Anxiety and depression mediate the relationship between digestive tract conditions and oral health-related quality of life in orthodontic patients.

Background: Anxiety and depression are common psychological problems in orthodontic patients whose diet habits and oral health status change frequently during treatment. However, relationships between anxiety and depression, digestive tract condition, and impaired oral health-related quality of life remain unknown. Materials and methods: In this study, clinical assessments, including anxiety, depression, digestive tract condition, and oral health-related quality of life, were collected from 769 outpatients in the orthodontic department using three self-reported questionnaires. Correlation analysis was used to investigate the relationships among different clinical assessments. A chained mediation analysis model was further conducted to explore the direct and indirect effects of these various clinical factors. Results: Changes in digestive tract conditions were positively correlated with the psychological status and oral health-related quality of life. Anxiety and depression partially mediated the relationship between them, and the indirect effect was 0.68 (30%), of which the mediation effect of anxiety accounted for 56%. Conclusion: Anxiety and depression mediate the relationship between gastrointestinal conditions and oral health. In particular, anxiety seems to play a significant mediating role. Our findings indicate that psychological status must be paid more attention to in future clinical practices and supervision for digestive tract symptoms of orthodontic patients.

China experts' consensus on preventive and interceptive orthodontic treatments of malocclusions of children.

Malocclusion is one of the three most common oral diseases reported by World Health Organization(WHO). In China, its incidence rate is rising. Malocclusion seriously affects the dental and maxillofacial function, facial appearance and growth development of nearly 260 million children in China, and what is more, it affects their physical and mental health development. Malocclusion occurrence is related to genetic and environmental factors. Early treatment of malocclusion can create a good dental and maxillofacial development environment, correct abnormal growth and control the adverse effects of abnormal genetic factors. It can effectively reduce the prevalence of children's malocclusion and enhance their physical and mental health. This is an urgent need from the economic perspective of our society, so it has great practical and social significance. Experts from the project group "standard diagnose and treatment protocols for early orthodontic intervention of malocclusions of children" which initiated by China National Health Institute of Hospital Administration wrote the "China Experts' Consensus on Preventive and Interceptive Orthodontic Treatments of Malocclusions of Children", which aims to guide and popularize the clinical practice, improve the clinical theory and practice level, and accelerate the disciplinary development of early treatment of children's malocclusion in China. The consensus elaborates the harmfulness of malocclusion and the necessity of early treatment, and brings up the principles and fundamental contents. Based on the law of dental and maxillofacial development, this paper puts forward the guiding suggestions of preventive and interceptive treatments in different stages of dental development ranging from fetus to early permanent dentition. It is a systematic project to promote and standardize the early treatment of malocclusion. Through scientific and comprehensive stratified clinical practice and professional training, the clinical system of early treatment of malocclusion in China will eventually be perfected, so as to comprehensively care for children's dental and maxillofacial health, and improve their oral and physical health in China.

Cloning and Functional Analysis of Phosphoethanolamine Methyltransferase Promoter from Maize (Zea mays L.).

Betaine, a non-toxic osmoprotectant, is believed to accumulate considerably in plants under stress conditions to maintain the osmotic pressure and promote a variety of processes involved in growth and development. Phosphoethanolamine N-methyltransferase (PEAMT), a key enzyme for betaine synthesis, is reported to be regulated by its upstream promoter. In the present investigation, by using the transgenic approach, a 1048 bp long promoter region of ZmPEAMT gene from Zea mays was cloned and functionally characterized in tobacco. Computational analysis affirmed the existence of abiotic stress responsive cis-elements like ABRE, MYC, HST, LST etc., as well as pathogen, wound and phytohormone responsive motifs. For transformation in tobacco, four 5'-deletion constructs of 826 bp (P2), 642 bp (P3), 428 bp (P4) and 245 bp (P5) were constructed from the 1048 bp (P1) promoter fragment. The transgenic plants generated through a single event exhibited a promising expression of GUS reporter protein in the leaf tissues of treated with salt, drought, oxidative and cold stress as well as control plants. The GUS expression level progressively reduced from P1 to P5 in the leaf tissues, whereas a maximal expression was observed with the P3 construct in the leaves of control plants. The expression of GUS was noted to be higher in the leaves of osmotically- or salt-treated transgenic plants than that in the untreated (control) plants. An effective expression of GUS in the transgenic plants manifests that this promoter can be employed for both stress-inducible and constitutive expression of gene(s). Due to this characteristic, this potential promoter can be effectively used for genetic engineering of several crops.

