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Hybrid ionomer cements (HICs) are aesthetic polyelectrolyte cements that have been modified with a resin. The setting of HICs occurs by both monomer polymerization and an acid-base reaction. In addition, HICs contain a resin, which is substituted for water. Thus, the competition between the setting reactions and reduced water content inherently limits polysalt formation and, consequently the bioactive interactions. In this study, we explored the effects of polybetaine zwitterionic derivatives (

ObjectivesTo investigate the relationship between circummaxillary sutures and miniscrew-assisted rapid palatal expansion (MARPE) success in adult male patients and to evaluate the correlation between the width of the sutures and the maxilla expansion ratio.Materials and MethodsThis retrospective study comprised 40 adult male patients treated with MARPE divided into a separation group (N = 20, mean age, 21.9 years) consisting of subjects with midpalatal suture opening and a nonseparation group (N = 20, mean age, 21.7 years) consisting of subjects with no midpalatal suture opening. Cone-beam computed tomography images were obtained before MARPE expansion for both groups and after expansion for the separation group. Vertical and horizontal skeletal relationships, palate length, and widths of 10 circummaxillary sutures before expansion were compared. The correlation between maxilla expansion ratio (jackscrew expansion to maxillary expansion ratio) and circummaxillary suture widths was also analyzed in the separation group.ResultsThere were no significant differences in age, vertical and horizontal skeletal relationships, and palate length between the two groups. Zygomaticomaxillary, pterygomaxillary, midpalatal, and transverse palatine sutures showed significantly greater width in the separation group (P < .05). The zygomaticomaxillary suture showed the greatest difference (Δ = 0.36 mm) between the groups. The zygomaticomaxillary and pterygomaxillary sutures showed significant positive correlation with the maxilla expansion ratio (P < .01).ConclusionsIn adult male patients, greater circummaxillary suture widths before MARPE expansion, especially zygomaticomaxillary and pterygomaxillary sutures, resulted in a better chance of successful suture separation and more maxillary expansion.

Polyalkenoate cement (PAC) is a promising material for regenerative hard tissue therapy. The ionically rich glass component of PAC encourages bioactive interaction via. the release of essential ions. However, PAC bioactivity is restricted owing to (i) structurally inherent cationic network formers and (ii) surface bacterial biofilm formation. These two factors cause a deficiency in ion release, further complicated by secondary infections and premature therapeutic failure. Here, a multivalent zwitterionic network modifier (mZM) is presented for upregulation of ionic exchange and bioactivity enhancement. By introducing a non-zero charged mZM into PACs, an increase in the proportion of non-bridging oxygen occurs. The network modification promotes ion channel formation, causing a multiple-fold increase in ion release and surface deposition of hydroxy-carbonate apatite (ca. 74%). Experiments ex vivo and animal models also demonstrate the efficient remineralization ability of the mZM. Furthermore, divalent cationic interaction results in bacterial biofilm reduction (ca. 68%) while also influencing a shift in the biofilm species composition, which favors commensal growth. Therefore, PAC modification with mZM offers a promising solution for upregulation of bioactivity, even aiding in customization by targeting site-specific regenerative therapy in future applications.

Objectives To compare skeletal and dentoalveolar changes of miniscrew-assisted rapid palatal expansion (MARPE) according to the length of the miniscrews. Materials and Methods This two-arm parallel-randomized controlled trial included 32 adult patients aged 19–35 years who received orthodontic treatment with MARPE. Patients were allocated to two groups, group long (L) and short (S), through block randomization according to the length of the miniscrews installed in MARPE. Cone-beam computed tomography was performed before expansion and after removal of the MARPE; superimposition of the images was conducted. The primary outcome included the amount of bone expansion and the change in the inclination of the anchorage teeth. The secondary outcome included the success rate of midpalatal suture opening and stability of the miniscrews. Blinding was performed during outcome assessment. Results The final sample comprised 31 patients. There was no significant difference in patient characteristics between group L (n = 16) and group S (n = 15). The change in the width of the processus zygomaticus (P = .010) and ectocanine (P = .001) was significantly higher in group L. A significantly higher success rate of the posterior miniscrews was seen in group L (P = .024). There was no statistically significant difference in the success rate of suture separation or change in tooth inclination. Notable complications were not reported. Conclusions MARPE with longer miniscrews can increase the amount of expansion of the maxillary basal bone and canine alveolar bone. Although it also aided in miniscrew stability, it did not guarantee successful midpalatal suture separation.

