[Comparison between MLO-Y4 osteocyte and osteoblast to support osteoclast formation in vitro].

Objective: To compare between MLO-Y4 osteocyte and osteoblast to support osteoclast formation in co-culture system.

Methods: MLO-Y4 cells and murine osteoblast cells were co-cultured with bone marrow cells with or without vitamin D₃ presence.Bone marrow cells were as control group.

Functional analysis of core binding factor a1 and its relationship with related genes expressed by human periodontal ligament cells exposed to mechanical stress.

Mechanical stress induces human periodontal ligament (PDL) cells to express an osteoblastic phenotype in vitro. Core binding factor a1 (CBFA1) is a key regulator of osteoblast differentiation. This study was designed to investigate the role of CBFA1 in alveolar bone remodelling, specifically the expression of CBFA1 messenger RNA (mRNA) in human PDL cells under mechanical stress and its up- and downstream relationships with other bone remodelling markers.

[Evidence-based quality assessment of 10-year orthodontic clinical trials in 4 major dental journals].

Objective: To assess the quality of orthodontic clinical trials published in 4 major dental journals in the past 10 years and establish the reference standard for orthodontic clinical trials and quality control of dental journals.

Methods: All the clinical trials published in Chinese Journal of Stomatology, West China Journal of Stomatology, Journal of Practice Stomatology and Chinese Journal of Orthodontics from 1999 to 2008 were searched. The demographic information of the papers was extracted and the quality of the clinical trials according to the consolidated standards of reporting trials (CONSORT) was assessed.

Root resorption before and after orthodontic treatment: a clinical study of contributory factors.

This clinical study evaluated factors related to root resorption before (T1) and after (T2) orthodontic treatment. Ninety-six subjects between 9 and 34 years (34 males and 62 females) who had been treated using fixed appliances for at least 1 year and who had panoramic radiographs at T1 and T2 were selected. The relationship between root resorption at T1 and T2, with regard to gender, age, extraction versus non-extraction patterns, specific teeth and treatment duration was investigated.

[A retrospective study for vertical control with high-pull headgear in the treatment of high angle cases].

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 degrees) were included in this study and all the patients were treated with extraction. Twenty patients in the study group and control group, respectively.

[Non-extraction treatment with self-ligating and conventional brackets].

Objective: To compare the dental change and the mechanism after non-extraction treatment between passive self-ligating and conventional bracket systems.

Methods: Twenty-six non-extraction crowding cases were selected. Half of them were treated with Damon3 self-ligating brackets and the others were treated with conventional brackets.

[Changes of Streptococcus mutans concentration of plaque during fixed appliance treatment].

Objective: To 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.

Methods: Twenty-eight patients undergoing fixed appliance treatment were observed. Ligature wire and elastomeric rings were applied on one side of arches, stochastically.

[Condylar lateral movements in patients with mandibular deviation].

Objective: To record condylar movements of patients with mandibular deviation and analyze their characteristics.

Methods: Computer 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.

[Stability of upper molars with the application of implant anchorage].

Objective: To investigate the stability of upper molars with the application of micro-screw implant anchorage during orthodontic treatment.

Methods: Fifteen adult patients with severe maxillary protrusion were included. Upper first premolars were extracted and upper posterior anchorage was reinforced with micro-screw implant in all patients.

[Posttreatment stability of four first bicuspid extraction cases treated with the Alexander technique--model analysis].

Objective: To evaluate the posttreatment stability of four first bicuspid extraction cases with the Alexander technique.

Methods: Fifteen patients, 8 males and 7 females in the permanent dentition were selected. The age range of the patients was 10.

[Application of straight wire appliance for pre- and post-surgical orthodontics].

Objective: To analyze the surgical patients treated with straight wire appliance for guidelines of clinical using of the appliance.

Methods: Totally 51 patients from Joint Clinic of Orthodontic Surgery, Peking University School of Stomatology with dentofacial deformities treated with straight wire appliance were analyzed. The patients were aged from 15 years to 34 years 5 months, average 18 years 9 months.

[An adjustable appliance in treatment of obstructive sleep apnea-hypopnea syndrome].

Objective: The research tended to approach applying of adjustable appliance in the treatment of obstructive sleep apnea-hypopnea syndrome (OSAHS).

Methods: 30 OSAHS patients (24 males and 6 females) participated in the adjustable group, with a mean age of (49.9 +/- 9.

[Treatment of OSAS with modified twin-block advancement appliances].

Objective: To introduce a new modified twin-block advancement appliance and investigate the effects on respiratory variables in patients with OSAS.

Methods: 29 patients with OSAS participated in the study and were fitted with modified twin-block appliances to hold the mandible in an anterior and inferior position. Polysomnography was performed with and without appliance insertion.

[Expression of OPG and RANKL at protein level in human periodontal ligament cells and the effect of 1alpha,25(OH)(2) vitamin D(3) on the secretion of OPG protein in vitro].

Objective: To study the expression of osteoprotegerin(OPG) and receptor activator nuclear factor kappa B ligand(RANKL) at protein level in human periodontal ligament cells (HPDLCs), and the effect of 1alpha,25(OH)(2) vitamin D(3) [1,25(OH)(2)vitD(3)] on the secretion of OPG protein in vitro.

Methods: HPDLCs were harvested in vitro by sequential digestion with trypsin and collagenase. The expression of RANKL in HPDLCs at protein level was tested by immunocyto-chemistry.

[Combined orthodontic-periodontal treatment on periodontal patients with anterior displaced incisors].

Objective: Combined orthodontic-periodontal treatment with supracrestal fiberotomy was undergone on the periodontal patients with anterior displacement of incisors. Evaluate of the changes before and after treatment.

Methods: Periodontal indices, periapical x-ray analysis, and model analysis were used for investigating the changes of alveolar bone height and periodontal health by orthodontic treatment following supracrestal fiberotomy of anterior displaced incisors on periodontal patients.

[The three-dimensional nonlinear finite element analysis of force system of the "rocking-chair archwire"].

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

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

Results: The 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.