Curative effect of TOMY self-ligation appliance technique in treatment of anterior crossbite and moderate crowding with non-extraction treatment:A case report and literature review / 吉林大学学报(医学版)

Objective:To observe the clinical effect of TOMY self-ligation appliance technique in the treatment of anterior crossbite and moderate crowding, and to explore its clinical application.Methods:A patient, manifested as anterior crossbite and moderate dentition crowing, diagnosed as Angle class Ⅲ subclass malocclusion, MaoⅡ1+Ⅰ1 malocclusion, high angle,and facial asymmetry, was selected.This patient was treated with TOMY self-ligation appliance technique without tooth extraction.The length and width of the dental arch, the width of the alveolar bone and the width of the basal arch were measured before and after treatment;the lateral radiographs of the patient were taken too.Results:After treatment,the upper and lower dentition arranged in neat rows, reached a neutral occlusal relationship;SNA, SNB and ANB had no obvious changes;the lip inclination of anterior teeth was increased by 10 degrees, and reached the normal value;the upper and lower dental arch width, alveolar bone width, basal bone arch width and dental arch length were lower than before treatment.Conclusion:For the patient with anterior crossbite and moderate dental crowding treated with non-extraction, the TOMY self-ligation technique can be considered to use, by increasing the arch width and length to improve the anterior crossbite and moderate crowding, in order to achieve the effective treatment.

Using Coben analysis to evaluate the therapeutic effect of maxillary protraction on maxillary maldevelopment / 华西口腔医学杂志

<p><b>OBJECTIVE</b>We aims to evaluate the therapeutic effect of maxillary protraction on maxillary maldevelopment using Coben analysis to illustrate the advantages of Coben analysis in identifying pathogenic mechanisms and in designing treatment plans for Class III malocclusions.</p><p><b>METHODS</b>A total of 120 patients were diagnosed to have skeletal Class I maloc- clusions with maxillary maldevelopment. These patients were selected as the subjects of the present research. Maxillary protraction was exerted to promote maxilla growth. Cephalometric analysis was conducted by using Coben analysis and angle analyses of Beijing Medical University to collect data before and after maxillary protraction.</p><p><b>RESULTS</b>According to Coben analysis measurements, the height of facies cranii increased after maxillary protraction. The depth of lower face decreased, whereas that of mid-face increased and the Ptm-A value increased significantly in the mid-face (P < 0.001). In the angle ana- lysis of Beijing Medical University, SNA, ANB, U1/NA, U1/SN, MP/SN, and Y-axis angles increased significantly (P < 0.001), whereas SNB, U1/L1 (P < 0.001), and L1/MP (P < 0.05) decreased.</p><p><b>CONCLUSION</b>Maxillary protraction has a significant effect on growing skeletal Class III malocclusions withthe chief mechanism of Ptm-A value just diagnosed as minor by Coben analysis. Coben analysis is visual and clear in identifying pathogenic mechanisms of Class III malocclusions.</p>

Compressive force regulates ephrinB2 and EphB4 in osteoblasts and osteoclasts contributing to alveolar bone resorption during experimental tooth movement / 대한치과교정학회지

OBJECTIVE: To investigate the involvement of ephrinB2 in periodontal tissue remodeling in compression areas during orthodontic tooth movement and the effects of compressive force on EphB4 and ephrinB2 expression in osteoblasts and osteoclasts. METHODS: A rat model of experimental tooth movement was established to examine the histological changes and the localization of ephrinB2 in compressed periodontal tissues during experimental tooth movement. RAW264.7 cells and ST2 cells, used as precursor cells of osteoclasts and osteoblasts, respectively, were subjected to compressive force in vitro. The gene expression of EphB4 and ephrinB2, as well as bone-associated factors including Runx2, Sp7, NFATc1, and calcitonin receptor, were examined by quantitative real-time polymerase chain reaction (PCR). RESULTS: Histological examination of the compression areas of alveolar bone from experimental rats showed that osteoclastogenic activities were promoted while osteogenic activities were inhibited. Immunohistochemistry revealed that ephrinB2 was strongly expressed in osteoclasts in these areas. Quantitative real-time PCR showed that mRNA levels of NFATc1, calcitonin receptor, and ephrinB2 were increased significantly in compressed RAW264.7 cells, and the expression of ephrinB2, EphB4, Sp7, and Runx2 was decreased significantly in compressed ST2 cells. CONCLUSIONS: Our results indicate that compressive force can regulate EphB4 and ephrinB2 expression in osteoblasts and osteoclasts, which might contribute to alveolar bone resorption in compression areas during orthodontic tooth movement.

