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Introduction: High‐flow nasal oxygen (HFNO), or transnasal humidified rapid‐insufflation ventilatory exchange (THRIVE), is a technique providing apneic oxygenation and a degree of ventilation during microlaryngeal surgery. Its use with laser has been questioned due to concern for airway fire. For fire to occur, a triad of ignition source, oxidizer, and fuel source must be present. By using HFNO and eliminating an endotracheal tube (fuel source), it is hypothesized that airway fire risk is minimal. We tested this theory with human cadavers using HFNO with increasing levels of FiO2 while performing microlaryngeal laser surgery. Methods: HFNO was placed on two cadavers, and oxygen was administered at incrementally increasing fraction of inspired oxygen (FiO2) concentrations (30%–100%). Laryngeal microsurgery was conducted with CO2 and KTP lasers applied for 30 s. Oxygen readings were taken at several anatomic locations along the body assessing oxygen concentrations in correlation with increasing FiO2 administration. Results: The use of CO2 and KTP laser on cadaveric vocal folds produced char but no spark or airway fire at any of the tested oxygen concentrations. Apart from the mouth, there was minimal increase in oxygen levels at the surrounding anatomic sites despite elevating FiO2 levels. Conclusion: HFNO may be safe to use during microlaryngeal laser surgery. By eliminating the endotracheal tube as a fuel source, risk of airway fire may be negligible. Our study safely applied CO2 and KTP lasers for an uninterrupted 30 s with HFNO at 70 L/min and 100% FiO2 producing no spark or fire. Level of Evidence: NA Laryngoscope, 135:223–226, 2025 [ABSTRACT FROM AUTHOR]

Objective : To evaluate the curative effect of Potassium titanyl phosphate (KTP) laser and pingyangmycin injection for adult laryngeal hemangiomas (ALH). Methods : This was a retrospective study conducted on patients treated with either KTP laser or pingyangmycin injection to assess the efficacy of both treatment and compare the effects on different types of adult laryngeal hemangioma. Results : The ordinal logistic regression test showed the surgery methods had no effect on the therapeutic results. On the contrary, the shape of ALH and the interaction between surgical procedures and ALH shape affected the prognosis of the ALH. This meant that the shape of ALH might be a confounding factor affecting the therapeutic effect of ALH. Thus, the Cochran–Mantel–Haenszel test which is a stratification analysis was used to assess the interaction between surgical procedures and ALH shape. Then better results were achieved using the KTP laser for the plane and raised types of ALH. Conclusions : The selection of surgical procedures (the KTP laser or pingyangmycin injection approaches) affects the treatment of ALH. For plane and raised ALH, the KTP laser may be recommended. [ABSTRACT FROM AUTHOR]

Objectives: Photoangiolytic lasers have yielded significant innovation in laryngeal surgery in the last 25 years. After the discontinuation of the potassium titanyl phosphate (KTP) laser, a novel 445-nm blue laser was developed. The optimal balance between a laser's desired tissue effects and collateral tissue damage is a major determinant of laser selection in microlaryngeal surgery. The shell-less incubation system for the chick chorioallantoic membrane (CAM) simulates the microvasculature of the human vocal fold and is useful for testing effects of laser settings and in simulated surgery. The aim of this study is to compare the tissue effects of the KTP and blue lasers using the shell-less CAM model. Methods: The shell-less incubation system contains: polymethylpentene film (used as a culture vessel), calcium lactate and distilled water supplementations. By using this system, the chick chorioallantoic membrane (CAM) can be fully exposed with a good field for surgery simulation. The effects of the 2 lasers (532 nm KTP and 445 nm blue) were quantified at clinically relevant energy settings and laser distances from target. Measures included imaging real-time vascular reactions in the CAM model, post-procedure histologic analysis of CAM tissue and temperature changes. Results: Vessel coagulation and rupture rates were less common with the blue laser compared with the KTP laser. Histologic analysis demonstrated less tissue disruption with the blue laser. Temperature changes were less with the blue laser. Conclusion: In this CAM model with specific conditions, the blue laser reveals less tissue damage than the KTP laser. Suitable working distance and power setting of the laser are necessary for desired tissue effects. Level of Evidence: Level 3. [ABSTRACT FROM AUTHOR]

Objective: To analyze oncological efficacy and voice outcomes of the 445‐nm blue laser (BL) in the treatment of early glottic carcinoma and compare results with the 532‐nm potassium‐titanyl‐phosphate (KTP) laser. Study Design: Single institution, retrospective chart review. Methods: All patients who underwent microlaryngoscopic KTP or BL laser excision of early glottic carcinoma from 2018 to the present day with at least 1‐year follow‐up were included. Primary and recurrent disease, including radiation and surgical failures, were included. Demographic data, voice outcomes and oncologic outcomes were compared between the two laser groups. Results: Forty‐nine patients met the inclusion criteria for the BL group and 88 for the KTP group, with average follow‐up of 635 and 1236 days, respectively. Oncologic outcomes were not significantly different, with disease‐specific survival rates of 95.9% for BL and 100% for KTP (p = 0.13), organ preservation rates of 98.0% for BL and 95.6% for KTP (p = 0.39), and local control rates of 93.9% for BL and 92.1% for KTP (p = 0.81). Both BL and KTP groups showed significant improvement in CAPE‐V (p = 0.04, 0.006 respectively) and VHI‐10 scores (p = 0.003, <0.00001) following surgery. Conclusions: Photoangiolytic removal of early glottic carcinoma with BL appears to be equally safe and effective as with KTP laser at minimum one‐year follow‐up, and with excellent voice outcomes. Additional study will be warranted over time to assess long‐term outcomes in BL patients. Level of Evidence: 3 Laryngoscope, 134:4656–4660, 2024 [ABSTRACT FROM AUTHOR]

