Efficacy of High-intensity laser therapy in patients with temporomandibular joint disorders: A systematic review and meta-analysis.

This study aimed to assess the effects of High-intensity laser therapy (HILT) on individuals suffering from temporomandibular joint disorders (TMDs). A search was conducted across six electronic databases for randomized controlled trials (RCTs) focusing on HILT for TMDs: PubMed, Scopus, Web of Science, ScienceDirect, EBSCOhost, Cochrane Library, the PEDro database and Google Scholar (last updated on July 18, 2024). Eligible studies were chosen by independent reviewers, and their quality was assessed with the Cochrane risk of bias tool (RoB). The main outcome was pain intensity (VAS), with secondary outcomes including mouth opening (mm), disability (JFLS-20), and quality of life (OHIP-14). A meta-analysis was conducted to assess the pooled effect by calculating mean differences (MD) for these variables (95% confidence level). The heterogeneity of the meta-analyses was explored using the I2 statistic. Three studies met the selection criteria and were included in the meta-analysis. The main RoB was the blinding of participant and treaters. Statistically significant differences (p < 0.05) in favor of HILT were observed for VAS and maximum mouth opening. The pooled effect showed an MD of -14.8 mm (95% CI:-27.1,-2.5) for pain intensity and 3.7 mm (95% CI:0.9,6.5) for mouth opening, changes that were assessed as clinically important. According to GRADE, the evidence was rated as important, and the certainty was moderate due to the heterogeneity between studies. A sensitivity analysis was not performed to address heterogeneity, primarily due to the limited availability of RCTs. HILT has been found effective in short-term pain relief and improvement of jaw opening in TMDs, potentially enhancing quality of life by facilitating activities such as chewing, jaw mobility, and communication. However, further research is needed to confirm its long-term effectiveness. Combining HILT with interventions such as occlusal splints or therapeutic exercises could potentially enhance its effects, leveraging the existing evidence supporting these treatments. It is important to note that the high RoB associated with the lack of blinding of participants and treaters may influence data collection, compromising the internal validity of findings in some studies.

Micronano Lasers Based on Aggregation-Induced Emission Molecules: Diverse Resonant Cavities Investigation.

Aggregation-induced emission (AIE) molecules have great potential to enhance the performance of micronano lasers due to their excellent aggregated luminescence properties, so it is valuable to expand their applications in micronano lasers. In this work, a typical AIE active fluorescent dye motif 9,10-bis(2,2-diphenylvinyl) anthracene (BDPVA) was selected as the gain medium. First, drop-casting was used to fabricate BDPVA single-crystal nanowires, which can be used as Fabry-Perot (FP)-type resonators with a lasing threshold of 49.4 µJ/cm2. Furthermore, we innovatively doped BDPVA molecules as gain mediums into external polymer Whispering-Gallery-Mode (WGM)-type resonators via the emulsion self-assembly method. Fabricated BDPVA-doped polystyrene (PS) microspheres exhibit a much lower lasing threshold of 9.04 µJ/cm2. These results prove that the BDPVA molecules, in addition to realizing the reported AIE single-crystal lasers, can also be used as a guest-doped gain medium in the resonant cavity for obtaining better fluorescence gain. In addition, multimode tunability of two types of lasers has been successfully achieved by tuning the structure of the resonant cavity. This work further expands the application potential of AIE materials and will provide a useful reference for the rational design and fabrication of photonic micronano laser components using AIE materials.

Enhanced quantification of chlorophyll a and its degradation products in olive oil using time-resolved laser-induced fluorescence fingerprint analysis.

Potential errors in the fluorescence analysis of chlorophylls and their degradation products, primarily due to spectral overlap and inner filter, are widely acknowledged. This study aimed to devise a sensitivity-enhanced technique for the concurrent quantification of chlorophyll a and its degradation products while minimizing effects from type-B chlorophylls. Initially, a time-resolved laser-induced fluorescence spectroscopic system was designed and tested on stardard chlorophyll samples. The origins, implications, and mitigation strategies of spectral overlap and the inner filter effect on the measured fluorescence intensity were thoroughly examined. Then, this methodology was proved to be efficacious within complex liquid matrices derived from olive oil. The experimental outcomes not only shed additional light on the mechanisms of chlorophyll fluorescence overlap and the inner filter effect, but also establish a general framework for developing spectrally and timely resolved fluorescence fingerprint analysis for the simultaneous quantification of chlorophylls and their degradation products at high concentrations.

