Diabetes and long duration leading to speech-, low/mid-, and high- frequency hearing loss: current evidence from the China National Health Survey 2023.

PURPOSE: To examine the effect of diabetes, duration of diabetes, and blood glucose on speech-, low/mid-, and high-frequency hearing loss. METHODS: In this cross-sectional study, 2821 participants aged 20-87 years in the China National Health Survey were included. Diabetes was defined as valid fasting blood glucose (FBG) of ≥ 7.0 mmol/L, a self-reported history of diabetes or the use of anti-diabetic medications. Speech-(500, 1000, 2000, and 4000 Hz), low/mid- (500, 1000 and 2000 Hz), and high-frequency (4000, 6000, and 8000 Hz) hearing loss was defined as pure tone average of responding frequencies > 20 dB HL in the better ear, respectively. RESULTS: In fully adjusted models, for speech-, low/mid-, and high-frequency hearing loss, compared with no diabetes, those with diabetes (OR[95%CI]: 1.44 [1.12, 1.86], 1.23 [0.94, 1.61], and 1.75 [1.28, 2.41], respectively) and with diabetes for > 5 years duration (OR[95%CI]: 1.63 [1.09, 2.42], and 1.63 [1.12, 2.36], 2.15 [1.25, 3.70], respectively) were at higher risk. High FBG level was associated with a higher risk of speech-, low/ mid-, and high-frequency hearing loss. And there were stronger associations between HL and diabetes, longer duration and higher in "healthier population" (no hypertension, no dyslipidemia and younger age). CONCLUSION: Diabetes, longer duration, and higher FBG level were independently associated with hearing loss for speech-, low/mid- and high-frequency hearing loss, particularly in higher frequency and "healthier population". Paying more attention to hearing loss in those populations could lower the burden of hearing loss.

[Innovative methods and developments in oral care. 3D planning in oral and maxillofacial surgery]. / Serie: Innovatieve technieken en ontwikkelingen in de mondzorg. 3D-planning in de mka-chirurgie.

With the use of cone beam computed tomography, intraoral scanning and 3D stereophotogrammetry, a virtual 3D head model of a patient can be reconstructed with image fusion. In this way, the malposition, deficiency and other anomalies at the level of bone, dentition and soft tissue can be quantified objectively. The desired position of the dentition, occlusion and soft tissue in the facial profile can be virtually drawn in and used as a guideline for treatment planning. Based on the principle of backward planning, it is possible to determine what repositioning of the jaw is required, where there is a need for bone augmentation and how many dental implants are necessary to obtain the desired treatment outcome. From this perspective, 3D treatment planning has become a treatment standard for the 4 clinical pillars supporting oral and maxillofacial surgery, specifically orthognathic surgery, implantology, craniofacial surgery and head & neck oncology. 3D planning has influenced today's workflow, planning of complex surgery and contributed to useful further innovations and efficient healthcare.

[Reconstruction after facial trauma with dento-alveolar injury]. / Reconstructie na aangezichtstrauma met dentoalveolair letsel.

While abroad, a healthy 36-year-old woman slammed head-on into a rock wall at high speed, resulting in significant facial trauma. The initial trauma care and first aid took place abroad. In the Netherlands, the woman was referred to the Department of Oral and Maxillofacial Surgery (OMFS) for reconstruction of her face and alveolar processes, gingiva and dentition. In view of the seriousness of the injuries, a 3D treatment plan was drawn up in a multidisciplinary collaboration with an OMF surgeon, an implantologist, dentist and dental technician. By making a digital setup of both the top and bottom front in advance, it was possible to work predictably. The first step consisted of bone augmentation by means of an iliac crest graft to reconstruct the major bone defects of the superior and inferior alveolar processes. Implants were then placed in the upper and lower jaws in the ideal position for the suprastructure by means of drill jigs. Within 10 months after the trauma, the implant bridges could be placed on individual zirconia frameworks to optimally restore oral function and aesthetics, completing the reconstruction.

