Comparison of fixed braces and clear braces for malocclusion treatment.

BACKGROUND: To study and compare the effects of clear aligners without brackets and traditional fixed aligners in orthodontic treatment. METHODS: The samples were collected from January 2022 to April 2023. The control group (n = 26) received orthodontic treatment using traditional fixed appliances. The research group (n = 20) received orthodontic treatment using the clear aligners without brackets. Compare the therapeutic effects and related evaluation indicators between two groups. RESULTS: The total effective ratio was compared between the 2 groups, and the study group was greater(P < 0.05). After treatment, the detected values of the periodontal condition indicators (plaque index, debris index, and gingival bleeding index), serum inflammatory factors (CRP, IL-6 and TNF-α) of the two groups, were less than before, also were all less than the control group. (P < 0.05). After therapy, in comparison of the control group, the value of mastication efficiency, comfort and psychological evaluation, sleep indicators and the points of the four dimensions of life quality in the study group was greater, and the detection results were obviously greater than before(P < 0.05). CONCLUSION: In the orthodontic therapy of sufferers with malocclusion, compared with the traditional fixed appliance, the clear aligners without brackets can enhance the treatment effects, improve the periodontal condition and masticatory function, and reduce the inflammatory responses, so that patients can feel more comfortable, thereby improving their psychology, sleep and quality of life. In the future, with the continual advancement of technology and people's pursuit of beauty, the application of clear aligners without brackets in orthodontic treatment will become more and more extensive. The continuous introduction of new materials and new technologies will further improve the effects and comfort of the clear aligners without brackets, reduce treatment time and discomfort, and also reduce patients' resistance to aligners, bringing patients a better treatment experience.

The effectiveness of photobiomodulation therapy on inferior alveolar nerve injury: A systematic review and META-analysis.

OBJECTIVE: The aim of this META-analysis was to evaluate the efficacy of photobiomodulation (PBM) therapy in the treatment of inferior alveolar nerve (IAN) injury due to orthognathic surgeries, extraction of impacted third molars and mandibular fractures. METHODS AND MATERIALS: A electric search was conducted by a combination of manual search and four electric databases including Pubmed, Embase, Cochrane library and Web of Science, with no limitation on language and publication date. Gray literature was searched in ClinicalTrials.gov and googlescholar. All retrieved articles were imported into ENDNOTE software (version X9) and screened by two independent reviewers. All analysis was performed using the REVMAN software (version 5.3). RESULTS: Finally, 15 randomized controlled trials met the inclusion criteria for qualitative analysis and 14 for META-analysis from 219 articles. The results showed that PBM therapy had no effect on nerve injury in a short period of time (0-48h, 14 days), but had significant effect over 30 days. However, the effect of photobiomodulation therapy on thermal discrimination was still controversial, most authors supported no significant improvement. By calculating the effective rate of PBM, it was found that there was no significant difference in the onset time of treatment, whether within or over 6 months. CONCLUSIONS: The results of this META-analysis show that PBM therapy is effective in the treatment of IAN injures no matter it begins early or later. However, due to the limited number of well-designed RCTs and small number of patients in each study, it would be necessary to conduct randomized controlled trials with large sample size, long follow-up time and more standardized treatment and evaluation methods in the future to provide more accurate and clinically meaningful results.

Improvement of the detection of human pulpal blood flow using a laser Doppler flowmeter modified for low flow velocity.

OBJECTIVE: Human pulpal blood flow (PBF) signals as measured by laser Doppler flowmeter (LDF) decrease with age. Although this decrease is considered to be due in part to slow blood flow, information regarding this velocity in humans has been lacking. The aims of the present study were to estimate the blood flow velocity in human dental pulp and to evaluate the validity of LDF modified for the measurement of slow blood flow. DESIGN: Mean blood flow velocities at the upper central incisor, gingiva, fingertip and forearm of 28 volunteers (mean age: 38.6 years old) were estimated using LDF with a frequency analyser. Blood flow signals at these measurement areas were recorded using two different LDFs: (a) one with a standard blood flow range; and (b) one modified for low blood flow velocity. RESULTS: The frequency range of the Doppler shift measured at the teeth with an opaque rubber dam was the narrowest (median: 4.3kHz) among all of the measurement areas. The estimated mean blood flow velocity was the slowest at the teeth with a dam (median: 0.18mm/s). LDF for low blood flow velocity detected larger and clearer pulsatile blood flow signals from the teeth with dams than did standard LDF. CONCLUSIONS: The present results indicate that the velocity of PBF in humans is very low and that LDF modified for the measurement of slow blood flow is appropriate for PBF measurement in humans.