Objective: This study aimed to compare the selective absorption of the 445‐nm Blue laser (BL) and the 532‐nm pulsed potassium‐titanyl‐phosphate (KTP) laser by blood vessels. Methods: Thirty‐six chicken eggs at day 14 of incubation were dissected to expose the chick chorioallantoic membrane (CAM). Third‐order vessels of the CAM were identified and irradiated using BL and KTP lasers using various settings at a laser‐to‐vessel distance of 3 mm using 0.4 mm fiber size. In total, 494 vessels segments were irradiated. Mean (standard deviation) number of irradiations for each setting was 26.0 (4.6), range from 15 to 39. Outcome measures included ablation rate (AR) and rupture rate (RR). Results: The two lasers were compared for AR and RR at long and medium pulse width (PW) associated with different power levels. At long PW (above 100 ms), BL showed significantly higher AR than KTP at high energy (600 mJ/pulse) and low energy (400 mJ/pulse); they did not show different AR and RR at medium energy levels (500 mJ/pulse). Using medium PW settings plus high and medium energy levels, BL and KTP showed relatively high AR and did not significantly differ in performance. However, at medium PW plus low energy (400–450 mJ/pulse), KTP showed significantly higher AR compared to BL. Conclusion: At long PW, BL appeared to show higher AR than KTP at high or low energy levels, but they showed equivalent performance at medium energy. At medium PW, both performed similarly from high to medium energy, but KTP appeared to perform better than BL at lower energy settings. Level of Evidence: NA Laryngoscope, 134:3220–3225, 2024 [ABSTRACT FROM AUTHOR]

Complete subglottic stenosis is often managed with surgical resection. However, involvement of the high subglottis can limit candidacy for open resection, and there are few treatment options for these patients. We refined an endoscopic approach that evolved into a tracheal rendezvous technique with T-tube placement as an alternative to open surgical resection. Here, we present our series, technique, and outcomes. A retrospective review was performed to identify patients who underwent endoscopic management of complete high subglottic stenosis at the University of California San Diego. The surgical technique was initially a two-step staged procedure and was subsequently revised to a single-stage procedure with stenosis ablation, dilation, and insertion of a T-tube, which was completed in one day. Patients were seen at regular follow-up intervals for reassessment. Five patients were identified with complete stenosis not amenable to surgical resection. The average age of the cohort was 44.8 years. The etiology of stenosis in all patients was related to prolonged intubation and tracheostomy, and the average length of stenosis was 19.6 mm. Stenosis resection was accomplished via laser ablation and balloon dilation, and the average T-tube length was 50.3 mm. All patients were discharged on postoperative day one. Two patients developed airway crusting within the T-tube and required emergency department visits. Decannulation was attempted in three patients, although failed in two. Tracheal rendezvous is a safe and effective procedure for patients with grade IV subglottic stenosis. This provides a feasible endoscopic alternative to patients who are not candidates for open surgical resection, ye are motivated to have phonatory capacity.

Background: Verrucae are benign proliferations caused by human papillomavirus. Treatment is needed for pain, bleeding, contagiousness, and cosmetically. Aims: The aim of this study is to evaluate the effectiveness of KTP laser treatment in verrucae, as well as side effects and recurrence rates. Patients and Methods: Patients who had Verrucae vulgaris (V. vulgaris) and Verrucae plantaris (V. plantaris) previously treated with KTP laser were scanned for their eligibility. Twenty‐nine patients who met the inclusion criteria were included. There was complete recovery in 24 patients (82.8%) and partial recovery in two patients (6.9%). Three patients (10.3%) were unresponsive to treatment after six sessions (no recovery). Two patients had mild pain during the application, and 65.4% of the patients had complete cosmetic recovery at the 3rd month follow‐up. Results: As a result, we found that the standard KTP laser can be an effective option for both types of verrucae. Conclusions: We think KTP laser treatment can be preferred for verrucae treatment. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to evaluate the antimicrobial efficacy of Potassium Titanium Phosphate (KTP) laser-activated irrigation solutions on intraradicular Enterococcus faecalis biofilms in invitro conditions by using a scanning electron microscope. Materials and Methods: 120 single-root, single canal permanent mandibular premolar human teeth were used. Sterilization and disinfection of the teeth were performed. E. faecalis biofilms were obtained after 4 weeks by re-inoculation procedures. Each group was divided into 6 groups consisting of 20 roots and root canal disinfection protocols were applied using irrigation solutions with 5.25% NaOCl, saline, super-oxidized water solution, 8ppm ozonated water, 2% CHX, 17% EDTA, all activated by KTP laser. It was smear-planted to a solid medium which split as before and after the disinfection applications for the aim of Counting Microorganism colonies from root canals and data were evaluated statistically. In this statistical evaluation one way ANOVA and Tukey tests were used. Before and after the irrigation procedures for presence and elimination of biofilm the root canals were processed for scanning electron microscopy and biofilm was examined on the standard images. Results: As a result of the statistical comparison performed among all groups, while NaOCl ensures the highest amount of elimination as a positive control group, the lowest amount of bacterial elimination was detected in the SF group that applied as the negative control group (P0,05), EDTA showed the lowest antibiofilm effect (P