[The 3D-printed surgical guides used during genioplasty]. / De 3D-geprinte zaag- en repositiemal voor een kinplastiek.

Genioplasty is a seemingly simple procedure performed to correct the bony chin. The results of the procedure are, however, strongly correlated with the experience of the surgeon. 3D-printed surgical guides could act as a transfer modality to translate the preoperative planning directly into the achieved result. Prospective studies evaluating the usefulness of the 3D-printed surgical guides have not yet been carried out and consensus regarding the best design is lacking. In order to become more familiar with working with surgical guides, a genioplasty using 3D-printed surgical guides was performed. The postoperative analysis of the achieved result showed minor differences compared to preoperative planning. Surgical guides have the potential to improve the accuracy and predictability of genioplasty. The design should be further refined and the added value of the guides should be confirmed by means of prospective research.

Virtual setup in orthodontics: planning and evaluation.

OBJECTIVES: The purpose of this study was to evaluate the clinical accuracy of virtual orthodontic setups by using a new CBCT-based approach. MATERIALS AND METHODS: Ten patients who underwent pre-surgical orthodontics were included in this study. Pre-treatment and pre-surgical cone-beam CT (CBCT) scans and digital dental models were available. The pre-treatment digital dental model was used to create an orthodontic virtual setup. The digital dental models were fused with the corresponding CBCT scans, and the two CBCT scans were aligned using voxel-based matching. Moving each individual tooth from the virtual setup to the final outcome allows the calculation of the accuracy of the virtual setup by using an iterative closest point algorithm. Differences between virtual setup and final outcome were recorded as well as the ICC between two observers. RESULTS: The inter-observer variability showed a high level of agreement between the observers. The largest mean difference between observers was found in the cranial/caudal direction (0.36 ± 0.30 mm) and the roll rotation (1.54 ± 0.98°). Differences between the virtual setup and final outcome were small in the translational direction (0.45 ± 0.48 mm). Rotational mean differences were larger with the pitch of the incisors (0.00 ± 7.97°) and molars (0.01 ± 10.26°) as largest difference. Excessive extrusion of all upper teeth and more anterior movement than planned were seen for both upper and lower arch. Lower molars showed less extrusion. CLINICAL RELEVANCE: The data of this study can be used to obtain more insight in the accuracy and achievability of orthodontic virtual setup. Tooth movement can now be studied in more details which can lead to new insights.

[Innovations in dentistry. The influence of build angle on the fit of a 3D printed occlusal splint]. / Serie: Innovaties in de tandheelkunde. Het effect van printoriëntatie op de pasvorm van een 3D-geprinte occlusale wafer.

3D virtual planning optimises the predictability of orthognathic surgery. The planning is based on a cone beam computed tomography-scan of the patient as well as a plaster model, and is transferred to the patient by a 3D printed occlusal splint. In 3D printing the build angle influences, among other things, the accuracy (in earlier research, proven in dental crowns), manufacturing time and capacity. In this research, using 10 plaster models, 3 different build angles (0°, 30° and 90°) are compared. The fit of the splints was tested by 2 physicians using plaster models. According to this small sample, the fit does not depend on the build angle. When considering the manufacturing time and capacity, there is a preference for the 90º oriëntation, because it increases the manufacturing capacity and decreases the manufacturing time per splint.

iTRAQ-based proteomics analysis reveals the deregulated proteins related to liver toxicity induced by melamine with or without cyanuric acid in mice.