Effect of Er:YAG Laser Application and Sandblasting on Shear Bond Strength of Veneering Ceramic to Zirconia Core.

Objectives: Porcelain chipping and delamination are among the shortcomings of all-ceramic restorations. This study aimed to assess the effect of laser irradiation and sandblasting on shear bond strength (SBS) of zirconia to veneering porcelain. Materials and Methods: In this in vitro, experimental study, 60 zirconia blocks were randomly divided into three groups (n=20) for surface treatment with Er:YAG laser, sandblasting, and no surface treatment (control). Each group was randomly divided into two subgroups (n=10) for porcelain application by the layering or the pressing technique. The surface roughness, SBS, and failure mode were determined and analyzed using two-way ANOVA, Tukey's HSD test, Chi-square test, and Pearson's correlation test (alpha=0.05). Results: The mean SBS was 8.16±3.66 MPa, 9.32±2.7 MPa, and 11.85±3.06 MPa in the control, laser, and sandblasting groups, respectively. The SBS was significantly different among the three groups (P=0.002). The failure mode of the three groups was not significantly different (P>0.05). The sandblasted group showed significantly higher surface roughness than the control and laser groups (P<0.001). Conclusion: Sandblasting yielded higher SBS particularly when the porcelain was applied by the layering technique. Although laser irradiation increased the SBS, the difference with the control group was not statistically significant.

The role of excimer light in dermatology: a review.

Excimer light is a subtype of NB-UVB that emits a 308 nm wavelength, and can provide targeted phototherapy treatment. The absorption of 308 nm light by skin cells leads to therapeutic response in various common and ultraviolet-responsive skin diseases, such as psoriasis and vitiligo, and photo-resistant skin diseases such as prurigo nodularis, localized scleroderma, genital lichen sclerosis, and granuloma annulare, cutaneous T-cell lymphomas, among others. Excimer light has few adverse reactions and overall is well tolerated by patients, furthermore, it can be performed in places that are difficult to access. This article aims to explain the therapeutic bases and applications of excimer light in current dermatology.

Safety and efficacy of lasers compared to cold knife in direct visual internal urethrotomy: a systematic review and Meta-analysis.

Cold knife urethrotome was introduced in 1971 and it had an 80% success rate. New advancements in this field have shed light on the use of various lasers such as carbon dioxide, Nd: YAG, KTP, Argon, Ho: YAG, and excimer lasers. It has been observed that cold knife urethrotomy has a higher recurrence rate than laser urethrotomy, but the superiority of either treatment modality has not been established yet. Data were thoroughly searched through PubMed, Scopus, and clinicaltrials.gov. We also used clinicaltrials.gov for ongoing and published research. The data was analyzed via R studio version 2023.12.1 (oceanstorm). For dichotomous variables, Odds Ratio (OR) were used to pool data and standardized mean difference was used for continuous variables with 95% confidence intervals (CIs). A total of 14 studies including 1114 participants were included in this meta-analysis. The results of the combined analysis revealed significant relation with a mean difference of 0.99 (95% CI: 0.37; 1.62), and favored laser group. The overall results have shown the laser to have a significant favorable profile demonstrating a recurrence, Odds Ratio of 0.42 (95% CI:0.27;0.65). Patients with laser therapy had a lower risk of complication rate (OR 0.49, 95% Cl: 0.35; 0.67). All the findings obtained by the analysis in this study favour lasers significantly over the cold knife technique especially when mean Qmax, with recurrence and complications taken into account.

Physical Treatments and Therapies for Androgenetic Alopecia.