Objective: This study evaluated the postoperative pain intensity in permanent teeth with symptomatic irreversible pulpitis treated by pulpotomy using physiological saline, sodium hypochlorite (NaOCl), or the potassium titanyl phosphate (KTP) laser. Materials and methods: Ninety patients diagnosed with symptomatic irreversible pulpitis in permanent molars were randomly divided into three groups according to the pulpotomy procedures. Preoperative pain levels were recorded. Complete hemostasis was achieved with physiological saline (control group), NaOCl, or the KTP laser after initial bleeding control. Patients were asked to mark their pain level on the visual pain scale at 6, 24, 48, and 72 h and 7 and 30 days depending on the severity of pain. The permanent restoration was completed after 7 days. Data were statistically analyzed using Kruskal-Wallis, Mann-Whitney U, Friedman, and Bonferroni tests at a significance level of p < 0.05. Results: According to the present study, the statistical difference between the groups in terms of preoperative pain and percussion pain levels was insignificant (p > 0.05). There was no significant difference between groups in terms of demographic data (p > 0.05). The postoperative pain level of the KTP laser group was significantly lower at 6 h compared with the saline group (p < 0.05). There was no significant difference between groups in terms of the postoperative pain level at other time intervals (p > 0.05). The highest pain scores were observed in all groups at 6 h (p < 0.05). Conclusions: The KTP laser can be preferred primarily for reducing postoperative pain in pulpotomy treatments. The KTP laser or NaOCl-assisted pulpotomy can be an effective treatment for pain reduction in permanent teeth with symptomatic irreversible pulpitis. This report is registered at clinicaltrials.gov (ID: NCT05424796). [ABSTRACT FROM AUTHOR]

Aesthetic medicine is a dynamically developing field of medicine. It has an impact not only on the improvement of the external appearance, but also on health and quality of life. Currently, vascular changes affect many patients and significantly diminish the condition of the skin. The development of modern laser therapy has contributed to the successful management of multiple skin conditions, among them vascular lesions. The aim of our study was to show the efficacy of repetitive 532 nm laser therapy in reducing vascular skin lesions located on the facial area. Observations were possible due to the implementation of System of Skin Analysis. We retrospectively analyzed the records of 120 patients (100 women and 20 men) using "VISIA" Skin Analysis System after 532 nm laser therapy. Treatment with the use of the 532 nm vascular laser turned out to be effective in reducing vascular changes in both women and men. The skin phototypes did not significantly affect the therapy efficacy. Neither the age of patients nor number of laser sessions affect therapy efficacy. 532 nm laser therapy is effective in reducing vascular skin lesions located in the face area. [ABSTRACT FROM AUTHOR]

Objective: Granular myringitis is a chronic and difficult-to-treat condition of the tympanic membrane. This paper presents a minimally invasive treatment technique using the potassium titanyl phosphate laser. Design: A retrospective case review of patients who underwent potassium titanyl phosphate laser treatment between 2015 and 2020 was performed. All patients underwent final telephone follow up in 2020 to ascertain whether they had any ongoing myringitis symptoms, and all were offered further face-to-face follow up. Results: Fourteen patients with myringitis were identified, with one patient having both ears affected. Of the 15 affected ears, 2 required a second treatment, resulting in a total of 17 laser treatment cases. At the first post-operative review, the appearance of the drum had improved in 10 out of 17 treatments (59 per cent). Conclusion: Potassium titanyl phosphate laser surface tympanoplasty may provide safe, quick and effective resolution of myringitis. [ABSTRACT FROM AUTHOR]

The use of the KTP 532 nm vascular laser in the treatment of erythema and telangiectasia caused by low temperature exposure - case report. A case report. The paper presents a case of effective treatment of frostbite vascular lesions in the face with the use of a 532nm KTP laser in a 55-year-old man with a long history of skin exposure to low temperatures. Aim. The aim of this study is to draw attention to the possibility of using laser therapy in the treatment of skin disorders that are a complication of exposure to low temperatures. In the article below, we present the reduction of vascular lesions of the facial skin during a series of laser treatments with the use of the 532nm laser, meeting the growing interest of patients and doctors in the use of laser therapy in the treatment of skin vascular lesions. Conclusions. The use of laser therapy with the KTP 532nm laser can be an important and effective element in the treatment of skin vascular lesions.

Objective: The incidence of post-operative glottic cyst (POGC) formation in patients treated with transoral laser microsurgery with potassium-titanyl-phosphate laser (TLM-KTP) photoablation of early glottic carcinoma (EGC) has not previously been described. Methods: A retrospective chart review was performed to identify all patients with early glottic cancer who underwent with single-modality TLM-KTP at our institution. Each patient received regular follow up with videostroboscopy for tumor surveillance. New glottic cysts seen on surveillance examinations were noted and their management was documented. Results: A total of 33 patients met inclusion criteria. Eight patients (24%) developed POGC's within the original geographic perimeter of the cancerous vocal fold(s): 6 in the infraglottic region and 2 near the vocal process, at an average of 8 months after their initial cancer surgery. Of these 8 POGC's, 7 were at the periphery of the original tumor distribution and 1 was in the center of it. No POGC's were associated with any change in voice. Four of the 8 POGC's were phonosurgically excised, all without evidence of malignancy on pathology. The remaining 4 were monitored: 2 were stable for an average of 49 months of follow up; the remaining 2 resolved spontaneously by 7 and 31 months after first identification. Conclusions: POGC's are a frequent sequela of TLM-KTP for EGC. While these results suggest that they are unlikely to represent submucosal recurrences, surgeons should have a low threshold to biopsy if there is clinical concern for such and should counsel patients pre-operatively about the potential for their formation. [ABSTRACT FROM AUTHOR]

