Advanced interdisciplinary treatment protocol for pediatric obstructive sleep apnea including medical, surgical, and orthodontic care: a narrative review.

OBJECTIVE: To suggest an updated interdisciplinary treatment protocol for pediatric obstructive sleep apnea (POSA) based on the integration of craniofacial growth modification into medical and surgical sleep practice. METHODS: PubMed, Scopus, and Cochrane library were searched up to February 2020 using keywords. Among 184 articles, 80 studies were finally included. An integrated treatment protocol for POSA encompassing craniofacial skeletal management as well as medical and surgical care was attempted. RESULTS: A differential diagnostic workflow for identifying the phenotype of POSA was suggested, and a phenotype-based treatment protocol for POSA was proposed. Despite the lack of high level of evidence, timely skeletal growth modification in three dimensions using craniofacial growth potential could be valuable treatment for upper airway development in POSA patients with craniofacial phenotypic cause. CONCLUSION: A novel precision treatment protocol will advance clinicians to determine the primary option or to apply the combined strategy for POSA patients.

Retrotransposon insertions associated with risk of neurologic and psychiatric diseases.

Transposable elements (TEs) are active in neuronal cells raising the question whether TE insertions contribute to risk of neuropsychiatric disease. While genome-wide association studies (GWAS) serve as a tool to discover genetic loci associated with neuropsychiatric diseases, unfortunately GWAS do not directly detect structural variants such as TEs. To examine the role of TEs in psychiatric and neurologic disease, we evaluated 17,000 polymorphic TEs and find 76 are in linkage disequilibrium with disease haplotypes (P < 10-6 ) defined by GWAS. From these 76 polymorphic TEs, we identify potentially causal candidates based on having insertions in genomic regions of regulatory chromatin and on having associations with altered gene expression in brain tissues. We show that lead candidate insertions have regulatory effects on gene expression in human neural stem cells altering the activity of a minimal promoter. Taken together, we identify 10 polymorphic TE insertions that are potential candidates on par with other variants for having a causal role in neurologic and psychiatric disorders.

Split orthodontic airway plate: An innovation to the utilization method of conventional orthodontic airway plate for neonates with Robin sequence.

Since the emergence of neonatal infant orthodontics for treatments of cleft lip and palate with or without Robin sequence (RS) in Europe in the 1950s, advancements in design and scope of its application have been remarkable. As the first institution to adopt orthodontic airway plate (OAP) treatment in the United States in 2019, we saw a need for innovation of the original design to streamline the most labor-intensive and time-consuming aspects of OAP utilization. A solution is introduced using a systematic split expansion mechanism to re-size the OAP periodically to accommodate the neonate's maxillary growth. To date, seven RS patients have received this modified treatment protocol at our institution. Each patient completed full treatment using only one OAP. This innovative utilization method is aptly named the split orthodontic airway plate (S-OAP). Details of the S-OAP and its modifications from conventional OAP are reported.

Development of a maxillomandibular arch form based on the center of resistance of teeth using cone-beam computed tomography.

INTRODUCTION: Controlling transverse discrepancies is necessary to ensure stable and functional occlusion. Altered molar inclinations can camouflage the transverse relationship. The purpose of this research was to evaluate the maxillomandibular relationship of the center of resistance (CR) of the arch form created by the CR of teeth and compare these CR arch forms by their skeletal patterns. METHODS: Sixty patients with minor crowding and normal posterior overjet were divided into 3 groups according to ANB angle: skeletal Class I group had ANB angle between 0° and 4° (n = 20), skeletal Class II group had ANB angle >4° (n = 20), and skeletal Class III group had ANB angle <0° (n = 20). The 3-dimensional coordinates of the CR were estimated using cone-beam computed tomography images and projected on the CR occlusal plane to obtain the 2-dimensional coordinates. The CR arch forms were constructed and evaluated using Matlab (MathWorks, Natick, Mass). RESULTS: On comparing maxillomandibular CR arch form widths, the maxilla was significantly larger than the mandible of the canine and first premolar. The mandible was larger in the first molar of the skeletal Class III group. The maxillomandibular CR arch form width ratios were between 0.97 and 1.35. On comparing maxillomandibular CR arch form areas, the maxilla was significantly larger than the mandible in the anterior segment, and the mandible was larger in the posterior segment. The ratios were between 0.86 and 2.25. In between-group comparison, the skeletal Class III group showed significantly greater arch forms in the mandible. CONCLUSIONS: CR arch forms had significant maxillomandibular differences throughout the arch. The maxillomandibular ratios could be a reference for site-specific transverse discrepancy analysis.