Androgenetic alopecia, the most common cause of hair loss affecting both men and women, is typically treated using pharmaceutical options, such as minoxidil and finasteride. While these medications work for many individuals, they are not suitable options for all. To date, the only non-pharmaceutical option that the United States Food and Drug Administration has cleared as a treatment for androgenetic alopecia is low-level laser therapy (LLLT). Numerous clinical trials utilizing LLLT devices of various types are available. However, a myriad of other physical treatments for this form of hair loss have been reported in the literature. This review evaluated the effectiveness of microneedling, pulsed electromagnetic field (PEMF) therapy, low-level laser therapy (LLLT), fractional laser therapy, and nonablative laser therapy for the treatment of androgenetic alopecia (AGA). It also explores the potential of multimodal treatments combining these physical therapies. The majority of evidence in the literature supports LLLT as a physical therapy for androgenetic alopecia. However, other physical treatments, such as nonablative laser treatments, and multimodal approaches, such as PEMF-LLLT, seem to have the potential to be equally or more promising and merit further exploration.

Electrocautery-Assisted Management of Aberrant Frena Causing Midline Diastema: A Case Report.

Various oral complications such as gingival recession, restricted lip movement and tooth malalignment are the result of an abnormal frenum. Management of these types of frenum is either frenectomy or frenotomy. Methods for performing frenectomies include the conventional scalpel technique, Z-plasty, Miller's technique, V-Y plasty, lasers, and electrocautery. This case report details the successful management of an abnormal frenum attachment using electrocautery to ease and reduce discomfort to the 19-year-old female patient, causing aesthetic concerns. For its precision, minimal bleeding and post-operative discomfort, electrocautery was chosen. This procedure was performed under local anaesthesia. There were favourable post-operative outcomes as the patient experienced minimal pain and rapid recovery from the surgical site. Significant improvement in gingival health was seen in the follow-up examination. This case demonstrates the efficacy of using electrocautery in managing abnormal frenum attachment while highlighting its benefits over traditional surgical methods for ease and reduced discomfort.

Establishment and review of educational programs to train optometrists in laser procedures and injections.

Current scope of practice for optometrists in many countries include topical and oral medication with injectable and lasers being added more recently to scope in the United States (US), Canada, the United Kingdom (UK) and New Zealand (NZ). This expanded scope of optometric practice improves access to eyecare and is critical since an ageing population with a higher prevalence of vision disorders and higher healthcare costs looms. Expanded scope has been shown alongside strong safety records. This review paper aims to investigate the expansion of optometric scope of practice regarding lasers and injectables in the US, UK, Canada, Australia and NZ. The design and delivery of post-graduation educational programs, curriculum frameworks for advanced skills and the metrics of laser procedures performed by optometrists will be discussed. The State of Oklahoma in the US was first to authorise optometrists to use lasers and injectables in 1988. As of 2024, qualified optometrists in the UK, in twelve states in the US, and specialist optometrists in NZ perform laser procedures. However, lasers and injectables are not within the current scope of optometric practice in Australia and Canada. Training courses such as Northeastern State University Oklahoma College of Optometry Advanced Procedures Course and Laser Procedures Course have been successfully designed and implemented in the US to train graduate optometrists. The outcomes of over 146,403 laser procedures performed by optometrists across the US have shown only two negative outcomes, equating to 0.001%. These metrics outline the effectiveness of these procedures performed by optometrists and show strong support for future optometric scope expansion. Eye health professionals, relevant educational institutions, advocacy groups, and policymakers are called upon to work collaboratively to expand the optometric scope of practice globally.

Effect of Fibroblast Growth Factor 2 and Low-Level Laser Therapy on the Adhesion and Proliferation of Periodontal Ligament Stem Cells.

Introduction: The adhesion ability of mesenchymal stem cells can significantly affect their viability and is considered a prerequisite for cell therapy. The current study sought to evaluate the effect of fibroblast growth factor 2 (FGF2) and low-level laser therapy (LLLT), either individually or in conjunction, on the adhesion and proliferation of periodontal ligament stem cells (PDLSCs) when applied on the first day of cell seeding. Methods: The experimental groups of this study comprised a control group and different combinations of adjunctive FGF2 (50 ng/mL) and LLLT with an 808 nm diode laser in one (LLLT-1) or two sessions (LLLT-2) of irradiation. The proliferation and adhesion of cells were evaluated by using the methylthiazolyl tetrazolium (MTT) assay and 4',6-diamidino-2-phenylindole (DAPI) staining. All experiments were done in triplicates on the first, third, and fifth days after cell seeding. Two-way ANOVA and post hoc Tukey tests were used to analyze the data of the MTT assay. P<0.05 was considered statistically significant. Results: One-day post-culture, only significant differences were found between the control group and the FGF2 (P=0.04) and FGF2+LLLT-2 application (P=0.04) groups. After three days post-cell culture, only a significantly higher proliferation rate was found in the control group than in the FGF2 group (P=0.01). After five days, the control group and LLLT-2 groups showed significantly higher amounts of proliferation compared to the other groups (P<0.05). DAPI staining qualitatively confirmed the results of the MTT assay. Conclusion: The LLLT can be applied to PDLSCs on the day of seeding without causing a notable decrease in their viability and adhesion. Conversely, the administration of FGF2 should be restricted on the seeding day and postponed to subsequent days as it may have adverse effects on their adhesion and proliferation.