Branchial anomalies can present in the parapharyngeal space, creating unique challenges in management. Historically, this approach warranted an open approach, including transcervical, transparotid with total parotidectomy and retromandibular dissection, or transmandibular dissection with mandibulotomy. However, the advent of minimally invasive transoral techniques and laser resection have allowed for successful resection of masses in this anatomical region without an external approach. We illustrate these advancements with the case of a 30-year-old man with globus sensation and throat discomfort, found to have a mass of the right posterolateral oropharynx causing severe airway obstruction. Imaging showed a parapharyngeal mass with extension to the carotid sheath and retropharyngeal space, which was successfully resected with potassium-titanyl-phosphate (KTP) laser using a minimally invasive transoral approach with no major complications. Transoral excision offers decreased morbidity and a cosmetically favorable outcome compared to transcervical excision. KTP laser may be safely used for transoral excision of a benign parapharyngeal mass.

Background: Lymphangioma is a benign but locally aggressive tumor that most commonly presents in childhood, often developing in the head and neck and rarely in the larynx. We present a rare Case of an adult with isolated laryngeal lymphangioma managed with potassium titanium phosphate (KTP) laser excision. Case description: A 40-year-old male was evaluated for tracheostomy after extubation failure in the setting of cardiogenic shock. Fiberoptic endoscopic evaluation of swallowing revealed a vascular-appearing glottic mass extending directly from the false vocal fold. Excision of the mass was performed using KTP laser with concomitant intraoperative decannulation. He has been monitored post-operatively with no signs of disease recurrence. Conclusions: Isolated laryngeal lymphangioma is extremely rare in adults. Historically, management has been aggressive, with early surgical resection with wide margins. This case report demonstrates an optimal treatment response to more conservative management using KTP laser, which was well suited for the mass given its vascularity and its location on the false vocal fold. Postoperative monitoring is crucial for patients with lymphangioma, given high risk of recurrence. Follow up with laryngoscopy has affirmed full recovery for this patient without any signs of recurrent or residual disease.

In the last decade, demand for metal-free esthetic restorations has grown considerably due to the development of materials to fulfill the need for an esthetic prosthesis. We examined the effects of erbium-doped yttrium aluminum garnet (Er:YAG), neodymium-doped yttrium aluminum garnet (Nd:YAG), and potassium titanyl phosphate (KTP) laser applications on the shear bond strength (SBS) of nanohybrid composite superstructures to zirconia and PEEK infrastructures. Zirconia and PEEK specimens were prepared with CAD/CAM technology in accordance with ISO 11405 standards. The disc-shaped samples were randomly separated into four groups (n = 8) according to applied laser type: no treatment and Er:YAG, Nd:YAG, and KTP lasers. Nanohybrid composite resin was applied as a veneering material to each infrastructure. After surface treatment of infrastructures by the lasers, the SBS test was carried out to determine the bonding of infrastructures, which were also examined with a stereomicroscope. The SBS were significantly higher in the PEEK specimens treated with the studied lasers. Nd:YAG laser was the most effective method, followed by Er:YAG laser and KTP laser. The lowest SBS value was obtained in the no-treatment group. Stereomicroscopically, the studied lasers produced different irregularities on the infrastructures. PEEK as a framework provides meaningfully higher bonding strength to composite resins compared to zirconia. Nd:YAG, Er:YAG, and KTP, in descending order, are efficacious in increasing the attachment of studied structures. [ABSTRACT FROM AUTHOR]

Objective: To assess the current practices and challenges of training office‐based procedures to laryngology fellows in the United States. Methods: An anonymous web‐based survey study was distributed to laryngology fellowship program directors, as listed by the American Laryngological Association. The survey was a 19‐item questionnaire with free‐text, Likert scale, and multiple‐choice answers. Results: Twenty‐two of 27 program directors (81.4%) replied to the survey. Many programs (8/16) have three or more laryngologists and do more than 10 procedures each week (10/16). Sixty‐nine percent (11/16) of directors had not been trained for office procedures in their fellowship. The fellows are allowed to be primary surgeon on 68.75% and 75% of vocal fold augmentation and laser procedures, respectively. The expected competencies for these procedures on graduation are average‐moderate and moderate. When program directors asked about the methods used for training, a minority of them use simulators (2/16), procedural checklists (2/16), or structured debriefing (2/16). The most commonly used methods were case‐based troubleshooting (13/16) and unstructured debriefing (13/16). Patients being awake and patients' expectations are seen as the most important obstacles. Most of the directors thought office‐based procedure training could be improved (14/16). The most common suggestions were using step‐wise checklists, simulator‐labs, and formal debriefings. Conclusion: This is the first study evaluating the training of office‐based laryngeal procedures during laryngology fellowship. Given the increasing importance of these procedures in practice and the herein identified barriers and need for improvement, fellowships should investigate the use of systematic training tools to improve fellow competency with office‐based procedures. Laryngoscope, 131:2054–2058, 2021 [ABSTRACT FROM AUTHOR]

