With recent increasing demand for aesthetics, the importance of smile has been recognized in aesthetic evaluation, and a system to produce face masks has become commercially available. We improved this system and clinically applied. The morphology of the dental arch represented by the curve of Spee and the significance of the face bow were easier to understand when the face mask also attached to the articulator than when the model alone was attached. Aesthetics is closely associated with function. Since this face mask is very effective for occlusal guidance, we evaluated the effects of the face mask from the stomatognathic aspect.
Attachment of a face mask allowed understanding of the visible tooth region and the 3-dimensional positional relationship from the lips to the teeth in the articulator. Since the source of fixation was obtained in the maxillary dental arch, relatively natural smile could be reproduced, and evaluation of the morphology of the teeth and dental arch became easier. Impression taking extending to the nose facilitated the importance of the face bow transfer.

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An endosseous implant is useful for the prosthesis of an edenturous jaw. The purpose of this study was an examination of bucco-lingual shape in the CT reconstructed images. The axial crosssectional data obtained were reconstructed as images on the oblique planes perpendicular to a curvature of the dental arch with “DentaScan” program (GE-Yokogawa, Tokyo) . The residual alveolar crest was categorized into six types in shape. The knife-edge shape was observed in 35-40% of upper and lower incisor areas, and the discrepant shape in 32% of lower molar area. These shapes could not be visualized without the sectional images of the alveolar bone. Results indicalte that the CT reconstructed image provides essential information on the presurgical assessment of dental implant.

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Osseointegrated implants have published on single tooth replacements and new prosthodontic concepts which were developed following new demands regarding abutment-screw stability and esthetics. It does require a prevent rotation system, between abutment and fixture. In tie IMZ^® Implant system, abutments are intended to act as stress-breaking elements between the fixtures and its superstructures, but they do not have this prevent rotation capability so far. Answering this requirement, 3i^® Company invented MOD titanium insert which makes possible for single tooth defects. This paper reports two cases, both using MOD titanium insert to prevent fixture rotation and e-PTFE membranes (Goa-Tex^® Regenerative Material) which were used to correct incongruences between the implant and bone defects site by using guided bone regeneration procedure.

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Prior to occlusal treatment in a 22-year-old famale with Angle class II division 2 accompanied by congenital missing teeth, mandibular movements were measured using a computerized axiograph system (CADIAX system) . The measurement showed anterior displacement of the articular disc of the left temporomandibular joint during mouth opening and closing. Therefore, the 3.0 mm anterior position immediately before displacement of the disc during mouth closing was designated as the therapeutic position. Using this position as the treatment goal, the occlusion was improved by orthodontic and prosthetic approaches. After application of the final prosthesis, mandibular move-ments were examined again using a CADIAX system. During mouth opening, no waves suggesting anterior displacement of the articular disc were observed, and relatively smooth movements suggesting harmony in the neuromuscular system were confirmed.

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The influences of condylar and Incisal paths to cusp path were computed theoretically basyed on the mathematical model of mandibular movement derived by Takayama and Hobo. An method for representing the computed results graphically was presented.
By this method, 1) the differences between the influences of condylar and Incisal paths, 2) the differences between the influences on 2nd molar, 1st molar and 2nd premolar, and 3) the linear character of the curves representing the influences of condylar and incisal paths to cusp path, are shown visually.
Utilizing the linear character of the curves, theoretical linear expressions on the influences of condylar and Incisal paths to cusp path were derived for each molar. The theoretical linear expres-sions were compared with the experimental linear expressions which were statistically derived by Ogawa et al. based on the measured results using an electronic mandibular movement measuring system with six degrees of freedom. It was proved that the theoretical and experimental expressions were approximately the same.

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GNATHOLOGY and GAKU-KOUGOU-GAKU (its Japanese translation) are traced to their origin.
GNATHOLOGY is composed of the prefix GNATH, the conjunction O and the suffix LOGY. GNATH comes from GNATHOS, which in Old Greek means jaw. O is a conjunction. LOGY comes from LOGIA in Latin and means doctrine, theory or science. Stallard H. is generally credited with composing the word Gnathology.
GAKU-KOUGOU-GAKU is made up of GAKU+KOUGOU+GAKU. GAKU means jaw in Japanese, KOUGOU means occlusion, and the final GAKU is the same as LOGY, meaning doctrine, theory or science. The word GAKU-KOUGOU-GAKU was thought up by the author.
GAKU-KOUGOU-GAKU is written _??_ _??_ _??_ _??_ in Chinese characters, which is the official term for Gnathology in Japan and other countries of the International Academy of Gnathology Asian Section.

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