Expression analysis of α-smooth muscle actin and tenascin-C in the periodontal ligament under orthodontic loading or in vitro culture.

α-smooth muscle actin (α-SMA) and tenascin-C are stress-induced phenotypic features of myofibroblasts. The expression levels of these two proteins closely correlate with the extracellular mechanical microenvironment. We investigated how the expression of α-SMA and tenascin-C was altered in the periodontal ligament (PDL) under orthodontic loading to indirectly reveal the intrinsic mechanical microenvironment in the PDL. In this study, we demonstrated the synergistic effects of transforming growth factor-ß1 (TGF-ß1) and mechanical tensile or compressive stress on myofibroblast differentiation from human periodontal ligament cells (hPDLCs). The hPDLCs under higher tensile or compressive stress significantly increased their levels of α-SMA and tenascin-C compared with those under lower tensile or compressive stress. A similar trend was observed in the tension and compression areas of the PDL under continuous light or heavy orthodontic load in rats. During the time-course analysis of expression, we observed that an increase in α-SMA levels was matched by an increase in tenascin-C levels in the PDL under orthodontic load in vivo. The time-dependent variation of α-SMA and tenascin-C expression in the PDL may indicate the time-dependent variation of intrinsic stress under constant extrinsic loading.

Effect of SOST gene deletion on the progression of renal interstitial fibrosis in obstructive kidney injury.

OBJECTIVES: The role of SOST/sclerostin in mediating tissue fibrogenic response to injury/inflammation remains largely unknown. Thus, we conducted this study to determine whether SOST/sclerostin plays a role in renal interstitial fibrosis (RIF) for the first time. METHODS: Unilateral ureteral obstruction (UUO) was performed to create obstructive kidney injury model. Twelvemale SOST knockout (SOST KO) mice and 12 age-matched wild-type (WT) mice were divided into three groups: sham surgery, UUO 3 d and UUO 7 d. The mice were sacrificed at each time point and kidney tissues were collected. Histopathological changes were evaluated by hematoxylin and eosin and Masson staining, while α-smooth muscle actin (α-SMA), type I collagen (Col-I) and fibronectin (FN) expression levels were detected by RT-PCR and western-blot. RESULTS: In sham control group, neither WT nor SOST KO exhibited fibrotic change. On 3 days after UUO, total renal histopathological score and fibrotic area were aggravated and α-SMA, Col-I and FN expressions were upregulated, but no difference was observed between WT and SOST KO. On 7 days after UUO, compared with WT, SOST KO mice showed higher total renal histopathological score and fibrotic area percentage, as well as a higher level of fibrogenic marker mRNA/protein expression (except for α-SMA mRNA and FN mRNA). CONCLUSION: It is supposed that SOST gene is involved in the regulation of RIF progression. In obstructive kidney injury, SOST gene deletion would probably enhance renal fibrogenic response and promote the progression of RIF. But more evidences are needed to further identify the role of SOST/sclerostin in mediating RIF progression.

[Orthodontic treatment of hyperdivergent skeletal Class II malocclusion].

Hyperdivergent skeletal Class II malocclusion has always been a challenge in orthodontics for both sagittal and vertical discrepancies. In recent years, many therapies had been proposed with varied mechanism and results. This article reviewed the clinical manifestation and pathological mechanism of hyperdivergent skeletal Class II malocclusion, as well as the effectiveness and key points of treatment for different therapies.

[The biological function of osteocytes].

