Molecular signaling and mechanisms of low-level laser-induced gene expression in cells involved in orthodontic tooth movement.

BACKGROUND: The study aimed to observe molecular signaling, including reactive oxygen species (ROS) and mitochondrial membrane potential (ΔΨm), to evaluate the alteration of gene expression by low-level laser therapy (LLLT) and the correlation between its mechanisms and the NF-kB pathway in cells involved in orthodontic tooth movement. METHODS: Osteoblast-like cells (MG63), immortalized periodontal ligament cells (iPDL), and M1 macrophage-like cells were irradiated by 980-nm LLLT with energy densities of 1 and 10 J/cm2 ΔΨm and intracellular ROS were monitored using fluorescent probes. The changes of mRNA expression were assessed using reverse transcription polymerase chain reaction (RT-PCR). NF-kB inhibitor, ROS scavenger, and ΔΨm suppressor were used to analyze signals associated with the regulation of gene expression. Finally, Western blot analysis was performed to confirm NF-kB signaling after LLLT. RESULTS: We found the increases of ΔΨm and ROS in all three cell types after LLLT, but no significant difference was observed between 1 and 10 J/cm2 LLLT. Regarding gene expression, some target genes were upregulated in MG63 6 h, 12 h, and 1 day after LLLT and in iPDL cells 12 h and 1 day after LLLT. However, no changes occurred in M1 cells. The inhibitor that significantly reduced most changes in gene expression was NF-kB inhibitor. Western blot analysis showed the increase in p-IkBα level after LLLT in iPDL and MG63, but not in M1. CONCLUSION: The 980-nm LLLT increased ΔΨm and ROS production in all three cell types. However, changes in gene regulation were found only in MG63 and iPDL cells, which related to the NF-kB pathway.

Occlusal function and electromyographic activity of masticatory muscles in skeletal Class III patients with different patterns of mandibular asymmetry.

BACKGROUND: Although jaw asymmetry is commonly seen in skeletal Class III patients, its correlation with occlusal function and masticatory muscle activity has not been fully elucidated. OBJECTIVES: The purpose of this study was to investigate the occlusal function and masticatory muscle activity in skeletal Class III patients with various patterns of mandibular asymmetry. METHODS: Forty-two patients and 10 normal participants were examined. The patients were categorised into three groups. Groups 1 and 2 exhibited menton and ramus deviation to the same side. Menton deviation was larger than ramus deviation in Group 1, whereas Group 2 showed the inverse relation. Group 3 patients showed menton and ramus deviation in opposite directions. Occlusal contact area (OCA), relative bite force (RBF), and temporalis anterior (TA) and masseter muscle (MM) activity at maximum clenching were measured using T-Scan Novus system and Bio-EMG-III. Statistical analysis was performed using the t-test, one-way analysis of variance with Bonferroni correction and Spearman correlation (α = .05). RESULTS: Compared with normal participants, the patients had smaller OCA and greater asymmetry in the distribution of masticatory muscle activity. Greater ramus deviation was associated with smaller OCA in Group 1 but with larger OCA in Group 3. In Group 1, greater menton deviation was related to stronger TA activity on the non-deviation side. In Group 2, greater ramus deviation was related to stronger MM activity on the deviation side. CONCLUSION: Deviation of the menton and ramus was individually related to OCA and masticatory muscle activity, and this relationship varied according to the pattern of mandibular asymmetry.

Digital workflow for mini-implant-assisted rapid palatal expander fabrication-a case report.

BACKGROUND: Non-surgical mini-implant assisted rapid palatal expansion, or midfacial skeletal expansion, is a paradigm-shifting concept that in recent years has expanded the envelope of orthopedic movement in the transverse direction for adult patients. Although adding mini-screws to a rapid palatal expander is not complicated, accurate and successful expansion strongly depends on the device's position and its relation to the resisting structures of the maxillofacial complex. CASE PRESENTATION: This article presents a digital workflow to locate the optimal position of the Midfacial Skeletal Expander (MSE) device in a CBCT-combined intraoral scan file and describes how to transfer the MSE position intra-orally with properly sized bands during the device fabrication. The complete digital workflow of MSE fabrication and its application for a Class III orthognathic surgical case is presented in detail. CONCLUSIONS: This report describes a completely digital process that can accurately position the MSE device according to the orientation and morphology of maxillary basal bone, which is crucial in adult cases demand maxillary expansion.

