Expression of Osterix mRNA and protein levels in cultured human periodontal ligament cells after mechanical stimulation / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To examine the expression of Osterix (Osx) mRNA and protein after application of mechanical force on human periodontal ligament cells (HPDLCs), and to investigate the role of Osx in orthodontic alveolar bone remodeling.</p><p><b>METHODS</b>HPDLCs were isolated and cultured in vitro with explant method. Approximately 2.5 x 10(5) cells were seeded onto six-well cell culture plates and then were exposed to centrifugal force for 1, 2, 4, 6, 8 or 12 h at 631 r x min(-1). The expression of Osx mRNA and protein was measured by reverse transcription-polymerase chain raction (RT-PCR) and Western blot respectively. Immunofluorescence assay was used to detect the expression and subcellular At the initial time point, Osx mRNA had a weak exlocalization of Osx protein by green fluorescence.</p><p><b>RESULTS</b>pression and protein was not detected. Under the mechanical stimulation, both mRNA and protein levels of Osx were upregulated in a time-dependent manner. Furthermore, Osx protein was translocated gradually from the cytosol into the cell nuclei.</p><p><b>CONCLUSION</b>The expression and activation of Osx were enhanced by mechanical stress in HPDLCs, which indicates that Osx may play an important role in HPDLCs osteogenic differentiation and periodontal tissue remodeling induced by mechanical stress.</p>

Effects of non-surgical treatment on temporomandibular joint of adult low-angle subjects with severe skeletal class III deformity / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate effects of non-surgical treatment on temporal mandibular joint(TMJ) of adult low-angle subjects with severe skeletal Class III deformity.</p><p><b>METHODS</b>Thirteen low-angle patients with severe skeletal Class III malocclusion (male 5, female 8) were included in the study. The average age was 21.3 years old. They were treated with OPA-K straight wire technique. Helkimo index evaluation was made before and after treatment. Lateral cephalometric films and corrected TMJ lateral cephalometric radiograghs were taken before and after treatment, and linear and area measurement were observed. All data were analyzed with SPSS 12.0 software.</p><p><b>RESULTS</b>After non-surgical treatment, Helkimo indexes of all patients redistributed. The line distance and area of anterior space in TMJ increased while the posterior space decreased. Linear percent decreased from 20.81% to 8.04%, and area proportion decreased from 1.62 to 1.01. Anterior space was the same as the posterior. Condyles and mandibles were retruded.</p><p><b>CONCLUSION</b>After non-surgical therapy in adult low-angle subjects with severe skeletal Class III malocclusion, condyles remove posteriorly from more anterior position to normal concentric position, and temporo-mandibular disorders symptom is relieved and cured effectively.</p>

Effects of first premolar extractions on third molar angulations / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To compare the inclinations of third molars of patients treated orthodontically with and without premolar extractions.</p><p><b>METHODS</b>Records of 37 first premolar extraction patients and 32 nonextraction patients were examined. The pretreatment and posttreatment panoramic radiographs were analyzed. The angles were measured between the long axis of the third molar and the occlusal plane and between the long axis of the third molar and the long axis of the second molar. Changes in third molar angulations from pretreatment to posttreatment for two groups were compared by Mann-Whitney U-test.</p><p><b>RESULTS</b>There were statistically significant difference between the extraction and nonextraction groups in the median angle formed by the long axis of third molar angulation relative to the occlusal plane (P<0.05) and the second molar (P<0.05) in mandible but not in maxillary. In the extraction group, at the end of the orthodontic treatment, the mandibular third molars showed more uprighting than did the maxillary third molars.</p><p><b>CONCLUSION</b>Orthodontic treatment involving premolar extractions improves mandibular third molar angulations.</p>