Lasers in Medical Science最新文献

This pilot case series aimed to investigate the feasibility and preliminary efficacy of photobiomodulation (PBM; also known as low-level laser therapy [LLLT]) applied to specific acupuncture points (PC6 and CV24) in managing the gag reflex during posterior single-tooth extraction. Participants with moderate-to-severe gag reflex (n = 20) were selected based on Gagging Severity Index (GSI) scores ≥ 3 during clinical examination. Gag reflex severity was measured using both the GSI and the Predictive Gagging Survey (PGS) before and after the procedure. LLLT (976 nm diode laser, 100 mW, 4 J/cm² per point, continuous-wave, 20 s per point, 8-mm diameter tip [spot area ≈ 0.50 cm²]) was administered immediately prior to extraction. Preoperative GSI scores (3.3 ± 0.6) underwent a significant decrease postoperatively (1.3 ± 0.5; P < 0.001). Concurrently, PGS scores showed a moderate positive correlation with baseline GSI. LLLT was found to be an effective method of controlling the gag reflex during posterior tooth extraction, thereby facilitating the procedure. In this pilot study, LLLT was associated with reduced gag reflex during posterior tooth extraction. However, the absence of a control group should be acknowledged as a limitation, and the findings should be interpreted with caution. Controlled trials are needed to confirm these preliminary results.

Laser acupuncture (LA) has been increasingly investigated as a non-invasive therapy for knee osteoarthritis (KOA), yet its clinical efficacy remains uncertain. To evaluate the effectiveness and safety of LA for pain, function, and mobility in KOA through a systematic review and meta-analysis. Randomized controlled trials (RCTs) comparing LA with sham, placebo, electroacupuncture, or standard care were identified from major databases. Outcomes included pain (VAS, WOMAC-Pain, NPRS, PI), function (WOMAC-Function), and range of motion (flexion). Risk of bias was assessed using RoB 2, and heterogeneity explored through subgroup analyses. Thirteen RCTs of 611 participants were included. LA did not significantly improve WOMAC pain (SMD 0.04; 95% CI - 0.36 to 0.45), pVAS (SMD 0.12; 95% CI - 0.91 to 1.15), or NPRS (SMD - 0.23; 95% CI - 0.58 to 0.12). Function showed a nonsignificant trend toward improvement (SMD - 0.32; 95% CI - 0.94 to 0.30), and knee flexion outcomes were also nonsignificant (SMD 0.10; 95% CI - 0.39 to 0.59). Substantial heterogeneity (I² > 70%) was observed across studies, likely related to differences in wavelength (650-904 nm), dosage, and acupoint protocols. Funnel plots did not suggest marked publication bias. Current evidence does not demonstrate statistically significant benefits of LA over comparators for pain, function, or flexion in KOA. Considerable heterogeneity and variability in laser parameters limit firm conclusions. Large, standardized RCTs with optimized parameters are needed to confirm efficacy and guide clinical application.Clinical trial number: Not applicable.

Purpose: Infrared low-level laser therapy (LLLT) has shown great promise in promoting cell proliferation and viability, making it a valuable tool in regenerative medicine. This study investigated how the interval between sessions shapes the response to 970 nm LLLT in murine osteoblast cultures by delivering three 10 J/cm² sessions separated by 24-48 h and measuring proliferation, reactive oxygen species (ROS), cytotoxicity, and apoptosis, with the goal of informing protocol design for bone regeneration.

Methods: Two osteoblast cultures were used, one control and the other LLL-treated group. The latter consisted of three irradiation sessions (10 J/cm² each) applied at 24, 48, and 96 h.

Results: The experimental results showed a significant increase in cell proliferation after two and three sessions (p < 0.05), while ROS levels progressively accumulated, peaking after the third session (p < 0.001). Cell viability remained above 90% in both groups during the first 48 h; however, a slight but significant reduction was observed in the LLLT group at 96 h. Apoptosis levels were lower in LLLT-treated cells during early phases (24-48 h), suggesting a transient cytoprotective effect that diminished after the third session. These findings indicate that infrared LLLT promotes cell proliferation without inducing cytotoxicity or programmed cell death.