Fully automated identification of cephalometric landmarks for upper airway assessment using cascaded convolutional neural networks.

OBJECTIVES: The aim of the study was to evaluate the accuracy of a cascaded two-stage convolutional neural network (CNN) model in detecting upper airway (UA) soft tissue landmarks in comparison with the skeletal landmarks on the lateral cephalometric images. MATERIALS AND METHODS: The dataset contained 600 lateral cephalograms of adult orthodontic patients, and the ground-truth positions of 16 landmarks (7 skeletal and 9 UA landmarks) were obtained from 500 learning dataset. We trained a UNet with EfficientNetB0 model through the region of interest-centred circular segmentation labelling process. Mean distance errors (MDEs, mm) of the CNN algorithm was compared with those from human examiners. Successful detection rates (SDRs, per cent) assessed within 1-4 mm precision ranges were compared between skeletal and UA landmarks. RESULTS: The proposed model achieved MDEs of 0.80 ± 0.55 mm for skeletal landmarks and 1.78 ± 1.21 mm for UA landmarks. The mean SDRs for UA landmarks were 72.22 per cent for 2 mm range, and 92.78 per cent for 4 mm range, contrasted with those for skeletal landmarks amounting to 93.43 and 98.71 per cent, respectively. As compared with mean interexaminer difference, however, this model showed higher detection accuracies for geometrically constructed UA landmarks on the nasopharynx (AD2 and Ss), while lower accuracies for anatomically located UA landmarks on the tongue (Td) and soft palate (Sb and St). CONCLUSION: The proposed CNN model suggests the availability of an automated cephalometric UA assessment to be integrated with dentoskeletal and facial analysis.

Geometry of anchoring miniscrew in the lateral palate that support a tissue bone borne maxillary expander affects neighboring root damage.

Anchoring miniscrews used for a tissue bone borne maxillary expander (C-expander) can fail if they contact tooth roots or perforate the maxillary sinus. Cone beam computed tomography images were reviewed retrospectively to evaluate the geometric factors of miniscrew placement in the palate that contribute to root proximity (RP) and sinus perforation (SP), and to investigate the differences of miniscrew placement depth (PD) and placement angle (PA) among the groups in each variable from 340 anchoring miniscrews on 70 patients whose C-expanders showed sufficient stability after palatal expansion for orthodontic treatment. Two types of miniscrews were used: a self-tapping miniscrew with 1.8 mm-in-diameter, and a self-drilling miniscrew with 1.6 mm-in-diameter. While the self-tapping larger diameter miniscrew influenced root proximity significantly, the screw location and PD affected the rate of sinus perforation. PA was significantly different between the right and left sides of the palate. The results of this study confirmed that root proximity and sinus perforation of anchoring miniscrews in a tissue bone borne palatal expander occurred due to certain risk factors, even when the palates were expanded successfully. Knowledge of these factors can help the clinician place miniscrews with less risk of root proximity or sinus perforation.

Force Distribution of a Novel Core-Reinforced Multilayered Mandibular Advancement Device.

A mandibular advancement device (MAD) is a commonly used treatment modality for patients with mild-to-moderate obstructive sleep apnea. Although MADs have excellent therapeutic efficacy, dental side effects were observed with long-term use of MADs. The aim of this study was to analyze the force distribution on the entire dentition according to the materials and design of the MADs. Three types of MADs were applied: model 1 (single layer of polyethylene terephthalate glycol (PETG)), model 2 (double layer of PETG + thermoplastic polyurethane (TPU)), and model 3 (core-reinforced multilayer). In the maxilla, regardless of the model, the incisors showed the lowest force distribution. In most tooth positions, the force distribution was lower in models 2 and 3 than in model 1. In the mandible, the mandibular second molar showed a significantly lower force in all models. The mandibular incisors, canines, and molars showed the highest force values in model 1 and the lowest values in model 3. Depending on the material and design of the device, the biomechanical effect on the dentition varies, and the core-reinforced multilayered MAD can reduce the force delivered to the dentition more effectively than the conventional single- or double-layer devices.