Introduction: Incidental papillomas of the pharynx can be found while examining the nasopharynx, oropharynx, and hypopharynx for other disorders of the head and neck. Purpose of the study is to explore the location, biopsy protocol, and decision to perform office-based versus operative management via potassium titanyl phosphate (KTP) laser when an oropharyngeal papilloma is discovered incidentally. Methods: A retrospective review of the senior author's patient population was performed using Current Procedural Terminology and/or International Classification of Diseases codes to identify patients who had KTP laser removal of incidental oropharyngeal papillomas. Patients were included based on the incidental nature of the papilloma and confirmed pathology report of squamous papilloma. Demographics, presenting complaint, lesion location, pathological analysis, type of intervention, and outcomes were recorded. When available, human papillomavirus (HPV) subtype was noted. Results: A total of 26 cases were identified, 13 females and 13 males. The median age at time of surgery was 58 years (range: 21-77). The most common presenting symptoms were difficulty swallowing and throat pain. The most common locations were the base of tongue, uvula, tonsils, and the soft palate. Of the 26 patients, 23 patients received KTP laser ablation therapy as an office-based procedure, while the remaining 3 were performed under general anesthesia in the operating room. Only 5 patients had a recorded recurrence that required reoperation. There were no operative or postoperative complications. There were 16 biopsy samples tested for HPV, where 12 were negative for HPV and 4 were positive for HPV. Conclusion: Oropharyngeal papillomas, when present, can be found incidentally during examination of the oropharynx for other symptoms. Office-based biopsy and KTP laser is a safe and efficient means of identifying and removing most oropharyngeal papillomas. [ABSTRACT FROM AUTHOR]

Objectives: Vocal cysts, common benign laryngeal lesions, often lead to voice disturbances. Total surgical enucleation presents challenges due to the delicate nature of vocal tissues. Conventional surgery carries risks of recurrence and decreased voice quality due to incomplete removal and potential vocal fold damage. This study investigates the efficacy of Potassium-Titanyl-Phosphate (KTP) laser-assisted marsupialization for the treatment of vocal cysts., Subjects and Methods: We retrospectively analyzed 78 patients who underwent either conventional surgery or KTP laser-assisted marsupialization to compare the voice outcomes and recurrence rates of the two groups., Results: KTP laser-assisted group (B) demonstrated significantly higher recurrence rates (18.4%) compared to conventional surgery group (5%). The mean time to cyst recurrence were 12.4months in group A and 10.9months in group B. The degree of postoperative improvement in all voice parameters was not significantly different between the two groups., Conclusions: While KTP laser-assisted marsupialization may offer some advantages such as reduced vocal fold damage and ease technique, the higher recurrence rates observed in this study suggest that this technique may not achieve cure rates comparable to conventional surgery. Therefore, careful consideration is necessary when selecting patients for this procedure, and further research is needed to refine the technique and evaluate its long-term efficacy., Level of Evidence: Level III., Competing Interests: Declaration of Competing Interest The authors have no funding, financial relationships, or conflicts of interest to disclose., (Copyright © 2024 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Objective(s): The objective of this study is to compare treatment outcomes for vocal fold polyps (VFPs) between operating room microlaryngoscopy and office-based photoangiolysis with the potassium titanyl phosphate (KTP) laser., Methods: Prospective nonrandomized cohort study of patients with VFPs undergoing microlaryngoscopy ("OR group") or KTP laser photoangiolysis ("KTP group"). Voice outcomes (patient-reported outcome measures [Voice Handicap Index-10 (VHI-10) and Singing VHI-10 (SVHI-10)], auditory-perceptual measures [Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V)], videostroboscopic characteristics [Voice-Vibratory Assessment of Laryngeal Imaging (VALI)], and acoustic and aerodynamic measures) were performed at baseline and regular intervals after intervention., Results: Forty-four subjects (17 OR group, 27 KTP group) with VFPs were enrolled. Mean VHI-10 significantly improved from baseline to each follow-up interval in both groups, except for the 1-2-week interval in the OR group. Mean SVHI-10 improved for both groups at some intervals. Growth curve models and time-to-event analyses for patient-reported outcomes did not differ between groups. There were significant improvements in all categories of auditory-perceptual voice quality and some categories of videostroboscopic characteristics in both groups. No significant trends were identified in acoustic and aerodynamic measures. Improvements in most outcomes did not significantly differ between groups or based on polyp size. There were no major complications., Conclusions: Significant improvements in patient-reported voice outcomes measures, auditory-perceptual voice evaluation, and videostroboscopic characteristics occur following surgical treatment of vocal fold polyps with either microlaryngoscopy or office-based KTP laser. Long-term voice outcomes do not significantly differ between treatment modalities., Level of Evidence: 3 Laryngoscope, 134:S1-S20, 2024., (© 2024 The American Laryngological, Rhinological and Otological Society, Inc.)