Biological properties of human periodontal ligament cell spheroids cultivated on chitosan and polyvinyl alcohol membranes.

BACKGROUND/PURPOSE: Multicellular spheroid cultures have attracted increasing attention in the field of periodontal regeneration. However, very few studies have reported the periodontal ligament (PDL) cell spheroid formation via biomaterials-induced processes. This study investigated the biological characteristics of human PDL cell spheroids formed on two hydrophilic polymer-based biomaterials, namely chitosan and polyvinyl alcohol. METHODS: The expressions of periostin, paxillin, hypoxia-inducible factor 1-α (HIF-1α), and vascular endothelial growth factor (VEGF) were analyzed. Cell migration ability was assessed using a scratch assay. Furthermore, PDL cell spheroids were cultured in 3D-printed polylactic acid scaffolds to evaluate mineralizing capability. RESULTS: Western blot analysis revealed increased expressions of periostin, HIF-1α, and VEGF in the 3D spheroids. After the spheroids were reseeded, the cells gradually migrated outward from the spheroids and time-dependent distribution of paxillin was observed. The cells migrating outward from the 3D spheroids demonstrated greater migration ability than that of 2D monolayer cells. Compared to the dissociated cells from a monolayer culture, the cell spheroids formed on the chitosan membrane exhibited elevated alkaline phosphatase activity and an increase in mineralized matrix deposition. CONCLUSION: The biomaterial-induced formation of PDL cell spheroids suggests a novel strategy for cell delivery in research and clinical applications of periodontal regeneration.

Differences of condylar changes after orthognathic surgery among Class II and Class III patients.

BACKGROUND/PURPOSE: The nature of susceptibility to condylar resorption after orthognathic surgery can be different between skeletal Class II and Class III populations, which was addressed by few in the past. The aim of the present study was to use cone-beam computed tomographic (CBCT) images to investigate the displacement and morphological changes of temporomandibular joints (TMJs) in patients received orthodontic treatment combined with orthognathic surgery. METHODS: Both Class III (n = 34) and Class II (n = 17) patients were compared through overall and regional superimpositions of the initial and posttreatment CBCTs. Two-sample t-test was used to identify significance between group differences. Pearson's correlation coefficient was used to address changes of TMJ and the amount of setback or advancement. RESULTS: The axial ramal angle increased significantly in Class III group and decreased in Class II groups after orthognathic surgery (p < FDR_p). For condylar dimensions, significant widths and lengths reductions were noted only in Class II group. However, no significant difference was found after comparing subgroup differences according to one-jaw and two-jaw options, nor any significant correlation found between the condylar changes and the amount of surgical movements. CONCLUSION: The nature of condylar susceptibility could result more from different skeletal patterns than the amount of surgical movements. However, the direction of mandibular surgery may contribute to different changes of condylar angle in axial section.

Airway increase after open bite closure with temporary anchorage devices for intrusion of the upper posteriors: Evidence from 2D cephalometric measurements and 3D magnetic resonance imaging.

OBJECTIVE: The aim of this study was to analyse morphological changes in the upper airways in patients with anterior open bite treated with temporary anchorage devices for intrusion of upper posterior teeth. MATERIALS AND METHODS: Twelve nonobese (body mass index: <25) anterior open bite patients between the ages of 19 and 44 years (mean age: 22.83 ± 8.19 years) were recruited for this study. Cephalometric radiographs and magnetic resonance imaging (MRI) scans before and after anterior bite closure without bracketing on anterior teeth were used to measure the upper airway, which was divided into retropalatal and retroglossal regions. RESULTS: The mandibular plane angle and lower facial height were significantly reduced by intrusion of the upper posteriors and autorotation of the mandible. The retroglossal airway width (AW2) and retroglossal area (RG area) measured on cephalometric radiographs both increased significantly after treatment. Retroglossal volume increased and the retroglossal width/length ratio decreased significantly in MRI analysis. All other measurements were not significantly changed. However, no statistically significant correlations were observed between all measurements in 2D and 3D images, with the exception of the AW2 linear measurement in 2D images correlating with the AP length in MRI axial view images (r = 0.56, P = 0.0430). CONCLUSION: Counterclockwise rotation of the mandible after anterior open bite closed using orthodontic treatment changed the airway morphology. Retroglossal volume significantly increased and the airway shape became less elliptical after bite closure.