Background Phosphate-based glass (PBG) is an attractive bioactive material for promoting the cellular regenerative response. PBG consists of glass network which contains phosphate as the main component and can be substituted into various therapeutic ions. Strontium (Sr) can stimulate osteogenic activity and inhibit the pro-inflammatory response. However, there are limited studies on the characterization and biological performance Sr-substituted PBG (PSr). In this study, PSr was characterized and its of immuno-osteogenic response potential was investigated for substituting Ca with Sr. Considering a priority for cellular activity, we compared the optimized PSr against the benchmark 45S5 bioactive glass (BG) for its effect on cellular bioactive response and regenerative hard tissue. Methods PSr groups were fabricated by a melt-quenching method; subsequently, they were characterized and their biological performance was investigated for the preference of PSr. Considering the clinically used BG as the benchmark, PSr was evaluated based on the cytotoxicity assay, osteogenic activity, pro-inflammatory response, and implantation of calvaria bone defect. Results PSr groups exhibited a glass structure and phosphate network similar to that of PBG. However, the results of ion release analysis showed that PSr6 was stable in accordance with Ca/P, Ca/Sr, and P/Sr ratios. Based on these results, the cellular response of PSr6 was the highest, which increased for the early osteogenic marker and inhibited the inflammatory response. Compared to the clinically used BG as the benchmark, PSr6 promoted osteogenic activity and suppressed inflammatory response. The results of in vivo study indicated that the new bone formation in the PSr6 was similar to that in benchmark BG. However, the limitation of this study was the four weeks of implantation. However, the results of our study suggest that PSr6 is promising for enhancing the immuno-osteogenic response and regenerating hard tissue with the optimized glass structure having Ca/Sr ratio of 2:1. Conclusions The developed PSr6 demonstrated stable physical properties, favorable cytocompatibility, and immune-osteogenic response. Compared with benchmark BG, PSr6 exhibited enhanced immuno-osteogenic response and regeneration of new bone and connective tissues. Therefore, PSr6 is a potential bone grafting material for regenerative hard tissue.

Objectives: This study was aimed to compare the histological pattern of bone modeling on either periodontal or periosteal side induced by lateral orthodontic tooth movement in different age groups. Material and Methods: A total of 50 male Sprague-Dawley rats (25 rats in the adult group – 52 weeks and 25 rats in the young group – 10 weeks) were utilized in this study. Each age group was classified into the control, 3 days, 7 days, 14 days, and 21 days groups (five rats in each) by the duration of experimental device application. A double-helical spring was produced using 0.014” stainless steel wire to provide 40 g lateral force to the left and right incisors. Hematoxylin-eosin staining, proliferating cell nuclear antigen (PCNA) immunohistochemical staining, fibroblast growth factor receptor 2 (FGFR2) immunohistochemical staining, and Masson trichrome staining were performed; and the slides were subject to histological examination. Results: In 7 days, active bone modeling represented by the scalloped surface was observed on the periosteal side of the crestal and middle alveolus at the pressure side in the young group, while similar changes were observed only on the crestal area in the adult group. In the young group, the number of PCNA-positive cells increased significantly on the crestal area and middle alveolus on the 3, 7, and 14 day groups, with subsequent decrease at 21 days. In the adult group, PCNA-positive cells were localized on the crestal area throughout the period. In the young group, FGFR2-positive cells were observed mainly on the crestal and middle alveolus at 3, 7, and 14 days than the control group. In the adult group, these cells appeared on the crestal and middle alveolus in the 3 days group, but mainly on the crestal area at 14 days. In the young group, FGFR2-positive cells were observed on the crestal and middle alveolus on the 3, 7, and 14 days groups more than on the control group. In the adult group, these cells appeared on the crestal and middle alveolus in the 3 days group, but mainly on the crestal area in the 14 days group. In Masson trichrome stain, an increased number of type I collagen fibers were observed after helical spring activation in both age groups. Large resorption lacunae indicating undermining bone resorption were progressively present in both young and adult groups. Conclusion: According to these results, orthodontic tooth movement may stimulate cell proliferation and differentiation primarily on the periosteal side according to progressive undermining bone resorption on the periodontal side. This response may lead to prominent bone modeling during tooth movement in the young group, compared to the relatively delayed response in the adult group.