Effectiveness of 2D radiographs in detecting CBCT-based incidental findings in orthodontic patients.

Some craniofacial diseases or anatomical variations are found in radiographic images taken for other purposes. These incidental findings (IFs) can be detected in orthodontic patients, as various radiographs are required for orthodontic diagnosis. The radiographic data of 1020-orthodontic patients were interpreted to evaluate the rates of IFs in three-dimensional (3D) cone-beam-computed tomography (CBCT) with a large field of view (FOV) and investigate the effectiveness and accuracy of two-dimensional (2D) radiographs for detecting IFs compared to CBCT. Prevalence and accuracy in five areas was measured for sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). The accuracies of various 2D-radiograph were compared through a proportion test. A total of 709-cases (69.5%) of 1020-subjects showed one or more IFs in CBCT images. Nasal cavity was the most affected area. Based on the CBCT images as a gold standard, different accuracies of various 2D-radiographs were observed in each area of the findings. The highest accuracy was confirmed in soft tissue calcifications with comprehensive radiographs. For detecting nasal septum deviations, postero-anterior cephalograms were the most accurate 2D radiograph. In cases the IFs were not determined because of its ambiguity in 2D radiographs, considering them as an absence of findings increased the accuracy.

Evaluation of a multi-stage convolutional neural network-based fully automated landmark identification system using cone-beam computed tomographysynthesized posteroanterior cephalometric images.

OBJECTIVE: To evaluate the accuracy of a multi-stage convolutional neural network (CNN) model-based automated identification system for posteroanterior (PA) cephalometric landmarks. METHODS: The multi-stage CNN model was implemented with a personal computer. A total of 430 PA-cephalograms synthesized from cone-beam computed tomography scans (CBCT-PA) were selected as samples. Twenty-three landmarks used for Tweemac analysis were manually identified on all CBCT-PA images by a single examiner. Intra-examiner reproducibility was confirmed by repeating the identification on 85 randomly selected images, which were subsequently set as test data, with a two-week interval before training. For initial learning stage of the multi-stage CNN model, the data from 345 of 430 CBCT-PA images were used, after which the multi-stage CNN model was tested with previous 85 images. The first manual identification on these 85 images was set as a truth ground. The mean radial error (MRE) and successful detection rate (SDR) were calculated to evaluate the errors in manual identification and artificial intelligence (AI) prediction. RESULTS: The AI showed an average MRE of 2.23 ± 2.02 mm with an SDR of 60.88% for errors of 2 mm or lower. However, in a comparison of the repetitive task, the AI predicted landmarks at the same position, while the MRE for the repeated manual identification was 1.31 ± 0.94 mm. CONCLUSIONS: Automated identification for CBCT-synthesized PA cephalometric landmarks did not sufficiently achieve the clinically favorable error range of less than 2 mm. However, AI landmark identification on PA cephalograms showed better consistency than manual identification.

Reverse Actuation of Polyelectrolyte Effect for In Vivo Antifouling.

Zwitterionic polymers have extraordinary properties, that is, significant hydration and the so-called antipolyelectrolyte effect, which make them suitable for biomedical applications. The hydration induces an antifouling effect, and this has been investigated significantly. The antipolyelectrolyte effect refers to the extraordinary ion-responsive behavior of particular polymers that swell and hydrate considerably in physiological solutions. This actuation begins to attract attention to achieve in vivo antifouling that is challenging for general polyelectrolytes. In this study, we established the sophisticated cornerstone of the antipolyelectrolyte effect in detail, including (i) the essential parameters, (ii) experimental verifications, and (iii) effect of improving antifouling performance. First, we find that both osmotic force and charge screening are essential factors. Second, we identify the antipolyelectrolyte effect by visualizing the swelling and hydration dynamics. Finally, we verify that the antifouling performance can be enhanced by exploiting the antipolyelectrolyte effect and report reduction of 85% and 80% in ex and in vivo biofilm formation, respectively.