A study on expression of basic fibroblast growth factors in periodontal tissue following orthodontic tooth movement associated with low power laser irradiation / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this study was to investigate the effects of low power laser on basic fibroblast growth factors (bFGF) expression in periodontal tissue during tooth movement.</p><p><b>METHODS</b>18 white rabbits were randomly divided into 6 groups with 3 rabbits in each group, including groups of 1, 3, 5, 7, 14 and 21 days. Under an anesthesia condition by 2% pentobarbital sodium, the stainless coil springs were fixed between the first maxillary molar and the incisor producing the force of 80 g. The right side of maxilla was considered as the experimental group under the irradiation of low power laser with the left side as the control groups. The expression of bFGF was investigated half-quantitatively through immunohistochemical analysis.</p><p><b>RESULTS</b>The expression of bFGF in periodontal tissue with irradiation of low power laser was higher than the control side. There were significant differences among the 5, 7, and 14 day groups. In the tension area of the experimental side, the expression of bFGF in the osteoblastic surface of alveolar bone was characteristically greater than that of the control side.</p><p><b>CONCLUSION</b>The laser of low power promotes the expression of bFGF in the periodontal tissue and alveolar bone remodeling.</p>

The effects of local administration of Zoledronate solution on the tooth movement and periodontal ligament / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of local administration of Zoledronate solution on the tooth movement and periodontal ligament.</p><p><b>METHODS</b>Orthodontic tooth movement of upper first molar was performed in 42 rats with coil spring. Zoledronate solution was injected into the palatal submucosal area adjacent to the left upper first molar in experimental group 3 days prior to the use of the appliance. In control group, same amount of 0.9% NaCl solution was injected into the palatal submucosal area adjacent to the left and right upper first molar. The injection was applied every third day. The application of mesial force lasted 0.3, 7, 14, 21 days respectively. After the rats were sacrificed, the distance of tooth movement was measured. Sections were stained and then observed with microscope.</p><p><b>RESULTS</b>1. The distance of tooth movement in the experimental group was significantly smaller than that in the control group. 2. The number of osteoclast on the pressure side in the experiment group was significantly smaller than that in the control group through the experimental period, but there was no distinct difference between experimental group and control group (except for 14 days) for the number of odontoclast in interradicular area. 3. The osteoclasts and odontoclasts were the main target cell of Zoledronate in periodontal tissue.</p><p><b>CONCLUSIONS</b>Zoledronate may be a useful agent for anchorage control and reducing the number of osteoclast on pressure side of alveolar bone.</p>

The effect of simvastatin on bone formation during the retention after orthodontic tooth movement / 实用口腔医学杂志

Objective:To investigate the effect of of simvastatin on bone formation and bone mineral density(BMD) during the retention after orthodontic tooth movement. Methods:Orthodontic tooth movement of upper first molar was performed in 40 rats with coil spring for 21 days. 40 rats were randomly allocated into 5 groups: basic control group,negative control group and 3 simvastatin groups(2.5 mg?kg-1, 5.0 mg?kg-1 and 10.0 mg?kg-1respectively).Rats in basic control group were killed when appliances were removed after 21 days.The experimental groups were administered simvastatin daily from 1 day before appliances removed for 4 weeks.The negative control group received the isotonic saline as control.4 weeks later all animals were anesthetized and killed. Level of serum Ca and P in blood, ALP, BGP and BMD were monitored.Results:①Between experimental groups and the negative control group, in amounts of ALP and BGP,the anterior were higher than the posterior (P0.05). ②The alveolar near the maxillary first molar,BMD of the basic control group was the highest(P