Objectives This study aimed to assess the success rate and the amount of suture separation after the miniscrew-assisted rapid palatal expansion (MARPE) procedure in relation to the chronological age and sex of the patients. Materials and methods The periapical radiographs of 215 subjects (95 male; 120 female; range, 6–60 years) who had undergone MARPE treatment were retrospectively analyzed. The success of suture separation was determined and, in suture-separated subjects, the amount of suture separation was evaluated by suture separation ratio calculated from the periapical radiograph obtained after active expansion. Association tests were performed using linear-by-linear association, the Jonckheere-Terpstra test, Fisher’s exact test, and the Mann–Whitney U test, and linear regression models were also developed. Results The success rate of suture separation was 61.05% in male, 94.17% in female, and 79.53% in both sexes. There was a statistically significant association between older age and suture nonseparation in male (p p = 0.221). In suture-separated subjects, there was a statistically significant trend toward a low amount of suture separation with older age subgroups in both sexes (p Conclusions Older patients treated with MARPE, particularly in male, may have a reduced likelihood of both success in suture separation and sufficient basal bone expansion. Clinical relevance This study demonstrates that clinicians should consider that the success rate of MARPE and the amount of suture separation may depend on chronological age and sex.

To evaluate changes in masticatory performance (MP) during the retention period after extraction and non-extraction treatment and compare it with MP in individuals with normal occlusion.Adult patients who had completed orthodontic fixed appliance treatment comprised the extraction and non-extraction treatment groups, and those with normal occlusion comprised the control group. Their mixing ability (MA), maximum bite force (MBF), and occlusal contact area (OCA) were recorded immediately after the fixed appliance was removed and at 1 month, 6 months, and 1 year post-treatment. The MA was measured via the two-color chewing gum MA test using ViewGum software, and the MBF and OCA were measured using Dental Prescale II system.MA immediately after orthodontic treatment was lower than that in the normal group but showed a time-dependent gradual increase during a 1-year retention period (P 0.01). The MA at 1 month post-treatment was not significantly different between the three groups (P 0.05). The MA revealed a significant correlation with the MBF and OCA (P 0.01).The MP immediately after orthodontic treatment was lower than that in the normal group but increased gradually, with levels comparable to those of the normal occlusion group at 1 month post-treatment. Further, extraction did not affect the recovery of the MP after orthodontic treatment.No other study has evaluated the changes in MP during the retention period after orthodontic treatment. The findings show that compared with MBF and OCA, the patients' MP improved faster to levels found in normal occlusion.

Low dose and accessibility have increased the application of cone beam computed tomography (CBCT). Often serial images are captured for patients to diagnose and plan treatment in the craniofacial region. However, CBCT images are highly variable and lack harmonious reproduction, especially in the head's orientation. Though user-defined orientation methods have been suggested, the reproducibility remains controversial. Here, we propose a landmark-free reorientation methodology based on principal component analysis (PCA) for harmonious orientation of serially captured CBCTs. We analyzed three serial CBCT scans collected for 29 individuals who underwent orthognathic surgery. We first defined a region of interest with the proposed protocol by combining 2D rendering and 3D convex hull method, and identified an intermediary arrangement point. PCA identified the y-axis (anterioposterior) followed by the secondary x-axis (transverse). Finally, by defining the perpendicular z-axis, a new global orientation was assigned. The goodness of alignment (Hausdorff distance) showed a marked improvement (> 50%). Furthermore, we clustered cases based on clinical asymmetry and validated that the protocol was unaffected by the severity of the skeletal deformity. Therefore, it could be suggested that integrating the proposed algorithm as the preliminary step in CBCT evaluation will address a fundamental step towards harmonizing the craniofacial imaging records.

