Effect of low-level laser therapy on orthodontic dental alignment: a systematic review and meta-analysis.

The aim of this study is to systematically summarize the available evidence regarding low-level laser therapy (LLLT) speed-up effect on dental alignment in comprehensive orthodontic treatment. An extensive electronic search was conducted in PubMed, ScienceDirect, Cochrane, Web of Science, and Scopus up to February 20, 2023. The Cochrane risk of bias tool and the Newcastle-Ottawa Quality Assessment Form were used by two authors independently to assess the risk of bias (RoB). Statistical analysis was performed by Review Manager 5.3. The eight eligible trials were reviewed and included in qualitative synthesis. Four studies reported the overall time of leveling and alignment (OLAT, days), enabling a synthesizing of the data. The meta-analysis results showed that LLLT significantly reduced the overall time of leveling and alignment compared to control group (MD=-30.36, 95% CI range -41.50 to -19.22, P<0.0001), with moderate heterogeneity (χ2=4.10, P=0.25, I2=27%). Based on the data available, statistically significant evidence with moderate risk of bias suggests that LLLT may have a positive effect on accelerating dental alignment. However, due to the differences in intervention strategy and evaluating method, the conclusions should be interpreted with caution.

CHN nanocomposites and nanocoating resist enamel white spot lesions by enhancing remineralization and antibacterial activity.

Enamel white spot lesions (WSLs) are usually caused by the dissolution of minerals (mainly calcium and phosphate) on the tooth surface due to the acidic environment in the oral cavity. Without timely intervention, WSLs may lead to white spots or a sense of transparency on the tooth surface, and even the formation of dental caries (tooth decay) in severe cases. The key to preventing and treating WSLs is inhibiting the activity of acid-producing bacteria and promoting the remineralization of demineralized enamel. In this study, the network structure formed by sodium tripolyphosphate (TPP) cross-linked chitosan was used to stabilize calcium phosphate, and the multifunctional nanocomposite was constructed by integrating antibacterial components of traditional Chinese medicine, honokiol nanoparticles (HK-NPs) and sodium fluoride to achieve the purpose of resisting cariogenic bacteria and remineralizing with sustained release of calcium and phosphate ions. Notably, we enhanced the remineralization effect of nanocomposites with the help of functional nanocoatings inspired by the mussel biomimetic coating. The experimental results show that the synergistic remineralization effect of nanocomposite and nanocoating is better than that of a single strategy. This multi-prong treatment strategy provides the theoretical and experimental basis for the clinical prevention and treatment of WSLs.

[Study on the changes of soft and hard tissue before and after early treatment of Classâ ¡skeletal malocclusion with Twin-block appliance].

PURPOSE: To investigate the effect of early correction with Twin-block appliance on soft and hard tissues of patients with Class Ⅱ skeletal malocclusion. METHODS: Sixty patients with Angle Class Ⅱ skeletal malocclusion were prospectively selected. The patients were divided into 2 groups, 30 cases in each group, by random number table method. Patients in the experimental group were treated with a Twin-block appliance combined with straight wire appliance, while patients in the control group were treated with a straight wire appliance. The soft and hard tissue indexes(SNA, SNB, ANB, U1-NA angle, U1-NA distance, L1-NB distance, L1-NB angle, U1-L1) before, and 12 months after treatment were measured. Soft tissue measurement indicators included UL-U1, LL-L1, over jet, overbite, E-upper-lip from the upper lip to the E-line, and the lower lip to the E-line, changes in the vertical distance (E-lower-lip), the dip angle of the sulcus, and the thickness of the soft tissue. SPSS 25.0 software package was used for statistical analysis of the data. RESULTS: U1-NA, U1-NA, L1-NB, L1-NB, overjet, overbite, E-upper-lip, and E-lower-lip were significantly less than the control group at 12 months and 36 months after treatment in the experimental group(P<0.05). U1-L1, nasolabial angle, sulcus angle, and soft tissue thickness of the experimental group were significantly greater than those of the control group(P<0.05). CONCLUSIONS: Twin-block appliance combined with straight wire appliance can significantly improve the relationship between the jaw and the soft and hard tissues of patients with Class Ⅱ skeletal malocclusion, and the long-term effect is good.