Orthodontically induced changes to the genetic profile in periodontal ligament tissue and cytokine release in gingival crevicular fluid - A pilot investigation.

Background/purpose: It has been known that genetic factors influence orthodontic tooth movement, however, scientific research on humans is lacking. Therefore, this study aimed to investigate dynamic changes to the genetic profile in human periodontal ligament (PDL) tissue and cytokine release in gingival crevicular fluid (GCF) during the first 28 days of orthodontic treatment. Materials and methods: Fifteen teeth from three patients were recruited. Full-mouth fixed appliances with extraction of four premolars and one maxillary third molar was planned for orthodontic treatment. GCF collection and tooth extraction were performed following force application for 0, 1, 3, 7, and 28 days. GCF was analyzed using multiplex immunoassay for 27 cytokines. PDL tissue was collected after extraction and submitted for RNA exome-sequencing using Illumina sequencing platform. Further analysis of differentially expressed genes (DEGs), gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and heatmaps were conducted. Results: GCF cytokine levels varied among three patients; some patients exhibited a peak cytokine level on Day 0 whereas others did so on Days 1-3. In RNA exome sequencing data, GO and KEGG analyses showed that genes associated with sensory receptors were upregulated on Day 1, genes involved in bone remodeling were upregulated on Days 3 and 28, and genes related to osteoclast differentiation were upregulated on Day 7. Conclusion: RNA sequencing data demonstrate that the specific types of genes are expressed at different time points, whereas the data on cytokine changes show a large variation in concentration levels and dynamic change patterns among the patients.

Craniofacial and olfactory sensory changes after long-term unilateral nasal obstruction-an animal study using MMP-3-LUC transgenic rats.

Nasal obstruction exerts considerable physiological effects on the respiratory system and craniofacial morphology during the developmental stage. This study used MMP-3-LUC transgenic rats for in vivo tracking of long-term expression in the rat nasal region after unilateral nasal obstruction. Skeletal changes of the craniofacial, nasal, and sinus regions were measured through micro-computed tomography examination and analysis with 3D image processing and calculation. Matrix metalloproteinase-3 and olfactory marker protein expression were also investigated through immunohistochemistry (IHC). Unilateral nasal obstruction significantly reduced the MMP-3 signal in the nasal region of MMP-3-LUC transgenic rats, which was mainly expressed in the respiratory epithelium. Long-term obstruction also caused morphological changes of the craniofacial hard tissue, such as nasal septal deviation, longer inter-jaw distance, and increased maxillary molar dental height. It also caused compensatory growth in olfactory nerve bundles and the olfactory epithelium, as confirmed by IHC. In our study, long-term unilateral nasal obstruction caused nasal septal deviation toward the unobstructed side, hyper divergent facial development including longer molar dental height, and reduced MMP-3 production. However, further investigation is necessary to explore the mechanism in depth.

Psychometric properties and factor structure of the traditional Chinese version of the Community Integration Questionnaire-Revised in traumatic brain injury survivors.

This study aimed to translate and validate the traditional Chinese version of the Community Integration Questionnaire-Revised (TC-CIQ-R) in patients with traumatic brain injury (TBI). We included participants aged ≥20 years and diagnosed as having TBI for ≥6 months from neurosurgical clinics. The 18-item TC-CIQ-R, Participation Measure - 3 Domains, 4 Dimensions (PM-3D4D), Extended Glasgow Outcome Scale (GOSE), and Taiwanese Quality of Life After Brain Injury (TQOLIBRI) were completed. The sample included 180 TBI survivors (54% male, mean age 47 years) of whom 87% sustained a mild TBI. Exploratory factor analysis extracted four factors - home integration, social integration, productivity, and electronic social networking - which explained 63.03% of the variation, after discarding the tenth item with a factor loading of 0.25. For criterion-related validity, the TC-CIQ-R was significantly correlated with the PM-3D4D; convergent validity was exhibited by demonstrating the associations between the TC-CIQ-R and TQOLIBRI. Known-group validity testing revealed significant differences in the subdomain and total scores of the TC-CIQ-R between participants with a mean GOSE score of ≤6 and >7 (all P  < 0.001). The TC-CIQ-R exhibited acceptable Cronbach's α values (0.68-0.88). We suggest the 17-item TC-CIQ-R as a valid tool for rehabilitation professionals, useful for both clinical practice and research in assessing community integration levels following TBI.

