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Objective: To evaluate the function of Piezol, an evolutionarily conserved mechanically activated channel, in periodontal ligament (PDL) tissue homeostasis under compressive loading. Materials and Methods: Primary human PDL cells (hPDLCs) were isolated, cultured, and then subjected to 2.0 g/cm² static compressive loading for 0.5, 3, 6, and 12 hours, respectively. The expressions of Piezol and osteoclastogenesis marker gene were assessed by semiquantitative reverse transcription-polymerase chain reaction. In addition, Piezol inhibitor, GsMTx4, was used to block the function of Piezol, and tumor necrosis factor-a was also used as a positive control. After 12 hours of compressive loading the PDLCs were co-cultured with murine monocytic cell line RAW264.7. Immunofluorescence, western blot, enzyme-linked immunosorbent assay, and tartrate-resistant acid phosphatase staining were also used to test the potency of PDLCs to induce osteoclastogenesis and the activation of nuclear factor (NF)-KB. Results: Piezol, cyclooxygenase-2, receptor activator of NF-κB ligand, and prostaglandin E2 were significantly upregulated under static compressive stimuli. GsMTx4 repressed osteoclastogenesis in the mechanical stress-pretreated PDLCs-RAW264.7 co-culture system. Furthermore, NF-κB signaling pathway was involved in the mechanical stress-induced osteoclastogenesis. Conclusions: Piezol exerts a transduction role in mechanical stress-induced osteoclastogenesis in hPDLCs. [ABSTRACT FROM AUTHOR]

Objective: To investigate the relationship between primary dysmenorrhea (PD) and orthodontic pain in female patients, and to test the hypothesis that the intensity and duration of orthodontic pain could be roughly predicted by severity of PD. Materials and Methods: One hundred twenty college females were enrolled and put into one of three groups--mild (Mi), moderate (Mo), or severe (S)--according to level of menstrual pain. Intensity of the orthodontic pain was measured by visual analog scale (VAS) on days 1, 2, 4, 7, 14, and 28 after archwire placement. Results: As the intensity of orthodontic pain declined with time, the three groups demonstrated different changes during the initial week. Mi had the lowest VAS scores, whereas S possessed the highest scores. In contrast, Mo stayed in between. Significantly positive correlations were found between the severity of PD and the intensity of orthodontic pain at each time point within the first 2 weeks. In addition, though the majority of subjects reported disappearance of pain by the end of the second week in both Mi and Mo, a large proportion of females still perceived pain in S. Conclusion: Females with higher levels of menstrual pain tended to perceive orthodontic pain with higher intensity and more prolonged duration. Thus, PD could potentially serve as a reference to predict orthodontic pain in clinical settings. [ABSTRACT FROM AUTHOR]

Objective: To investigate the occlusal configurations of the hyperdivergent skeletal Class II malocclusion and their alterations during the camouflaging treatment in an attempt to identify occlusal changes that might be related to mandibular counterclockwise rotation. Materials and Methods: Cephalograms of 126 subjects with hyperdivergent skeletal Class II malocclusion and 126 subjects with a clinically normal skeletal pattern were chosen. Several measurements were calculated and compared between the groups. To examine the effects of treatment, two groups were established according to mandibular rotation: counterclockwise rotation (CCR) and the opposite clockwise rotation (CR). After 40 subjects were excluded, the other 86 Class II subjects were assigned to CCR (n = 22) and CR (n = 64). Their pretreatment (T1), posttreatment (T2), and postretention (T3) cephalograms were obtained. Measurement changes (T3-T1) were analyzed in each group and compared between groups. Results: Compared with the normal skeletal pattern, the cant of the occlusal plane (OP) of the study subjects was significantly steeper and the vertical heights of the incisors were significantly larger for the malocclusion. Compared with the changes in CR, there was a prominent reduction of the OP canting with remarkable intrusion of the maxillary incisor in CCR. Conclusion: Increased OP canting with overerupted incisors is evident in the hyperdivergent skeletal Class II malocclusion. During the camouflaging treatment,'reduction of OP canting could occur. It was accompanied by mandibular counterclockwise rotation and intrusion of the maxillary incisor. [ABSTRACT FROM AUTHOR]