Ingesta de cuerpos extraños magnéticos en la edad pediátrica. Caso clínico de localización y extracción endoscópica con ayuda de un imán / Ingestion of magnetic foreign bodies during the paediatric age. Case report, location and endoscopic extraction aided by a magnet

La ingesta accidental de más de un imán puede producir complicaciones graves. Los protocolos actuales recomiendan la extracción endoscópica de ser posible. El objetivo de este trabajo es presentar un caso clínico de una ingesta de dos imanes y la técnica endoscópica de extracción. Niño de 11 años que acudió a Urgencias tras la ingesta de dos imanes, asintomático. En la radiografía de abdomen, se identificaron dos cuerpos extraños radiopacos, aparentemente unidos, en la cámara gástrica. Se realizó una endoscopía bajo anestesia general en quirófano. Para facilitar la extracción, se colocó, encima de la pared abdominal, a nivel gástrico, un imán de neodimio. En la endoscopía, se observaron dos pequeños imanes localizados y fijados en la cara anterior del estómago. Una vez localizados, se retiró el imán externo y se procedió a su extracción con cesta

The ingestion of more than one magnet can cause multiple complications. Current protocols recommend endoscopic extraction if possible. We report a patient who swallowed two magnets and the endoscopic extraction technique. An 11-yearold boy presented at the Emergency Room after ingesting two small magnets, being asymptomatic. In the abdominal x-ray two radiopaque bodies were identified at the gastric chamber, apparently together. A gastroscopy was done in the operating room under general anaesthesia. To enable the extraction, a neodymium magnet was placed externally at the abdominal wall. In the endoscopic image, the two magnets were fixed to the anterior gastric wall. Once located, the neodymium magnet was removed and the two magnets were retrieved with an endoscopic basket.

Evaluation of quality of life and visual acuity after posterior capsulotomy with neodymium: YAG laser in adults / Avaliação da qualidade de vida e da acuidade visual após capsulotomia com Neodymium: YAG laser em adultos

Abstract Purpose: To determine the impact of neodymium:YAG (Nd:YAG) laser posterior capsulotomy on quality of life and visual acuity in adults. Methods: A prospective study that included patients over 65 years old with clinical indications for Nd: YAG laser capsulotomy. On the day of the procedure, corrected distance visual acuity tests, slit-lamp examination and posterior capsule opacification (PCO) photo documentation were performed, followed by application of the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). The PCO rate was evaluated with Evaluation of Posterior Capsule opacification (EPCO 2000) software. Four weeks after the posterior capsulotomy, corrected distance visual acuity was measured, and the NEI-VFQ-25 was applied again. Complications were also reported. Results : Sixty eyes from 45 patients were enrolled in the study. The mean age was 71.51 ± 6.38 years (65 to 93). Comparing the results before and after the Nd:YAG laser capsulotomy, there was a statistically significant improvement in quality of life according to the NEI-VFQ-25 (p<0.001) and in visual acuity (p=0.0). The mean score in NEI-VFQ-25 Questionnaire before capsulotomy was 62.07 ± 20.90 (16.81-95.90) and after was 83.95±19.49 (20.68 - 100.0). The mean CDVA before the procedure was 0.75 ± 0.35 LogMAR (0.1-1.3) and after was 0.21 ± 0.20 LogMAR (0.0-1.3). The mean PCO rate measured by the EPCO software was 0.688 ± 0.449. There was a positive correlation between the EPCO score and the total score of quality of life after Nd: YAG laser capsulotomy (r=0.845, p=0.00). Damage to intraocular lens was the only complication observed in six eyes (10%). Conclusion: Nd: YAG laser capsulotomy, in addition to improving visual acuity, is able to improve quality of life.