Evaluation of interradicular space, soft tissue, and hard tissue of the posterior palatal alveolar process for orthodontic mini-implant, using cone-beam computed tomography.

INTRODUCTION: To investigate the anatomy of the posterior palatal alveolar process, which is often used for placement of the orthodontic mini-implant (OMI), and to suggest simple guidelines for safe placement of OMI. METHODS: Cone-beam computed tomography (CBCT) scans of 60 patients (30 men, 30 women; age range, 18-39 years; average age, 25.8 years) was used to measure the palatal interradicular distance, the palatal bone thickness, and the palatal soft-tissue thickness. Measurements were performed on the area from the maxillary canine to the maxillary second molar based on the vertical distance apical from the cementoenamel junction. The CBCT data were analyzed by Bonferroni correction for multiple testing and the multivariable mixed linear model. RESULTS: The palatal interradicular distance was the widest between the second premolar and the first molar and the narrowest between the first and second premolars. The palatal bone thickness at interdental sites was the thickest between the first and second premolars and the thinnest between the first and second molars. The interdental palatal soft-tissue thickness from the canine to the second premolar was thicker than any other area. There were minor measurement differences between genders and positive correlations between vertical distance from the cementoenamel junction plane and all of the parameters. CONCLUSION: In this study, we evaluated the anatomy of the posterior palatal area using CBCT scans of adult patients. The data will provide guidelines to the clinicians before OMI placement in the posterior palatal alveolar process.

Treatment outcomes of various force applications in growing patients with skeletal Class III malocclusion.

OBJECTIVES: To evaluate skeletal, dentoalveolar, and soft tissue changes between intraoral light force application and extraoral heavy force application in growing patients with skeletal Class III malocclusion. MATERIALS AND: Methods: A retrospective study was conducted with pretreatment and posttreatment lateral cephalometric data from 50 subjects with skeletal Class III malocclusion. In the first group (15 boys, 10 girls; 8.67 ± 2.13 years old), each subject wore a biocreative horseshoe appliance (CHS) with two Class III elastics that exerted a force of 200 g. In the second group (13 boys, 12 girls; 8.96 ± 1.82 years old), each subject wore a Petit-type facemask and a lingual arch with hooks fixed to the maxillary arch with a total force of 700 g. Both groups of patients were instructed to wear the appliance approximately 14 hours a day, and 22 linear measurements and 8 angular measurements were evaluated. Changes of measurements from each group were compared by paired t-tests, considering a 5% significance level. RESULTS: Forward growth of the maxilla, improvement of the maxilla-mandible relationship, and upper incisor flaring were achieved in both groups without any statistically significant difference between them. Lateral cephalometric analysis also showed that U1 exposure, IMPA (Angle between mandibular plane and mandibular incisor axis), FMIA (Angle between FH plan and mandibular incisor axis), and L1-APog (Angle formed by the intersection of tooth axis of lower incisor and A-Pog line, Distance from lower incisor edge to A-Pog line) showed statistically significant differences. Lower incisors were inclined lingually in the CHS group. CONCLUSIONS: During treatment of skeletal Class III malocclusion, the CHS with light Class III intermaxillary elastics therapy exhibits similar orthopedic changes to the maxillary complex and more dental changes to the lower anterior teeth compared with facemask therapy.

Automatic Cephalometric Landmark Identification System Based on the Multi-Stage Convolutional Neural Networks with CBCT Combination Images.

This study was designed to develop and verify a fully automated cephalometry landmark identification system, based on multi-stage convolutional neural networks (CNNs) architecture, using a combination dataset. In this research, we trained and tested multi-stage CNNs with 430 lateral and 430 MIP lateral cephalograms synthesized by cone-beam computed tomography (CBCT) to make a combination dataset. Fifteen landmarks were manually and respectively identified by experienced examiner, at the preprocessing phase. The intra-examiner reliability was high (ICC = 0.99) in manual identification. The results of prediction of the system for average mean radial error (MRE) and standard deviation (SD) were 1.03 mm and 1.29 mm, respectively. In conclusion, different types of image data might be the one of factors that affect the prediction accuracy of a fully-automated landmark identification system, based on multi-stage CNNs.

Computerized Assessment of Occlusion and Muscle Activity during Use of a Multilayer Clear Retainer: A Preliminary Study.