Conclusion: The results demonstrate that applying three infrared LLLT sessions of 10 J/cm² applied at 24, 48, and 96 h promotes osteoblastic proliferation and viability without inducing cytotoxicity or apoptosis. The proposed protocol, defined by energy dose and irradiation timing, provides a safe and effective strategy for bone tissue engineering.

Purpose: Transoral robotic surgery (TORS) is an established surgical approach for oropharyngeal squamous cell carcinoma (OPSCC). Carbon dioxide (CO₂) laser offers high cutting precision and minimal collateral thermal injury, yet its use in TORS remains underreported. The purpose of this study is therefore to describe the first UK case series detailing the use of CO₂ laser via hollow waveguide in TORS.

Methods: Eight patients (six male, two female; mean age 60 years) presenting with either left tonsillar (seven cases) or right tongue base (one case) OPSCC underwent primary TORS resection with CO₂ laser at a tertiary UK head and neck centre between October 2020 and May 2024. Cases were selected based on tumour stage, anatomical suitability and patient preference. The CO₂ laser (SmartXide Trio, 3-10 W, ultra-pulse mode) was delivered via hollow waveguide mounted on one of the arms of the Da Vinci robotic system. Outcome measures included histological margin status, peri- and postoperative complications, swallowing function, and hospital length of stay.

Results: All tumours were completely excised; two of the eight had close margins on the primary specimen but were clear on additional sampling. No intraoperative complications occurred, and all procedures were completed without conversion. All patients resumed oral intake without nasogastric feeding. Mean hospital stay was 2.75 days, with no airway compromise, catastrophic bleeding, or significant swallowing dysfunction.

Conclusion: CO₂ laser dissection in TORS for OPSCC represents a viable surgical approach with acceptable postoperative functional outcomes and may possibly demonstrate reduced thermal injury compared with monopolar electrocautery.

Cutaneous aging is characterized by gradual structural and functional alterations, including collagen breakdown and reduced elasticity. In recent years, several energy-based modalities have been introduced to address these changes. The aim of this study was to assess the effectiveness of a 675 nm laser and microfocused ultrasound (MFU), applied individually or in combination, for the treatment of facial aging. This retrospective analysis included 115 patients, allocated into three groups: Group A (675 nm laser), Group B (MFU), and Group C (combined protocol). Efficacy was evaluated through the Fitzpatrick Wrinkle Scale (FWS), the Baker Gravitational Ptosis Classification (BGP), and standardized photographic assessments at 1, 3, and 6 months following treatment. At the 6-month evaluation, individuals treated with the combined protocol exhibited a more pronounced improvement in wrinkle reduction (FWS: from 1.88 to 1.13) and laxity reduction (BGP: from 2.78 to 1.55) compared with either single-treatment group. No major side effects were observed. The combined application of the 675 nm laser and MFU appears to potentiate collagen remodeling and skin tightening more effectively than monotherapy. Further prospective studies are needed to validate these results and further clarify the molecular pathways involved.

Several parameters influence the effectiveness of photobiomodulation therapy (PBMT) in improving skin flap viability, yet the role of the number of treatment sessions remains underexplored. The present study aimed to evaluate the effect of different numbers of laser PBMT sessions on skin flap viability. Thirty-two Wistar rats were randomly divided into four groups: G1 (PBMT simulation), G2 (PBMT for 2 consecutive days), G3 (PBMT for 5 days), and G4 (PBMT for 7 consecutive days). Treatment began immediately after surgery with the following parameters: GaAlAs diode laser, 660 nm wavelength, continuous mode, spot size of 0.04 cm² (probe in contact with the skin), 90 J/cm² fluence, 40 mW output power, 90 s application time, and 3.6 J of energy per point with irradiation at three points and 24-hour intervals between sessions according to each group's protocol. On the 7th postoperative day, tissue was collected from the irradiated area for analysis of necrotic area, vessel and mast cell morphometry and immunohistochemistry for angiogenesis markers. G2 showed the smallest necrotic area and a higher percentage of VEGF- and HIF-1α-positive cells compared to G1. Short PBMT protocols improved flap viability versus controls and produced outcomes comparable to extended regimens, supporting relevance for translational research.