A combined usages of the lasar irradiations and excisional treatment of the facial portwine stain were reported. The prominent shrinkages of the portwine stains after the laser irradiations were seen which were followed with the stepwise excision of the tumor.

View full abstract

Surgical treatment of widely spreading port-wine stain on the red lip, such as mucous skin graft and local skin flap from oral mucosa, can not preserve its special feature.
19 cases of port-wins stains on the red lip were treated by argon laser (4.2-5.6J/cm², pulse beam). Consequently, good blanching results were obtained in 10 cases (53%), without broken any special feature of red lip. Any side effects such as hypertrophic scars and depigmentation were not noticed. Especially in the 10 cases of small superficial located type, 7 cases (70%) got good results. But in the 9 cases of widely deep located type, good results were only 3 cases (33%). Although argon laser treatment of deeply located type has its limit, it is found that argon laser is the best method for the red lip port-wine stain.

View full abstract

An uptake of fluoride into human enamel treated with fluoride solution after laser irradiation was studied by means of electron probe microanalysis (EPM). Sound human enamel was soaked into an acidurated phosphate fluoride solution (APF) for 24 hours after irradiation of normal pulse Nd-YAG laser with an energy density 50J/cm². The distributions of fluoride, phosphate and calcium were represented by X-ray image and color mapping. A large amount of fluoride penetrated into the enamel from the enamel surface to the depth of 100μm.

View full abstract

Distribution of fluoride, phosphate and calcium in the enamel was investigated by means of EPM. Linear scanning of the enamel soaked into APF after laser irradiation showed a remarkable peak of fluoride profile within 20μm of surface zone, a lesser elevation of calcium profile and a reduced phosphate profile within 100μm zone. Therefore, the phenomena were indicated that a large amount of calcium fluoride was formed in the enamel. By washing IM KOH for 24 hours, a reduction of acid resistance of the enamel only soaked into APF for 24 hours was observed, but the enamel soaked into APF after laser irradiation maintained a remarkable resistance against acid decalcification.

View full abstract

The biological effects of irradiation with cw Nd: YAG laser on the pulp of rat molar teeth were examined histopathologically. Right after the irradiation, the pulp showed exudative inflammatory changes with hyperemia and focal degeneration of odontoblasts. One week later of irradiating with rats, inflammatory changes were improved. One month later, there was marked proliferation of the undifferentiated mesenchymal cells at the lased area. Subsequently the odontoblast layer became prominent followed by the production of the predentin at 4 months later. Six months later, the size of the pulp space was reduced by the continued deposition of the secondary dentin-like tissue. These cellular dynamics was not observed in the non-lased control dental pulp.
These results suggested that the once irradiation of cw Nd: YAG laser to the rat molar teeth would cause prolonged biological effects on the pulp tissue.

View full abstract

The new treatment method of hypersensitive dentine by low energy laser irradiation has been studied. This new treatment method, however, is not always equally effective in all cases. Furthermore, it is not cleared why such an effectiveness occurs. And then, in order to examine this interesting phenomena, this study was carried out. An irradiation apparatus had the following features; continuous wave at a wavelength of around 780nm; the laser energy, 3mW~30mW. The results were as follows: 1) In the group of degree I, all cases were effective. 2) In this group of degree II, 43 out of 46 (93%) were effective. 3) In the group of degreeIII, all cases were not effective. 4) the effectiveness by laser irradiation was seemed to be occured by the central synaptic inhibition rather than the nerve ending irritation.

View full abstract

Endodontic therapy is one of the most important treatment in dentistry. The conventional endodontic therapies,however,have a lot of problems in their complexity,uncompletenets and taking too much treatment time.
The authors have made an effort toward technical inovation for the endodontic therapy using Nd-YAG laser. This paper shows possible Nd-YAG laser techniques for endodontic therapy and discusses the effectivenss and the applicability of each technique based on their experimental results.

