, thereby significantly reducing the computation time.

RESULTS

We evaluated the proposed method with the comparison to several promising registration techniques. Our experimental results using three datasets demonstrated that the proposed method exhibited higher registration accuracy (i.e., 2.85, 1.92, and 7.73 times smaller distance errors for individual datasets) and smaller computation time (i.e., 4.12 times faster registration) than one of the state-of-the-art methods. Moreover, the proposed method worked considerably well for partially scanned data, whereas other methods suffered from the unbalancing of information between the CT and scanned data.

CONCLUSIONS

The proposed method was able to perform fully automatic and highly accurate registration of dental CT data and 3D scanned models, even with severe metal artifacts. In addition, it could achieve fast registration because it did not require any preprocessing for iso-surface reconstruction from the CT data.

Influence of planning software and surgical template design on the accuracy of static computer assisted implant surgery performed using surgical guides fabricated with material extrusion technology: An in vitro study

OBJECTIVES

This in vitro study aimed to assess the influence of the planning software and design of the surgical template on both trueness and precision of static computer assisted implant surgery (sCAIS) performed using surgical guides fabricated using material extrusion (ME).

METHODS

Three-dimensional radiographic and surface scans of a typodont were aligned using two planning software (coDiagnostiX, CDX; ImplantStudio, IST) to virtually position the two adjacent oral implants. Thereafter, surgical guides were created with either an original (O) or modified (M) design with reduced occlusal support and were steam sterilized. Forty surgical guides were used to instal 80 implants equally distributed among four groups: CDX-O, CDX-M, IST-O, and IST-M. Thereafter, the scan bodies were adapted to the implants and digitised. Finally, inspection software was used to assess discrepancies between the planned and final positions at the implant shoulder and main axis level. Multilevel mixed-effects generalised linear models were used for statistical analyses (p = 0.05).

RESULTS

In terms of trueness, the largest average vertical deviations (0.29 ± 0.07 mm) could be assessed for CDX-M. Overall, vertical errors were significantly dependent on the design (O < M; p ≤ 0.001). Furthermore, in horizontal direction, the largest mean discrepancy was 0.32 ± 0.09 mm (IST-O) and 0.31 ± 0.13 mm (CDX-M). CDX-O was superior compared to IST-O (p = 0.003) regarding horizontal trueness. The average deviations regarding the main implant axis ranged between 1.36 ± 0.41 ° (CDX-O) and 2.63 ± 0.87 ° (CDX-M). In terms of precision, mean standard deviation intervals of ≤ 0.12 mm (IST-O and -M) and ≤ 1.09 ° (CDX-M) were calculated.

CONCLUSIONS

Implant installation with clinically acceptable deviations is possible with ME surgical guides. Both evaluated variables affected trueness and precision with negligible differences.

CLINICAL SIGNIFICANCE

The planning system and design influenced the accuracy of implant installation using ME-based surgical guides. Nevertheless, discrepancies were ≤ 0.32 mm and ≤ 2.63 °, which may be considered within the range of clinical acceptance. ME should be further investigated as an alternative to the more expensive and time-consuming 3D printing technologies.

Influence of the Printing Orientation on Parallelism, Distance, and Wall Thickness of Adjacent Cylinders of 3D-Printed Surgical Guides

This in-vitro study aimed to evaluate the influence of the printing orientation on parallelism, distance, and thickness between adjacent cylinders of 3D-printed surgical guides. CAD software was used to design a surgical guide with two adjacent parallel cylinders (reference); the design was saved as standard tessellation software (STL) and 63 samples were printed using three different orientations (0, 45, and 90 degrees). A metrology digital microscope was used to measure the distance, the angle and the thickness of the guides cylinders. Afterwards, the printed guides were scanned and cloud comparison software was used to compare STL files from the printed guides against the reference CAD model. One-way analysis of variance and Tukey test were used for multiple comparisons between groups and significance was p < 0.05. The printing orientation affected the distance between cylinders, the parallelism and the wall thickness. In addition, there were global deviations in all printing orientations. Printing with 90 degrees orientation produced almost-parallel cylinders but walls thicker than the reference model; all the cylinders converged toward the coronal but printing at 0 degrees produced the closest distance to the reference value. Within the limitations of this experimental in-vitro study it can be concluded that all the printing orientations influence the angle, the distance, and the thickness between adjacent cylinders of a surgical guide. Printing at 90 degrees produces the best global correspondence with the master model.