Orthodontic force regulates metalloproteinase-3 promoter in osteoblasts and transgenic mouse models.

BACKGROUND/PURPOSE: Previously we demonstrated up-regulation of matrix metalloproteinase-3 (MMP-3) in human osteoblasts under compression and in bony specimens of experimental orthodontic tooth movement (OTM). Here, we studied the temporal characteristics of compression stimulation in human and mouse osteoblast cell lines, and generated a transgenic mouse model for assessing the MMP-3 expression during OTM. MATERIALS AND METHODS: We investigated MMP-3 expressions in human and murine osteoblasts through RT-PCR and luciferase assay, after compressive force loading. Inhibitors were added to identify the possible mechanisms for signal transduction. A human MMP-3 promoter was isolated, cloned and transfected to generate a transgenic mouse with a green fluorescent protein reporter. OTM was then initiated to observe the location and time course of transcriptional regulation of MMP-3 signals. RESULTS: We found changes in the transcription of MMP-3 in response to mechanical force applied to both human and mouse osteoblast cell lines, suggesting that the response is positive across species. Cloned human MMP-3 promoter may cause the response of luciferase to 1% compression. Moreover, p38 inhibitor exerted a down-regulatory effect on MMP-3 promoter expression, although the inhibitory effect didn't reach a significant level. In the transgenic mouse OTM model, we again found increased expression of MMP-3 in response to mechanical force loading around the periodontal ligament. CONCLUSION: Mechanical force can stimulate MMP-3 expression, possibly through the p38 MAPK pathway, with its strongest signal occurring at 24 h. The mechanical responsiveness in MMP-3 promoter regions can be observed in both humans and rodents in vitro and in vivo.

Simplified orthognathic surgical treatment using non-surgical asymmetric maxillary expansion: A case report.

BACKGROUND: Transverse problems can be exacerbated by highly compensated occlusion in patients with skeletal asymmetry, which makes pre-surgical decompensation harder to achieve. OBJECTIVE: This case report describes a case of combined orthognathic surgery with facial asymmetry. We used pre-orthodontic surgical simulation to visualize the goal for presurgical orthodontics, planning for a one-jaw surgical treatment option. METHODS: The planned asymmetric expansion was performed using a maxillary skeletal expander (MSE II) with surgical corticopuncture over only the left side before MSE activation. Surgery was performed to achieve mandibular left outward yaw rotation to correct the patient's facial asymmetry after the planned amount of expansion was reached. RESULTS: The results showed substantial improvement of facial aesthetics as well as skeletal symmetry. Cooperation and communication between surgeon and orthodontist ensured that the final results were satisfactory.

Architectural changes in alveolar bone for dental decompensation before surgery in Class III patients with differing facial divergence: a CBCT study.

This study aimed to investigate alveolar bone change around mandibular anterior teeth during orthodontic decompensation in patients with skeletal Class III malocclusion and different vertical facial patterns. The records of 29 consecutive Class III patients selected from those pending two-jaw orthognathic surgery were divided into low (≤ 28°), average (30°-37°), and high (≥ 39°) mandibular plane angle (MPA) groups. The DICOM files of CBCT scans and STL files of digital dental models, taken before (T1) and after (T2) presurgical orthodontic treatment, were imported into Dolphin imaging software to reconstruct dentoskeletal images. T1 and T2 images were superimposed and analyzed for bone thickness and height at the level of root apex on each mid-sagittal slice of six mandibular anterior teeth. Differences between T1 and T2 were analyzed by non-parametric tests and mixed-effect model analysis. The results showed that the measurements of alveolar bone height generally decreased after treatment, regardless of MPA. The facial divergence, incisor irregularity, tooth site, treatment time, and change in proclination were identified as the significant factors affecting alveolar bone thickness and height during treatment. The presurgical orthodontic treatment to decompensate mandibular anterior teeth should be very careful in all MPA groups.