View full abstract

This time, we measured the fluorescence decay time of HpD in aqueous solution. We have used picosecond YAG laser system and obtained values for the rate constant of energy transfer from excited hematoporphyrin. In our experiment, the decay time of HpD fluorescence (λ=630nm) was 10^-8 sec. and we could not observe the double decay pattern.
From this result, we obtained the decay time of intramoleculer coupling from S₁ to T₁ state, on order of 10^-8 sec. in aqueous system. Using these values, we calculated the quantitiy of the producted singlet oxygen by resolving the rate equation.

View full abstract

Deep brain irradiation with Nd-YAG Laser was experimentally studied in 25 adult cats. The quartz fiber of Nd-YAG Laser with a convex tip was inserted into the thalamus and a spheric lesion was successfully made. Smoke of vaporized or burned tissue was led out through a Tefron coated guide tube. Four distinct zones (vaporized, carbonized, necrotized and edematous zones) were identified and no bleeding was seen in any zone. The size of the lesion can be controlled according to the delivered Laser energy (irradiation time×power) with continuous irradiation but not with pulse irradiation. Temperature of the Laser irradiated tissue was measured. With pulse irradiation temperature increased by 3.2 degrees at point 15mm away from the irradiation center.

View full abstract

The changes of intracellular calcium and pH have been focused on the analysis of mechanism in the cerebral ischemia. Heterogeneity of cerebral ischemia is one of the problems for analysis of the relationships between cerebral blood flow, energy metabolisms, intracellular calcium and pH using electrode monitoring method. For the overcome of these problems, simultaneously topographic mapping method of oxyhemoglobin, NAD/NADH redox state, intracellular calcium, and/or pH have been studied using laser photographic spectroanalysis. Quin II-AM and 2, 7-bis (carboxyethl) carboxyfluorescein were used as intracellular calcium and pH probes, respectively.
The disturbance of hydrogen electron transport system with energy crisis promoted the increasing of intracellular calcium with severe acidosis have been documented on the irreversible cerebral ischemia.

View full abstract

A real-time mapping system for tissue temperature was developed for monitoring rapid changes of excised bovine liver temperature in irradiation of YAG laser by an indepth probe.
The 7cm long thermocouples were fixed vertically in the 0.8cm thick silicone board to form a hexagonal matrix consisting of 37 points with 4.2cm diagonal length. Collection of 37 temperatures is completed by a data logger 7V13 (Nippondenki San-ei) in 1 second. Those data are transferred to a hard disk (10M) of a computer PC9800 -m2 (Nippondenki). The mapping is displayed on the screen consisting of lines which correspond to each 20°C temperature range.
One mapping formation takes 5 seconds. 6 imagings in 1/5 reduced size for time course series and 37 points in digital figures can be displayed on the screen in arbitrary phase with the date and time.

View full abstract

Basic Studies on Histoclastic Effects of Contact Type Nd-YAG Laser Irradiation. The contact type of laser irradiation therapeutics were practiced by trial use of micro-tips made of a new ceramics, as an improved application of endoscopic Nd-YAG laser therapeutics. In the case of contact irradiations under endoscopy, however, diagonal irradiations or pressed contact irradiations unintentionally happen sometimes and the safety of micro-tip operation for effluvium, which is known for historic ruptures at the contacting region, has become a subject of discussion. The extent of damages given to the tissues by 3 different types of contact type of micro-tips has been studied by applying diagonal or depressed irradiations on gastric mucosa of normal dogs under celiotomy. However, there was no significant difference in reaching depth observed between diagonal irradiation and vertical irradiation. The circular type and the cutter type of micro-tips give damages to deeper regions by pressed contact compared with the tip type. And yet it is safe, if the irradiation be made at an output of 30 Watts within 1 second. On the other hand, with the same energy (eg. 30w x 1 sec or 10w x 1 sec) there were no differences in histoclastic effects observed under the same pressure by application of the contact type of micro-tips.

View full abstract

Effect of combined coaxial irradiation by high peaked pulse wave form CO2 and Nd-YAG laser on microvasculature was examined in experimental animals. Soft X-ray microangiography and histopathology of brain after combined coaxial irradiation revealed the same effect on microvasculature as after Nd-YAG laser exposure. Broad avascular or oligovascular area in the irradiated and the surrounding edematous tissure was found at the exposure site. In the edematous layer the vessels were shown to be narrowed and tapered. In the tissue around the edematous layer some vessels were dilated and congested, which are not so significantly affected as in CO2 laser exposure alone.