Comparison of Two Chosen 3D Printing Resins Designed for Orthodontic Use: An In Vitro Study

(1) Background: In recent years, 3D printing has become a highly popular tool for manufacturing in various fields such as aviation, automobiles, plastics, and even medicine, including dentistry. Three-dimensional printing allows dentists to create high-precision models of teeth and jaw structure, and enables them to develop customized tools for patients' treatment. The range of resins used in dentistry is quite large, and this branch is developing rapidly; hence, studies comparing different resins are required. The present study aimed to compare the mechanical properties of two chosen resins used in dentistry. (2) Materials and methods: Ten specimens each of two types of 3D-printable resins (BioMed Amber and IBT, developed by Formlabs) were prepared. The samples were printed on a Formlabs Form 2 3D printer according to ISO standards. Samples for the compression test were rectangular in shape (10 ± 0.2 mm × 10 ± 0.2 mm × 4 ± 0.2 mm), while the samples used for the tensile test were dumbbell shaped (75 mm long, with 10 mm end width and 2 mm thickness). Tensile and compression tests of both materials were performed in accordance with the appropriate ISO standards. (3) Results: The BioMed Amber resin was more resistant to compression and tensile forces, thus implying that the resin could withstand higher stress during stretching, pulling, or pushing. The IBT resin was less resistant to such loads, and failure of this material occurred at lower forces than those for Biomed Amber. An ANOVA test confirmed that the observed differences were statistically significant (p < 0.001). (4) Conclusions: Based on the properties of both materials, the IBT resin could be better used as a tray for placing orthodontic brackets through an indirect bonding technique, while the BioMed Amber resin would be more useful as a surgical guide for placing dental implants and mini-implants. Further potential fields of application of the resins should be investigated.

Computer-Guided Osteotomy with Simultaneous Implant Placement and Immediately Loaded Full-Arch Fixed Restoration: A Case Report

Aim: This case report aims to illustrate a clinical protocol that allows for the rehabilitation of patients requiring extensive osteotomy, simultaneous implant placement, and full-arch, screwed-in prosthetics in one session. This protocol allows for the improvement of the aesthetics and functionality of the fixed implant-supported prosthesis through the preoperative planning of all surgical procedures, including osteotomy, and of the prosthesis through the application of 3D-printing technology for the creation of surgical templates and prostheses. Methods: This case report concerns a 72-year-old patient, ASA1, who, following diagnosis, the establishment of a treatment plan, and the provision of informed consent, opted for an immediate, full-arch rehabilitation of the lower arch. The digital planning stage started with the correct positioning of the fixtures. The proper bone levels were found and used to guide the creation of the provisional screwed-in prothesis. Two templates with the same supports (landmarks/pins) were then 3D-printed: a positioning template, including a slit to assist the surgeon during the osteotomy, and a surgery template to assist the surgeon during the implants’ positioning. A screwed-in prosthesis encased in resin C&B MFH (NEXTDENT®, Soesterberg, The Netherlands) was delivered. Minimal occlusal adjustments were performed. Results: In a single clinical session, through careful planning and the pre-operative 3D printing of a prosthesis, a temporary implant-supported prosthetic rehabilitation was possible in a case that required an extended osteotomy. Clinically, the correspondence between the virtual design phase and the final realization was consistent. At a functional level, the provisional prosthesis required minimal occlusal adjustments and the DVO values obtained in the immediate post-operative period were found to be comparable to those of the virtual design. By planning the final position of the bone and the implants in advance, it was possible to deliver a full-arch prothesis with proper implant emergence, occlusal vertical dimensions, and occlusal relationship. Conclusion: This fully digital protocol allows the clinician to preview and plan the osteotomy and implant surgery as well as the delivery of the temporary, immediately loaded, complete, fixed prosthesis in patients who are candidates for post-extraction surgery with the need for severe osteotomy.