The administration of melamine alone or its combination with cyanuric acid was shown to have certain liver toxicity. However, the injury mechanism of melamine-related toxicity to liver remains poorly understood. In the present study, we investigated the deregulated proteins related to liver toxicity induced by melamine with or without cyanuric acid in mice using iTRAQ quantitative proteomics technique. A total of 166 proteins were significantly changed by the melamine treatment, of which, 36 proteins were up-regulated and 130 proteins were down-regulated. Whereas, 242 proteins were significantly changed by the combined treatment of melamine and cyanuric acid, of which 81 proteins were up-regulated and 161 proteins were down-regulated. The enriched analysis of GO terms and KEGG pathway on the altered proteins showed that both enriched main GO terms and KEGG pathways appear to be different between the two kinds of treatments: melamine and mixture of melamine and cyanuric acid. Based on western blotting technique, it was confirmed that the expression of three proteins: heat shock protein 70 (HSP70), protein disulphide isomerase 6 (PDIA6) and heat shock 70 kDa protein 4-like (HSPA4L) were agreement with the findings in iTRAQ-Based quantitative analysis. These identified proteins might participate in the regulation of a wide range of biological processes, such as immune and inflammatory function, unfolded proteins response in endoplasmic reticulum, DNA damage, and the apoptosis of liver cells. These results from this study provide a new way to gain insight into the mechanisms of melamine-related toxicity to liver in animals.

Postoperative socket irrigation with drinking tap water reduces the risk of inflammatory complications following surgical removal of third molars: a multicenter randomized trial.

OBJECTIVES: The primary aim of the present study was to evaluate the effectiveness of postoperative irrigation of the socket with drinking tap water on inflammatory complications following lower third molar removal. MATERIAL AND METHODS: A multicenter randomized controlled trial was carried out from June 2013 to June 2014. In one arm of the study, patients were instructed to irrigate the tooth socket and surgical site with a Monoject® Curved 412 Tip Syringe (Tyco/healthcare-Kendall, Mansfield, MA, USA) with tap water. In a second arm of the study, the standard postoperative instructions did not include irrigation instructions. The incidences of alveolar osteitis and wound infection were recorded for each group and analyzed by the Fisher's exact test. RESULTS: A total of 280 patients with 333 mandibular third molars were analyzed. According to the intention-to-treat (ITT) analysis, inflammatory complications occurred in 18 cases in the Monoject® group (11.4 %) compared to 34 cases (19.1 %) in the control group (p = 0.04). These complications were associated with significant worse outcomes regarding quality of life, pain, and trismus and caused significantly more missed days of work or study. Female gender, age >26, bone removal, deep impacted third molars, less experienced surgeons, and a high amount of debris at the surgical site were also identified as risk factors for developing inflammatory complications following lower third molar removal. CONCLUSION: Irrigation of the surgical site with drinking tap water using a curved syringe following removal of third molars is effective in reducing the risk of inflammatory complications. CLINICAL RELEVANCE: Water is a very accessible, cost-effective irrigant without side effects and the results from this study have proven that it can be used to reduce the risk of inflammatory complications and associated morbidity following lower third molar removal.

Three-dimensional facial analysis in acromegaly: a novel tool to quantify craniofacial characteristics after long-term remission.

PURPOSE: The exact quantification of craniofacial characteristics in patients with acromegaly is important because it provides insight in the pathophysiology of the disease and offers a tool to evaluate the effects of treatment on tissue specific endpoints. However, until recently this was not feasible due to limitations of available cephalometric methods. The new technique of three-dimensional (3D) cephalometry enables the accurate quantification of facial anatomical characteristics of both soft tissue and bone. This is the first study that uses 3D cephalometry to analyze craniofacial disproportions in patients in long-term remission of acromegaly. METHODS: Sixteen patients in remission of acromegaly for over 24 months (50% male, mean age 56.0 ± 10.7 years, mean body mass index 29.3 ± 5.5 kg/m(2)) were compared to 16 matched control subjects. A 3D cone beam computed tomography scan and 3D stereophotograph of each individual were acquired and analyzed using 3D cephalometry. RESULTS: In addition to an accurate quantification of the classical craniofacial characteristics, 3D cephalometry, shows that many typical soft tissue deformities persist, even after long-term remission. Furthermore, we found that, compared to controls, the patients in remission of acromegaly have a wider face at the level of the zygoma and longer maxilla (p < 0.05). CONCLUSIONS: 3D cephalometry is an attractive novel imaging modality to accurately investigate craniofacial disproportions of both soft tissue and bony parts of the face in patients with acromegaly, which makes it a promising technique for future research purposes and clinical practice.