970 nm low-level laser affects bone metabolism in orthodontic tooth movement.

OBJECTIVE: During orthodontic tooth movement (OTM), the speed of movement depends on the rate of bone turnover. In this study, we used a rat model to investigate the effect of 970 nm low-level laser therapy (LLLT) on OTM under different dose and frequency protocols. METHODS: We first compared the OTM rates between the OTM only control and the OTM + LLLT group (1250 J/cm2) in Experiment 1 and showed that LLLT significantly increased OTM. In Experiment 2, we employed 3 different LLLT protocols: the low-dose group and the high-dose group receiving 5 doses of 750 J/cm2 and 15,000 J/cm2 of LLLT every 3 days, respectively, and the early high-dose group which received 5 daily doses at 15,000 J/cm2 at the beginning of the experiments. The OTM-only control group received no LLLT. Tooth movement rate was measured through sequential silicone impressions. MicroCT was also performed to evaluate bone de-mineralization rate. Bone histmorphometry was used to compare the bone turnover rate between LLLT group and control group. Finally, TRAP, Osteocalcin, and VEGF expression is evaluated by immunohistochemistry (IHC) in tissue sections. RESULTS: When LLLT treatment was given every three days, both the 1250 J/cm2 and 15,000 J/cm2 groups showed significantly increased OTM compared to the control group. No significant difference was observed in the 750 J/cm2 group, or in the early irradiation group, when compared with controls, although 750 J/cm2 showed the same trend of accelerating OTM. The MicroCT result of rat maxilla demonstrated that LLLT increased bone remodeling and showed decreased bone mineral density and bone volume/total volume in the furcation areas of the maxillary first molars at the end of experiment. LLLT without OTM increased bone turnover as evidenced by fluorochrome incorporation. Immunohistochemistry analyses revealed high osteocalcin expression at later stages of OTM in the LLLT group, while VEGF expression was highly induced in the LLLT + OTM group at an early stage. CONCLUSION: Our results suggest that the 970 nm LLLT increases the rate of OTM in a dose-sensitive and frequency-dependent manner. Further animal and human studies are needed to determine the optimal timing and dosage of LLLT for OTM acceleration.

Effects of a family involvement program in patients with central-line insertion.

The purpose of this study was to evaluate the effects of family-involved care on caregivers' self-efficacy, the degree of satisfaction with central-line care, and the occurrence of central-line-associated bloodstream infections (CLABSIs). We adopted a pretest-posttest quasi-experimental design, recruiting 62 participants from 2009 to 2010. Family caregivers in the experimental group received instructional guidance before collaboratively participating in patient care, whereas the control group received routine care. Our results indicated that in both groups, the overall posttest scores for self-efficacy were significantly higher than the pretest scores. The score for the question "When the patient moves around, how confident are you with ensuring catheter safety?" was significantly higher in the experimental group than in the control group. Satisfaction with the provision of central-line care was also significantly higher in the experimental group than in the control group. CLABSIs did not occur in either group of patients.

[The effectiveness of an intervention program to promote physical activity among female adolescents in a vocational nursing school].

The purpose of this research was to explore the impact of a physical activity program on exercise knowledge, exercise attitude, exercise self-efficacy, exercise behavior, and cardiorespiratory fitness among female students. A vocational nursing school was selected by purposeful sampling. The experimental group (n=88) and control group (n=89) each contained two classes which were randomly selected from 11th grade classes in the vocational nursing school. All participants completed a structured questionnaire, including an exercise knowledge scale, an exercise attitude scale, an exercise self-efficacy scale, and a cardiorespiratory fitness activities scale at both the pre-test and the post-test stages. An 800-meter running test was used to test the cardiorespiratory fitness of participants. One week after the pre-test, the experimental group received a 12-week physical activity program, while the control group did not receive any intervention. The statistical analysis included percentage, mean, one-way ANOVA, pair-t test and repeated-measures two-way ANOVA. The results showed that improvements in exercise attitude, exercise self-efficacy, exercise knowledge and 800-meter running among the experimental group were significantly higher than among the control group. However, there was no significant effect on the score for cardiorespiratory fitness activities. The results of this research could be used as a reference for school health professionals to promote physical activities for female adolescents.