Lasers in Medical Science最新文献

The aim of the study was todescribe the clinical features, optical coherence tomography (OCT) and fundus autofluorescence (FAF) imaging in patients with choroidal and retinal tumors. Ninety eyes of 89 patients with treatment-naive macular, midperipheral, and juxtapapillary choroidal and retinal tumors were retrospectively included in the study. All patients underwent a complete ophthalmic examination, B-mode ultrasonography, OCT, and FAF imaging. OCT and FAF images taken at the time of diagnosis were reviewed retrospectively. Choroidal nevus (CN), choroidal malignant melanoma (CMM), optic disc melanocytoma (ODM), circumscribed choroidal hemangioma (CCH), and choroidal osteoma (CO) displayed dome-shaped contour on OCT, while choroidal metastases (CM) showed a lumpy bumpy contour. CN had preserved choriocapillaris. Choroidal compression was observed in all choroidal tumors except CCH which showed vascular expansion. CMM was the most common lesion displaying overlying lipofuscin. Intraretinal fluid was seen mostly in CCM and CCH. Subretinal fluid (SRF) was usually observed in CM, CMM, and CCH. Drusen and pigment epithelial detachment (PED) were noted in CN. While the pattern of hyperautofluorescence (hyper-AF) was most marked in CMM, other tumors including CCH and CM occasionally showed similar FAF appearance. Comparing CN and CMM; CN displayed more drusen and PED (p = 0.024 and p = 0.037 respectively) and CMM showed more SRF, intraretinal fluid, and shaggy photoreceptor (p = 0.040, p < 0.001, and p < 0.001 respectively). CN displayed more hypo-AF and iso-AF (p < 0.001) while CMM showed significantly more diffuse and patchy hyper-AF (p < 0.001). Characteristic findings in OCT and FAF guide clinicians in the differential diagnosis of choroidal and retinal tumors and allow for earlier detection and improved treatment outcomes.

This brief report aimed to investigate the optical absorbance spectra of normal, dysplastic, and malignant epithelial cell lines under normal and nutritional stress conditions. HaCAT (keratinocyte), DOK (oral dysplastic), and oral squamous cell carcinoma (OSCC) cell lines (CA1, Luc4, SCC9) were evaluated regarding their optical absorbance after culture with 0-10% fetal bovine serum. Absorbance measurements indicated that HaCAT under serum starvation exhibited higher absorbance at blue (430 nm) and near-infrared (906 nm) wavelengths. DOK showed absorption at 440 nm and 945 nm. OSCC cells showed absorption peaks at blue (400-428 nm) and near-infrared. These findings highlight the importance of tailoring PBM parameters to individual needs to achieve optimal absorption and effectiveness. Moreover, the higher absorption peaks in the blue region support further studies to elucidate the potential use of blue light in oral dysplastic lesions and OSCC.

Hypertrophic scars (HTSs) are the result of an abnormal healing process resulting from burns and other severe traumas. The symptoms of that condition include skin irritation, discomfort, and itching. This study aimed to assess the efficacy of fractional carbon dioxide (CO₂) laser therapy alone or with triamcinolone or 5-fluorouracil (FU) in the treatment of early post-burn hypertrophic scars (HTSs) that develop during the first 6 months after the injury. A prospective, randomized, single-blind comparative study was conducted on 30 patients aged 16-65 with hypertrophic scars (HTS) resulting from burns. Patients had no prior treatment for their scars. We randomly assigned participants to one of three groups: Group A received fractional CO₂ laser therapy alone, Group B received fractional CO₂ laser therapy with topical 5-fluorouracil, and Group C received fractional CO₂ laser therapy with topical triamcinolone acetonide. All treatment groups showed significant improvements (p < 0.05) in overall scar severity and height. Patients in Group C (fractional CO₂ laser + triamcinolone) demonstrated significant improvements in scar pliability, height, and pigmentation (p < 0.05). In contrast, patients in Group B (fractional CO₂ laser + 5-FU) showed significant reductions in scar vascularity, pliability, and height following treatment (p < 0.05). While all groups reported minor changes in pain and itching, there were no significant differences in these symptoms between Group B and Group C. HTSs of this trial revealed reductions in overall scar surface area and thickness and improvement of pliability and pigmentation; however, there was not statistically significant difference between the effect of 5-fluorouracil and triamcinolone acetonide (TAC), suggesting that neither drug offers better efficacy over the other. Level I, singleblinded randomized control study.

