ABSTRACT
BACKGROUND:Lingual movable wing is a new type of lingual orthodontic technique and the different stretching lengths of the wring affect the torque control effect of anterior teeth.However,there is yet no related biomechanical research. OBJECTIVE:To investigate the displacement trend of dentition during adduction of mandibular anterior teeth and the effect of different wing stretching lengths on the biomechanical effect of mandibular anterior teeth. METHODS:The data of the mandible and lower dentition were collected by cone-beam CT and reconstructed using Mimics software to establish a three-dimensional finite element model of mandibular anterior teeth adducted by the lingual movable wing.The ANSYS software was used to analyze the initial displacement of the mandibular anterior teeth under the following conditions:A,2 mm stretching length;B,2.5 mm stretching length;C,3 mm stretching length;and D,3.5 mm stretching length. RESULTS AND CONCLUSION:The trend of initial displacement of lower dentition:The central incisors moved lingually with depression,the lateral incisors and canines moved mildly lingually with mesial lingual torsion,the second premolar was tilted distally with a marked lingual inclination and the first molar showed an overall mesial inclination with mesial crown eversion.Therefore,in the adduction cases of mandibular tooth extraction,attention should be paid to the lingual movement of the second premolar,which could be offset by corresponding techniques in clinic.The trend of anterior tooth displacement in all directions:from condition A to condition D,in the sagittal direction,the difference value in crown-root displacement of central incisors changed from-11.891 μm to-5.757 4 μm,indicating that the central incisor changes from oblique movement to overall movement.The difference value in crown-root displacement of lateral incisors changed from-11.828 1 μm to-6.711 45 μm,and that of canines changed from-7.572 3 μm to-4.695 5 μm,indicating that the oblique movement of the lateral incisors and canines is also changing to an overall movement.In the vertical direction,from condition A to condition D,the reduction of incisors was gradually increased,while that of canines was gradually decreased.These findings indicate that the stretching length of the wing can affect the oblique movement trend of the anterior teeth.As the wing continues to stretch,the torque control of the lower anterior teeth will become better.
ABSTRACT
Objective:To investigate the expression of programmed cell death protein 1 (PD-1), programmed cell death ligand 1(PD-L1), and lymphocyte-activation gene 3(LAG-3) in different subsets of lymphocytes and their relationship with the immunologic imbalance in preeclampsia.Methods:We enrolled 25 cases of singleton pregnant women with preeclampsia who were delivered by cesarean section in the Shandong Provincial Hospital Affiliated to Shandong First Medical University from May 2019 to January 2020 as the preeclampsia group. According to the allocation ratio of 1∶1 matched for the date of cesarean section and pregnancy week at delivery, another 25 healthy singleton pregnant women underwent elective cesarean section were selected as the normal group. The decidua tissue was obtained during cesarean section. The expression levels of PD-1, PD-L1, and LAG-3 on decidual T cells, natural killer (NK), and natural killer T (NKT) cells were measured by flow cytometry and compared between the two groups using two independent samples- t test. Results:(1) The expression of PD-1 on decidual T cells and NK cells of the preeclampsia group were lower than those of the normal group (37.84±3.82 vs 57.02±3.89, t=3.529, P<0.001; 3.28±0.48 vs 5.69±0.99, t=2.184, P=0.034), but did not differ significantly in the expression on decidual NKT cells ( P=0.461). PD-L1 expression on decidual NK cells of preeclampsia group was lower than that of the normal group (0.60±0.11 vs 1.32±0.19, t=3.319, P=0.002), but showed no significant difference in the expression level on T cells and NKT cells (both P>0.05). The preeclampsia group was noted for a lower expression of LAG-3 on decidual T cells and NKT cells compared with the normal group (2.32±0.36 vs 4.09±0.67, t=2.335, P=0.024; 35.40±4.97 vs 56.27±4.49, t=3.282, P=0.002), while showed no significant difference in the expression level of NK cells ( P=0.112). Conclusions:The decreased expression of PD-1, PD-L1, and LAG-3 in the decidual lymphocyte subsets may be involved in the immunologic imbalance of preeclampsia through the over-activation of immunocytes at the maternal-fetal interface.
ABSTRACT
This study aimed to evaluate the expressions and clinical significance of bone Gla-protein [BGP], bone alkaline phosphatase [B-ALP] and C-terminal telopeptide of type I collagen [CTX] in patients with osteoporosis [OP], and to provide evidence for developing individualized treatment plans. Seventy-two OP patients in our hospital were selected as an OP group, and another 72 healthy subjects were used as a control group. Their BGP, B-ALP and CTX levels as well as bone mineral density [BMD] values were measured. The correlations between BGP, B-ALP and CTX levels and BMD values were determined. The BGP level of the OP group [[5.61 +/- 5.52] ng/ml] was significantly higher than that of the control group [P<0.05], but the levels of B-ALP and CTX did not differ significantly [P>0.05]. The BMD values of femoral neck and Ward's triangle in the OP group were negatively correlated with the B-ALP levels [P<0.05]. For women OP patients, the BMD values of femoral neck and Ward's triangle were also negatively correlated with the B-ALP levels [P<0.05]. The BMD of femoral neck in the control group was negatively correlated with the CTX level [P<0.05]. Determining BGP, B-ALP and CTX levels can evaluate the bone metabolism degree, which provides evidence for clinical typing of OP and developing treatment strategies