Relevant factors of posterior mandible lingual plate perforation during immediate implant placement: a virtual implant placement study using CBCT

BACKGROUND

To explore the influence of cross-sectional type and morphological parameters at the mandibular molar sites on lingual plate perforation (LPP) during the immediate implant placement (IIP).

METHODS

181 implants were virtually placed in the mandibular molar sites on the cone beam computed tomography (CBCT). Each cross-section of the implantation site was divided into the Undercut (U)/Parallel (P)/Convex (C) types. Morphologically relevant parameters were measured on the cross-sections, including width of the upper end (Wb), width of the lower end (Wc), vertical height (V), angle between the natural crown axis and the alveolar bone axis (∠β), LC depth (LCD), LC height, and angle between the horizontal line and the line connecting the most prominent point and the most concave point of lingual plate (∠α). Besides, the distance from the end of the virtual implant and the lingual bone plate of the cross-section (D_IL) was calculated. Relationships between all the morphologically relevant parameters and the D_IL were further analyzed.

RESULTS

A total of 77 (42.5%) cross-sections were classified as U-type, which was the most common one, accounting for 63% of the second molar regions. All LPP cases and most of the nearly LPP (87.9%) cases occurred at the U-type cross-sections, and the relationship between the D_IL and the morphological parameters can be expressed by a multivariate linear equation.

CONCLUSIONS

The occurrence rate of U-type cross-sections in the second molar region was very high, and the risk of LPP should be considered during IIP. Except for the U-type, significant large LCD, small Wc, and large ∠β were the important relevant factors. CBCT and multivariate linear equations could help to assess the LPP risk and provide a reference for implant placement design pre-surgery.

Computer-Aided Design and Computer-Aided Modeling (CAD/CAM) for Guiding Dental Implant Surgery: Personal Reflection Based on 10 Years of Real-Life Experience

Traditional dental implant surgery has been challenged by the phenomenal progression in computer-assisted surgery (CAS) that we have been witnessing in recent years. Among the computer-aided technologies, computer-aided design and computer-aided manufacturing (CAD/CAM) techniques represent by far the most attractive and accepted alternatives over their dynamic counterpart, navigational assistance. Based on many years of experience, we have determined that CAD/CAM technology for guiding dental implant surgery is valuable for rehabilitation of the anterior maxillary region and the management of complete or severe partial edentulism. The technology also guarantees the 3D parallelism of implants. The purpose of the present report is to describe indications for use of CAD/CAM dental implant guided surgery. We analyzed the clinical and radiological data of thirteen consecutive edentulous patients treated using CAD/CAM techniques. All of the patients had stable cosmetic results with a high rate of patient satisfaction at the final follow-up examination. No intra- and/or postoperative complications were encountered during any of the steps of the procedure. The application of CAD/CAM techniques produced successful outcomes in the patients presented in this series.

Digital Planning for Immediate Implants in Anterior Esthetic Area: Immediate Result and Follow-Up after 3 Years of Clinical Outcome-Case Report

In this case report, we demonstrate how the correct positioning of implants, associated with optimal gingival conditioning, and the correct choice of biomaterial can yield very predictable and fantastic aesthetic results.

OBJECTIVE

We aimed to use dental implants to rehabilitate the area of elements #11 and #21 in a satisfactory surgical and prosthetic manner, using guided surgery, connective tissue, nano-biomaterials, and a porcelain prosthesis.

