Since “Oral Health for a Healthy Life” was the theme of World Health Day held in Tokyo at 1994, the importance of oral health has been emphasized. In this review, the author emphasized the role of the dental hygienist in oral health care. Ecological characteristics and pathological factors of oral bacteria were discussed. Although more than 300 bacterial species can be found in the human oral cavity, a limited number of bacterial species show pathogenicity in this region. Most of them have their own adhesive factors including fimbrial structure. Cariogenic bacteria such as mutans streptococcus produce water insoluble polysaccharide from sucrose, which plays an important role in colonization and cariogenicity. A noncariogenic sugar substrate, xylitol, is an attractive sugar for preventing root surface caries in the elderly. In order to remove and clean, mechanical debridement is very important. Proffessional plaque control by dental hygienist is very effective. Usefulness of antimicrobial rise such as Listerine was also discussed. Chronic oral infectious diseases are known to cause secondary problems such as nephritis and arthritis. Furthermore, oral bacterial species often cause many kinds of systemic infectious diseases such as pneumonia and bacterial endocarditis. It is well known that keeping of oral cavity clean is the most effective method for preventing not only oral infectious diseases but also the systemic diseases described above.
In conclusion, dental hygienists can play an important role in oral health care, especially in the control of oral infectious diseases.

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Presently focus on the assessment of implants has moved away from the aspects of biological tolerance and become concentrated on dynamics and aesthetics. There is no doubt that the permanence of implants is largely dependent upon the maintainence of good oral hygiene, and the extent of control. This report deals with the occlusal contact factors presented in a situation where one side of the lower mandibular edentulous area has been reconstructed.
Furthermore, we examined the direction in which the changes in method were taking, and the effects an implant had on the surrounding supporting area.

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The technique “Root canal operation with the super file” has been publicity approved for these ten years since when the auther published this technique as a paper in the dental magazines, etc. The object of this paper is the presentation of this technique and a study of its affection on dental treatment.
At first, skill in fundamental operation of hand instruments is required before the performance this technique. Then, the super file developed by the author is installed into a codeless contra-angle. Cutting root canals and giving vibration to teeth by the pulse cutting method, root canal is completed, thus, it can be seen that this enables following beneficial features which cannot be realized by ordinary endodontic treatment ;
(1) removal of only debris and soft dentin in a large quantity without excessive cutting when preparing a root canal.
(2) attainment to the target apex in a short time.
(3) easy getting the home position any diseased tooth.
(4) enabling to wear gloves. etc.
In addition, the author also developed a new method of effective root canal irrigation.

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On restorative treatment, it has been used Check bite method to avoid interference on functional movement. Recently, it has been developed and clinically used an articurator with mechanism for condyle path adjustment on working side.
But, inspite of difference between outwards and return course, only one of them, of course outwards path, has been measured.
It is problem that condyle path is changeable according to position and morphology of guiding tooth.
On the other hand, new prosthodontic theory and an articulator have been brought forward to solve the problem.
Now, I presented two cases and discussed, one was treated with traditional theory, the other was treated with new theory, the results as follows ; On traditional check bite method, condyle path had been changed by past of time, and on new theory the same result obtained.

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Clinical dentists perform abutment teeth preparation of vital teeth in daily practice. For convenience, some dentists always perform this procedure under local anesthesia. Pain sensitivity of the dental pulp to stimulation differs among individuals and according to sex, the site of tooth, age, preparation form, and the skill of the operator.
There have been studies on the relationship between age and pain sensitivity but not those on the relationship between age and the necessity for anesthesia (2% Xylocaine with epinephrine) . We found a correlation between age and the frequency of anesthesia.

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We use standard cephalograms and duplicate dentures in fabrication of complete dentures. The use of duplication dentures simplifies dental laboratory procedures, shortens time required for these procedures, and facilitates the diagnosis at the clinic. The combined use of standard cephalograms allows objective evaluation of shifts in the anteroposterior jaw position and the state of improvement in the occlusal plane of the denture and the arrangement position of the anterior tooth area after operation. The use of duplicate dentures in combination with cephalograms is clinically useful.

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The golden ratio among the heights of facial areas is used as aesthetic criteria in orthodontic diagnosis. However, in the aesthetics of the living body, functional beauty with functional elements is originally important.
We attempted to establish a scientific method of clinically determining the appropriate occlusal height by Ricketts' cephalic analysis for removable prostheses and the golden ratio among heights of facial areas.
The mean golden ratio among heights of facial areas in 25 edentulous subjects was 1.61296 and the standard deviation was 0.1005.
This value was similar to the mean golden ratio (1.612) calculated by Yazawa and Takayama based on Ricketts' heights of each area of the face.