View full abstract

A purpose of this study is forcused on the discussions concerning technical and physical problems which will be existed on the application of the simultaneous power delivery of CO and Nd: YAG laser by a single ir glass fiber for the new variable functioned laser treatment system. First, the distributions of two different kind of the output beam from the fiber were measured by means of scanning of the small sized ir detector. The fine agreement of the exposure view of CO laser and Nd: YAG laser from the fiber were obtained. Second, the effect of simultaneous exposure of these beams on living tissue were investigated in vitro. The results showed that the alteration of the power ratio of these beams induced the continuous variable function of light irradiation on living tissue.

View full abstract

C-A thermo couple was inserted into various parts of the mandibulae of dogs and the temperatural changes in the mandibulae following Nd-YAG laser irradiation were obserbed. The influence on mandibulae tended to be more localized around the irradiated sites than on soft tissues. Furthermore, bone defects, 3mm in diameter and 2.5mm in depth, were formed with Nd-YAG laser or bur at the mandibulae. The bones, 25×5×3mm in size, around the defect were collected, and the load necessary for the bone destruction was measured timewise. In 2 weeks after the operation, the strength of bones was decreased, however, in 4 weeks, the strength increased gradually. These changes were remarkable in bur.

View full abstract

For malignant neoplasms, the laser surgery has much advantages. Especially laser irradiation after tumor resection could be effective in preventing the local recurrence. It obtained better result on survival compared with surgery without laser instrument.
But, in experimental study, the vascular rich granuloma developed in the field of laser irradiation, where implanted DAB liver cancer cells grew fast too larger tumor than the control group in rat. From this result, there is a problem left in the indication of laser irradiation following the resection of malignant neoplasms.

View full abstract

The subject of this paper is to point out the clinical significance of the difference between single mode and multimode irradiation of the carbon dioxide laser through the basic experiments. Multimode lasers are easier to perform flat and bloodless vaporization in oncological surgery than the single mode CO₂ laser because it is easier to obtain an optimum power density quickly. On the other hand, the single mode CO₂ laser is an excellent laser knife because it is sharp, but it is too sharp to perform flat vaporization. These impressions of laser surgeons were confirmed by comparative studies using both an acrylic block and the brain of a rabbit.

View full abstract

We made a study of rat submandibular gland folloWing subtotal ectomy by CO₂ laser. The purpose of this study was to examine its clinical application to submandibular gland.
Subtotal ectomy of submandibular gland was made with the focused beam of CO₂ laser LASERY 60. In 1 hour, 1, 2, 4, 7, 14, 21, and 28 days after ectomy, function test using ^99mTcO₄^-, histpathological examination and vascular observation was performed.
From 1 hour to 4 days, the uptake value of ^99mTcO₄^- was about 30% higher than control and remarkable inflammation was observed. But since 7 days after, the uptake value was almost as same as control and the inflammation was redused in a lapse of time.

View full abstract

The development of pulsed lasers, such as a gold vapor laser (G V L), has attracted interest in terms of the possible role it could play in HpD photodynamic therapy (PDT).
In this study the effects of a GVL were compared with those of a continuous wave argon-dye laser in term of tissue penetration and tumoricidal effects.
The benefit of the former was thought to be two more times as compared with that of the latter.
The better results obtained by a GVL may be related to the longer extinction length.

View full abstract

Laser photodynamic therapy (PDT) with hematoporphyrin derivative has recently been given increasing attention. Many investigators have recognized that PDT is an effective local treatment of early stage central type lung cancer.
To clarify clinical effectiveness due to PDT, a bronchofiberscopic brushing cytology was performed chronologically.
The initial cytomorphological changes, swelling of cytoplasm, eosinophilic staining of cytoplasm and nucleolysis were occured after 10 minutes argon dye laser irradiation (200mW/cm²). 4 days after PDT, repair cells with promonent nucleoli appeared. Recovery to normal epithelium was recognized 4 weeks after PDT.