Resumo Objetivo: Determinar o impacto da capsulotomia posterior com laser de neodímio: YAG (Nd: YAG) na qualidade de vida e na acuidade visual em adultos. Métodos: Estudo prospectivo que incluiu pacientes acima de 65 anos com indicação clínica para capsulotomia com laser de Nd: YAG. No dia do procedimento, foram realizados testes de acuidade visual corrigida, exame com lâmpada de fenda e fotodocumentação da opacificação da cápsula posterior (OCP), seguido da aplicação do National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). A taxa de OCP foi avaliada utilizando o software de avaliação de opacificação de cápsula posterior (EPCO 2000). Quatro semanas após a capsulotomia posterior, a acuidade visual corrigida foi medida, e o NEI-VFQ-25 foi aplicado novamente. Complicações também foram relatadas. Resultados: Sessenta olhos de 45 pacientes foram incluídos no estudo. A idade média foi de 71,51±6,38 anos (65 to 93). Comparando os resultados antes e após a capsulotomia com laser Nd: YAG, houve melhora estatisticamente significante na qualidade de vida de acordo com o NEI-VFQ-25 (p <0,001) e na acuidade visual (p = 0,0). A média do escore total do questionário NEI-VFQ-25 pré capsulotomia foi de 62.07 ± 20.90 (16.81-95.90) e pós foi de 83.95 ±19.49 (20.68 - 100.0). A AVCC antes do procedimento foi 0.75 ± 0.35 LogMAR (0.1-1.3) e após foi 0.21 ± 0.20 LogMAR (0.0-1.3). A taxa média de OCP medida pelo software EPCO foi de 0,688 ± 0,449. Houve correlação positiva entre o escore EPCO e o escore total de qualidade de vida após a capsulotomia com laser de Nd: YAG (r = 0,845, p = 0,00). O dano à lente intraocular foi a única complicação observada em seis olhos (10%). Conclusão: A capsulotomia com laser Nd: YAG, além de melhorar a acuidade visual, é capaz de melhorar a qualidade de vida.

A Split-Face, Single-Blinded, Randomized Controlled Comparison of 532 nm Picosecond Neodymium-Doped Yttrium Aluminum Garnet Laser versus 532 nm Q-Switched Neodymium-Doped Yttrium Aluminum Garnet Laser in the Treatment of Solar Lentigines

Non-Surgical Management of Gastroduodenal Fistula Caused by Ingested Neodymium Magnets / 대한소아소화기영양학회지

Foreign body ingestions pose a significant health risk in children. Neodymium magnets are high-powered, rare-earth magnets that is a serious issue in the pediatric population due to their strong magnetic force and high rate of complications. When multiple magnets are ingested, there is potential for morbidity and mortality, including gastrointestinal fistula formation, obstruction, bleeding, perforation, and death. Many cases require surgical intervention for removal of the magnets and management of subsequent complications. However, we report a case of multiple magnet ingestion in a 19-month-old child complicated by gastroduodenal fistula that was successfully treated by endoscopic removal and supportive care avoiding the need for surgical intervention. At two-week follow-up, the child was asymptomatic and upper gastrointestinal series obtained six months later demonstrated resolution of the fistula.

Neodymium Oxide Induces Cytotoxicity and Activates NF-κB and Caspase-3 in NR8383 Cells / 生物医学与环境科学（英文）

We investigated whether Nd2O3 treatment results in cytotoxicity and other underlying effects in rat NR8383 alveolar macrophages. Cell viability assessed by the MTT assay revealed that Nd2O3 was toxic in a dose-dependent manner, but not in a time-dependent manner. An ELISA analysis indicated that exposure to Nd2O3 caused cell damage and enhanced synthesis and release of inflammatory chemokines. A Western blot analysis showed that protein expression levels of caspase-3, nuclear factor-κB (NF-κB) and its inhibitor IκB increased significantly in response to Nd2O3 treatment. Both NF-κB and caspase-3 signaling were activated, suggesting that both pathways are involved in Nd2O3 cytotoxicity.

