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.

Effects of low-level laser therapy on orthodontic miniscrew stability: a systematic review.

BACKGROUND: Miniscrews as auxiliary anchorage devices in orthodontic treatment have definite advantages and efficacy. The aim of the present study was to investigate the scientific evidence including randomized controlled trials (RCTs) or controlled clinical trials (CCTs) to support the application of low-level laser therapy to improve miniscrews stability in orthodontic treatment. METHODS: An extensive literature research was conducted with the Cochrane Library, PubMed, EMBASE, Web of Science and ScienceDirect without language limitations. All searches were inclusive until June 2020. The Cochrane Risk of Bias Tool was used to assess the risk of bias (RoB) in the included RCTs. RESULTS: Through the electronic searches, 428 titles and abstracts were identified. From these, 4 articles were retrieved for review, and 3 of these met the inclusion criteria. Two RCTs reported increased miniscrews stability with low-intensity laser therapy, but the other one reported no difference. Except one study assessed as "high risk of bias" the other two were rated as "low risk of bias". CONCLUSION: There is insufficient evidence to support or refute the effectiveness of LLLT for improvement of miniscrew stability. Further studies with a better study design, reliable evaluation method, comprehensive evaluation intervals and appropriate loading protocol are required to provide more reliable evidence for the clinical application of LLLT.

[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.

[Clinical observation of using Er,Cr:YSGG water laser to control endondontic interappointment pain].

PURPOSE: This study was to explore the role of Er, Cr：YSGG water laser in relieving endodontic interappointment pain (EIAP) during root canal therapy. METHODS: A total of 272 cases with chronic pulpitis and chronic periapical periodontitis were selected from the Department of Endodontics of our hospital from June 2015 to June 2017, they were randomly divided into 2 groups, 136 cases in each group. After routine root canal preparation, the teeth in group A were sealed with calcium hydroxide paste after Er, Cr : YSGG water laser treatment, while teeth in group B were sealed with calcium hydroxide paste. Caviton (GC company, Japan) was used for temporary fillings in both groups, occurrence and outcomes of postoperative EIAP were recorded and compared. SPSS 17.0 software package was used for statistical analysis. RESULTS: Among the two groups, there was no significant differences in EIAP (P>0.05) immediately and 1 week after surgery, but there was significant difference in the occurrence of EIAP between the first day, the second day and the third day after surgery (P<0.05). Group A had the lowest incidence of EIAP. CONCLUSIONS: Er, Cr: YSGG water laser can effectively reduce pain after root canal therapy, and can effectively shorten pain duration for patients; therefore, it is worthy of wide clinical application.