The effect of combined surgery and physiotherapy on the facial asymmetry in patients with congenital muscular torticollis: a retrospective cohort study.

The aim of this study was to assess the influence of surgical therapy, intraoperative evaluation, and immediate physiotherapy on the facial asymmetry of patients with congenital muscular torticollis (CMT). Patients who underwent a combination of unipolar sternocleidomastoid muscle release with perioperative physiotherapy between 2014 and 2020 in the Department of Oral and Maxillofacial Surgery, Radboud University Medical Center, Nijmegen were enrolled. Three-dimensional photographs of the face acquired 2 months preoperatively and 1.5-2 years postoperatively were assessed. Based on 43 patients, there was a significant improvement in the asymmetry indices (angles between bilateral exocanthion, bilateral cheilion, and nasion-gnathion lines): mean ± standard deviation reductions in indices (Ex-Ex)-(Ch-Ch), (Ex-Ex)-(Na-Gn), and (Ch-Ch)-(Na-Gn) of 0.88 ± 1.08° (P < 0.001), 1.04 ± 1.26° (P < 0.001), and 0.21 ± 1.06° (P = 0.024), respectively. Analysis of covariance (ANCOVA) showed that intervention at an early age (P = 0.017) and left-sided torticollis (P = 0.030) were associated with a significantly greater improvement in the facial asymmetry. This study found that the use of combined surgery and physiotherapy reduced the facial asymmetry of patients with CMT at 2 years postoperatively. Early intervention and left-sided torticollis were associated with a greater improvement in the facial asymmetry. This indicates that attention should be given to early intervention and right-sided CMT cases postoperatively.

Does facial asymmetry vary between subjects of different age groups? A 3D stereophotogrammetry analysis.

This study was aimed to assess whether facial asymmetry increases with age and to examine potential gender differences using 3D stereophotogrammetry. A prospective cross-sectional study was performed. 3D photographs were acquired from 600 control subjects, 300 male, 300 female, and were stratified into 15 different age groups ranging from 0 to 70+. The 3D photographs were postprocessed and mirrored. The original and mirrored faces were surface-based matched using an iterative closest point algorithm. The primary outcome variable, facial asymmetry, was evaluated by calculating the absolute mean distance between the original and mirrored images. The primary predictor was age. Pearson's correlation was used to assess the correlation between facial asymmetry and age. The average overall facial asymmetry was 0.72 mm (SD 0.72 mm; range 0.25 - 3.04 mm). Mean facial asymmetry increased significantly with age, from 0.45 mm in the age group of 0-4 years to 0.98 mm in the age group of 70+ (p<0.001). Facial asymmetry was positively correlated with age (Pearson's r = 0.55; p<0.001). Male subjects were significantly more asymmetric compared to females, 0.77 mm and 0.67 mm, respectively (p<0.001). This study indicates that facial asymmetry significantly increases with age and is significantly larger in males than in females.

Challenges in conducting clinical research in primary care dentistry.

The integration of dentistry into primary health care is crucial for promoting patient well-being. However, clinical studies in dentistry face challenges, including issues with study design, transparency, and relevance to primary care. Clinical trials in dentistry often focus on specific issues with strict eligibility criteria, limiting the generalizability of findings. Randomized clinical trials (RCTs) face challenges in reflecting real-world conditions and using clinically relevant outcomes. The need for more pragmatic approaches and the inclusion of clinically relevant outcomes (CROs) is discussed, such as tooth loss or implant success. Solutions proposed include well-controlled observational studies, optimized data collection tools, and the integration of artificial intelligence (AI) for predictive modelling, computer-aided diagnostics and automated diagnosis. In this position paper advocates for more efficient trials with a focus on patient-centred outcomes, as well as the adoption of pragmatic study designs reflecting real-world conditions. Collaborative research networks, increased funding, enhanced data retrieval, and open science practices are also recommended. Technology, including intraoral scanners and AI, is highlighted for improving efficiency in dental research. AI is seen as a key tool for participant recruitment, predictive modelling, and outcome evaluation. However, ethical considerations and ongoing validation are emphasized to ensure the reliability and trustworthiness of AI-driven solutions in dental research. In conclusion, the efficient conduct of clinical research in primary care dentistry requires a comprehensive approach, including changes in study design, data collection, and analytical methods. The integration of AI is seen as pivotal in achieving these objectives in a meaningful and efficient way.