Objective: The aim of this study is to analyze the age-related changes in the bony recession and cortical bone remodeling induced by lateral orthodontic tooth movement, using a three-dimensional micro-computed tomography (CT) analysis. Material and Methods: A total of 40 male Sprague-Dawley rats were divided into two distinct age groups (young, 10 weeks and adult, 52 weeks). Double-helical springs exerting 40 g of force were applied to central incisors to analysis of changes in lateral cortical bone and tooth movement with age and time. The young and adult rats were divided into four subgroups, T0 (0 week), T1 (1 week), T2 (2 weeks), and T3 (3 weeks), depending on the period of wearing the appliance. Micro-CT image was taken on each dissected pre-maxilla specimen. In each subgroup, distance between the center of teeth, suture width, tooth displacement, bony recession, and bone volume was evaluated. Results: The changes in the distance between the center of teeth and the suture width were significantly greater in the young group. However, the change in the tooth displacement showed no significant difference between groups. In the young group, bony recession of outer cortical layer was observed at T1 (P < 0.05), but the amount of recession gradually decreased at T2 and T3. In contrast, in the adult group, bony recession increased gradually over observation period (P < 0.05). The bone volume decreased at T1 (P < 0.05), but recovered at T2 and T3 in both groups. Conclusion: The compensatory bone formation occurs in the pressure side of cortical bone more significantly in the young group than in the adult according to the lateral displacement of incisor in rats. The reduced bone reaction in the adult is considered a limiting factor of the excessive tooth movement in the compromised treatment of skeletal malocclusion.

ObjectivesThe use of 16S ribosomal RNA gene sequencing analyses has rapidly increased in clinical oral studies. However, cohort-based clinical research has not sufficiently accounted for the periodic stability in oral microbiota. Herein, we aimed to assess the stability of the oral microbiome across time from an intervention-free “healthy” cohort. Materials and MethodsWe obtained 33 supragingival samples of 11 healthy participants from the biobank. For each participant, we processed one sample as baseline (T0) and two samples spaced at monthly (T1) and quarterly (T2) intervals for 16S ribosomal RNA gene sequencing analysis. ResultsWe observed that taxonomic profiling had a similar pattern of dominant genera, namely Rothia, Prevotella, and Hemophilus, at all-time points. Shannon diversity revealed a significant increase from T0 (pp

Objectives To evaluate changes in masticatory performance (MP) during the retention period after extraction and non-extraction treatment and compare it with MP in the subjects with normal occlusion. Materials and Methods Adult patients who had completed orthodontic fixed appliance treatment comprised the extraction and non-extraction treatment groups, and those with normal occlusion comprised the control group. Their mixing ability (MA), maximum bite force (MBF), and occlusal contact area (OCA) were recorded immediately after the fixed appliance was removed and at 1 month, 6 months, and 1 year post-treatment. The MA was measured by the two-color chewing gum MA test using ViewGum software, and the MBF and OCA were measured using Dental Prescale II system. Results MA immediately after orthodontic treatment was lower than that in the normal occlusion group but showed a time-dependent gradual increase during a 1-year retention period (P 0.05). The MA showed a significant correlation with the MBF and OCA (P

Orthodontic diagnosis is a comprehensive procedure that integrates various information obtained from the facial and occlusal structure as well as patient's individual needs. Hence it is not easy to imagine if the artificial intelligence(AI) would eventually replace the conventional diagnostic process. Nonetheless, recent advances in the machine learning and artificial intelligence have been applied to the cephalometric tracing and model analysis via automated image recognition, exhibiting relatively high reliability. Based on the cumulated experiences and research outcomes, orthodontic diagnostics have taken a small step towards an automated process. Considering that the orthodontic diagnosis starts from the recognition of the space discrepancy between the initial status and idealized occlusion, semi-automated three-dimensional visualized treatment objectives (VTO) may be established. This article covers the brief overview of the current status in machine learning especially focusing on the image recognition. Recent advances in the fabrication of three-dimensional VTO using surface landmarks and automated setup process is demonstrated. In the near future, a more clinically relevant VTO can be utilized using the imaginary center of resistance, to provide useful clues to the orthodontists in many of the borderline cases between extraction and non-extraction, and between surgery and non-surgery.