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In the treatment of edentulous patients, determination of vertical occlusal height, inclination of the occlusal plane and proper anterior guidance have been fundamental and difficult subjects for fabricating a individual total prosthesis. In this communication, we describe the novel approach to fabricate the total prosthesis based on the information obtained from analysis of roentogenocephalogram and record of functional condylar path collected by computerized axiography. Values of lower facial height (LFH) and the ratios of upper facial height (N-ANS) and lower facial height (ANS-Gn) to the total facial height (N-Gn) were measured and evaluated in order to determine the vertical dimension of new prosthesis. Furthermore, functional condylar paths with mandibular open-close, protrusion-retrusion, and mediotrusion-medioretrusion movements were utilized to evaluate the neuromuscular function of masticatory system. Sequential functional guidance occlusion scheme described by Slavicek was incorporated onto new prosthesis. These approach were able to provide the harmonious relation of anterior and posterior guidance in orofacial muscular function.

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For appropriate production of the morphology and the occlusal relationship in prostheses, the Guided Bone Regeneration method (GBR method) has long been used in defective areas where the amount of bone is inadequate for insertion of implants into the optimal position. The success rate of this method is high in cases such as wounds after tooth extraction in which four walls are surrounded by bone. However, in cases such as dehiscence and fenestration in which a space for bone regeneration is necessary, bone regeneration as expected does not sometimes occur because of subsidence of the membrane due to pressure by external soft tissue or incomplete fitness and fixation of the membrane.
Therefore, we improved the following procedures and observed good postoperative courses : 1) design of the incision line, 2) space making using an autogenous bone trabecula, 3) the state of fixation of the membrane using a Thread Mate System (TMS), and 4) the suturing method.

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This study is to clearly an influence of abutments on bone loss of implants. The bone loss of implants which were with use of UCLA and Standard abutment was investigated according to the range of age and the period after operation. They were under function for 3 to 6 years. The number of UCLA and Standard abutment was 60. The amount of bone loss was measured with pen-apical X-ray films which were taken with parallelig technique.
The following results were obtained ;
1, The bone loss of the mesial and distal side around fixtures was recognized in UCLA and Standard abutment.
2. The mesial and distal bone loss on UCLA and Standard abutment had no significance between the range of age and the period after operation. Comparing the mesial with the distal bone loss among abutments, the tendency that the amount of distal bone loss after 6 years was less than other years was shown, and also there was a significance (p<0.05) between UCLA and Standard abutment.

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The location and direction of the screw access hall in the upper structures may have great influences on esthetics, occlusal contacts, pronunciation, sensivity of tongue, and the strength of both porcelain and metal. For example, in many cases of anterior restorations, if the direction of fixture implanted corresponds with that of screw access hall, screw access halls locate on labial side of prosthesis. Therefore, the problem of esthetics comes to take place. On the other hand, there is a possibility that screw access halls on the occlusal table prevent from establishing correct tooth contacts. Finally the prognosis of final restorations depends on it.
But altering the location and direction of screw access hall makes it possible to resolve those problems above mentioned. Here we will propose the management of screw access hall for implant laboratory procedure.

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In the case of maxillary protrusion, the bone resorption of maxillary alveolar bone is not observed after tooth extraction. In this case report, a denture base of the anterior shape in the maxillary denture was made the none denture base form to improve a protrusive feeling of a maxillary denture. And the magnetic attachment was used to stability of overdenture. As a result, it was provided clinically good condition in esthetic and functional.

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In prosthetic treatment, impression taking and bite taking are important when any prosthetic method is selected.
This is because reproducibility of the positional relationship among abutment pieces and the antagonistic relationship between the maxilla and mandible in the articulator markedly affects production of prostheses using the articulator.
In particular, when implants are connected at their suprastructure, the accuracy of the reproducibility of this positional relationship is an important problem the markedly affects prognosis.
Implants and the jaw are connected in an ankylotic way. Therefore, when implants are connected at their suprastructure, slight errors (including those in screws for fixation of the suprastructure) not only affect prostheses but also may cause certain problems in the connection between the implants and jaw.
Therefore, impression taking methods considering the characteristics of each type of implants have been used.
Noting that the provisional restoration in the Octa System of ITI implants is retrievable, we used this provisional restoration in impression·bite taking for the final prosthesis production. Compared with conventional impression·bite taking methods, this method was useful for reproducing the positional relationship among the implants and the maxillomandibular occlusal relationship.

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This clinical report is a 23-year record of a case that was practiced on the basis of gnathology.
In the initial oral examination, it was apparent that the patient's oral condition was on the edge of collapse. In 1975, primary full mouth reconstruction was completed successfully by bite raising. In the first-year recall, in 1976, her oral condition was stable and her oral function was normal. However, it was to be our last contact with the patient for 20 years. But, 3 years ago, the patient visited our clinic with complaint of swelling in the anterior teeth's area. Finally, anterior guidance in the partially reestablished and recovery was carried out, by placing implants in the maxillary anterior teeth's region. As a result, occlusal reconstruction has been accomplished, and then recovery resulted in the improve-ment of the oral function and esthetics. Today, 3 years after the procedure, the patient is satisfied with the result.