Detecting Mandible Fractures in CBCT Scans Using a 3-Stage Neural Network.

After nasal bone fractures, fractures of the mandible are the most frequently encountered injuries of the facial skeleton. Accurate identification of fracture locations is critical for effectively managing these injuries. To address this need, JawFracNet, an innovative artificial intelligence method, has been developed to enable automated detection of mandibular fractures in cone-beam computed tomography (CBCT) scans. JawFracNet employs a 3-stage neural network model that processes 3-dimensional patches from a CBCT scan. Stage 1 predicts a segmentation mask of the mandible in a patch, which is subsequently used in stage 2 to predict a segmentation of the fractures and in stage 3 to classify whether the patch contains any fracture. The final output of JawFracNet is the fracture segmentation of the entire scan, obtained by aggregating and unifying voxel-level and patch-level predictions. A total of 164 CBCT scans without mandibular fractures and 171 CBCT scans with mandibular fractures were included in this study. Evaluation of JawFracNet demonstrated a precision of 0.978 and a sensitivity of 0.956 in detecting mandibular fractures. The current study proposes the first benchmark for mandibular fracture detection in CBCT scans. Straightforward replication is promoted by publicly sharing the code and providing access to JawFracNet on grand-challenge.org.

Surgical accuracy in 3D planned bimaxillary osteotomies: intraoral scans and plaster casts as digital dentition models.

The aim of this study was to assess whether the use of intraoral scans (IOS) is an eligible alternative to conventional plaster casts in terms of surgical accuracy of three-dimensionally planned bimaxillary osteotomies. This retrospective cohort study included patients who underwent bimaxillary surgery between 2016 and 2020 in the Department of Oral and Maxillofacial Surgery at Radboud University Medical Center, Nijmegen. Three-dimensional virtual planning was performed with the use of plaster casts in one group and IOS in the other group. Cone beam computed tomography scans were acquired preoperatively and at 1 week following surgery. By using voxel-based matching, the maxillary movements were quantified in six degrees of freedom. The primary outcome variable, surgical accuracy, was defined as the difference between the planned maxillary movements and those achieved. Of 152 patients, 113 were documented with plaster casts and 39 with IOS. The surgical accuracy was comparable in terms of maxillary vertical, sagittal, and transverse translations, as well as roll and yaw. Maxillary pitch (difference 0.55 ± 0.26°; P = 0.001) was in favour of the IOS group. This study demonstrated that IOS can be used as an alternative to conventional plaster casts in the three-dimensional planning of bimaxillary osteotomies.

Virtual occlusion in orthognathic surgery.

The aim of this retrospective study was to determine whether a virtually created occlusion is as accurate as a conventionally created occlusion. Seventeen orthognathic patients were included in the study, which was conducted in a university clinic. Plaster cast models were obtained and digitized. Two experienced observers created the conventional (gold standard) and virtual occlusion to assess inter-observer variability. One observer created the conventional and virtual occlusion a second time to assess the intra-observer variability. The criterion for accepting the virtual occlusion was that the difference between the gold standard and the virtual occlusion was not larger than the intra-observer variability for the gold standard. A non-parametric Kruskal-Wallis H test was performed to detect statistically significant differences between the intra- and inter-observer groups for both the conventional and virtual occlusion. No statistically significant differences were found between the different groups. The difference between the conventional and virtual occlusion group was 0.20mm larger than the intra-observer variability of the gold standard. The virtual occlusion tool presented here can be utilized in daily clinical practice and makes the use of physical dental models redundant.

