Influence of orthodontic force on osteoprotegerin and osteoprotegerin ligand mRNA expression in the inflammatory periodontal tissues / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore certain principle of how osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) take part in the periodontal tissues remodeling under the combined influence of inflammation and orthodontic force.</p><p><b>METHODS</b>The positive signals of OPG and OPGL mRNA were measured with in situ hybridzation after orthodontic tooth movement in the experimental periodontitis groups and control ones.</p><p><b>RESULTS</b>The OPG and OPGL mRNA expression intensity in the experimental group showed difference from control. All their optical density index reached a peak in day 2, respectively.</p><p><b>CONCLUSION</b>OPG and OPGL play important roles in the periodontal reconstruction induced by inflammation irritation and orthodontic force, and complex interaction could exist between the two factors.</p>

Integrin 3 mRNA changes after orthodontic teeth movement in periodontitis rats / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the integrin beta3 mRNA changes after orthodontic treatment on normal teeth and periodontitis teeth in rats.</p><p><b>METHODS</b>96 adult SD rats of 10 weeks old were randomly divided into normal tooth move-ment group and periodontitis tooth movement group. The rats in the two groups were sacrificed after 0 d, 12 h, 1 d, 3 d, 5 d and 7 d of tooth movement. The alveolar specimens were prepared. The integrin beta3 mRNA were detected using in situ hybridization in the specimens. The OD index of positively stained osteoclasts for integrin beta3 mRNA after orthodontic tooth movement in the two groups were measured and compared.</p><p><b>RESULTS</b>There were weak positive signals on the cytoplasm of osteoclasts in periodontum in both groups after 12 hours and 3 days force activation. No positive signals were detected in the rest samples. There was no difference in the OD of positive stained osteoclasts between normal and periodontitis groups. Strong expressions were present on cells with one or two nuclei in the alveolar marrow.</p><p><b>CONCLUSION</b>It is suggested that integrin beta3 mRNA is related with osteoclasts maturation and migration in orthodontic tooth movement.</p>

The clinic skill in fixed appliance based on characteristics of Chinese normal occlusion / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the bracket placement and arch wire bending based on ethnic differences and individual differences of normal occlusion.</p><p><b>METHODS</b>The prominence, tip, torque, upper first molar offset of crown and arch form between Chinese and Caucasian normal occlusion were compared.</p><p><b>RESULTS</b>The results showed the ethnic differences of prominence, tip, torque, upper first molar offset of crown and arch form between Chinese and Caucasian normal occlusion. The placement of bracket was influenced by the crown morphology.</p><p><b>CONCLUSION</b>The adjustments of the bracket placement and arch wire bending with Edgewise and pre-adjusted appliance are necessary to adapt to ethnic difference and individual difference.</p>

The integrin beta1 mRNA changes after orthodontic movement of teeth in periodontitis rats / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To study the integrin beta1 mRNA changes after orthodontic tooth movement in normal teeth and periodontitis teeth of rats.</p><p><b>METHODS</b>The OD of positively stained osteoclasts for integrin beta1 mRNA using in situ hybridzation was detected after orthodontic tooth movement in normal teeth and periodontitis teeth groups.</p><p><b>RESULTS</b>Integrin beta1 mRNA expression were detected on all osteoclasts in tooth movement samples of normal and periodontitis teeth. There were stronger positive signals after given orthodontic force in both of the two groups. But no differences were found after 0.5, 1, 2, 3, 5, 7, 10 days since orthodontic tooth movement. The integrin beta1 mRNA signals in normal tooth movement group were not different from that in periodontitis group.</p><p><b>CONCLUSION</b>The integrin beta1 of osteoclasts may play a role in the stability and remodeling of periodontal ligament in orthodontic tooth movement. There were no difference in the OD of integrin beta1 mRNA staining in orthodontic tooth movement between normal teeth group and periodontitis teeth group.</p>

A comparative study of the bracket bond failure between adults and adolescents receiving fixed orthodontic therapy / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the bracket bond failure and its causes between adult and adolescent patients during fixed orthodontic therapy.</p><p><b>METHODS</b>Bracket bond failure data of 30 adults and 30 adolescents, receiving fixed orthodontic therapy, have been collected within the first 12 visits, respectively. The compliance has been analyzed with survival analyse between the two groups.</p><p><b>RESULT</b>The general bracket bond failure rate in the adult group is lower than that of the adolescent group and the difference is significant (p < 0.05). In the adolescent group, the failure rate for mandibular anterior teeth is highest and different from that of the adult group (p < 0.05). The failure rate resulted from biting hard food is ranked No. 1.</p><p><b>CONCLUSIONS</b>The compliance of the adults receiving fixed orthodontic therapy is better than that of the adolescents. The investigation of bracket bond failure causes is beneficial in helping orthodontists improve orthodontic practice and raise clinical efficiency. The survival analysis is effective in evaluating the bond failure.</p>