The aim of this preliminary study was to evaluate the short-term changes of occlusal contacts and muscle activity after orthodontic treatment during the use of a multi-layer clear retainer. Evaluation was done with the T-scan and BioEMG systems. A total of 18 subjects were included, who were evaluated at three time intervals-T0 at debonding, T1 at one month after retainer delivery, and T2 at four months after retainer delivery. The T-scan and electromyography (EMG) data were recorded simultaneously. The T-scan system recorded the occlusion time, disclusion time and force distribution. The EMG waves were quantified by calculating the asymmetry index and activity index. The time variables changed but not significantly. Occlusal force decreased in the anterior dentition and increased in the posterior dentition during T0-T2. There was no clear evidence of a relationship between unbalanced occlusal forces and muscle activity. In most subjects, the temporalis anterior muscle was more dominant than the masseter muscle. From this preliminary computerized study, there were no significant changes in the state of the occlusion or muscle activity during the short-term retention period.

Miniplate-anchored maxillary protraction in adolescent patients with cleft lip and palate: A literature review of study design, type and protocol, and treatment outcomes.

OBJECTIVE: To review the study design, type, protocol, and treatment outcomes of miniplate-anchored maxillary protraction (MAMP) in adolescent patients with unilateral or bilateral cleft lip and palate. SETTING/SAMPLE POPULATION: Five retrospective and two prospective studies (n = 138 patients) were selected as per the inclusion criteria. MATERIALS AND METHODS: The study design, type, protocol of MAMP and the amount of skeletodental change were investigated. RESULTS: Two studies adopted type 1 (two miniplates at the infrazygomatic crest with a facemask), four studies adopted type 2 (four miniplates at the infrazygomatic crest and mandibular symphysis and use of intermaxillary elastics), and one study compared the two types. The mean start age was older than 10 years except one study. The mean duration was less than 1 year in two studies, between 1 and 2 years in three studies, and more than 2 years in two studies. The type 1 used 500 g/side for 12-14 h/d, and the type 2 used three increase methods (100, 200, 250 g/side; 75, 150, 250 g/side; 150, 200, and 250 g/side) for 24 h/d. The ranges of A point advancement were 0.5°-4.2° in ΔSNA and 1.7-5.6 mm in ΔA-vertical reference plane, respectively. The ranges of rotation of the palatal plane, occlusal plane, and mandibular plane were -1.5° to 2.0°, -2.0° to 2.0°, -1.5° to 3.2°, respectively. The increase of overjet was ranged from 2.3 to 5.8 mm. CONCLUSION: The MAMP therapy is effective for the correction of maxillary hypoplasia in adolescent cleft patients despite different types and protocols.

Palatal temporary skeletal anchorage devices (TSADs): What to know and how to do?

OBJECTIVES: Since palatal temporary skeletal anchorage devices (TSADs) have become important tools for orthodontic treatment, this narrative review was aimed to provide an updated and integrated guidelines for the clinical application of palatal TSADs. SETTING AND SAMPLE POPULATION: A narrative review article including researches on palatal TSADs in orthodontics related to anatomy, success rate and clinical application. MATERIALS AND METHODS: The anatomical characteristics, success rate and its consideration factors and clinical application of palatal TSADs based on the direction of tooth movement were evaluated. RESULTS: To improve the stability of TSADs, hard tissue factors such as bone depth, cortical bone thickness, bone density and soft tissue thickness were evaluated. Anatomically risky structures, including the nasopalatine foramen, canal and the greater palatine foramen, nerve, vessel need to be identified before placement. The success rate of palatal TSADs was greater than that of the buccal inter-radicular space. Palatal TSADs have been used for various purposes because they can control tooth movement in all directions and, three-dimensionally; their applications include the retraction of anterior teeth, protraction of posterior teeth, distalization, intrusion, expansion and constriction. They can be applied directly or indirectly to the lingual arch or transpalatal arch. Design modifications using splinted 2 miniscrews have been suggested. CONCLUSION: Palatal TSADs allow clinicians to perform minimally invasive and easy placement with good stability by understanding the anatomical characteristics of the palatal region, and they show good control over 3-dimensional tooth movements in various clinical cases.