Maxillary transverse deficiency often manifests as a posterior crossbite or edge-to-edge bite and anterior crowding. However, arbitrary arch expansion in mature patients has been considered to be challenging due to the possible periodontal adverse effects such as alveolar bone dehiscence and gingival recession. To overcome these limitations, nonsurgical maxillary expansion of the basal bone has been demonstrated in young adults. However, the age range for successful orthopedic expansion has remained a topic of debate, possibly due to the underlying individual variations in suture maturity. This case report illustrates nonsurgical, miniscrew-assisted rapid palatal expansion (MARPE) in a 60-year-old patient with maxillary transverse deficiency accompanied by anterior and posterior crossbites, crowding, and gingival recession. The use of MARPE allowed relief of crowding and correction of the crossbite without causing significant periodontal adverse effects.

Ankylosis of a molar during active growth leads to a significant vertical bone defect, extrusion of the opposing molar, and inclination of adjacent teeth. Treatment timing is an essential factor for the patient's quality of life. Early extraction of the ankylosed molar and protraction of the second molar is challenging because of the difficulty of tooth movement and the uncertainty of the normal eruption of the third molar. In view of the uncertainty of eruption of the mandibular third molar, it is essential to assess the potential for eruption according to the developmental stage of the third molar and to secure sufficient space for eruption. In this case report, a girl with an ankylosed right mandibular first molar and an advanced vertical bone defect was treated via early extraction of the ankylosed molar along with the intrusion of the maxillary molar and mesial root movement of the second molar before the initiation of third molar root formation. Restoration of the vertical bone defect was noted at the end of treatment. In addition, spontaneous eruption of the third molar was observed, which was in contrast to the mesioangular impaction of the contralateral third molar. This case emphasizes the importance of treatment timing to increase the chance of utilization of the third molar.

Poly (methyl methacrylate) (PMMA) is a commonly used material for the fabrication of biomedical appliances. Although PMMA has several advantages, it is susceptible to microbial insults with practical use. Therefore, different bioactive nanomaterials, such as nanoceria (CeN), have been proposed to enhance the properties of PMMA. In this study, we investigated the effect of the incorporation of CeN into PMMA with and without the use of mesoporous silica nanoparticle (SBA-15) carriers. The unmodified PMMA specimens (control, CTRL) were compared to groups containing SBA-15, CeN, and the synthesized SBA-15 impregnated with CeN (SBA-15@CeN) at different loading percentages. The mechanical and physical properties of the different SBA-15@CeN groups and their effects on cell viability were investigated, and the optimal CeN concentration was identified accordingly. Our results revealed that flexural strength was significantly (P 0.01) reduced in the SBA-15@CeN

Previously, in the case of malocclusion owing to skeletal discrepancy in adults, the amount of tooth movement was limited since there was no reliable skeletal anchorage device. The only way to treat this case was by repositioning the maxilla and mandible via orthognathic surgery, but most patients are reluctant to undergo surgery owing to the risk and expenses incurred. However, with the current introduction and use of miniscrews as temporary anchorage devices, the entire dental arch can be relocated to a target position without surgery, thus broadening the scope of non-surgical orthodontic treatment compared to the past. For a non-surgical approach to improve skeletal discrepancy, anteroposterior, vertical and transverse displacements of the dental arch are necessary. In this case, the localization of the centre of resistance of the whole arch must precede the appliance design with an appropriate biomechanical design. Especially, in the transverse dimension, the envelope of discrepancy is reportedly narrow, and the tooth movement must accompany the orthopaedic correction involving the midpalatal suture expansion. Recently, in adults with transverse maxillomandibular discrepancy, miniscrew-assisted rapid palatal expansion (MARPE) can be performed. Moreover, compared to surgically assisted rapid palatal expansion, MARPE reduces the cost to the patient and achieves clinically acceptable stable maxillary expansion. In this article, we will discuss the role of total arch movement and MARPE in widening the scope of non-surgical orthodontic treatment, despite the inherent limitations of miniscrews' mechanical aspects.