View full abstract

Effects of laser radiation on the vessels were studied. YAG laser was employed for the recanalization of the obstructed arteries with ceramic tips. Fluorescein and argon laser were used for the induction of the intravascular thrombus. The combination of hematoporphyrrin derivatives and argon dye laser caused rapid destruction of the arterial wall cells. Clinical applications of these modalities are expected for various vascular prcedures.

View full abstract

The term“Selective action”means that molecules or part of molecles of same type undergo considerable changes under laser irradiation. It is said that such changes can be caused by photoionization or photodissociation with subsequent chemical reactions. We measured the change of optical density on the components of nucleic acid using Nd-AYG (λ;266 nm, pulse duration; 15 ps, repetition; 0.5 Hz, peak power; 2 GW/cm²) as reported by Letohkov et.al. But, we could not detect the change of optical density induced by high-power picosecond ultraviolet laser pulses. The life time of excited singlet state might be shorter than that supposed by Letohkov et.al and the short life time leads the very low quantum yield product on Nd-YAG FHG irradiation.

View full abstract

A real-time mapping system for tissue temperature, comprising of 37 thermocouples and a computer, was devised. Temperature distribution was displayed with the real time change of isothermal lines. Indepth irradiation of YAG laser under the echosonographic monitering was applied on the resected bovine liver. The temperature along the peripheral border of the coagulated liver tissue was estimated to be around 50°C. High temperature vapor gasses generated around the fiber tip was suspected to play an important role to determine the deep-seated temperature distribution. This gas might cause heat injury of the unexpected normal tissues by conducting through bile ducts and blood vessels. It was suggested vapor gas simultaneously produced in irradiation should be eliminate.

View full abstract

This study aims at finding the spectral properties to respective wavelengths for the oral tissues and the penetrating depth of diode laser of 830nm. As the result, it was found that submaxillary glands and the tongue are easily influenced by wavelengths and the range of wavelengths suitable for oral applications is 830-900nm.Diode laser have the loss of approximately 50% due to superficial reflections and further reduced in the tissues due to diffusion and absorptions.

View full abstract

Skin blood flow was measured using intradermal xenon-133 dissolved in saline for use with a gamma camera interfaced to a minicomputer and using the laser flowmeter. A good linear relation was demonstrated between the two methods with a correlation coefficient of 0.90.
This technique of laser speckle flowmeter has practical advantages to assess the quantity of skin blood flow noninvasively.

View full abstract

Noninvasive monitoring method of cerebral oxygen metabolisms, intracranial pressure, cerebral blood flow and vascular compliance have been developed using infrared diode laser and skull impedance plethysmographic method.
These methods have been based on the analysis of physiological phenomenons: 1) oxygenated cytochrome aa₃ absorbe the superpermiable infrared 790-840nm lights, 2) total hemoglobin has a equal infared absorption value at the two differnt wave lengths, 785nm and 837nm and 3) the skull bone is synchronized fluctuating to the cerebral hemodynamic movements.

View full abstract

Power spectrum analyses are conducted experimentally for laser speckle signals produced by skin blood flow. Several different types of the optical fiber probe consisting of a pair of fibers, i. e., irradiation and detecting fibers, are tested and their signals are compared. It was found that the ratio of the high frequency to the low one in the speckle signal becomes larger with an increase of the separation distance of the fiber pair in the probe.

View full abstract

We have developed the technology to obtain uniform laser intensity,“Kaleidoscope”, for the purpose of using for a ruby laser for treatment of nevus. This technology has been applied to development of an argon laser system for treatment of hemangioma.
The argon laser has the continuous wave oscillation, and it can not irradiate a wide field at a time unlike a ruby laser, because of low light intensity. Then we invented the following method.
A hand piece houses 16 glass pillars, each measuring 2x2mm in cross section. Four pillar arranged in one row, and four rows are 1mm apart each other. The gap of 1mm is necessary to ensure the therapeutic effect (Zebra Effect). The laser light is introduced sequentially into each pillar through the optical fibers. This laser light scanning device is named by us“Kaleidoscanner”. The argon laser system with“Kaleidoscanner”has the following advantages, among others, over the conventional laser irradiation method. (1) Uniform intensity and high power density of irradiation, (2) Irradiation under constant condition, (3) Easy to treat desease.