Objectives: The primary objectives were to report oncologic outcomes of transoral laser microsurgery with potassium-titanyl-phosphate (KTP) laser (TLM-KTP) ablation of early glottic cancer (EGC). The secondary objectives were to report vocal outcomes and to analyze factors that might influence outcomes. Methods: A multi-institutional, retrospective analysis of consecutive patients treated for T1 or T2 glottic squamous cell carcinoma undergoing TLM-KTP ablation with at least 2 years of follow-up was performed. Patients with prior radiation or surgery for laryngeal disease were excluded. Primary outcome measures included: surgical failures requiring radiation or laryngectomy, disease-specific survival (DSS), and overall survival (OS). Secondary outcome measures included: pre- and postoperative Voice Handicap Index-10 (VHI-10) scores. The effects of smoking status, stage, and anterior commissure involvement on outcomes were analyzed. Results: Overall 88 patients met inclusion criteria (83% male, 79.5% current or former smokers). Mean age was 68 (standard deviation (SD): 12). Mean follow-up was 39.5 months (SD: 15.3). Staging included 50 T1a, 21 T1b, and 20 T2 tumors, including three metachronous second primaries. Radiation and/or laryngectomy avoidance was achieved in 87/88 (98.9%) of patients, inclusive of 24 patients requiring KTP re-treatments. Two patients had biopsy-proven recurrence (2.3%), but only 21 of 24 re-treated patients received a formal biopsy. No patients died from laryngeal cancer. DSS and OS were 100% and 92.3%, respectively. The mean VHI-10 scores were 19.3 preoperatively, 3.8 at 6-months postop, and 3.8 at 2-years postop. Smokers had a longer interval to re-treatment (P =.03), patients with T2 lesions had a shorter interval to re-treatment (0.02), and patients with T2 lesions presented with worse initial VHI-10 scores (0.002). Conclusions: A multi-institutional, retrospective case series of TLM-KTP ablation of EGC demonstrated excellent oncologic outcomes when close surveillance and proactive re-treatments were utilized. Disease-specific survival, overall survival, and vocal function were excellent. Additional studies are necessary to further analyze the merits and risks of this treatment approach. [ABSTRACT FROM AUTHOR]

In clinical dentistry, the strength of bonding zirconia posts to root canal dentinal walls currently needs enhancement, and laser application can be an important contribution owing to its features that accommodate adjustable modifications on dental materials. Herein, the effect of different laser treatments applied to dentin surfaces on the strength of bonding zirconia posts to root canal dentinal walls is evaluated by using the pull-out bond strength test in a laboratory setting. A total of 40 single-rooted permanent mandibular premolar teeth that were freshly extracted were used here. The root canal preparation steps were performed using the crown-down technique. Custom-made zirconia posts were produced using CAD/CAM technology. Prior to the application of resin cement, the internal surfaces of the root canals were irradiated using Nd:YAG, Er:YAG, and KTP lasers. Pull-out tests were performed on each specimen by using a universal testing machine. One-way analysis of variance and Tukey post hoc tests were used to compare the pull-out bond strength data. The bond strengths of the laser-treated specimens were greater than those of the untreated controls (p < 0.05). While the value of the pull-out bond strength after Nd:YAG laser treatment was significantly higher than the values obtained after the applications of the Er:YAG and KTP lasers (p < 0.05), the pull-out bond strength after Er:YAG laser treatment was considerably greater than that after KTP laser treatment (p < 0.05). The bond strength between the root canal dentin and the CAD/CAM custom-made zirconia post was improved upon using all the laser modalities in current laboratory settings, among which, application of the Nd:YAG laser was the most successful. [ABSTRACT FROM AUTHOR]

Background & objectives: Inferior turbinate hypertrophy (ITH) is a common condition causing nasal obstruction. This study was undertaken to compare the efficacy of potassium titanyl phosphate (KTP) laser and diode laser in the reduction of the turbinate size. Methods: This randomized controlled trial included 209 patients with ITH. Pre-operative symptoms were assessed based on the Nasal Obstruction Symptom Evaluation (NOSE) score. Diagnostic nasal endoscopy was done to rule out other nasal sinuses. Nasal mucociliary clearance was measured by saccharin transit time (STT). Postoperatively, the NOSE score, STT and complications were assessed at days one and two, at one week, one month and three months. Results: Of the 209 patients analyzed at day one, the median NOSE score was 50 in the diode group and 40 in the KTP group, and at three months, 15 in the diode group and five in the KTP group. KTP laser showed a 93 per cent improvement in the NOSE score as compared to 77 per cent improvement shown by diode laser group. Among the intra-operative complications, of the 104 patients in the diode group, 6.73 per cent had burning sensation and 91.43 per cent had bleeding, and of 105 patients in the KTP group, 54.29 per cent had burning sensation and 36.54 per cent had bleeding. Among the post-operative complications in the KTP group, 32 and 34 per cent had bloody nasal discharge on days one and two, compared to 12 and 14 per cent in diode group. Crusting was present in 61 and 49 per cent on days one and two in KTP group as compared to 9 and 15 per cent in diode group, respectively. In the KTP group 30 per cent had synechiae as compared to 10 per cent in diode group. Interpretation & conclusions: KTP laser was more efficacious than diode laser in improving the NOSE scores but with slightly increased rate of complications in early post-operative period. Both the lasers impaired the mucociliary clearance mechanism of the nose till three months of post-operative follow up. [ABSTRACT FROM AUTHOR]

An open, prospective, nonrandomized study of 122 children with infantile hemangiomas aged 1 to 24 months was conducted to evaluate the effectiveness and safety of treatment with multiline laser equipment using the Nd:YAP Q‐Sw/KTP emitters with the combined use of two wavelengths of 1079/540 nm. The average age of the children was (6.3 ± 0.3) months, 22 of them were boys (18.0%) and 100 were girls (82.0%). An erythometry and ultrasound examination were performed to determine the depth of the neoplasm, to assess its blood flow, and the presence and diameter of the supply vessels. Studies of these indicators were conducted for patients before and after the treatment. Laser treatment was performed on 109 patients with 119 hemangiomas. A total of 81 superficial hemangiomas underwent a short course of laser therapy (2‐5 procedures) and remaining patients with 38 combined hemangiomas received a long course of laser treatment, consisting of 6 to 10 procedures. Restoration of normal color, skin relief, and the absence of scars were noted in post‐treatment sample on evaluation. After the course of treatment, erythometry readings corresponded to the values of normal skin and decreased to 110 to 80 cu. Ultrasound examination showed vascular formation and feed vessels were not visualized. [ABSTRACT FROM AUTHOR]