Osteocytes are the most abundant and longest-surviving cells in bone tissue. Through cell synapses, osteocytes keep in contact with each other and with other types of cells on bone matrix surface, constituting a dynamic and active cell regulation network in bone homeostasis. Osteocytes can directly sense mechanical stimulus, translate it into biochemical signals and send to other cells. In addition, osteocytes can mediate bone remodeling by secreting a variety of cytokines. In summary, it is indicated that osteocytes play a crucial role in skeletal mechanotransduction, and they also act as the major regulator responsible for skeletal metabolic balance and microenvironment homeostasis. The integrated network of osteocytes is essential to maintain the normal function of bone tissue.

Biofeedback treatment for sleep bruxism: a systematic review.

PURPOSE: The aim of this systematic review was to evaluate the efficacy of any biofeedback treatment on sleep bruxism. METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, ISI Web of Science, System for Information on Grey Literature in Europe, Chinese Biomedical Literature Database, and PsycINFO up to October 2012 for randomized controlled trials and controlled clinical trials involving biofeedback treatment for sleep bruxism. Reference lists of relevant studies were hand searched. Quality assessment and data extraction were performed by two reviewers independently. RESULTS: Seven eligible studies involving 240 participants were finally included. Three of them had moderate risk of bias, and four had high risk of bias. In an electromyographic-measured sleep bruxism episode, meta-analysis showed no significant difference between contingent electrical stimulation and blank control (95% confidence interval = -12.33, 3.38, P = 0.26). Moreover, five studies reported electromyographic activity index. Due to the diversity of biofeedback modalities (auditory, electrical, and visual stimulus) and controls (splint, occlusal adjustment, etc.), these data were unable to be pooled, so only qualitative description was provided. CONCLUSIONS: In the current stage, there is no powerful evidence to support the use of biofeedback technology on sleep bruxism treatment. Contingent electrical stimulation which is defined as a kind of biofeedback modality shows no effect on reducing sleep bruxism episode compared with the no-treatment group. Although many studies support the efficacy of biofeedback treatment, more large sample-sized randomized controlled trials which adopt uniform outcome index are necessitated to verify its application.

Expression of osteocalcin during surgically assisted rapid orthodontic tooth movement in beagle dogs.

PURPOSE: To investigate the expression of osteocalcin during rapid orthodontic tooth movement aided by alveolar surgery in beagle dogs. MATERIALS AND METHODS: Eight male beagles were used, and bilateral mandibular second premolars were extracted for distalization of the first premolars against the third premolars by orthodontic NiTi coil spring with a force of 100 gm. Right and left mandibular sides were randomly assigned to experimental and sham sides, and alveolar surgery was performed only on the experimental side to reduce the osteal resistance on the mesial side of the extraction socket. Distance of tooth movement was measured once a week during the first 4 weeks. Two beagles were sacrificed after 1, 2, 4, and 8 weeks of orthodontic force application, and expression of osteocalcin was demonstrated by immunohistochemistry and quantified with computer-aided image analysis. RESULTS: The average total movement of the first premolars in 4 weeks on the experimental side (1.868 +/- 0.022 mm) was approximately double that on the sham side (1.008 +/- 0.057 mm). As regards the average total anchorage loss, no significant difference (P > .05) was revealed. Dynamic osteocalcin concentrations presented at 4 time periods (P < .05). The staining intensity of osteocalcin on the experimental sides was higher than the corresponding sham sides, and that on the compression sites higher than the corresponding tension sites (P < .05). CONCLUSIONS: The results suggested that alveolar surgery might serve as an effective and safe way to accelerate orthodontic tooth movement, and promote the rate of bone remodeling as revealed by the expression of osteocalcin.

[The properties of different orthodontic rectangular arch wires in torsion].