View full abstract

In the therapy with a coagulator, a fiber probe as a guide for laser energy is inserted through the guide for a forceps of an endoscope.
In so far as a forward beaming laser radiation probe, it is almost impossible to radiate the lateral wall of such narrow hollow organ as the esophagus.
We developed very suitable lateral beaming probes for the treatment to be seemed almost impossible with a forward beaming probe.
We investigated the radiation conditions of this lateral beaming probe technologocally and came to the conclusion that this lateral beaming probe can be practially used with small leakage of laser beam in the other direction at which laser beam is radiated.
We tested these lateral beaming probes to check whether treatment with them do affect the human body or not, by using fresh meat. The test results showed there were no harmful affects on human body.

View full abstract

New ceramic endoprobes are able to contact with the aimed lesion during Nd-YAG laser exposure with water infusion and durable by irradiation under the power of 30 W within 2 seconds. Endoscopic laser hyperthermia was carried out with endoprobe (wide divergent micro rod) and thermosenser through the 2 channel upper GI endoscope(GIF-2T). According to histological studies, wide superficial mucosal damage appeared under the power of 5 W keeping the temperature at 42.0±1.0°C for 10 minutes. Maintenance of the temperature at the therapeutic level in the canine stomach by foot switch of Nd-YAG laser was not easy. This is the first report that the computed thermo-system is newly developed. Also, farther studies to find out the sutable factors for endoscopic hyperthermia will be made in the near future.

View full abstract

In the photodiagnosis system employed with HpD,“Xe-Flash Lamp and Fiber system”was applied to detect the fluorescence from the HpD. The results of animal study indicated that this system had a capability of the detection of cancerous tissue.

View full abstract

The variable functioned laser treatment system which has a flexible optical fiber as its transmission line has been suggested by the authors. A high-intensity simultaneous power delivery of co laser and Nd: YAG laser by As₂S₃ it glass fiber is described in this paper as a fundamental study. The diameter of core of the fiber was 400μm. The fiber used in this experiment had the clad layer which was made of Teflon FEP. Co laser beam and Nd: YAG laser beam were combined on a ZnSe plate by means of transmission and reflection, respectively. The delivery power of 14W was carried out on the condition of which the power ratio of these lasers was 1: 1. The light intensity of the output end in this case was over 11kW/cm². This results of the power delivery suggest the attainability of the new laser treatment system described above.

View full abstract

In a medical CO₂laser system for clinical use, it is necessary to develop the new type laser beam guide. As this one technique, a light guide by metal-polymer compound structure hollow tube was developed with aluminum foil and teflon. The length of one unit tube is ca. lm. It emission beam was converged to spot size ca. 0.5mm with cylindrical and convex lens. The guide tube have flexibility, it is bent easily to a roundshape at radius above ca. 10cm, the twist is also possible. The emitted power was obtained ca. 80w (cw) for incident power 95w (cw) by 1m length tube. The transmittance was ca. 85% per 1 meter.

View full abstract

We irradiated the gastric mucosa of the rabbi t by Nd-YAG laser, using a round micro-tip and examined the tissues macroscopically and histologically to evaluate the effect and safety of contact irradiation of Nd-YAG laser. Even at 15W perforation of the gastric wall could occur by strongly pushing the tip. Therefore we treated two early gastric cancers (IIa+IIc and IIa) and one gastric adenoma by low power (15W, 0.5sec) and weak contact irradiation of Nd-YAG laser. The disappearance of IIa+IIc was comfirmed by endoscopy and its biopsy, but II a and the adenoma were not obtain complete treatment only by contact laser irradiation.

View full abstract

To overcome disadvantages with an optical quartz fiber used in laser endoscopy, five types microprobes made of artificial sapphire (Al₂O₃), i. e., tip type probe, rod type probe, round tip type probe, cutter type probe and high divergent rod type probe were developed. Assessing the efficacy and safety of these probes, animal experiments were performed with the Nd-YAG laser during laparotomy. The results obtained revealed that various contact irradiations using laser microprobes were more safe and effective than the non-contact irradiations. On the basis of this results, we attempted a wide variety of clinical applications. The results suggest that the tip type probe is applicable to the treatment of protruded tumors of G. I. tract and hemostasis of G.I. bleeding, and the rod type probe and the round tip type probe are of benefit to the treatment of G.I. stensis. Furthermore, we are currently performing experimental and clinical studies on endoscopic local hyperthermia using a high divergent rod type probe and low power laser irradiation for depressed cancer.