Dowling-Degos disease: a therapeutic challenge: report of a family with no response to laser treatments

La enfermedad de Dowling-Degos (DDD), conocida también como 'anomalía reticulada y pigmentada de las flexuras' es una rara genodermatosis autosómica dominante. Se caracteriza por la aparición de máculas hiperpigmentadas de configuración reticulada; afectando principalmente los grandes pliegues como las axilas e ingles. Pudiendo, además, comprometer otros pliegues como cervicales, antecubitales, submamarios e interglúteos. Otras características asociadas son las lesiones tipo comedones y los pits palmo-plantares. Presentamos el caso de una familia con enfermedad de Dowling-Degos sin respuesta al tratamiento con laser Nd:YAG y CO2. Se realiza una revisión de la literatura de los tratamientos disponibles.

Dowling-Degos disease (DDD), also known as "reticulate pigmented anomaly of the flexures", is a rare autosomal dominant genodermatosis. DDD is characterized by an acquired reticular skin hyperpigmentation which begins in the axillae and groin. It later involves other body folds, including neck, inner aspects of the arms and thighs, inframammary, and intergluteal folds. Associated features include comedolike lesions on the neck or back, pitted facial or perioral scars, and epidermoid cysts. Herein we present a family (proband, mother, grandmother) with DDD that were treated with Q-switched Nd:YAG laser and CO2 laser without response. Treatment options are discussed and the available literature is reviewed.

Treatment of Laser Therapy-Induced Punctate Leukoderma Using a 308-nm Excimer Laser

Punctate leukoderma presents as numerous, distinct, round or oval depigmented spots. Recently, laser therapy-induced punctate leukoderma associated with various Q-switched laser and carbon dioxide laser have been reported. A 25-year-old man presented with numerous, discrete, round, confetti-like, depigmented macules on his left neck. He had undergone 3 sessions of 532-nm Q-switched Neodymium: Yttrium-Aluminum-Garnet laser treatment for café-au-lait macules three years ago. After the last laser treatment session, the punctate leukoderma had been developed. We started treatment with the 308-nm excimer laser twice a week. After 7 months of treatment duration, complete repigmentation was achieved without serious adverse effects. We recommend the 308-nm excimer laser as an effective treatment modality for laser therapy-induced punctate leukoderma.

Underestimated risks of rare-earth magnet ingestion in children: when does it need surgery?

This review discusses an underestimated risk of rare-earthmagnet (henceforth, magnet) ingestion in children and its surgical indication. Due to the ubiquity of magnets, the incidence of magnet ingestion has rapidly increased. While most foreign body ingestions show spontaneous passage, multiple magnet ingestion requires surgery in 30%-70% of the cases. Multiple magnets can attract each other across the bowel wall, leading to pressure necrosis, and subsequently, fistula, perforation, obstruction or volvulus. After recognizing magnet ingestion, the number of magnets should be checked using radiographs. In case of multiple magnet ingestion, surgery should be promptly considered.

A study on the changes in attractive force of magnetic attachments for overdenture

PURPOSE: Although magnetic attachment is used frequently for overdenture, it is reported that attractive force can be decreased by abrasion and corrosion. The purpose of this study was to establish the clinical basis about considerations and long term prognosis of overdenture using magnetic attachments by investigating the change in attractive force of magnetic attachment applied to the patients. MATERIALS AND METHODS: Among the patients treated with overdenture using magnetic attachments in Dankook University Dental Hospital, attractive force records of 61 magnetic attachments of 20 subjects who re-visited from July 2013 to June 2014 were analyzed. Dental magnet tester (Aichi Micro Intelligent Co., Aichi, Japan) was used for measurement. The magnetic attachments used in this study were Magfit IP-B Flat, Magfit DX400, Magfit DX600 and Magfit DX800 (Aichi Steel Co., Aichi, Japan) filled with Neodymium (NdFeB), a rare-earth magnet. RESULTS: Reduction ratio of attractive force had no significant correlation with conditional variables to which attachments were applied, and was higher when the maintenance period was longer (P<.05, r=.361). Reduction ratio of attractive force was significantly higher in the subject group in which attachments were used over 9 years than within 9 years (P<.05). Furthermore, 16.39% of total magnetic attachments showed detachment of keeper or assembly. CONCLUSION: Attractive force of magnetic attachment is maintained regardless of conditional variables and reduction ratio increased as the maintenance period became longer. Further study on adhesive material, attachment method and design improvement to prevent detachment of magnetic attachment is needed.