CASE REPORT

A 32-year-old male patient presented with bone loss of elements #11 and #21, which was proven radiographically and clinically. Thus, oral rehabilitation with the use of dental implants was required. It was decided to proceed via digital planning with the DSD program (Digital smile design) and with the software Exoplan, (Smart Dent-Germany) whenever it was possible to plan immediate provisional and accurate dental implant positioning through reverse diagnostics (Software Exoplan, Smart Dent-German). The dental elements were extracted atraumatically; then, a guide was established, the implants were positioned, the prosthetic components were placed, the conjunctive tissue was removed from the palate and redirected to the vestibular wall of the implants, the nano-graft (Blue Bone^®) was conditioned in the gaps between the vestibular wall and the implants, and, finally, the cemented provision was installed.

RESULTS

After a 5-month accompaniment, an excellent remodeling of the tissues had been achieved by the implants; consequently, the final prosthetic stage could begin, which also achieved a remarkable aesthetic result.

CONCLUSIONS

This report demonstrates that the correct planning of dental implants, which is associated with appropriate soft tissue and bone manipulation, allows for the achievement of admirable clinical results.

The Impact of Technological Innovation on Dentistry

Technology has revolutionized the way dentists are able to treat their patients. These technological advances have paved the way for the creation of virtual patient models utilizing these 3-dimensional intra-oral patient models, cone bean computer tomography (CBCT) radiograph scans, extraoral 3-dimensional scans, and jaw motion tracings to create a patient-specific model. These models are advantageous in planning surgical treatments by providing 3-dimensional views of vital anatomical structures to accurately identify the location, size, and shape of a structure or defect in order to plan accordingly. Virtual augmentation of either hard tissue (bone) and/or soft tissue (i.e., gingiva) can also be accomplished.Technology has allowed the capture of the dynamic motions of the jaw and combined them with the virtual patient to develop permanent restorations in harmony with the patient's orofacial complex. With the introduction of new technology in the realm of digital dentistry, patient care is being brought to a new and higher level. This creates a level of more optimal care that a dentist can deliver to patients.

Comparison of the Compression and Tensile Modulus of Two Chosen Resins Used in Dentistry for 3D Printing

(1) The CAD/CAM technique exploiting 3D printing is becoming more and more popular in dentistry. The resins are used in all the dental specialties, including conservative dentistry, prosthodontics, surgery, and orthodontics. The interest in investigating the different properties of dental materials has been an aim of researchers. The purpose of the presented study was to compare the properties of two 3D-printable dental resins (both rigid, used for medical purposes). (2) Methods: Ten blocks of two-type shapes were printed on a printer designed for medical use. The tensile modulus and compression were investigated and compared. The axial compression test was performed according to the PN-EN ISO 604:2003 norm, while the tensile test was performed according to the PN-En ISO 527-1-2019 (E) norm. In the first test, the sample size of the perpendicular shape was 10 ± 0.2 mm × 10 ± 0.2 mm × 4 ± 0.2 mm and in the second it was 75 mm, the end width 10 mm, and the thickness 2 mm. (3) Results: The statistical analysis based on ANOVA tests showed that all the obtained results were statistically significant. Both of the examined materials had similar properties and were resistant and stable in shape. The tensile modulus and compression tests performed on them gave similar results. They also showed high durability to compression and tensility. (4) Conclusions: Both of the examined materials were durable and rigid materials. BioMed Amber was more resistant to compression, while Dental LT clear was more resistant in the tensility test. Although both resins had similar physical properties, it is still disputable whether the chosen materials could be used interchangeably.