View full abstract

Using the Nd-YAG laser with ceramics-tip which was newly developed by us, clinical evaluation of the treatment in head and neck tumors was reported.
This laser technique may be useful as one of the most promising tools for less-bleeding surgery in patients with head and neck tumors as well as for its plastic surgery using deltopectoral skin flap or myocutaneous island flap, etc.

View full abstract

We have used the He-Ne laser for arthritis in RA patients and in peripheral neuritis etc.
The result has been satisfactory with the recognition of He-Ne laser as;
(1)Ant-inflammatory effect.
(2) Circuiration enhancement.
(3)Analgesic
(4)Organic improvement of chronic inflammation leading to lessening of edema, inproving ROM and in peripheral neuritis, the improvement of muscle stiffness has been immediate. The historogical studies will compare the lesions with the unlased lesions.

View full abstract

In our last report, we presented our experience with the Panalas 4000, a diode laser pain attenuator, in treating 670 cases of pain. Here, we would like to another 1000 cases, or an increase of 50% over last time, treated over an 8 month period. Treatment was so effective that it rendered an attempt to evaluate it by a double-blind test almost useless: all the patients knew immediately which instrument was the laser, since relief from pain was almost immediate. Painful areas or acupuncture points were irradiated for 5 to 30 second, and when, in this 30 second period, the pain did not cease, it was re irradiated later after irradiating another related spot, in the Ohshiro two-point method. The average of sessions per patient doubled to 11.7 times, although each session was shortened by a full minute to 6 minutes. Results were favorable and generally similar to the first trial, with an overall effectivity rate of 94%. Ailments included stiff and inflamed shoulders, lumbago, occiputal and sciatic neuralgia, arthritis of the elbow, etc. Therapy seemed most effective for inflammation of the shoulder joint and occiputal neuralgia.

View full abstract

We reported earlier on the effectivity of the diode laser in relieving pain in athletes. We would like to present a thermographic evaluation of 92 new cases and compare them to the previous report. Immediate and overall effects are assessed in terms of pain alleviation, improved mobility, and patient satisfaction. Both amateur and professional tennis, baseball and golf players were treated, and a thermographic analysis of the symptoms and treatment were done. Younger athletes recovered faster than older ones.

View full abstract

This study aims at applications of Ga-Al-As diode laser to patients with TMJD having pains as their chief conplaint and at the same time finding out of changes in myotonia and pains with elapsing of time before and after irradiation of laser beams were meassured by means of EMG. Consequently the silent period which showed a shortening tendency in the preoperative measurements made a significant increase after irradiation showing the approximate value compared with the control group.

View full abstract

Using a low-power GaA1As diode laser. 331 cases of lumbago were treated before Sept. 1985. Thermograms were taken before and after laser irradiation to measure changes in skin temperature and assist in evaluating treatment effectivity. Different temperature patterns were observed for different types of pain, e.g., lower extremial pain exhibited a heat spot around the lumbosacrum with lower temperatures at the end of neuromeres. Laser irradiation induced an equalization of temperature distribution and relieved pain. We feel the two are correlated. Results improved with repeated treatments.

View full abstract

He-Ne laser therapy has been trially applied to 55 cases of various kinds of deseases in oral and maxillo-facial surgery using SOFT LASER 632 of Mainfar Ltd., and their clinical applicability to this field has been survayed evaluating the therapeutic effects. As the results, the laser was proved to have anti-inflammatory effect, activating effect on wound healing, analgesic effect and so on, as well as popularly known. In addition to these, depigmentation effect on vasculargenous nevus in oral mucosa has been newly found.