Effects of Nd: YAG laser irradiation on the root surfaces and adhesion of Streptococcus mutans / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aimed to evaluate the effects of treatment with different powers of Nd: YAG laser irradiation on root surfaces and Streptococcus mutans (S. mutans) adhesion.</p><p><b>METHODS</b>Extracted teeth because of severe periodontal disease were divided into the following four groups: control group, laser group 1, laser group 2, and laser group 3. After scaling and root planning, laser group 1, laser group 2, and laser group 3 were separately treated with Nd: YAG laser irradiation (4/6/8 W, 60 s); however, the control group did not receive the treatment. Scanning electron microscopy (SEM) was used to determine the morphology. S. mutans were cultured with root slices from each group. Colony forming unit per mL (CFU·mL⁻¹) was used to count and compare the amounts of bacteria adhesion among groups. SEM was used to observe the difference of bacteria adhesion to root surfaces between control group (scaling) and laser group 2 (6 W, 60 s), thereby indicating the different bacteria adhesions because of different treatments.</p><p><b>RESULTS</b>Morphology alterations indicated that root surfaces in control group contain obvious smear layer, debris, and biofilm; whereas the root surfaces in laser group contain more cracks with less smear layer and debris. The bacteria counting indicated that S. mutans adhesion to laser group was weaker than that of control group (P<0.05). No statistical significance among the laser groups (P>0.05) was observed. Morphology alterations also verified that S. mutans adhesion to laser group 2 (6 W, 60 s) was weaker than that of control group (scaling).</p><p><b>CONCLUSIONS</b>This study demonstrated that Nd: YAG laser irradiation treatment after scaling can reduce smear layer, debris, and biofilm on the root surfaces as compared with conventional scaling. The laser treatment reduces the adhesion of S. mutans as well. However, Nd: YAG laser irradiation can cause cracks on the root surfaces. In this experiment, the optimum laser power of 6 W can thoroughly remove the smear layer and debris, as well as relatively improve the control of thermal damagee.</p>

The Efficacy and Prognostic Factors for Long Pulse Neodymium: Yttrium-Aluminum-Garnet Laser Treatment on Onychomycosis: A Pilot Study

No abstract available.

Prospective Comparison of Dual Wavelength Long-Pulsed 755-nm Alexandrite/1,064-nm Neodymium:Yttrium-Aluminum-Garnet Laser versus 585-nm Pulsed Dye Laser Treatment for Rosacea

BACKGROUND: Rosacea treatments including oral/topical medications and laser therapy are numerous but unsatisfactory. OBJECTIVE: To compare the effectiveness of the dual wavelength long-pulsed 755-nm alexandrite/1,064-nm neodymium: yttrium-aluminum-garnet laser (LPAN) with that of 585-nm pulsed dye laser (PDL) for rosacea. METHODS: This was a randomized, single-blinded, comparative study. Full face received four consecutive monthly treatments with LPAN or PDL, followed-up for 6 months after the last treatment. Erythema index was measured by spectrophotometer, and digital photographs were evaluated by consultant dermatologists for physician's global assessment. Subjective satisfaction surveys and adverse effects were recorded. RESULTS: Forty-nine subjects with rosacea enrolled and 12 dropped out. There were no significant differences between LPAN and PDL in the mean reduction of the erythema index (p=0.812; 3.6% vs. 2.8%), improvement of physician's global assessment (p=1.000; 88.9% vs. 89.5%), and subject-rated treatment satisfaction (p=0.842; 77.8% vs. 84.2%). PDL showed more adverse effects including vesicles than LPAN (p=0.046; 26.3% vs. 0.0%). No other serious or permanent adverse events were observed in both treatments. CONCLUSION: Both LPAN and PDL may be effective and safe treatments for rosacea.