Different external bleaching procedures utilizing highly concentrated hydrogen peroxide formulations can be used for tooth bleaching and tooth whitening. Whitening is the removal of superficial discoloration of the teeth, whereas bleaching constitutes the removal of stains on and in tooth substance by means of oxygen radicals. Light can be used to enhance or accelerate the bleaching process. In most cases, the effect of light is limited to heating of the bleaching formulation and this process differs from "true photobleaching". Photobleaching or photodynamic bleaching is a process where light from a laser or non-coherent light source is used to drive molecular changes in light-sensitive compounds, and where the discoloration or bleaching of the teeth is caused as a result of the generation of reactive oxygen species. Secondly, it is also possible to photobleach colored organic compounds and especially those that are inherently resistant to the action of the oxygen free radicals. At present, true photobleaching can only be performed with the KTP laser (532 nm) in conjunction with a red colored highly concentrated hydrogen peroxide gel. Furthermore, it has also been demonstrated that the use of the KTP laser with the Smart Bleach system is safe: no intrapulpal temperature elevations beyond 5.5°C have been registered, and there is no risk of enamel microhardness decrease. KTP laser bleaching can be considered a noninvasive esthetic procedure, and hence is the least invasive procedure of what is called today minimally invasive dentistry. [ABSTRACT FROM AUTHOR]

At present, the only system providing laser bleaching (of stains on and in tooth substance) with photothermal, photochemical, and photocatalytic activation of the bleaching gel is the combined use of the KTP laser (λ = 532 nm) with the Smart Bleach gel (SBI). Moreover, this system offers the advantage of performing true photobleaching, meaning that the problem of persisting intense discoloration resistant to the action of the oxygen free radicals - such as results from tetracyclines -can be solved. [ABSTRACT FROM AUTHOR]

When confronted clinically with the problem of tooth discolouration, the basic strategy is to first identify the aetiology of the discolouration, and then to apply the selected treatment, using the philosophy "as much as required, but as little as necessary." For internal discolourations, green laser light from a KTP or argon laser is able to elicit photochemical reactions both within tooth structure and within a bleaching gel applied onto the labial surface. The unique optical and chemical interactions makes photochemical bleaching possible through promoting oxidation events in a controlled manner. This paper outlines a clinical approach to the diagnosis and management of patients with tooth discolouration, and summarises the technical and clinical aspects of the Smarthbeach system for laser whitening. While extremely useful for routine in-surgery whitening treatments, the system is also able to treat severe tetracycline staining, to achieve pleasing improvements in appearance. A case is presented to illustrate the application of the Smartbleach system in these more challenging situations. A simple objective method for assessing tooth shade changes during laser whitening is also described. [ABSTRACT FROM AUTHOR]

Several cases illustrating the use of Er:YAG, argon, KTP, Nd:YAG, and diode laser in cavity preparation, photopolymerization, bleaching, endodontics, and periodontics, respectively, are presented. The hemostatic and bacteriocidal properties of lasers are highlighted. [ABSTRACT FROM AUTHOR]

Several cases are presented which show that by the use of a KTP laser, bleaching can be performed more predictably, faster, and more safely, even in severe cases of tetracycline staining. [ABSTRACT FROM AUTHOR]

Objective:The objective of this study was to evaluate the antimicrobial activity of different power settings of potassium-titanyl-phosphate (KTP) laser in experimentally infected root canals.Methods:A total of 119 freshly extracted human single-rooted teeth with mature apices were selected for study. After preparation and sterilization, the specimens were inoculated with 15 µL Enterococcus faecalis for 24 hours at 37°C. The contaminated roots were divided into five experimental groups (1W, 1.5W, 2W, 3W, and 4W KTP laser), one negative control [sodium hypoclorite (NaOCl)] group, and one positive control [sterile saline (SF)] group of 17 teeth each. Before and after applications in the groups, samples retrieved with sterile paper points from the root canal were transferred to tubes containing 5 mL of the brain heart infusion broth. Next, 10 μL of these suspensions were placed at two different sides of the blood agar medium. Bacterial reduction was counted according to the colony-forming units and data were statistically analyzed using the Kruskal–Wallis and Tukey’s tests.Results:The maximum decrease occurred in the 2.5% NaOCl (100%±0.00%) group. This decrease was followed by decreases in the following KTP laser groups: 4W (94.26%), 3W (87.98%), 2W (77.43%), SF (68.80%), 1.5W (65.89%), and 1W (52.08%). Statistically, the difference between the 1W KTP laser group and all groups and the difference between the 2.5% NaOCl group and all groups, except the 4W KTP laser group, were found to be significant (p