Review on 3D printing in dentistry: conventional to personalized dental care

The CAD (Computer-aided design) and CAM (computer-aided manufacturing) have most applications in the manufacturing of fully automated, personalized dental devices and tailor-made treatment plans. 3D printing is one of the most rapidly expanding and new methods of manufacturing different things because of its on-demand and high productivity within the cost-effective manner which have a variety of applications in healthcare, pharmaceuticals, orthopaedics, engineered tissue models, medical devices, defence industries, automotive and aerospace sectors. Due to its emerging applications in the various sectors, the healthcare, Industries, and academic sectors are attracted towards the 3D printed materials. This review talks about the dental implants, polymers that are employed in concocting dental implants, critical parameters, and challenges which are to be considered while preparing these implants, advantages of 3D printing in the field of dentistry and the current trends. it discusses the variety of applications of 3D printed materials in the field of dentistry. Along with their method of fabrication, their critical process parameters (CPPs) are also discussed.

Guided implant surgery with R2Gate®: A multicenter retrospective clinical study with 1 year of follow-up

PURPOSE

To present the results obtained with a novel sleeveless and keyless guided implant surgery system.

METHODS

Inclusion criteria for this multicenter clinical retrospective study were fully or partially edentulous patients who had been treated with a sleeveless and keyless guided implant surgery system (R2Gate®, Megagen), and who had been rehabilitated with fixed restorations, with a minimum follow-up of 1 year. All surgeries and prosthetic procedures were conducted following the same protocol, and data were obtained from the patients' medical records. The outcomes were the fit and stability of the surgical guide, any intra-operative and immediate post-operative complications, any biologic and prosthetic complications that occurred during the 1-year follow-up period, implant survival, and prosthetic success.

RESULTS

Sixty patients were selected for the installation of 124 implants, through a guided procedure: 66 sleeveless, keyless surgical guides were manufactured. The incidence of immediate intra-operative (lack of space: 12.1%; lack of implant stability 2.6%) and immediate post-operative (pain and discomfort: 6.6%; mild swelling 3.3%) complications was low. In total, 112/124 implants (90.3%) were successfully placed with a guided procedure, in 52 patients; among them, 82 (73.2%) were placed with a flapless procedure. Thirty fixtures supported single crowns (SCs), 42 fixed partial dentures (FPDs) and 52 full-arch (FA) restorations. Sixty-two fixed prosthetic restorations (30 SCs, 22 FPDs and 10 FAs) were delivered; among these restorations, 15 (24.1%) were subjected to immediate functional loading. All implants (100%) survived. Two implants had peri‑implant mucositis (1.6%), two SCs had abutment screw loosenings (1.6%), two FAs and one FPD had ceramic chipping/fracture (2.4%), for an overall prosthetic success amounting to 88.7%.

CONCLUSIONS

Within the limits of this study, this novel guided surgery system appeared to be clinically reliable; further studies are needed to confirm these results.

STATEMENT OF CLINICAL RELEVANCE

The use of sleveless and keyless surgical guides can be clinically reliable and may be represent a valid option for the surgeon.

Periodontal soft tissue increase induced by periodontally accelerated osteogenic orthodontics surgery

Objectives

To quantitatively assess periodontal soft tissue changes, including gingival thickness and keratinized gingiva width after periodontally accelerated osteogenic orthodontics (PAOO) surgery by digital measurements. 

Methods

This study enrolled 15 maxillaries with 89 anterior teeth and 16 mandibles with 94 anterior teeth from Chinese adult patients with skeletal Angle Class III malocclusion for whom PAOO surgery was proposed during orthodontic treatment. Intraoral scanning and cone beam computed tomography (CBCT) examinations were performed before PAOO surgery and 6 months after the surgery. Keratinized gingiva width was measured on the digital model acquired by intraoral scanning. The gingival thickness was measured using a digital three-dimensional (3D) model based on the combination of digital intraoral scanning and CBCT data.