Long-Term Follow-Up of Adverse Consequences after Nd:YAG Laser Treatment for Posterior Capsular Opacification

PURPOSE: To evaluate the long-term follow-up of adverse effects after neodymium: yttrium-aluminum-garne (Nd:YAG) laser treatment for posterior capsular opacification (PCO). METHODS: In this study, 152 patients (184 eyes) diagnosed with PCO and who received Nd:YAG laser posterior capsulotomy with at least 5 years of follow-up were retrospectively analyzed to evaluate the clinical adverse consequences after Nd:YAG laser posterior capsulotomy. RESULTS: The mean age in the study group was 63.2 +/- 4.2 years and the mean follow-up period was 6.2 +/- 0.6 years. Vitreous floaters (8.1%) were the most common complication followed by reactive anterior uveitis (5.9%) and transient increase in intraocular pressure of more than 30 mm Hg (5.4%). Other complications included primary Nd:YAG laser failure (2.7%), recurrent lens epithelial remnant proliferation (1.6%), cystoid macular edema (1.1%), corneal edema (0.5%), retinal tear (0.5%), and rhegmatogenous retinal detachment (0.5%). CONCLUSIONS: Although Nd:YAG laser treatment is the most effective and safe method, surgeons should be aware of the occasional complications such as recurrent lens epithelial remnant proliferation, retinal tear, and rhegmatogenous retinal detachment through long-term follow-up.

Avaliação da força de repulsão entre magnetos de neodímeo ferro boro usados em tratamentos intra e extra bucais / Evaluation of repulsion force between Neodymium Iron Boron magnets used for intra and extra oral treatments

Os magnetos de Neodímio Ferro Boro (Nd2Fe14B) apresentam excelentes propriedades magnéticas e compatibilidade biológica, embora sejam frágeis e possuam baixa resistência à corrosão. As forças de atração magnética de magnetos de terras raras têm sido empregadas em sistemas de retenção, principalmente associadas aos implantes osseointegráveis, em próteses bucais e próteses faciais, bem como em aparelhos ortodônticos. Este estudo avalia o comportamento das forças de repulsão magnética, em função do volume e comprimento do eixo magnético, quando submetidos a afastamentos, de modo que esta propriedade física seja empregada em odontologia. Vinte e quatro corpos de prova, com um ou dois pares de magnetos de Nd2Fe14B, com diferentes formas e volumes variados, foram submetidos a ensaio mecânico para mensuração das forças de repulsão magnética, em condições de afastamentos que variaram entre 0,0 e 20,0 mm. Os dados observados mostram que, considerando-se uma mesma área superficial de polo, a força de repulsão magnética varia em função do comprimento do eixo magnético. Os dados relativos ao afastamento foram submetidos a análise de variância (p0,05), tendo-se observado que o aumento da distância entre os magnetos diminui significantemente a força de repulsão magnética na maioria dos corpos de prova. No afastamento 0,0 mm as forças magnéticas de repulsão dos subgrupos mantêm uma sequência crescente a partir do subgrupo de menor volume de magnetos ao subgrupo de maior volume de magnetos, os quais permanecem nessa sequência nos afastamentos iniciais

A força de repulsão magnética gerada por magnetos pequenos varia menos em função do aumento do afastamento. Conclui-se que a variação da força de repulsão magnética, dada a mesma área superficial de polo, apresenta uma relação direta com o volume e com o eixo magnético onde, quanto maior o volume ou o comprimento do eixo magnético, maior a força de repulsão magnética. A relação direta entre volume e força de repulsão magnética não se altera frente aos afastamentos inicais, tendendo a se tornar imensurável com o aumento da distância. A força de repulsão magnética mantém uma relação inversa com a distância entre os pares de magnetos. Este ensaio mecânico indica que a força de repulsão magnética apresenta, assim como a força de atração magnética, uma curva hiperbólica de redução frente ao aumento do afastamento.