View full abstract

Using a Nd -AG laser for endoscopy we sreated one case of tracheal tumor, seven cases of pulmonasy cancer, two cases of gastric cancer, and one case of intrabronchial thrombus. Among these cases, interesting cases are presented, and problems encountered are reported.
(1) Since swelling occurs in the tissue and respiratory disturbance occur after YAG laser irradiation, it is necessary to treat them from before the procedure.
(2) The YAG laser was effective as a method of removing an intrabronchial thrombus.
(3) In the treatment of early gastric cancer with the YAG laser, only the superficial mucous coat is irradiated. After irradiation, deep ulcer formation is seen, and it has been thought that the cancerous lesion falls off accompanying the formation of the ulcer.
(4) To remove a tumor projecting into the bronehial lumen, removal was completed effectively with a Fogarty catheter after YAG laser irradiation, but it is dangerous because of bleeding before the tumor is fully carbonized and coagulated with laser irradiation.
(5) In the case of using a non-contact type of YAG laser, if an index is placed on the optical fiber with tape, the tip from contamination from touching the tumor or the like.

View full abstract

In the past four and half years, we have used the CO₂ laser in 462 cases. This means, as illustrated, that 50.9%of the 908 general surgical operations in this particular period have been performed with the CO₂ laser. The principle laser we currently use is the Aloka's LMC-352 CO₂ laser. For some cases, we have recently had an opportunity to use the latest model CO₂ laser with a modified KRS-5 optical fiber developed by the Matsushita Electric Industrial Company. The device has been found superior to the mirror joint articulating system in operative mobility and capable of providing sufficient power and power density for general surgical applications.
The laser has been used successfully on practically all surgical organs, as shown in the Fig.3 and 4, with a number of great benefits. It reduces blood loss, prevents infections, shortens operation time, lessens postoperative exudation and minimizes pain and edema in most cases.

View full abstract

Three types of GaAlAs diode lasers,“790nm, 10mW (max. power)”,“790nm, 20mW (max. power)”and“830nm, 10mW (max. power)”, have been trially applied to 165 cases of various kind of deseases in oral and maxillo-facial surgery and their clinical applicabilitys to this field were survayed evaluating the therapautic effects.
As the result, the lasers were proved to have anti-inflammatory effect,activating effect on wound healing, analgesic effect and so on, just as popularly known. In addition to these, depigmentation effect on oral mucosa and others have been newly found out in these GaAlAs diode lasers.

View full abstract

The diode laser was used in treating 110 cases of oral and maxillofacial diseases (including 36 diseases of nervous system, 20 postoperative complications, 17 inflammation, 33 temporomandibular arthrosis and 7 glossodynia).
The diode laser exerted effects on 24 cases of nervous system diseases, 14 cases of postoperative complications, 8 cases of inflammation, 16 cases of temporomandibular arthrosis and 3 cases of glossodynia. And significant effects were obtained in 4 cases of the trigeminal neuralgia and 2 cases of the hypesthesia. In these cases symptoms almost disappeared immediately after radiation.
Also the diode laser had great therapeutic effects on myogenic trismus, muscular pain and contraction with temporomandibular arthrosis. And this therapy inflicted neither pain nor side effects on all patients.
Therefore it seemed that the diode laser therapy was safety and availabe for treating diseases of nervous system, postoperative comolications, inflammation and temporomandibular arthrosis.

View full abstract

The present report is concerned with the laser operation performed at the department of ENT, Kitasato University Hospital, from January 1984 to August 1985. Eighty eight cases are involved. Among them, 29 oral diseases, 48 throat diseases, and 11 other diseases were the subjects of the operation.
Errorneous irradiation with laser may be hazardous, and wound healing might be delayed, which are the shortcomings of the laser operation. However less hemorrhage, less pain after the operation, and shorter time of operation may be encountered as the advantageous features of laser operation. The laser operation is a prospective mean of surgical operation.

View full abstract

We have employed CO₂Laser Surgery for the disease of oral cavity, pharynx and larynx since 1983. Many of them showed satisfactory progress but some cases had recurred. They are the adhesion of vocal cord, the granuloma of larynx, the carcinoma of larynx and the carcinoma of buccal memblane. We intend to examine the indication and the technoque for CO₂Laser surgery based on tease exprience. And then we will strive for the improvement of prognosis.

View full abstract