Quantitative data regarding photothermal and damage processes during pulsed laser irradiation of blood are necessary to achieve a better understanding of laser treatment of cutaneous vascular lesions and improve numerical models. In this study, multiple experimental techniques were employed to quantify the effects of single-pulse KTP laser (λ = 532 nm, τp = 10 ms) irradiation of whole blood in vitro: high-speed temperature measurement with a thermal camera in line-scan mode (8 kHz); optical coherence tomography (for determination of coagulum morphology); and transmission measurement with a co-aligned laser beam (λ = 635 nm). Threshold radiant exposures for coagulation (4.4-5.0 J/cm2) and ablation (approximately J/cm2) were identified. Thermal camera measurements indicated threshold coagulation temperatures of 90-100 °C, and peak temperatures of up to 145 °C for sub-ablation radiant exposures. Significant changes in coagulum thickness and consistency, and a corresponding decrease in transmission, were observed with increasing radiant exposure. The Arrhenius equation was shown to produce accurate predictions of coagulation onset (using appropriate rate process coefficients). The significance of dynamic effects such as evaporative loss and dynamic changes in optical properties was indicated. Implications for numerical modeling are discussed. Most importantly, the threshold temperatures typically quoted in the literature for pulsed laser coagulation (60-70 °C) and ablation (100 °C) of blood do not match the results of this study.

The effects of cooling, laser irradiation, and laser irradiation with cooling on blood vessels were investigated with Color Doppler Optical Coherence Tomography (CDOCT). CDOCT may contribute to an understanding of the dynamics of laser-blood vessel interactions and aid in better optimization of laser parameters to be used. In this study, hamster dorsal skin flap window vessels were irradiated with a KTP laser operating at 532 nm. Irradiation sites were imaged with CDOCT prior to, during, immediately after, and several days after irradiation. KTP laser parameters were: radiant exposures in the range of 7-14 J/cm2, 3 mm spot size, and 10 ms pulse duration. Magnitude and color Doppler images provided information such as vessel size, depth, and changes in blood flow velocity. Vessel constriction, temporary occlusion, and changes in flow were frequent results of laser irradiation visualized with CDOCT. In addition, the effects of cooling alone were imaged with CDOCT and its effects on blood vessel flow and morphology were investigated before and after laser irradiation.

Quantitative data regarding photothermal and damage processes during pulsed laser irradiation of blood are necessary to achieve a better understanding of laser treatment of cutaneous vascular lesions and improve numerical models. In this study, multiple experimental techniques were employed to quantify the effects of single-pulse KTP laser (λ = 532 nm, τp = 10 ms) irradiation of whole blood in vitro: high-speed temperature measurement with a thermal camera in line-scan mode (8 kHz); optical coherence tomography (for determination of coagulum morphology); and transmission measurement with a co-aligned laser beam (λ = 635 nm). Threshold radiant exposures for coagulation (4.4-5.0 J/cm2) and ablation (approximately J/cm2) were identified. Thermal camera measurements indicated threshold coagulation temperatures of 90-100 °C, and peak temperatures of up to 145 °C for sub-ablation radiant exposures. Significant changes in coagulum thickness and consistency, and a corresponding decrease in transmission, were observed with increasing radiant exposure. The Arrhenius equation was shown to produce accurate predictions of coagulation onset (using appropriate rate process coefficients). The significance of dynamic effects such as evaporative loss and dynamic changes in optical properties was indicated. Implications for numerical modeling are discussed. Most importantly, the threshold temperatures typically quoted in the literature for pulsed laser coagulation (60-70 °C) and ablation (100 °C) of blood do not match the results of this study.

The effects of cooling, laser irradiation, and laser irradiation with cooling on blood vessels were investigated with Color Doppler Optical Coherence Tomography (CDOCT). CDOCT may contribute to an understanding of the dynamics of laser-blood vessel interactions and aid in better optimization of laser parameters to be used. In this study, hamster dorsal skin flap window vessels were irradiated with a KTP laser operating at 532 nm. Irradiation sites were imaged with CDOCT prior to, during, immediately after, and several days after irradiation. KTP laser parameters were: radiant exposures in the range of 7-14 J/cm2, 3 mm spot size, and 10 ms pulse duration. Magnitude and color Doppler images provided information such as vessel size, depth, and changes in blood flow velocity. Vessel constriction, temporary occlusion, and changes in flow were frequent results of laser irradiation visualized with CDOCT. In addition, the effects of cooling alone were imaged with CDOCT and its effects on blood vessel flow and morphology were investigated before and after laser irradiation.

Purpose: To evaluate three methods for treating adult laryngeal hemangiomas: conventional chemotherapy, CO2 laser combined with chemotherapy, and KTP laser. And to identify risk factors that affected the prognosis of the lesions. Method: A retrospective analysis was performed on the data from patients with adult laryngeal hemangiomas treated by one of three aforementioned methods, the curative efficacy, and safety of those methods was compared. Results: All cases were confirmed by suspension micro-laryngoscope examination. Pre- and post-treatment clinical photographs were taken and the outcomes were graded. Thirty-eight patients in 48 different cases were enrolled in the study between June 2010 and June 2016, and some patients were treated more than once. The treatment efficacy of the KTP laser was higher than that of chemotherapy according to the Kruskal-Wallis ANOVA test; however, the ordinal logistic regression showed that the choice of surgical procedure did not affect the treatment results; only the size of the bases of the lesions affected the prognosis of adult laryngeal hemangiomas. Conclusions: Pingyangmycin injection, KTP laser, and CO2 laser combined with chemotherapy are safe and effective methods for the treatment of adult laryngeal hemangiomas. The size of base of the lesion affects the prognosis of the hemangiomas. [ABSTRACT FROM AUTHOR]