Neodymium Iron Boron (Nd2Fe14B) magnets exhibit excellent magnetic properties and demonstrate biological compatibility, despite of their fragility and low resistance to corrosion. The magnetic attraction forces of rare earth magnets have been used in retention systems mainly associated with osseointegrated implants, in oral and facial prostheses, as well as orthodontic appliances. This study evaluates the repulsion forces of magnets, varying volume and length of magnetic axis when subjected to vertical distance, in order to assess the usefulness of such physical property in clinical situations. Twenty-four specimens, with one or two pairs of Nd2Fe14B magnets, presenting different shapes and various volumes, were subjected to mechanical testing so as to measure magnetic repulsion forces, under conditions of vertical pole face separation ranging from 0.0 to 20.0 mm. Repulsive magnetic force varies depending on the length of the magnetic axis, when considering the same surface area of a pole. Analysis of Variance - (p0.05) indicated that by increasing the distance between the pairs of magnets, magnetic repulsion force significantly reduces in most of the specimens. Starting at a 0.0 mm distance, the magnetic repulsion forces keep an enhancing sequence from lower to higher magnetic volume, holding these characteristics during initials distances. Repulsion magnetic forces generated by small magnets varies less as the distance increases.

The results indicate the repulsion magnetic force variation, fixing the same pole surface area, presenting a direct relationship between volume and magnetic axis, since the increase of the volume or of the magnetic axis length leads to a higher magnetic repulsive force. The relationship between volume and magnetic repulsion force does not vary at initial distance. Nevertheless, when such distance increases, the force between the magnets significantly decreases. The magnetic repulsion force holds an inverse relationship with respect to the distance between magnets pairs. This mechanical test indicates that the magnetic repulsion force, as well the magnetic attraction force, present a hyperbolic curve of force reduction due to the increasing vertical distance.

Nd: yag laser capsulotomy and complications

To evaluate the complications of Nd: Yag laser when applied on postoperative posterior capsule opacification [PCO], following extra capsular cataract extraction [ECCE] with intraocular lens [IOL]. Analytical and descriptive study. Eye OPD of DHQ Hospital, PMC and Clinic of Professor Zia ud Din Ahmad, Faisalabad. From Jan 2006 to Jan 2007. There were 120 patients; age ranged from 15 years to 80 years with post operated extra capsular cataract extraction with posterior capsular opacification. A Proforma was made which included detailed history of diabetes, hypertension, time period of cataract extraction, other relevant surgical or medical history, and examination e.g. Visual acuity, slit lamp examination, intraocular pressure measurement [applanation tonometry] dilated posterior capsule examination and slit lamp biomicroscopy etc. The patients were kept under observation for 5 hour and called for follow up after one week. Out of 120 patient s 70 eyes showed visual improvement from 6/18 to 6/6 [58.34%], while 30 Shown visual acuity improvement from count figures to 6/24 [25%], mild anterior uveitis occurred in 8 cases [6.67%], corneal damage in 2 cases [1.6%] while transient raised Intraocular Pressure [IOP] in 7 cases [5.83%]. The damage to IOL observed in 3 [2.5%], the corneal damage was seen in 2 cases [1.67%]. The Nd; Yag Laser is very effective, cheap and easy mode of treatment for PCO with minimal post laser complications

analysis of force between attractive magnets used in orthodontics

To compare the results of hard and soft attractive magnet combinations to the gold standard Neodymium Iron Boron Magnets used for extrusion of impacted maxillary canines. Experimental and comparative study. Eastman Dental Institute and Hospital, London, UK in collaboration with Department of Physics and Astronomy University College of London [UCL] during 1996-1998. In vitro experiments with combinations of hard and soft magnets of different morphologies. Load Cell Transducer was used to record the force levels in grams with magnets placed in different vertical, horizontal and angular offsets. Three-dimensional mesh plots were created to visualize force level decay with increasing distance. The results were compared with previous study on hard magnet combinations only and observed for "edge effect". The present study force levels were very low albeit the edge effect was negligible. Although the edge effect phenomenon present with powerful hard magnets was minimal or nearly absent with the hard and soft magnet combination - the overall force levels were too low to be of any use in clinical scenario for extrusion of deep impacted canines

