Among eight subjects whose anterior guidances had been changed and their condylar paths were measured before and after, a case in which the subject's immediate mandibular lateral translation had disappeared was found. This suggests a possibility that condylar paths including i.m.t. can be controlled by adjusting its anterior guidance. To reflect i.m.t. to the occlusal surfaces, one has to make centric slides by grinding the fossae of the opposing teeth, for cusp tips which intercuspate to the fosae of the opposing teeth so as to move towards working side by the amount of i.m.t.. As the result, there cause a dilemma that one must make horizontal slides of the centric artificially which must not exist in the centric. According to this study, it becomes questionable to give cusp tips any centric slides corresponding to the i.m.t..

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The amount of disocclusion on nonworking side during lateral movement of the mandible was measured on subject's study models, using a leaf gauge and keeping canine teeth on those study models as they were. The results showed that the average amount of disocclusin on nonworking side during lateral movement is 1.10±0.36mm. Molars were arranged in order of magnitude of disocclusion first and second premolar portion, first molar and second molar. Further, there were no molar of which the amount of disocclusion is zero, being the minimum value of them 0.2mm.

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Mesio-distal and vertical distances between incisal point and intercondylar axis were measured by newly devised method. Balkwill's angle was computed from the measuerd data, and the average value of 25.8° was obtained, which coinciding well with the anatomical data.

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When upper and lower anteriors occlude with leaf gauge between them, the condylar head is impinged upon the anterior-superior aspect of the mandibular fossae via the central part of the anterior disk, which results in tension of anterior belly of temporalis and superior head of lateral pterygold muscle.
When occlusal registration is made with impression material on posteriors with leaf gauge placed on anteriors, superficial layers of masseter and medial pterygold muscle start contracting. Therefore electric discharge of superficial layers of masseterincrease in comparison with the level which is recorded when leaf gauge alone is present between upper and lower anteriors.
Comparison of the antero-posterior position of the mandible and the inter-cuspal position of the normal subject showed that the former exists 0.2mm posterior to the inter-cuspal position. (Fig.8) This corresponds well to the established knowledge. Therefore it is considered that a combined use of EM-II and K-6 with the leaf gauge technique is the optimal method of occlusal registration at present.

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As a basis for analysing the mandibular movement and occlusion utilizing diagrams drawn in actual dimensions or their like figures, various occlusal planes were studied in relation with the horizontal reference planes in Part I ¹. In this paper, the correspondence of an occlusal plane to a reference plane were studied. The Camper's plane defined by Gysi corresponds to the prosthetic occlusal plane, and the horizontal reference plane defined by Guichet to an occlusal plane which was drawn tangent to the Spee's curve at the incisal point.

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A simple method for the measuring Incisal path length and the condylar path length during potrusive movement, utilizing mounted diagnostic casts, silicone impression material and modeling compoud, is presented.
The results of measurments for twenty patients during protrusive movement showed that the Incisal path length was 4.1±1.1 mm while the condylar path length was 4.0±1.1 mm. The correlation coefficient between two measurement were 0.96 (p=0.01) . From this results, the amounts of vertical and horizontal overlaps of incisors were estimated, resulting values were 2.9±0.9mm and 2.9±0.9mm, respectively.

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