Comparative effects of the conventional, ultrasonic, and laser-activated irrigation on penetration depth of three photosensitizers in the root canal system.

OBJECTIVES: This study compared the effects of conventional, ultrasonic, and laser-activated irrigation (LAI) on penetration depth of three photosensitizers (PSs) in the root canal system. MATERIALS AND METHODS: In this in vitro, experimental study, 120 extracted anterior teeth were decoronated such that the remaining root length was standardized at 12 mm. After root canal instrumentation with the ProTaper rotary system and irrigation with 5.25% NaOCl, the roots were assigned to 12 groups for the application of toluidine blue (TB), curcumin, and phycocyanin PSs combined with the LAI using erbium laser with 0.4 mm and 0.6 mm tips, ultrasonic activation, and conventional irrigation. The specimens were sectioned apicocoronally, and the dye penetration depth was quantified in the coronal, middle, and apical thirds under a stereomicroscope at x20 magnification. Data were analyzed by the Kruskal-Wallis and Dunn test (alpha=0.05). RESULTS: The effects of irrigation technique, PS type, and their interaction on dye penetration depth were significant at the apical, middle, and coronal thirds (P<0.0001). TB + LAI with 0.4- and 0.6-mm laser tips showed the highest penetration depth while phycocyanin + LAI or conventional irrigation showed the lowest penetration depth at all areas. Dye penetration depth was the highest in the coronal, and the lowest in the apical third. CONCLUSION: The LAI technique with erbium laser (0.4- and 0.6-mm tips) enhanced the penetration depth of TB. The tested irrigation techniques had no significant efficacy for enhancement of the penetration depth of curcumin and phycocyanin.

Comparative evaluation of the effectiveness of concentrated growth factor alone and in combination with diode laser application in the treatment of intrabony periodontal defects: A clinical and radiographic split-mouth study.

Background: Applying autologous growth factors and diode laser in periodontal therapy enhances fibroblast-mediated new attachment and osteoblastic differentiation. Hence, this study compared and evaluated the effectiveness of concentrated growth factor (CGF) alone and with diode laser application in managing intrabony periodontal defects. Methods: Ten patients with stage III periodontitis were included in this study. All the patients underwent an open flap debridement (OFD) procedure followed by CGF membrane placement in the intrabony defect in site A, whereas, in site B, after OFD, all the patients underwent diode laser irradiation before CGF membrane placement. Plaque and gingival bleeding index (PI & GBI), PPD, and clinical attachment level (CAL) were evaluated at baseline and 3 and 6 months later. Bone fill (BF), BF%, bone crest changes (BCC), and BCC% were assessed radiographically at six months postoperatively. Results: Significant reductions in PI and GBI scores, probing pocket depth (PPD), and CAL gain were observed at both sites 3 and 6 months from baseline. A significant reduction in PPD and CAL gain was noted between sites, which were higher in site B than in site A with a mean difference of 0.70±0.05 mm and 1.30±0.18 mm, 0.90±1.89 mm at 3 and 6 months, respectively. Radiographic measurement showed better BF, BF%, BCC, and BCC% at both sites at six months, which were higher at site B than at site A but statistically insignificant. Conclusion: The combination of CGF and diode laser application has demonstrated successful and promising results in terms of regeneration, improving the clinical and radiographic parameters.

Development and commissioning of a broadband online X-ray spectrometer for the SXFEL Facility.