Clear Lens Extraction for the Correction of Severe High Myopia: Seven-year Follow-up

PURPOSE: To evaluate the postoperative outcomes and complications 7 years after clear lens extraction (CLE) for the correction of high myopia. METHODS: The medical records of 23 eyes of 15 patients who had undergone CLE to correct myopia higher than -12 diopter and who could be followed up for more than 7 years were reviewed. A scleral tunnel incision and continuous curvilinear capsulorhexis were made, followed by phacoemulsification and posterior chamber intraocular lens implantation. Refractive error, visual acuity and postoperative complications were recorded. RESULTS: Mean follow-up was 98.2 (84~118) months. Posterior capsular opacification developed in 12 eyes (52.2%) and neodymium: YAG laser posterior capsulotomy was performed in 7 eyes. Retinal detachment developed in 3 eyes of 2 patients at 6 months, 34 months, and 9 years after CLE. At 7 years after CLE, the spherical equivalent (SE) of 14 (60.9%) of 20 eyes was within +/- 2 diopter of targeted refractive error. Shift to myopia occurred by 1 diopter compared to SE at 1 year after CLE. Best corrected visual acuity improved by 2 lines in 14 eyes (60.9%) and was 0.5 or better in 17 eyes (73.9%). CONCLUSIONS: CLE for correction of high myopia had good visual outcomes with acceptable predictability. However, long term follow-up revealed gradual increase of serious complications like retinal detachment, posterior capsular opacification, and myopic shift by 1 diopter between 1 year and 7 years after CLE.

The effect of magnetism(Neodymium magnet) on bone formation around titanium implants inserted into the tibia of rabbit / 대한치과보철학회지

STATEMENT OF PROBLEM: There are many articles that showed that the magnetism affected the bone formation around titanium implant. It means that a proper magnetism made the osseointegration improved around the implant. So after additional research on the other effect of magnetism on bone formation in implant therapy, we can conclude its possibility of clinical application on implant treatment. PURPOSE: The purposes of this study were to find out the intensity of magnetic field where magnetism in the titanium implant specimen inserted into the bone could affect the bone formation, and to discover the possibility of clinical application in the areas of dental implants and bone grafts. MATERIAL AND METHOD: Ten adult male rabbits(mean BW 2Kg) were used in this study. Titanium implant specimens were surgically implanted on the mesial side of the tibia of rabbits. Neodymium magnets(Magnedisc 500, Aichi Steel Corp. Japan) were placed into the implants of experimental group except control group, just after placement of the titanium implants. At 2, 4 and 8 weeks after the surgery, the animals were sacrificed, specimens were obtained and stained with Hematoxylin-Eosin for light microscopic evaluation and histomorphometric analysis. CONCLUSION: The results were as follows: 1. In radiographic findings, increased radiopacity downward from crestal bone was observed along the titanium implant specimen at experimental period passed by 2,4, and 8 weeks in both control and experimental group. 2. In histoiogic findings, increased new bone formation was shown in both control and experimental group through the experiment performed for 2,4, and 8 weeks. More new bone formation and bone remodeling were shown in experimental group. 3. In histomorphometric analysis, the bone contact ratios were 11.9% for control group and 38.5% for experimental group(p<0.05).

The change of bone formation according to magnetic intensity of magnet placed into titanium implant specimens / 대한치과보철학회지

