Long-term prognosis of any dental treatments including orthodontics, periodontics, prosthodontics, implantology and craniomandibular disorders, depends on occlusal stability of the dentition. Several concepts of occlusion have been introduced and successfully applied for occlusal reconstruction. Althogh many important rules and principles are recommended for establishing ideal types of occlusion, few refered with clinical guidelines of therapeutic occlusion that is applicable for every dental treatment.
In this anticle, four pinciples consisting of centric related occlusion, anterior coupling, anterior disclusion and occlusal stability are described. Resolution of the occlusal symptoms would be obtained by fulfilling those principles. Further, four clinical guidelines for occlusal scheme are presented. These guidelines make therapeutic occlusion being applicable for daily practice effectively and in an atraumatic manner.

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During prosthetic treatment of the edentulous patient, the gothic arch is used to adjust the condylar path of the articulator by taking the check bite and determining the horizontal position of the mandible. In addition, attempts have been made to examine mandibular function through variations in the form of the gothic arch registration and the position of the tapping point. I would like to report a case where joint noises were observed during opening and closing movements and radiographs suggested condylar deviation despite a typical registration of the gothic arch and concentration of the tapping point at the apex.

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Since Gibbs published “Cuspal Fracture Odontalgis” in 1954, a large number of researchers have presented papers on tooth fractures. However, most of them were concerned with teeth that had been treated with root canal fillings or restorations. I found that there was clenching, and that hairline fractures had arisen even in the intact vital teeth of patients that had not received any dental treatment and whose oral cavities had absolutely no caries or periodontal disease. I also noticed that the fracture lines followed the central grooves or fissures in the buccal and lingual surfaces. Therefore, in such cases it seems that the fractures arose solely as a result of so called “stress” or “occulusion” which is composed and affected by the gnathostomatic system. However, dental treatment would not be a causative factor here at all.
I studied a sample of 83 subjects who clenched their teeth. Group A was comprised of 14 subjects who actually had hairline fractures. Four of them refused to allow occlusal analysis involving diagnosis of the occlusion. Group B was comprised of 21 subjects who had no hairline fractures and no defects in the teeth, although they clenched their teeth. Group C was 48 subjects who clenched their teeth and had dental defects that seemed associated with this clenching.
Examination and analysis were carried out on the above 83 subjects. Standardized models were fabricated based on the HIP plane of three of the subjects from group A who had hairline fractures in teeth that had never received any dental treatment. In order to examine the condition of the mesiodistal and buccolingual contacts and the occlusion of the occluded maxillary and mandibular models, two sets of each model were cemented with adhesive cement after reference lines were scribed where sectioning was planned at the pits, fissures and cusp tips of the models. Following the lines where sectioning was planned, one of the models was sectioned mesiodistally, and the other buccolingually, and photographs were taken.
Based on the findings, the occlusal conditions were graphed, each physical characteristic of the structural elements of the teeth was incorporated, and finite element analysis was carried out. In addition, specimens were carefully taken from extracted impacted wisdom teeth, the wet compressive strength was determined, and investigations were also made as to how the fracture of the tooth structural elements would occur.
It became clear that the fracture line would run vertically along the central groove and fissures on the buccal and lingual surfaces. I would like to make it clear that the hairline fractures to which I am referring are limited to the above mentioned definition, and are fundamentally different from previously reported cuspal fractures, root fractures that occur in endodontically filled teeth, and traumatic fractures.
Based on the above fundamentals, I would like to report how to identify those patients who are likely to have the primary factors that might produce hairline fractures, and discuss prevention and treatment methods.

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Treatment for temporomandibular disorders (TMD) have changed variously with the times because the etiology of TMD was not well-defined, and points of view from various disciplines resulted in a complex overview, area such as prosthodontics, oral surgery, orthodontics, orthopedics, otorhinolaryngology, and psychiatrics. The principal treatment methods for TMD from the '30s to the '60s were the occlusal treatment, and from the '70s to the '80s anatomical approaches like a disk repositioning appliance, or arthroscopic surgery were emphasized. In the 1990's, the concepts have been changing from the treatment to the conservative management on the grounds of treatment failures in the past decades and reconsideration of what constitutes TMD. Signs and symptoms of TMD had been called the “TMD triad”: joint/muscle pain, limited range of motion, and joint sounds. However, at present, the major problem is considered to be pain, and the elimination of painful limited mouth opening should be the prime clinical focus in treating this disease.
Since the relationship between head posture and mandibular function, and between the forward head posture and TMD have been stated, the efficacy of physical therapy has been recognized. While some studies have reported on the efficacy of physical therapy for such cases as myofacial pain and dysfunctional patients, for internal derangement of TMJ patients, and for post operative TMJ surgical patients, the relationship between the treatment and the improvement was not clear in these studies because of too many methods being applied to the patients.
In this study, the subjects were the patients suffering from he myofascial pain and dysfunction patients with limited mouth opening (17 females and 4 males) . This was followed by rating according to the Research Diagnostic Criteria of NIDR. However, patients who had already been treated in the other clinics, obvious occlusal interference, prostheses of broad area, history of orthodontic treatment, recent facial or cervical trauma and other medical history were excluded. The maximum unassisted mouth opening was measured immediately before and after the mouth opening training including the posture correction. The patients were then given instruction to correct faulty posture in sitting, standing, sleeping, eating, and other activities in order to achieve behavioral modification in daily life.The measurements were made and the instructions given every month, and carried out for 12 months. The degree of pain intensity at maximum mouth opening and the disturbance of mouth opening in daily life were simultaneously evaluated on a 100mm visual analogue scale (VAS) . Mouth opening training and posture correction were performed simultaneously. Sitting on a stool, the patient leaned backwards slightly with no support, allowing full movement of the head. Mouth opening was effected as much as possible by the subject alone without any help from the examiner. This opening training was performed just three times at each monthly appointment for 12 months. We gave instruction to all patients on correcting posture in their daily life. These were basically proper to Japanese traditional life style. The patients were given this instruction for 12 months. The extent of the maximum unassisted mouth opening after training was significantly greater than that before training at the first appointment. The VAS scores of pain intensity at maximum mouth opening and disturbance in daily life after 6 and 12 months were significantly decreased compared with those at the first appointment in each group. These findings suggested that the posture correction in daily life was efficacious in alleviating the myofascial pain and dysfunction patients with limited mouth opening.