A broadband online X-ray spectrometer has been designed and commissioned at the SUD beamline of the Shanghai Soft X-ray Free-Electron Laser Facility, which can deliver both SASE and seeded FEL pulses to user experiments, spanning the photon energy range of 50-620 eV. The resolving powers of the spectrometer calibrated via online measurement at 92 eV and 249 eV are ∼20000 and ∼15000, respectively, and the absolute photon energy is characterized by an electron time-of-flight spectrometer. The high energy resolution provided by the spectrometer can differentiate the fine structure in the FEL spectrum, to determine its pulse length.

Maxillary labial frenectomy: a randomized, controlled comparative study of two blue (445 nm) and infrared (980 nm) diode lasers versus surgical scalpel.

BACKGROUND: This study aimed to compare the intra and postoperative complications of frenectomy procedure with a surgical scalpel versus 445 nm and 980 nm diode lasers. METHODS: This randomized controlled clinical trial was conducted on 174 patients requiring maxillary labial frenectomy. After completion of fixed orthodontic treatment and primary closure of maxillary diastema, the patients were randomly assigned into three groups (n = 58): group 1 (frenectomy via 445 nm diode laser, continuous-wave, 1.5 W), group 2 (frenectomy via 980 nm laser, continuous-wave, 1.7 W), and control group (V-Y plasty technique via scalpel). Intra-operative bleeding, discomfort in chewing and speaking, pain, and tissue healing were compared among the groups immediately, at 7 and 30 days postoperatively using the Kruskal-Wallis, Mann-Whitney, and Chi-square tests. RESULTS: Pain scores were significantly lower in group 1 compared to group 2 (immediately and day 7, P < 0.05). Significant faster tissue healing at days 7 and 30 were observed in group 1 compared to group 2 (P < 0.05). Group 1 was superior to the control group regarding lower intraoperative bleeding, discomfort in chewing and speaking (immediately and day 7), lower pain (immediately and day 7), and tissue healing (day 7) (P < 0.05 for all). Group 2 was significantly superior to the control group in lower intraoperative bleeding, discomfort in chewing and speaking (immediately and day 7), and better tissue healing (day 7) (P < 0.05 for all). CONCLUSIONS: In conclusion, diode laser frenectomy resulted in significantly lower intra and postoperative complications compared to the scalpel. Moreover, 445 nm diode laser showed significantly superior effects compared to 980 nm diode laser. TRIAL REGISTRATION: The study protocol was registered on 29.10.2022 at the Iranian Registry of Clinical Trials ( www.irct.ir ) (registration number: IRCT20220630055326N1).

Early Peri-Implant Bone Healing on Laser-Modified Surfaces with and without Hydroxyapatite Coating: An In Vivo Study.

(1) Objective: The aim of this study was to assess the biological behavior of bone tissue on a machined surface (MS) and modifications made by a laser beam (LS) and by a laser beam incorporated with hydroxyapatite (HA) using a biomimetic method without thermic treatment (LHS). (2) Methods: Scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM/EDX) was performed before and after installation in the rabbit tibiae. A total of 20 Albinus rabbits randomly received 30 implants of 3.75 × 10 mm in the right and left tibias, with two implants on each surface in each tibia. In the animals belonging to the 4-week euthanasia period group, intramuscular application of the fluorochromes calcein and alizarin was performed. In implants placed mesially in the tibiofemoral joint, biomechanical analysis was performed by means of a removal torque (N/cm). The tibias with the implants located distally to the joint were submitted for analysis by confocal laser microscopy (mineral apposition rate) and for histometric analysis by bone contact implant (%BIC) and newly formed bone area (%NBA). (3) Results: The SEM showed differences between the surfaces. The biomechanical analysis revealed significant differences in removal torque values between the MSs and LHSs over a 2-week period. Over a 4-week period, both the LSs and LHSs demonstrated removal torque values statistically higher than the MSs. BIC of the LHS implants were statistically superior to MS at the 2-week period and LHS and LS surfaces were statistically superior to MS at the 4-week period. Statistical analysis of the NBA of the implants showed difference between the LHS and MS in the period of 2 weeks. (4) Conclusions: The modifications of the LSs and LHSs provided important physicochemical modifications that favored the deposition of bone tissue on the surface of the implants.

Micro-to-Nanoscale Characterization of Femtosecond Laser Photo-Inscribed Microvoids.

