Objective:To study the expression of osteoprotegerin(OPG)and receptor activator nuclearfactor kappa B ligand(RANKL)at protein level in human periodontal ligament cells(HPDLCs),and theeffect of 1?,25(OH)_2 vitamin D_3[1,25(OH)_2 vitD_3] on the secretion of OPG protein in vitro.Meth-ods:HPDLCs were harvested in vitro by sequential digestion with trypsin and collagenase.The expressionof RANKL in HPDLCs at protein level was tested by immunocyto-chemistry.Enzyme-linked immuno-adsordent assay(ELISA)was used to detect the OPG protein which was secreted into the culture mediumby HPDLCs cultured with and without 10~(-8) mol/L 1?,25(OH)_2 vitD_3 on the 0,2nd,4th,and 6th days,respectively.Results:RANKL protein was detected on the membrane and plasma of HPDLCs,and OPGprotein was secreted in the culture medium.The secretion of OPG protein was down-regulated by 10~(-8)mol/L 1?,25(OH)_2 vitD_3.Conclusion:HPDLCs have the bone metabolism system of OPG/RANKL,which works during the process of 1?,25(OH)_2 vitD_3 inducing HPDLCs.The conclusion has laid thegroundwork for the study on bone remodelling mechanisms of HPDLCs.

OBJECTIVETo evaluate the dynamic changes of Streptococcus mutans concentration of plaque during fixed appliance treatment and the effects of two materials of ligation on Streptococcus mutans concentration.

METHODSTwenty-eight patients undergoing fixed appliance treatment were observed. Ligature wire and elastomeric rings were applied on one side of arches, stochastically. The dynamic changes on the quantity and percentage of Streptococcus mutans were observed before and after fixed appliance bonding.

RESULTSStatistically significant increase of the quantity and percentage of Streptococcus mutans was found after fixed appliance bonding, and the percentage of Streptococcus mutans in the plaque around the brackets ligated with elastomeric rings was more than that of ligature wire at the beginning of fixed appliance bonding, statistically.

CONCLUSIONSThe finding suggested that the caries-associated capability of the plaque increased after bonding and there was greater caries-associated capability of the plague on the teeth when elastomeric rings was used than that of the plague when ligature wire was used at treatment beginning. The ligature wire is recommended in the fixed appliance treatment.

Adolescent ; Bacterial Adhesion ; Child ; Colony Count, Microbial ; Dental Caries ; prevention & control ; Dental Plaque ; microbiology ; Female ; Humans ; Male ; Orthodontic Appliances ; microbiology ; Orthodontic Brackets ; microbiology ; Streptococcus mutans ; physiology

Adult ; Alveolar Process ; abnormalities ; Bone Screws ; Female ; Humans ; Incisor ; abnormalities ; Malocclusion ; therapy ; Tooth Extraction

OBJECTIVETo investigate the factors relating to root resorption after orthodontic treatment.

METHODS96 cases treated with fixed appliances were selected. The panoramic radiographs before and after treatment were examined. The relationship between root resorption after treatment (RRAT) and the variables including sex, age, extraction or nonextraction approach, tooth location, treatment duration and the root resorption before treatment (RRBT) were analyzed by multiple variance analysis and stepwise multivariate linear regression analyses.

RESULTS(1) There were statistically significant differences in root resorption in relation to gender (estimate of RRAT for female: 0.41, that for male: 0.34), extraction (estimate of RRAT for the extraction group: 0.43, that for non-extraction: 0.31), anterior or posterior teeth (estimate of RRAT for the anterior teeth: 0.59, that for the posterior teeth: 0.12). (2) The estimate of RRAT for the upper teeth was 0.40, and that for the lower teeth was 0.37. There were no statistically significant differences. (3) Using multiple regression analysis, age, duration and RRBT were associated with RRAT (R = 0.59, R(2) = 0.35).

CONCLUSIONS(1) Factors including gender, extraction or not and anterior or posterior teeth have influences on the RRAT. More root resorption was found in female or extraction cases. Anterior teeth were more susceptible to root resorption relative to posterior teeth. (2) Age, treatment duration and RRBT can explain approximately 35% of the RRAT. Root resorption aggregated when it was present before treatment. The age and treatment duration were lightly related to the root resorption.

Adolescent ; Adult ; Age Factors ; Child ; Female ; Humans ; Male ; Orthodontics, Corrective ; adverse effects ; Regression Analysis ; Root Resorption ; etiology ; Sex Factors ; Time Factors

OBJECTIVETo record condylar movements of patients with mandibular deviation and analyze their characteristics.

METHODSComputer aided diagnosis axiography (CADIAX III) was used to record and analyze condylar lateral movements in 31 patients (9 males, 22 females and the age range 12 - 26, mean age 18 years old) with mandibular deviation. Paired-t test and rank sum test were used to compare condylar movements. Multinomial logistic analysis was used to clarify the relationship between condylar movement and mandibular deviation.

RESULTSThe condylar lateral movements in patients with mandibular deviation were asymmetric. The tracing of the shifted side was longer than the contralateral side (P < 0.01). The transverse inclination of the shifted side was smaller than the contralateral side (P < 0.01). With the increase of deviation, the movement length difference between the two sides increased and the length of contralateral side decreased (P < 0.01).

CONCLUSIONSThe patients with mandibular deviation not only have morphological asymmetry but asymmetric condylar movement length and inclination in lateral movements. There is specific relationship between condylar movement and mandibular deviation.