Melasma significantly impacts life quality, and while various laser therapies show promise, rigorous comparative studies, especially between the novel Picosecond Alexandrite Laser (PSAL) and the traditional combined modality of Q-switched and Long-pulse Nd: YAG Lasers (QLNYL), are notably lacking. This study aims to fill this gap by evaluating the efficacy and safety of these modalities, providing insights into their comparative advantages for clinical practice. In a prospective, evaluator-blinded study, 40 participants with Fitzpatrick Skin Types (FST) III and IV underwent three treatment sessions at four-week intervals with either PSAL or QLNYL. Efficacy was primarily assessed by changes in Melasma Area and Severity Index (MASI) scores at baseline, 4, 8, 12, and 24 weeks, along with patient satisfaction evaluations at the 12- and 24-week marks, and safety assessments conducted throughout the study. Both groups experienced significant reductions in MASI scores post-treatment. Overall, the improvement in MASI scores in the QLNYL group significantly surpassed that in the PSAL group (P = 0.010). Patient satisfaction was comparably high between groups, and no significant differences were noted in safety profiles. The PSAL group showed a slightly higher incidence of adverse reactions (not significant) and significantly higher pain scores (P = 0.018). Recurrence rates at the 24-week follow-up were 10.5% for PSAL and 0% for QLNYL, with no significant difference. Both PSAL and QLNYL proved effective in treating melasma, with the traditional combined modality of QLNYL demonstrating superior efficacy in FST III-IV. Safety profiles were similar comparable.

Backgrounds and aims: Submental skin laxity (SSL), manifesting as sagging skin and double chin, can significantly affect patients' self-perception and social interactions. While surgical treatments exist, non-invasive methods are increasingly sought for their minimal recovery time. This study assesses the safety and effectiveness of a novel microwave-based device for treating SSL, aiming to provide long-term improvements in skin tightness and appearance.

Materials and methods: Ten female patients with moderate to severe SSL underwent two treatments spaced 30 days apart using a 2.45 GHz non-invasive microwave device, with a specific handpiece. Treatment sessions lasted 10 min each, targeting the submental region. The Submental Skin Laxity Grade (SMSLG) was assessed before treatment and 12 weeks after the final session. Safety was monitored, and standardized photographs were taken for clinical evaluation.

Results: All patients showed a significant reduction in SSL, with SMSLG scores improving from a mean of 3.6 at baseline to 2.3 after 12 weeks. No adverse effects were reported, and patients experienced minimal discomfort during and after the treatment sessions. Photographs revealed visible improvements in skin tone and tightness across all cases.

Conclusions: The microwave-based treatment demonstrated significant efficacy in reducing SSL and improving skin tone with minimal side effects, offering a promising alternative to surgical interventions. This non-invasive approach provides effective outcomes in fewer sessions and may represent a new standard for non-surgical skin tightening in aesthetic dermatology.

Objective: This study aims to quantitatively compare the effects of standard needle irrigation (SNI), passive ultrasonic irrigation (PUI), EDDY, photon-initiated photoacoustic streaming (PIPS), and shock wave-enhanced emission photoacoustic streaming (SWEEPS) on the apical extrusion of irrigation solutions in teeth with severe canal curvature.

Materials and methods: Seventy-five teeth with a single root and canal, and curvature angles ranging from 20° to 40°, were selected for this study. Root canal curvatures were measured from buccolingual and mesiodistal radiographs using ImageJ software (version 1.48v; National Institutes of Health, Bethesda, MD, USA). The samples were randomly assigned to five groups (n = 15) based on the irrigation activation methods: SNI, PUI, EDDY, PIPS, and SWEEPS. An irrigation activation procedure was performed for 90 s using a total of 6 ml of 2.5% sodium hypochlorite (NaOCl) (Wizard, Istanbul, Turkey) in all samples. The Myers-Montgomery experimental model was used to simulate periapical tissues and limit the amount of extruded solution. The extruded irrigation solution was collected from the drainage cannula using an insulin syringe.

Results: The data on the amount of apical extrusion of irrigation solution were analyzed statistically using the Kruskal-Wallis and Mann-Whitney U tests, with a significance level set at P < 0.05. While the highest mean solution extrusion was observed in the SNI and PUI groups, the PIPS group showed less extrusion compared to the other groups. However, no statistically significant difference in the amount of apical extrusion of irrigation solution was found among all the irrigation activation methods tested.

Conclusions: Within the limitations of this study, all irrigation activation methods tested on teeth with severe curvature resulted in a certain amount of solution extrusion. However, no significant difference was identified among the irrigation activation methods tested.

Clinical relevance: When these irrigation activation methods are tested on teeth with varied canal anatomies, the amount of apical extrusion of the irrigation solution may vary.

The present study investigates the potential contribution of Photobiomodulation (PBM) to the regeneration of the bone following the extraction of the first mandibular molar in rats. The study evaluates the efficacy of PBM, using both Low-Level Laser Therapy (LLLT) and Light-Emitting Diode Therapy (LEDT), as promotors of osteoblastic activity and the formation of new bone. Study design, setting, and sample: 45 male Wistar rats were divided randomly into three groups of 15 individuals - (i) control group (left lower molar removed only), (ii) the LLL group (molar removed, followed by LLLT), and (iii) the LED group (molar removed, followed by LEDT). Each of these groups was divided into three subgroups of five rats, which were monitored for 7, 14 or 28 days following the extraction of the tooth. For analysis, the bone of the right mandibular hemiarch was extracted and the specimens were stained with Hematoxylin and Eosin. Microscopic morphological analysis revealed that the LED therapy had promoted greater bone remodeling activity at 7 and 14 days post-extraction, whereas the LLLT promoted the generation of more mature bone tissue, but more slowly overall. The quantitative analysis revealed a significant increase in the area of bone activity and the osteoblast count in both PBM groups in comparison with the control. Photobiomodulation, using either low-level laser or LED therapy, is effective for both bone regeneration and osteoblast activity following dental injury in rats. While the LED therapy initially presented higher levels of remodeling activity, the laser produced more mature bone tissue over time. These findings indicate that PBM is a promising therapeutic alternative for healing bone, with the potential for the improvement of postoperative outcomes in dental practise.