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I am sorry that I have to report this case 10 years earlier than planned. This is because Dr. Yoshitane Tanaka, who was expected to be the president of this meeting (15th scientific meeting of the Japan Academy of Gnathology) passed away on November 22, last year.
I was requested by Dr. Tanaka to do maintenance in this patient. Crowns had been already applied to _??_ and a partial denture to _??_ by Dr. Tanaka. In particular, there were temporomandibular signs that the patient was not aware of. At the initial consultation, a pocket of several mm was present in a deep area, and slight general bleeding from the gingiva was observed. The bridge applied to (4) 3 (2) and the crown applied to 1 were flail. However, I left the prosthetic treatment performed by Dr. Tanaka as intact as possible, and good stable occlusion was obtained. Stable occlusion has been maintained for more than 13 years since then. I pray for the repose of Dr. Tanaka's soul and report this case, recalling him.

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For occlusion stability, it is needless to say that the vertical stop of the posterior and the anterior guidance are the most important.
And, when we think about occlusal support, support by the natural teeth is best.
Second is Crown-Bridge, next is Implant and denture is at the bottom.
For a long span, we must decide to choose Implant or denture, for the point of support, Implant is standing priority, but it is not countermeasured in every case.
The denture is chosen in several conditions.
In that case, we must try to eliminate as many possible weakpoints of the denture with the maintenance of the rigid occlusal support as the key point.

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The periodontal tissue attachment loss is highly advanced due to inflammation of infection and occlusal trauma. In the case of mobility of teeth and/or missing teeth, present teeth will not be support occlusion. So this condition will lead to inclination of anterior teeth, lip side and temporomandibular joint dysfunction. I saw such condition that the posterior bite collapse in ordinary clinical examinations many times. As this time, for the protection of the periodontal tissue, and occlusion, temporomandibular joint, (so-called, the periodontal prosthesis) is recommended. In the case of advanced periodontal disease, the crown root ratio will be large. How to control of occlusal force and beautify will become a big subject of concern.
In this case, I obtained good results by using overdenture with coping for the maxilla and using Konus kronen-Teleskope for the mandible.

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Due to advances in medicine, the mean life span has been markedly prolonged in both Japanese males and females, resulting in an aging society. However, the life cycle of the teeth is much shorter than the mean life span. In addition, once this cycle begins to be destroyed due to loss of many teeth, the balance of the stomatognathic system is lost, and function decreases, imposing a great burden on the digestive organs. One dental treatment method of restoring the tooth defect area is osseointegrated·implants. This method has long-term effectiveness and can inhibit the cycle destroyed due to loss of teeth. We report a patient in whom occlusion was reconstructed by prosthetic treatment with a mandibular implant.

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The view points of recent dental implant that had established a concept of osseointegration have been more strongly esthetic requirement especially in the site of premolar or anterior teeth. However, the former type of standard abutment have not been corresponded to these esthetic cases. Accordingly, the purpose of this present report was to introduce the technique of my custom-made abutment for Screw-Vent Implant^® (Dentsply Co.) that was devised for esthetic and good adaptation between fixture and abutment and to discuss about advantage or disadvantage points of these abutments.
The case was 56 years old female and was placed a Screw-Vent Implant^® (Dentsply Co.) in anterior site on maxilla. The base of connection to fixture of this custom-made abutment was manufactured standard plastic sleeve, and the part of abutment was in casting metal by original form. The results suggest the following advantage points :
1) good effective for strong angulation case of anterior site
2) acquire the free space for manufacturing of superstructure
3) acquire good adaptation between the abutment and the fixture
4) available for cementing the superstructure

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In fabrication of complete dentures, there is a method of adjusting the oral state using treatment dentures. After completion of adjustment, treatment dentures contain various oral information. We developed a method of reproducing as much information in treatment dentures as possible in the articulator. Duplicate dentures of treatment dentures after completion of adjustment were produced. Impression taking, face bow transfer, and bite taking were performed using this duplicate denture. This method facilitated reproduction of oral information in the articulator compared with the conventional method.

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In the treatment for CMD, treatment before application of chiropractic is necessary. Muscle tension should be adequately removed by the finger pressure method before correction.
We report a patient in whom the finger pressure method was perfomed before correction of the temporomandibular joint.
The finger pressure method before correction of the joint improved the range of motion of the joint and allowed unstrained correction using the improved motion. In addition, pain was reduced

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The primary illumination for the oral cavity is only the operating light in the unit. However, using this illumination alone, its optical axis differs from the visual axis of the operator, causing shadows.
We used glasses with a light and lens (Orascopic) and obtained good results. This light is fixed in the mid-area of the glasses, i. e., above the nose. Therefore, the optical axis of this light is in accord with the visual axis of the operator, causing no shadows.

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