Sagittal condylar inclinations during lateral motions of mandibles were measured by Checkbite method utilizing the Panahoby semi-adjustable articulator and the Hoby Checkbite sensor, and compared with the Computer Pantograph data.
The Checkbite samples were taken at the position where condyles moved 5mm away from each centric position. The Computer Pantograph measures condylar path in high accuracy starting from the centric position to the position where condyle moves about 3mm away from the centric position which corresponds to the functioning range of molar.
The number of subjects were twelve. As the result, the correlation coefficient as high as 0.825 was obtained between the Checkbite and Computer Pantograph data. The regression line derived from these data indicates fairly good coincidence of the Checkbite data with Computer Pantograph data. The root mean square error of the Checkbite data against the Computer Pantograph data was 5.77 degrees which falls within 15% of the measured value. Sagittal condylar inclinations measured by Checkbite method during protrusive motions were less accurate than those measured during lateral motions.
As a conclusion, it is proved that sagittal inclination data mesured by Checkbite method can be used practically for prosthetic operation within its limitation, providing the use of the Checkbite sensor and the data measured during lateral motion.

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Temporomandibular joint dysfunction is defined as a noninflammatory disease which has the three major symptoms of temporomandibular joint arthralgia, joint sounds, and abnormalities in mandibular movements. In other words, since this is the name of a set of symptoms and not a disease itself, the origin is not fixed and it has many varieties.
When we historically consider the theories on the origin of temporomandibular joint dysfunction, three main schools appear.
1) The theory of mechanical pressure due to the condyle.
2) The theory of the exacerbation of tension in the muscles of mastication due to occlusal abnormalities.
3) The psychophysiological theory due to stress.
The disease state of temporomandibular joint dysfunction expresses itself as 1) temporomandibular joint arthralgia, and 2) impaired mandibular movements, and although its physiological analyses have been performed, it is difficult at the present stage to give a unified discussion of the origin of the disease since various factors overlap one another creating a vicious cycle.
Concerning the relationship of actions of the mouth closing muscles and irritations in the oral cavity, in particular mechanical irritations to the periodontal membrane and the temporomandibular joint disc, in general sharp stimuli of short duration have an inhibiting effect on the closing muscles while slow, continuous stimuli have an excitatory effect. However, the effect on these muscles varies even with the same stimulus.
Research is presently being carried out into central nervous system activity concerning the question of what types of stimulation at what time exacerbate the activities of the closing muscles.

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There has been cosiderable discussion concerning whether or not occlusal problems induce temporomandibular joint dysfunction. This has been a matter of great concern in the field of dentistry for many years. Ever since the concept of occlusal disease was put forward in recent years which says occlusal problems, in particular premature contacts, are related to emotional and psychological stress, in daily clinical dentistry attention has come to be centered for the most part on occlusal interferences.
We discussed the relationship of what is called temporomandibular joint dysfunction and occlusal problems, centering on a portion of our test results which investigated the influence on the body of a small trial occlusal interference of 100 microns thickness.
Because even an easily overlooked, small occlusal interference in daily clinical practice can exert considerable influence on various parts of the body, and because it has been suggested that this may be the primary factor in what is called temporomandibular joint dysfunction, we dentists must be aware of the importance of occlusion on the masticatory and functional occlusion systems, as well as other areas which are affected by occlusion.

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Beginning around 1900 there has been a large amount of trial and error development in the materials, shapes, and techniques for dental implants as artificial roots which have today come to be applied to strengthening and restoring the function of the'gnathostomatic system. Thus it is thought that in the future dental implants will bring about a big revolution in prosthetic methods for missing teeth, and will become an indispensible technique in general clinical dentistry.
However, the relationship of built up areas on the structure on the implant and plaque on the base region are extremely important. In these regards, adding in trials of hyeine and occlusion using a temporary bridge which has the purpose of stabilizing the implant, we are seeking a configuraion which ideally and effectively protects the health of the periodontal tissues for the patient himself.
Implants as artificial roots promise great hope and high favorable acceptance when oral rehabilitation is strictly observed, and when protection of the periodontal tissues and reconstruction of functional occlusion of the structures on the upper region of the implant are carried out.

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