Accuracy and clinical fit of milled versus rapid prototyped orthognathic surgical splints.

Three-dimensional (3D) printing has become an integral part of orthognathic surgery. However, there is a lack of studies evaluating accuracy of orthognathic surgical splints fabricated from subtractive milling versus additive 3D printing. The primary aim of this in-vitro study was to compare the differences in trueness between milled and 3D-printed splints, while the secondary aim was to compare the differences in clinical fit of these splints. A sample of eight patients was selected, and STL files of the final orthognathic surgical splint were used to fabricate three splints for each of the eight cases. The first splint was fabricated by subtractive milling (SM), whereas the second and third splints were 3D printed with Digital Light Processing (DLP) and Laser Stereolithography (SLA), respectively. Paired superimposition of scans was performed using a reference model. The clinical fit of the splints to the printed models was also assessed. The mean root mean square (RMS) deviations for the SM, SLA, and DLP were 0.11 ± 0.02, 0.16 ± 0.02 and 0.14 ± 0.02 respectively. The post-hoc analysis showed that the SM splints had the highest accuracy (p < 0.01). However, DLP splints showed the best clinical fit, followed by SM and SLA. In conclusion, splints fabricated by SM were more accurate than those fabricated by 3D printing, although this difference may not be clinically significant. The site, rather than the magnitude of the errors, may have a greater effect on the clinical usability of splints. In general, SM and DLP splints demonstrated a good clinical fit and were suitable for the fabrication of surgical splints.

The effects of VY closure on lip morphology after Le Fort I maxillary advancement: A systematic review.

VY closure of the Le Fort 1 incision may commonly be indicated to mitigate the lip shortening effects of maxillary advancement. The objective of this systematic review was to investigate if VY closure prevents lip shortening when compared with conventional continuous closure (CS) methods, in patients who underwent le fort 1 maxillary advancement. PubMed, Embase, and Cochrane Library databases were accessed. Hand searching was also performed. Observational studies, non-randomised and randomized controlled trials were included if Le Fort 1 maxillary advancement was performed to correct a dentofacial deformity. Comparisons were made between VY and CS, and morphological changes to the upper lip were evaluated. The demographic data, study methodology, magnitude of maxillary movements and outcomes related to the lip morphology (length, vermillion exposure, thickness and angulation) were extracted. The search yielded 487 articles. Six studies were included after the application of the selection criteria. A total of 100 and 94 patients received CS and VY respectively. VY was not found to reliably prevent lip shortening. VY was more likely to mitigate lip shortening when there is a large maxillary advancement. It was consistent for a protrusive or "rolled-out" lip morphology to occur after a VY closure. This was demonstrated by the increase in lip vermillion exposure, thickness, and angulation. VY closure was a useful adjunctive technique in patients undergoing large maxillary advancements to mitigate the lip shortening effect from the procedure. Surgeons who employ this technique must also be aware of the consequence of a more protrusive lip with increased vermillion exposure and assess if this would be aesthetically desirable for the individual patient.

Virtual surgical planning in orthognathic surgery: a dental hospital's 10-year experience.

PURPOSE: The primary objective of this study was to evaluate how the utilization of virtual surgical planning (VSP) and the epidemiological profile of patients undergoing orthognathic surgery (OGS) have changed in the past decade. METHODS: The records of patients who had undergone orthognathic surgery at a national dental hospital were reviewed. Trends in VSP, epidemiological data, presentation of dentofacial deformity, and management details were recorded. RESULTS: A total of 1184 patients were included in this study. The majority of the patients seeking treatment in this dental hospital were young Chinese adults with dentofacial deformities requiring bimaxillary surgeries. Most patients presented with a skeletal Class III pattern (79.0%), and asymmetry was diagnosed in 80.8% of all cases. CONCLUSION: There was an initial slow pick-up rate for VSP, but this rapidly increased to a high adoption rate of 98.7-100% between 2019 and 2021. Together with an increasing body of evidence suggesting greater accuracy in VSP, utilization in this technology can be enhanced with greater familiarity with the technology and improvements in the VSP services.

Evaluation of the accuracy of cone beam computed tomography (CBCT) generated tooth replicas with application in autotransplantation.

OBJECTIVES: The primary aim of this study was to assess the linear and geometric accuracy of 3-dimensional (3D) printed tooth replicas when compared to the actual tooth. The secondary aims were to compare the accuracy of three different 3D printers and to evaluate dimensional changes of tooth replicas after sterilization. METHODS: A sample of 16 teeth were selected from recruited patients. Segmentation was carried out to generate files from the patient's cone beam computed tomography (CBCT) data, Tooth replicas were then printed using three printers making use of Polyjet, laser stereolithography (SLA) and digital light processing (DLP) technology respectively. These replicas, along with the actual tooth, were scanned by an optical scanner. Replicas were sent for sterilization and scanned again. Paired superimposition of the scans was performed. RESULTS: A mean length difference of 0.36 mm and mean geometric (root mean square [RMS]) difference of 0.56 mm was found. Qualitative analysis showed that the replicas were generally larger in size. Repeated ANOVA tests showed that the Polyjet printer had the highest accuracy (p<0.0001). After sterilization, there was an overall mean length difference of 0.10 mm and RMS deviation of 0.02 mm. CONCLUSION: This study found that there was a significant difference in linear and geometric measurements of the tooth replicas when compared to the actual tooth. This study also provides evidence that the printer which made use of Polyjet technology was able to produce more accurate models than SLA or DLP printers. Printed tooth models demonstrated clinically insignificant changes after heat sterilization. CLINICAL SIGNIFICANCE: 3D printed tooth replicas derived from the patient's CBCT data may be used in autotransplantation to increase predictability of the procedure. In order for this novel digital approach to realize its potential, it is critical to address questions as to how accurate the various printing technologies are in fabricating replicas.

Scoping review: Facilitators and barriers in the adoption of teledentistry among older adults.

OBJECTIVE/BACKGROUND: Access to oral health care among older adults is a key issue in society, which has been exacerbated by social distancing measures and lockdowns during the COVID-19 pandemic. Older adults would greatly benefit from teledentistry, yet little information exists on the enablers and challenges of adopting this technology for use with this group. The aim of this scoping review is to summarise the applications and key factors associated with the adoption of teledentistry among older adults. MATERIALS AND METHODS: This scoping review was developed in accordance with Arksey and O'Malley's five-stage framework and the Joanna Briggs Institute scoping review protocol guidelines. Publications on teledentistry involving direct clinical services for older adults aged 60 and above were included. Publications that focused solely on teleeducation were excluded. A systematic search was carried out on major electronic databases until 25 August 2020. Out of 1084 articles screened, 25 articles were included. Facilitators and barriers were categorised using the socio-ecological model. RESULTS/DISCUSSION: Teleconsultation and telediagnosis were the most reported applications of teledentistry among older adults. Reported policy-level factors were data privacy issues (n = 7) and regulations (n = 17). Community-level facilitators and barriers included the availability of resources (n = 15) and support (n = 3). Familiar care settings (n = 2) and effective administration (n = 20) were key organisational-level factors. Staff attitudes and education (n = 23) and individual patient knowledge, attitudes and practices (n = 10) can influence teledentistry adoption while complex medical conditions (n = 8) may pose a challenge. CONCLUSION: Key factors in the uptake of teledentistry among older adults span across policy, community, organisational, interpersonal and individual factors. Commonly reported barriers included technical issues, lack of funding, consent issues and cognitive impairments.