Results

The mean gingival thickness before surgery was 0.91 ± 0.32 mm and 1.21 ± 0.38 mm at 6-month after PAOO. Patients showed periodontal soft tissue increase with a mean gingival tissue gain of 0.30 ± 0.33 mm. At 1 mm, 2 and 3 mm apical to cemento-enamel junction (CEJ) levels, the gingival thickness increase of the mandible was higher than that of the maxilla (0.38 ± 0.30 mm vs. 0.24 ± 0.31 mm, 0.43 ± 0.35 mm vs. 0.26 ± 0.41 mm, 0.36 ± 0.27 vs. 0.25 ± 0.32 mm, respectively, all P < 0.05). Moreover, the sites of gingival thickness ≤ 1 mm before surgery showed more tissue gain than the sites > 1 mm (0.36 ± 0.32 mm vs. 0.18 ± 0.31 mm, P < 0.001). The mean keratinized gingiva width at T0 was 3.88 ± 1.22 mm, and increased 1.05 ± 1.24 mm 6 months after PAOO surgery. Moreover, a digital 3D model for gingival thickness measurement based on the combination of digital intraoral scanning and CBCT displayed high reliability and accuracy with an intra-class correlation coefficient (ICC) of 0.897.

Conclusion

PAOO could improve an insufficient quantity of periodontal soft and hard tissues in patients with skeletal Angle Class III malocclusion, including the gingival thickness and keratinized gingiva width. A digital 3D model based on the combination of digital intraoral scanning and CBCT data could provide a new digital measurement of gingival thickness with high accuracy and reliability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02566-8.

Finite Element Study of Stress Distribution with Tooth-Supported Mandibular Overdenture Retained by Ball Attachments or Resilient Telescopic Crowns

Objective The removable partial denture must keep health of the remaining teeth and the supporting tissues through the distribution of chewing forces on the abutment teeth and alveolar process.

This study aimed to evaluate stress distribution with canines-supported mandibular overdenture retained by two different attachment types: ball attachments or resilient telescopic crowns.

Materials and Methods Two 3-dimensional finite element models consisting of the cortical mandible bone, cancellous mandible bone, oral mucosa, canines, periodontal ligaments, the two attachment types, and overdenture were simulated. The models were imported into the mathematical analysis software Ansys Workbench V 15.0. All materials were considered to be homogeneous, isotropic, and linearly elastic. A vertical bilateral load of 120 N was applied to the central fossa of the first molars. The von Mises stress was calculated for canines, cortical, and cancellous bone.

Results The maximum von Mises stress of the ball attachments model was 35.61, 4.28, 7.82, and 1.29 MPa for canines, cortical alveolar bone of canines, cortical alveolar bone at the distal end of the overdenture, and cancellous alveolar bone of canines, respectively. The maximum von Mises stress of the resilient telescopic crowns model was 39.22, 4.74, 7.06, and 1.05 MPa for canines, cortical alveolar bone of canines, cortical alveolar bone at the distal end of the overdenture, and cancellous alveolar bone of canines, respectively.

Conclusion Resilient telescopic crowns distribute the stresses between canines, alveolar bone of canines, and overdenture supporting alveolar bone. Ball attachments transfer less stress to the canines and cortical alveolar bone of the canines, but more stress to the cancellous alveolar bone of canines and alveolar bone at distal end of the overdenture. Resilient telescopic crowns are preferred over ball attachment when the abutment teeth have good periodontal support.

Guided Biopsy of a Radiopaque Lesion Simultaneous with Dental Implants’ Placement: A Multidisciplinary Approach

Background: New technologies and techniques allow us to offer better solutions for patients’ needs. Specifically, guided surgery is usually flapless, and the resulting prosthetic rehabilitation often includes immediate loading. Thus, bleeding risk is controlled, and more comfortable prosthetic procedures are performed. Guided surgery decreases surgical risks and is less invasive. The aim of this article is to present a case of guided osteotomy for bone biopsy and implant placement. Methods: CBCT was performed for the patient’s bone examination, an optical scanner was used for intra-oral images, and surgical certified software was applied for the osteotomy planning and the surgeon’s guide realization. Case report: The patient’s question is about left maxilla prosthetic rehabilitation. During the oral cavity and X-ray examination, a radiopacity with a feathered edge was found; in order to detect the finding, a CBCT was performed, and the surgery was planned. A bone biopsy was performed simultaneously with the implant’s placement through a drill guide. The specimen sent for histological exam showed osteosclerosis. Conclusions: It is the opinion of the authors that by involving and combining close collaboration and communication, several professional specializations (clinicians and radiologists) can improve the treatments for better patient care.