Objective The aim of this study was to evaluate the stability of bimaxillary surgery involving bilateral intraoral vertical ramus osteotomy performed with or without presurgical miniscrew-assisted rapid palatal expansion (MARPE) in adult patients with skeletal Class III malocclusion. Methods A total of 40 adult patients with skeletal Class III malocclusion were retrospectively divided into two groups (n = 20 each) according to the use of MARPE for the correction of transverse maxillomandibular discrepancy during presurgical orthodontic treatment. Serial lateral cephalograms and dental casts were analyzed until 6 months after surgery. Results Before presurgical orthodontic treatment, there was no significant differences in terms of sex and age between groups. However, the difference of approximately 3.1 mm in the maxillomandibular intermolar width was statistically significant (p < 0.001). Two days after surgery, the mandible had moved backward and upward without any significant intergroup difference. Six months after surgery, the maxillary intercanine (2.7 ± 2.1 mm), interpremolar (3.6 ± 2.4 mm), and intermolar (2.0 ± 1.3 mm) arch widths were significantly increased (p < 0.001) relative to the values before presurgical orthodontic treatment in the MARPE group; these widths were maintained or decreased in the control group. However, there was no significant difference in surgical changes and the postsurgical stability between the two groups. No significant correlations existed between the amount of maxillary expansion and postsurgical mandibular movement. Conclusions MARPE is useful for stable and nonsurgical expansion of the maxilla in adult patients with skeletal Class III malocclusion who are scheduled for bimaxillary surgery.

Background This prospective randomized clinical trial aimed to evaluate the immediate and short-term skeletal, dentoalveolar, and periodontal effects of rapid palatal expansion (RPE) and miniscrew-assisted RPE (MARPE) in adolescent and young adult patients. Methods This study followed a two-arm, parallel, randomized clinical trial design that recruited patients with transverse maxillary deficiency in a 1:1 allocation ratio. Forty patients (14 men and 26 women) requiring maxillary expansion were randomly allocated to the RPE (n = 20, age = 14.0 ± 4.5) or MARPE (n = 20, age = 14.1 ± 4.2) groups. The assignment was performed via computer-generated block randomization, with a block size of four. Upon identical (35 turns) amount of expansion, low-dose cone-beam computed tomography images were taken before treatment (T0), immediately after expansion (T1), and after a 3-month consolidation period (T2). The primary outcome of this study comprised the assessment of midpalatal suture separation. Secondary outcomes included, skeletal, dentoalveolar, and periodontal measurements, which were performed at each time point. Results The frequency of midpalatal suture separation was 90% (18/20) and 95% (19/20) for the RPE and MARPE groups, respectively. A greater increase in nasal width in the molar region (M-NW) and greater palatine foramen (GPF) was observed immediately after the expansion (T1-T0) and consolidation periods (T2-T0) in the MARPE group compared to the RPE group (P P P Conclusions Midpalatal suture separation was observed in 90% and 95% of patients in the RPE and MARPE groups, respectively. Both RPE and MARPE groups exhibited significant triangular basal bone expansion and skeletal relapse during consolidation. Under identical amounts of expansion, the MARPE group showed lower decrease in the skeletal, dentoalveolar and periodontal variables after consolidation. The reinforcement of RPE with miniscrews contributes to the maintenance of the basal bone during consolidation period. Trial registration WHO Institutional Clinical Trials Registry Platform (IRB No. KCT0006871 / Registration date 27/12/2021).

This study evaluates the accuracy and efficiency of automatic tooth segmentation in digital dental models using deep learning. We developed a dynamic graph convolutional neural network (DGCNN)-based algorithm for automatic tooth segmentation and classification using 516 digital dental models. We segmented 30 digital dental models using three methods for comparison: (1) automatic tooth segmentation (AS) using the DGCNN-based algorithm from LaonSetup software, (2) landmark-based tooth segmentation (LS) using OrthoAnalyzer software, and (3) tooth designation and segmentation (DS) using Autolign software. We evaluated the segmentation success rate, mesiodistal (MD) width, clinical crown height (CCH), and segmentation time. For the AS, LS, and DS, the tooth segmentation success rates were 97.26%, 97.14%, and 87.86%, respectively (p DS), the means of MD widths were 8.51, 8.28, and 8.63 mm, respectively (p AS > LS), the means of CCHs were 7.58, 7.65, and 7.52 mm, respectively (p DS, AS), and the means of segmentation times were 57.73, 424.17, and 150.73 s, respectively (p