Adolescent ; Adult ; Child ; Female ; Humans ; Jaw Abnormalities ; physiopathology ; Male ; Mandibular Condyle ; pathology ; physiopathology ; Movement ; Young Adult

OBJECTIVEThe purpose of this study was to qualitatively and quantitatively analyze the initial force system of "rocking-chair archwire" on every tooth.

METHODSThree-dimensional finite element model of "rocking-chair archwire" was set up, and nonlinear method was used to analyze the force system.

RESULTSThe archwire exerted intruding force, labial force, lingual-root torque and mesial-labial moment on incisors; Extruding force, lingual-root torque and mesial-labial moment were applied on canines and premolars; The archwire also created intruding force, buccal force, buccal-root torque and mesial-labial moment on molars.

CONCLUSIONS"rocking-chair archwire" produced a complicated force system. While intruding incisors, molars and extruding premolars. It has a tendency to induce tooth rotation and tipping.

Dental Stress Analysis ; Finite Element Analysis ; Humans ; Malocclusion ; therapy ; Orthodontic Appliance Design ; Orthodontic Wires ; Orthodontics, Corrective ; methods

BACKGROUNDRecent studies have indicated that chronic stress may give rise to brain damage, which is related to the genesis of depression. The purpose of this study is to investigate the effects of extract of Ginkgo biloba (EGb) and venlafaxine on depression.

METHODSRats were treated with chronic and comprehensive stress to create a depression model. Immunohistochemistry was used to detect the expression of brain-derived neurotrophic factor (BDNF) in the hippocampal CA3 neurons of rats treated with different drugs. Behavioral changes of these rats were also examined.

RESULTSThe expression of BDNF in the hippocampal CA3 neurons of the depression model decreased with a reduction in exploring behavior and a significant increase in fecal production. The expression of neuron nitric-oxide synthase (nNOS) protein also increased in the rats compared to normal controls. The rats treated with EGb and venlafaxine showed an increase in expression of BDNF and exploring behavior compared to untreated rats, but a decrease in nNOS and fecal production.

CONCLUSIONSRats sustain damage to the brain after being subjected to chronic and comprehensive stress. Our research has indicated that combined EGb with venlafaxine enhances the protection of neurons and decreases damage to the brain, while relieving the side effects of synthetic antidepressants.

Animals ; Antidepressive Agents, Second-Generation ; administration & dosage ; Brain Injuries ; complications ; metabolism ; Brain-Derived Neurotrophic Factor ; biosynthesis ; Cyclohexanols ; administration & dosage ; Depression ; drug therapy ; etiology ; Drugs, Chinese Herbal ; administration & dosage ; Ginkgo biloba ; chemistry ; Hippocampus ; metabolism ; Male ; Phytotherapy ; Rats ; Rats, Wistar ; Venlafaxine Hydrochloride

OBJECTIVE: To investigate the relationship among perceived stress,sleep and fatigue status; and to analyze the effect of sleep status in mediating and regulating perceived stress and fatigue status in soldiers that were acutely exposed to high altitude for the first time. METHODS: A total of 700 soldiers that were acutely exposed to high altitude for the first time were investigated with convenient sampling. They were evaluated using Perceived Stress Scale,Sleep Status Self-evaluation Test,and Fatigue Scale-14. The mediating effect was analyzed by structural equation model,and the moderating effect was analyzed by hierarchical regression analysis. RESULTS: The total score of fatigue among soldiers that often took part in recreational activities was significant lower than that who did not( P < 0. 01). The total score of fatigue among soldiers that had training injury was significant higher than that who had not( P < 0. 01). The total score of fatigue among soldiers that had high training expectations was significant higher than that that didn't have high training expectations( P < 0. 01). Sleep status,sense of overload and training expectations had remarkable predicting effect on fatigue status among soldiers that were acutely exposed to high altitude for the first time( P < 0. 01). Sleeping status has a complete mediating effect on the sense of prediction,sense of overload and fatigue status( P < 0. 01),and has a moderating effect on the sense of control,sense of overload and fatigue status( P < 0. 01). CONCLUSION:s Perceived stress and sleeping status had close relationship with fatigue status among soldiers that were acute exposed to high altitude for the first time. Sleeping status has intermediary and regulating effect between senses of overload and fatigue state.

Postnatal mesenchymal stem cells have the capacity to differentiate into multiple cell lineages. This study explored the possibility of dental pulp stem cells (DPSCs) for potential application in tendon tissue engineering. The expression of tendon-related markers such as scleraxis, tenascin-C, tenomodulin, eye absent homologue 2, collagens I and VI was detected in dental pulp tissue. Interestingly, under mechanical stimulation, these tendon-related markers were significantly enhanced when DPSCs were seeded in aligned polyglycolic acid (PGA) fibre scaffolds. Furthermore, mature tendon-like tissue was formed after transplantation of DPSC-PGA constructs under mechanical loading conditions in a mouse model. This study demonstrates that DPSCs could be a potential stem cell source for tissue engineering of tendon-like tissue.

Objective To assess the effectiveness of vertical control with high-pull headgear in the treatment of high angle cases.Methods Forty high angle cases(MP-SN＞40°)were included in this study and all the patients were treated with extraction.Twenty patients in the study group and control group,respectively.Totally 14 cephalometric measurements were selected for the assessment.Paired t-test and indepeodent t-test were used in the analysis.Results No significant differences were found between the two groups(P＞0.05).In the study group,after treatment Y angle,MP-SN angle,MP-FH angle and U6-PP distance increased 1.9°,1.5°,2.3°and 1.1 mm,respectively(P＜0.01).Conclusions High-pull headgear could not provide effective vertical control in high angle cases.