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A simple method for measuring supero-inferior position of an arbitrary point on a dental model mounted on an articulator has been developed and tested.
1. A beak-like pointer was fixed to the inner side of one of the jaws of the Digimatic Caliper (Mitsutoyo Co., Tokyo, Japan) for measuring supero-inferior position of an arbitrary point (for example, cusp tip, fossa, etc.) including concave one on a dental cast attached to a mounting plate for mounting on an articulator.
2. Using the Digimatic Caliper modified with a beak-like pointer, three fixed points on the same dental model were measured by three testees. The average standard deviations in the test, was 0.18mm in the measurment of supero-inferior positions.
3. By means of the Digimatic Caliper with a beak-like pointer revised in this study, supero-inferior position of an arbitrary point on a dental cast can be measured simply with accuracy of 5 times of the past method.
However, since the setting accuracy of the anterior reference point greatly influences the measurement error of supero-inferior position of a point on a dental cast, precaution is necessary for setting accuracy of the anterior reference point.

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The purpose of this study was to compare the occlusal contact area, occlusal pressure and occlusal force between the students (12-18 years old) with individual normal occlusion and malocclusion.
Dental Prescale^® were used for measurment. The number of materials were 173 students (male 85 and female 88) with individual normal occlusion and 151 students (male 70 and female 81) with malocclusion.
All students were undergone dental examination and questionnaires about the episode of TMD and orthodontic treatment. The training to bite the sheet for measurment was done beforehand. The results were as follows; The students who had malocclusion had shown the lower occlusal contact area and lower occlusal force than students with normal occlusion. Especially in students with crowding, posterial crossbite, and open bite, it has shown lower figures about occlusal contact area and occlusal force. From the point of the relationship between the masticatory function and the growth of face, it suggests that the malocclusion should be treated as soon as earlier, especially crowding, posterial crossbite and open bite.

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We placed full arch bite plates in the mandible of four adult subjects who had no apparent problems with pronunciation or hearing, and raised the vertical dimension of occlusion 4 and 8 mm. We then investigated the effect on static palatograms. We found that as the vertical dimension was elevated, there was a tendency for the tongue to retrude for vowel and fricatives, and there was a tendency for the antero-posterior width of the tongue contact to narrow for plosives and affricate, which form a closure zone.

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This method is to systematize the process flow which is from clinical side to technical work by built in a provisional restoration with new concept. The provisional restoration with new concept has an unique feature that is given an occlusal criteria proposed by Hobo, Takayama et al, beside providing an individual teeth tray worked on the working model, in addition to the concept of the conventional provisonal restoration.
The provisional restoration with new concept is called “The Particular restoration” hereafter. It's written concretely and briefly as follows.
After precise impression, the particular restoration which meets an occlusal criteria suggested by Hobo et al is made and installed in the oral cavity. It is taken out from oral cavity after it is established the occulsion functioually and a patient's agreement is recieved. Then the duplicate is made. Its duplicate is tentatively installed in the oral cavity, the particular restoration is attached occlusion impression as an ideal individual teeth tray and is utilized on the working model.
After all, impression, occlusion taking and check bite are obtained as almost same condition as restoration works functional status in the oral cavity and the functional condition of occlusal plate can be transfered to the final restoration changed with wax by being the particular restoration through the core of occlusal plate.
The method described above is named “RAPCO system” which is abbreviation of Restoration with acquired proper condition after occlusion system.

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In the case of oral rehabilitation, requiring a prosthetic treatment for the full mouth, a provisional restoration is previously applied and immediate adhesive resion is added to this. And the case of partially missing teeth, a partial denture was used as prosthesis. There are some problems with partial denture, which are no esthetic, no functional and no useful. Therefor a new prosthetic method were improved.
In this case report, we carry out treatment using Brånemark Implant and Konus telescope denture. And to evaluate the occlusion and mandibular movement at the first examination, provisional restoration and final restoration, we use MKG (Mandibular Kinesiogram) and black silicon bite on intercuspal occlusal position. We would like to report the clinical progress during treatment.

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Once a defect develops in the teeth or dental arch, balance is lost in the oral cavity, there is a deterioration in functions of the oral cavity such as ingestion of food, mastication, deglutition, and pronunciation, and there is a loss of form and esthetics in the dentition and facial features. These problems can create difficulties in daily social life.
When carrying out prosthetic treatment in the area of a defect, it is necessary to determine what form the final prosthesis will take after adequately discussing with the patient his complete health history, his age, and the type of prosthesis desired. This is necennary regardlenn of whether the defect area is restored with a removable or a fixed type prosthesis, whether the remaining teeth are left is place and incrporated into the prosthetic treatmant, or whether extractions are aggressively carried out.
Among the available treatments, osteointegrated implants, which are backed up by long-term shientific evidence, are today being carried out as a very effective technique with high predictability for the prosthetic restoration of defects.

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