Development of artificial intelligence model for supporting implant drilling protocol decision making

PURPOSE

This study aimed to develop an artificial intelligence (AI) model to support the determination of an appropriate implant drilling protocol using cone-beam computed tomography (CBCT) images.

METHODS

Anonymized CBCT images were obtained from 60 patients. For each case, after implant placement, images of the bone regions at the implant site were extracted from 20 slices of CBCT images. Based on the actual drilling protocol, the images were classified into three categories: protocols A, B, and C. A total of 1,200 images were divided into training and validation datasets (n = 960, 80%) and a test dataset (n = 240, 20%). Another 240 images (80 images for each type) were extracted from the 60 cases as test data. An AI model based on LeNet-5 was developed using these data sets. The accuracy, sensitivity, precision, F-value, area under the curve (AUC) value, and receiver operating curve were calculated.

RESULTS

The accuracy of the trained model is 93.8%. The sensitivity results for drilling protocols A, B, and C were 97.5%, 95.0%, and 85.0%, respectively, while those for protocols A, B, and C were 86.7%, 92.7%, and 100%, respectively, and the F values for protocols A, B, and C were 91.8%, 93.8%, and 91.9%, respectively. The AUC values for protocols A, B, and C are 98.6%, 98.6%, and 99.4%, respectively.

CONCLUSION

The AI model established in this study was effective in predicting drilling protocols from CBCT images before surgery, suggesting the possibility of developing a decision-making support system to promote primary stability.

Investigation of the palatal soft tissue volume: a 3D virtual analysis for digital workflows and presurgical planning

Background

In mucogingival and implant surgery, an autologous soft tissue graft from the palate is the gold standard for reconstructing missing keratinised soft tissue and volume. Previously, presurgical measurements of the graft harvesting site were described with two-dimensional (2D) linear measurements. The present observational clinical study aimed to evaluate a three-dimensional (3D) measurement method for determining the present palatal soft tissue volume for each patient individually.

Methods

Pre-existing cone beam computed tomography (CBCT) scans of 20 patients were converted into 3D Standard Tessellation Language models of the bone surface. Intraoral impressions of the maxilla were taken and digitised to visualise the gingival surface. The resulting virtual models of bone (reference value) and gingival (actual value) surfaces were merged, with tooth surfaces used for registration. The region between the central incisors and the hard palate was subdivided into 5 regions of interest (ROIs). The distance between palatal bone and gingival surface was analysed both volumetrically and linearly, and the results were statistically evaluated for the ROIs.

Results

The average gingival surface area on the palate was 19.1 cm², and the mean volume was 58.2 cm³ (± 16.89). Among the ROIs, the mean linear value was highest in the most distal region, from the second molar to the hard palate (4.0 ± 1.09 mm) and lowest in the canine region (1.9 ± 0.63 mm). For mean distance, significant differences were found for the anterior palate and the most posterior palate in comparison with all other ROIs (p < 0.01). The volume measurements also declined significantly and steadily between the posterior (1.9 ± 1.0 cm³) and anterior palates (0.4 ± 0.2 cm³).

Conclusions

By merging digital data, palatal soft tissue could be quantified virtually. The results were reliable and comparable to previous findings with linear measurement methods. This 3D soft tissue volume analysis method fully exploited the diagnostic potential of data that are frequently collected for presurgical planning in oral surgery (i.e., CBCT + surface scans). This evaluation method might be useful for volumetric and linear measurements in other applications in anatomy and for determining palatal soft tissue dimensions in the planning stage before surgical interventions.

Trial registration

This observational clinical trial was retrospectively registered in the German Clinical Trials Register, reference number: DRKS00023918.