PURPOSE: The purposes of this investigation were to discover the possibility of clinical application in the areas of dental implants and bone grafts by investigating the bone formation histologically around specimen which was depending on the intensity of magnetic field of neodymium magnet inside of the specimens. MATERIAL AND METHOD: 1. Measurement of magnetic intensity - placed the magnet inside of the specimen, and measured the intensity of magnetic field around the 1st thread and 3rd thread of specimen 20 times by using a Gaussmeter(Kanetec Co., Japan). 2. Surgical Procedure - Male rabbit was anesthetised by constant amount of Ketamine (0.25ml/kg) and Rompun (0.25ml/kg). After incising the flat part of tibia, and planted the specimens of titanium implant, control group was stitched without magnet, while experimental groups were placed a magnedisc 500(Aichi Steel Co., Japan) or magnedisc 800(Aichi Steel Co., Japan) into it, fixed by pattern resin and stitched. 3. Management after the surgery. - In order to prevent it from the infection of bacteria and for antiinflammation, Gentamycin and Ketopro were injected during 1 week from operation day, and dressed with potadine. 4. Preparation of histomorphometric analysis - At 2, 4 and 8 weeks after the surgery, the animals were sacrificed by excessed Ketamine, and then, specimens were obtained including the operated part and some parts of tibia, and fixed it to 10% of PBS buffer solution. After embedding specimens in Technovit 1200 and B.P solution, made a H-E stain. Samples width was 75micrometer. In histological findings through the optical microscope and using Kappa image base program(Olympus Co. Japan), the bone contact ratio and bone area ratio of each parts of specimens were measured and analyzed. 5. Statistical analysis Statistical analysis was accomplished with Mann Whitney U-test. RESULTS AND CONCLUSION: 1. In histomorphometricl findings, increased new bone formation was shown in both control and experimental groups through the experiment performed for 2, 4, and 8 weeks. After 4 weeks, more osteoblasts and osteoclasts with significant bone remodeling were shown in experimental groups. 2. In histomorphometric analysis, the bone contact ratios were 38.5% for experimental group 1, 29.5% for experimental group 2 and 11.9% for control group. Experimental groups were higher than control group(p<0.05)(Fig. 6, Table IV). The bone area ratios were 60.9% for experimental group 2, 46.4% for experimental group 1 and 36.0 % for control group. There was no significantly ststistical difference between experimental groups and control group(p<0.05)(Fig. 8, Table VII) 3. In comparision of the bone contact ratios at each measurement sites according to magnetic ntensity, experimental group 2(5.6mT) was higher than control group at the 1st thread (p<0.05) and experimental group 1(1.8mT) was higher than control group at the 3rd thread(p<0.05)(Fig. 7, Table V, VI). 4. In comparision of the bone area ratios at each measurement sites according to magnetic intensity, experimental group 2(5.6mT) was higher than control group and experimental group 1(4.0mT) at the 1st thread(p<0.1) and experimental group 2(4.4mT) was higher than experimental group 1(1.8mT) at the 3rd thread(p<0.1)(Fig. 9, Table IX, X). Experiment group 2 was largest, followed by experiment group1 and control group at the 3rd thread of implant. There was a significant difference at the 1st thread of control group and experiment group 2. and at 1st thread and 3rd thread of experiment group 1 and 2, and not at control group experiment group 1.(p<0.1)

A prospective, randomized comparison of Nd:YAG and sequential argon-YAG laser iridotomy in Filipino eyes

Methods: A prospective, randomized, controlled trial was performed involving patients requiring laser iridotomy who were randomized either to Nd:YAG laser or sequential argon-Nd:YAG laser iridotomy. Iris-perforation success rate, the average number of laser shots and amount of laser energy used, the intraocular pressure (IOP) after laser treatment, and the rate of complications were compared. The prelaser pupil size was correlated with the iris perforation success rate. Results: Forty-one eyes underwent laser iridotomy (23 Nd:YAG and 18 sequential). All eyes had patent iridotomies. There was no difference between the two groups in terms of the number of Nd:YAG laser shots delivered (p=0.97) and amount of Nd:YAG energy used (p=0.64). The total amount of laser energy used was higher in the sequential group (p=0.003). There was no significant difference in the IOP and complication rates after treatment. A positive correlation was seen between prelaser pupil size and number of Nd:YAG shots needed to enlarge (r=0.38, P=0.01). Conclusion: Nd:YAG laser alone and sequential argon-Nd:YAG have comparable success in attaining patency of laser iridotomy, IOP control, and rate of complications in dark irides of Filipinos.