OBJECTIVE: To study the properties of orthodontic rectangular arch wires in torsion. METHODS: By using the torsion measurement apparatus, torsion moments and angles of four kinds of orthodontic wires (0.46 mm x 0.63 mm and 0.48 mm x 0.63 mm stainless steel wires, and the same size nickel-titanium wires) were tested respectively in a 0.56 mm-slot first maxillary incisor bracket. According to the torsion moments and angles, scatter graphs were drawn to fit the load-deflection curves of four kinds of wires and their linear equations were calculated. According to the equations, the torsion stiffness and the play angles of the wires at 20 N mm correspondingly were calculated. RESULTS: The torsion stiffness of four kinds of wires were 4.909, 6.417, 1.325 and 1.363 N mn/degrees, the torsion angles of different wires were 19.14 degrees, 15.33 degrees, 36.83 degrees and 35.07 degrees at 20 N mm respectively. CONCLUSION: The torsion stiffness of stainless steel wires was bigger than that of the same cross-section dimensional nickel-titanium wires. The difference of torsion stiffness between two dimensional nickel-titanium wires is smaller, while the difference of torsion stiffness between two stainless steel wires is larger.

[Effect of loop configuration on appliance stiffness of stainless steel round wire].

OBJECTIVE: To investigate the effect of loop configuration on appliance stiffness of stainless steel round wire. METHODS: Some stainless steel round wires with various cross-sectional dimension (0.36, 0.41, 0.46 mm) were selected. Box loops, double horizontal loops, and double vertical loops were manufactured according to established parameters, and loading experiments were carried out with a micro-orthodontic archwire testing apparatus. RESULTS: When the cross-sectional dimension and the span were identical, the appliance stiffness of the box loops, double horizontal loops, and double vertical loops increased successively. CONCLUSION: Configuration of loops exert a great influence on appliance stiffness, and the mechanical properties of box loop are optimal. The force generated by box loop was lighter, slowly decreasing, and easier to be controlled. The activation range of box loop (0.41 mm) was appropriate when the produced optimal moment was between 0.01-0.02 N.m. Box loop (0.41 mm) is preferred to rectify the individual tooth with mild or moderate mesiodistal displacement.

[Bending mechanical properties of NiTi round wire].

OBJECTIVE: To investigate the bending mechanical properties and provide reference for orthodontists to select the proper wires during alignment stage. METHODS: In order to analyze the load deflection rate of NiTi round wire quantitatively, some NiTi round wires of different cross-sectional dimension (0.36, 0.41, 0.46 mm) were selected. Then loading-unloading experiments were carried out with the micro-orthodontic archwire testing apparatus and double end bending test could be accomplished with the wire in a 0.56 mm x 0.71 mm standard incisor edgewise bracket slot. RESULTS: Under the load of 0.03 N.m, 0.36 and 0.41 mm NiTi round wire showed excellent super-elasticity, while 0.46 mm NiTi round wire didn't. When the optimal moment produced by the archwire was between 0.01 N.m and 0.02 N.m, the bending range of 0.36, 0.41 and 0.46 mm NiTi round wires was from 21.0 degrees to 49.5 degrees , 7.2 degrees to 23.7 degrees , and 6.5 degrees to 9.5 degrees , respectively after deducting the contact angle. CONCLUSIONS: On the premises of yielding effective orthodontic force, the preferable NiTi round wire for alignment was the one which could produce continuous and slowly declining force.

[Proliferation of myofibroblast in periodental tension side during orthodontic tooth movement of beagle dogs].

OBJECTIVE: To examine the proliferation of myofibroblast in periodental tension side of beagle dog during experimental tooth movement in orthodontics. METHODS: By the fixed orthodontic appliance, the five beagles were treated with 100 g forces that moved medially the maxillary first premolar, and the treatment lasted for four weeks. Using transmission electron microscope and immunohistochemistry, the proliferation of myofibroblast and expression of alpha-smooth muscle actin (alpha-SMA) were evaluated at week 1, 2, 3, 4 or 8 respectively after the orthodontic treatment. RESULTS: During the total of four weeks, the expression of a-SMA increased in week 1 and reached the maximum in week 2; in week 4, the expression of alpha-SMA went back to normal level. Transmission electron microscopy showed that the myofibroblast contained the dense body appearing in cytoplasm. CONCLUSION: The myofibroblast exists in periodontium and is concerned with the orthodontic tooth movement.