Green lasers have a stronger effect on promoting osteoblast differentiation, which is critical for orthodontic tooth retention. This study investigated the impact of green laser photobiomodulation on orthodontic tooth retention in rats. A total of 100 male Sprague-Dawley rats were divided into two groups: Group A (control) and Group B (green laser irradiation). The left upper first molar was moved using a 0.20-mm nickel-titanium coil spring applying a force of 50 g for 3 weeks. The coil spring was then replaced with a 0.25-mm ligature wire to establish an orthodontic tooth retention model. Group B received green laser irradiation on the periodontium surrounding the molars. Retention devices were removed on days 1, 4, 10, 13, and 21. After 3 days of recurrence, the rats were sacrificed on days 4, 7, 13, 16, and 24. The left maxillary molar region was scanned using 3Shape to assess recurrence, and micro-computed tomography was used to evaluate alveolar bone density. Tissue staining was performed to observe periodontal remodeling and bone morphogenetic protein-2 (BMP-2) expression. Over time, the recurrence rate of the molar decreased significantly in both groups (P < 0.01), while alveolar bone density and BMP-2 expression increased (P < 0.01). Group B showed a lower recurrence rate and higher bone density, BMP-2 expression, and osteoblast counts than Group A. Green laser photobiomodulation promoted periodontal tissue remodeling, increased osteoblast numbers, stimulated new bone formation, and reduced the recurrence rate during orthodontic tooth retention in rats.

Bone regeneration is a complex process influenced by inflammation and pathological conditions. Efforts to enhance this process include chemical and physical interventions, with PBMT therapy showing promise in improving bone regeneration. Despite conflicting findings in existing literature, this review aims to synthesize clinical evidence on using therapy (PBMT) in bone regeneration and explore its potential clinical applications. A systematic search was performed on electronic databases such as Web of Science, Scopus, and PubMed from the beginning until May 2024 for randomized clinical trials that reported the result of PBMT on bone regeneration. The search strategy involved using a mix of relevant medical subject headings (MeSH) terms and pertinent keywords such as photobiomodulation therapy, low-level laser therapy, bone, regeneration, PBMT, and LLLT. From an initial search identifying 1920 articles, this review centered on 13 articles for analysis, predominantly utilizing radiographical or cone-beam computed tomography (CBCT) assessments. Among these, 7 studies indicated that photobiomodulation therapy (PBMT) did not have a significant impact on bone regeneration. Conversely, 4 studies showed a substantial enhancement in bone density and regeneration with PBMT. Furthermore, 2 studies investigated the impact of varying laser characteristics on case and control groups, concluding no significant difference. In spite of the conflicting results from studies mentioned above, it appears that photobiomodulation has shown positive effects on bone reconstruction. However, further research is necessary to optimize the selection of physical parameters of laser such as wavelength, energy density, and power, as they are crucial for optimizing the effectiveness of photobiomodulation for clinical use.

It is not uncommon for individuals receiving radiotherapy for head and cancers to experience dry mouth sensation (xerostomia), salivary hypofunction (hyposalivation) and taste changes. The present study aimed to evaluate the short-term effectiveness of biweekly photobiomodulation therapy (PBMT) in managing these radiotherapy-induced adverse effects and its impact on oral health-related quality of life. Ten patients who developed xerostomia and hyposalivation secondary to radiotherapy for head and neck cancer were included. The study assessments included clinician-based [the stimulated (SSF) and unstimulated salivary flow (USSF) and taste change questionnaire] and patient-based measures [Shortened Xerostomia Inventory (SXI) and Oral Health Impact Profile (OHIP-5)]. The 10 participants (males = 5, females = 5) had a mean age of 52 (± 15) years. Half were diagnosed with nasopharyngeal squamous cell carcinoma. From visits 1 to 8, 80% showed increased USSF and/or SSF, but these were limited and not significant (p > 0.05). Nevertheless, 80% of the patients had lower xerostomia scores, 60% had less dryness frequency, and 40% showed taste improvement. Improvement in oral health-related quality of life was only observed in 30% of the participants. Strong proportional correlations were found between USSF and SSF as well as SXI and OHIP-5 at study visits 1 and 8 (p < 0.05). The findings showed the usefulness of PBMT in reducing xerostomia and taste changes and possibly increasing salivary flow over a 4-week duration. However, randomised clinical trials are needed to assess the long-term effectiveness of PBMT compared to other management options.Clinical study registration: The study was prospectively registered with the US National Library of Medicine's clinical trial registry on 13 September 2022 [ClinicalTrials.gov ref: NCT05538169].