Three-dimensional stereophotogrammetry measurement of facial asymmetry in patients with congenital muscular torticollis: a non-invasive method.

The aim of this study was to evaluate three-dimensional (3D) stereophotogrammetry based methods for measuring craniofacial asymmetry in patients with congenital muscular torticollis (CMT). This study focused on the differences in craniofacial asymmetry in CMT patients compared with a healthy control group using 3D photographs. The difference in facial asymmetry between the CMT group and control group was measured using two methods to analyse facial asymmetry in distinct anatomical regions: (1) mirroring and surface-based registration to analyse the overall facial asymmetry; (2) the 'coherent point drift' based method. Thirty-one patients with CMT and 84 controls were included in the study. A statistically significant difference was found between the CMT patients and a healthy control group. The measured facial asymmetry for the CMT group was 1.71±0.66mm and for the controls 0.46±0.14mm (P<0.05). A significant difference was found in surface ratio for the cheek, nose and the forehead region (P<0.05). With its minimal invasive character, 3D stereophotogrammetry is a useful tool in measuring the facial asymmetry associated with CMT and to quantify the treatment-induced facial changes. In the future 3D facial data could be used to create a ranking-scale to categorize the severity of facial asymmetry.

The use of xenografts to prevent inferior border defects following bilateral sagittal split osteotomies: three-dimensional skeletal analysis using cone beam computed tomography.

The aim of this retrospective study was to investigate grafting in the osteotomy gap during bilateral sagittal split osteotomy (BSSO), using a xenograft and fibrin glue. Hard tissue defects in the inferior mandibular border were assessed using cone beam computed tomography scans taken 1 week and 1year postoperatively. The study group of 20 patients underwent bone grafting during BSSO (mean age 26.1years; mean horizontal displacement 8.5mm) and the control group of 20 patients did not (mean age 30.2 years; mean horizontal displacement 7.6mm). The mean height of the mandibular defects was significantly lower in the study group, but there was no significant difference in volume measurements between the groups. Grafting had a negligible effect on large displacements (9.0-15.0mm), which might have been due to an inadequate amount and/or positioning of the graft, or to poor dimensional stability. This may be resolved by improved graft positioning or by using a different kind of (xeno)graft.

Comparative evaluation of the biocompatible and physical-chemical properties of poly(lactide-co-glycolide) and polydopamine as coating materials for bacterial cellulose.

The aim of this study was to investigate the influence of poly(lactide-co-glycolide) (PLGA) and polydopamine (PDA) as coating materials on the tensile strength, surface performance, in vitro cell behavior and the in vivo material-tissue reaction of bacterial cellulose (BC) membranes. The coated membranes were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electron microscopy (SEM), demonstrating that the PDA forms the dispersion phase and penetrates into the BC substrates while PLGA only adheres to the BC surface. Mechanical tests and fractured surface morphology reveal that penetration of PDA into BC membranes enhances the mechanical strength by strongly bonding the nanofibers. The PLGA coated BC membrane obtained by adhesion debonds from the BC substrate under stress, leading to a decrease in the mechanical strength of the membrane. The in vitro cell culture experiments were established to assess cell attachment and spreading by SEM and DAPI (4',6-diamidino-2-phenylindole) staining and expression of collagen I, which showed a better performance on the PDA-BC than on the PLGA-BC and bare BC membranes. However, the in vivo results of the rabbit back implantation indicated that BC membrane surface modification by PDA is not effective for cell proliferation and collagen accumulation when compared to bare and PLGA coated BC, whereas PLGC-BC were surrounded by a thicker layer of connective tissues with slight neovascularization demonstrating superior tissue integration. PDA based materials still have a long way to go before clinical applications. However, PLGA coating has excellent biocompatibility in clinical as well as in experimental use.