Fiber Bragg gratings are key components for optical fiber sensing applications in harsh environments. This paper investigates the structural and chemical characteristics of femtosecond laser photo-inscribed microvoids. These voids are at the base of type III fs-gratings consisting of a periodic array of microvoids inscribed at the core of an optical fiber. Using high-resolution techniques such as quantitative phase microscopy, electron transmission microscopy, and scattering-type scanning near-field IR optical microscopy, we examined the structure of the microvoids and the densified shells around them. We also investigated the high-temperature behavior of the voids, revealing their evolution in size and shape under step isochronal annealing conditions up to 1250 °C.

Unusual case of Reinke's oedema.

This case report describes a man in his mid 40s, with a history of chronic smoking, who presented with dysphonia. He underwent microlaryngoscopy and biopsy for a suspicious lesion on the anterior right vocal cord. Mask ventilation proved difficult on induction of general anaesthesia due to a solid lesion acting as a ball valve into the glottis. This mass was LASER debulked and sent for histopathology. This demonstrated a haematoma, likely traumatic in origin, with some polypoidal features, consistent with advanced Reinke's oedema. Reinke's oedema is a benign condition where chronic inflammation causes fluid accumulation within the vocal cords. Long-standing inflammation leads to disarrangement of the vocal cord lamina propria, causing fluid accumulation and thereby resulting oedema of the vocal cords. This process can subsequently lead to polyp formation and can cause gravelly voice. This case report describes the potential airway sequelae of this benign condition.

Fixed-target pump-probe SFX: eliminating the scourge of light contamination.

X-ray free-electron laser (XFEL) light sources have enabled the rapid growth of time-resolved structural experiments, which provide crucial information on the function of macromolecules and their mechanisms. Here, the aim was to commission the SwissMX fixed-target sample-delivery system at the SwissFEL Cristallina experimental station using the PSI-developed micro-structured polymer (MISP) chip for pump-probe time-resolved experiments. To characterize the system, crystals of the light-sensitive protein light-oxygen-voltage domain 1 (LOV1) from Chlamydomonas reinhardtii were used. Using different experimental settings, the accidental illumination, referred to as light contamination, of crystals mounted in wells adjacent to those illuminated by the pump laser was examined. It was crucial to control the light scattering from and through the solid supports otherwise significant contamination occurred. However, the results here show that the opaque MISP chips are suitable for defined pump-probe studies of a light-sensitive protein. The experiment also probed the sub-millisecond structural dynamics of LOV1 and indicated that at Δt = 10 µs a covalent thioether bond is established between reactive Cys57 and its flavin mononucleotide cofactor. This experiment validates the crystals to be suitable for in-depth follow-up studies of this still poorly understood signal-transduction mechanism. Importantly, the fixed-target delivery system also permitted a tenfold reduction in protein sample consumption compared with the more common high-viscosity extrusion-based delivery system. This development creates the prospect of an increase in XFEL project throughput for the field.

Non-contact elasticity contrast imaging using photon counting.

Significance: Tissues' biomechanical properties, such as elasticity, are related to tissue health. Optical coherence elastography produces images of tissues based on their elasticity, but its performance is constrained by the laser power used, working distance, and excitation methods. Aim: We develop a new method to reconstruct the elasticity contrast image over a long working distance, with only low-intensity illumination, and by non-contact acoustic wave excitation. Approach: We combine single-photon vibrometry and quantum parametric mode sorting (QPMS) to measure the oscillating backscattered signals at a single-photon level and derive the phantoms' relative elasticity. Results: We test our system on tissue-mimicking phantoms consisting of contrast sections with different concentrations and thus stiffness. Our results show that as the driving acoustic frequency is swept, the phantoms' vibrational responses are mapped onto the photon-counting histograms from which their mechanical properties-including elasticity-can be derived. Through lateral and longitudinal laser scanning at a fixed frequency, a contrast image based on samples' elasticity can be reliably reconstructed upon photon level signals. Conclusions: We demonstrated the reliability of QPMS-based elasticity contrast imaging of agar phantoms in a long working distance, low-intensity environment. This technique has the potential for in-depth images of real biological tissue and provides a new approach to elastography research and applications.