Reliability and accuracy of cone beam computed tomography versus conventional multidetector computed tomography for image-guided craniofacial implant planning: An in vitro study.

PURPOSE: To assess the reliability and accuracy of linear measurements on three-dimensional (3D) cross-sectional images, both acquired with cone beam computed tomography (CBCT) and multi-detector row CT (MDCT). Bone thickness was evaluated with regard to image-guided planning of craniofacial implant surgery. MATERIALS AND METHODS: Five dry human skulls were used. Cuts were made with a circular bone saw at the ideal implant positions in the nasal, orbital, and temporal regions prior to acquisition of CBCT and MDCT scans. After imaging examination, bone width was assessed by three independent observers using a caliper and defined as a reference. In the next step, cross-sectional images of the regions with the aforementioned cuts were reconstructed from 3D virtual models generated from the digital DICOM datasets with the use of 3D image-based planning software. Subsequently, linear measurements were performed. The systematic difference and interobserver and intraobserver variation of MDCT and CBCT linear measurements were compared with the physical measurements at different locations in the nasal, orbital, and temporal region, respectively. Also, the potential influence of different gray-level values was investigated. The quantitative accuracy of distance measurements was performed using a two-way analysis of variance (ANOVA) and variance component analyses. Only differences with P values < .05 were considered significant. RESULTS: All radiologic measurements showed a significant overestimation of the bony dimensions, reaching more than the used voxel sizes of 0.3 mm for CBCT and 0.5 mm for MDCT. For CBCT, an average measurement bias of 0.39 to 0.53 mm and for MDCT of 0.57 to 0.59 mm was found. MDCT images showed less interobserver variation in linear measurements on cross-sectional images from 3D virtual models compared with CBCT images. Contrast settings statistically significantly influenced linear measurements of bone width for CBCT images (P < .0015) and interobserver variation on MDCT imaging (P < .029). CONCLUSION: Both CBCT images (KaVo 3D eXam Imaging System) and MDCT images (Aquilion ONE, Toshiba) showed a highly consistent submillimeter overestimation of the anatomical truth in assessing bone thickness of nasal, orbital, and temporal regions of ex vivo specimens. When using CBCT and MDCT images for presurgical assessment, one should be aware of the overestimation of the cortical bone thickness.

Effect of skin tone on the accuracy of hybrid and passive stereophotogrammetry.

BACKGROUND: Three-dimensional (3D) surface images acquired from stereophotogrammetry are increasingly being used to plan or evaluate treatment by plastic surgeons. Stereophotogrammetry exists in active, passive, and hybrid forms. Active and hybrid stereophotogrammetry are believed to capture darker surfaces more accurately than passive stereophotogrammetry. The purpose of this study was to investigate whether skin tone has a clinically relevant effect on the accuracy of hybrid and passive stereophotogrammetry. MATERIALS AND METHODS: Seven subjects with different skin tones were recruited. 3D-printed face and breast were spray-painted in six different colors, ranging from white to black. The skin tones and paint colors were objectified by measuring their melanin index. 3D photos of the subjects and 3D prints were acquired with hybrid and passive stereophotogrammetry. These 3D photos were matched with specialized software, and their geometric differences were calculated. RESULTS: None of the 3D photos showed a clinically relevant mean inaccuracy. On the 3D prints, hybrid stereophotogrammetry resulted in a smaller standard deviation of the inaccuracies than passive stereophotogrammetry (0.20 ± 0.06 mm vs. 0.35 ± 0.07 mm, p < 0.001). Passive stereophotogrammetry yielded a correlation between the melanin index of the spray paint colors and the standard deviation of the inaccuracy (Pearson's R = 0.60, p = 0.04). On human subjects, no correlation or difference in standard deviation of the accuracy was found. CONCLUSION: Skin tone does not influence the accuracy of hybrid and passive 3D stereophotogrammetry in a clinically relevant way.