The present study was designed to establish an electrophysiological indicator for estimating muscle pain in anesthetized animals. The paw withdrawal reflex evoked by mechanical pressure of the hind paw was used as a possible candidate of behavioral pain model. The EMG associated with the paw withdrawal reflex was recorded from the tibialis anterior muscle, and the area of integrated EMG for 1 s was measured as the magnitude of EMG activity. The threshold for EMG was 20.2±1.5 mmHg. The magnitude of EMG was significantly decreased by an intraperitoneal administration of morphine (1 mg/kg). These results suggest that the paw withdrawal reflex is closely related to painful sensation, and that EMG activity of the tibialis anterior muscle is applicable as an electrophysiological indicator to noxious stimulation of the paw and an expressible indicator for estimating the magnitude of pain.

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Given that the proportion of people over 65 years old has risen to 21.0% of the population in Japan, clinicians need to evaluate the outcomes of complete denture treatment through evaluations by dentists and patients to provide highquality treatment. The purpose of this study was to collect evaluations and clarify the relationship between the treatment and evaluations them by dentists and patients.
Twenty patients (6 male, 14 female; mean age, 78 years) wearing complete dentures were enrolled after providing informed consent. Scores for complete denture, supporting tissue, chewing function, satisfaction and quality of life (QOL) were used as factors for evaluation. These factors were evaluated at two stages in the complete denture treatment: at initial visit to the hospital (initial visit); and just before insertion of the new dentures (just before). We compared scores obtained on initial visit and just before, and calculated correlation coefficients for changes in scores.
Adjustment of the old dentures influenced all evaluations at both times. Satisfaction scores increased from initial visit to just before (p<0.05), with few exceptions. A significant negative correlation was seen between complete denture score, chewing function score and satisfaction score on initial visit and changes in scores from initial visit to just before. In cases with high evaluation of old dentures, just before scores tended to decrease. No significant correlation was apparent between evaluations by dentists and patients.
Adjusting old dentures and relationships were clarified. Disagreement of evaluations by dentists and patients suggests that both evaluations should be performed comprehensively.

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In recent, dental Implants with various diameters have been clinically used. Although it is considered that the thicker implants can resist larger occlusal force, this theory is not clarified by quantitative data. The aim of this study was to evaluate by using geometrical analysis for the relevancy between diameter of dental implants and fracture load, which is given from tensile-breaking test.
Fracture load of both prosthetic screw and abutment screw (Nobel Biocare and 3i) were measured with a universal testing machine. The influence of the diameter of the implant for fracture load was geometrically analyzed for simulating the single-tooth implant. Cusp slope angle was designed at 30 degrees.
Fracture load of the screws were increased with the increace of diameter of the screws. Fracture load of the screw made of titanium alloy (Nobel Biocare) was greater than that of the screw made of gold alloy (3i). On the other hands, maximum resistance load of the prosthetic screw increased according to increase the diameter of the platform.Maximum resistance load of abutment screw decreased according to increase the height of the implant.

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This study investigated chemical components of coronal and radicular dentin using Fourier transform infrared spectroscopy. Five bovine teeth were divided into coronal and radicular portions, and coronal and radicular dentin slabs were prepared horizontally. The area intensities of amide I, amide II, amide III and phosphate of the coronal and radicular dentin were evaluated by Fourier transform infrared spectroscopy at two locations per tooth. The mean area intensities were compared statistically by one-way ANOVA and Fisher's PLSD tests. The amide I area intensity of coronal dentin was 8.67±2.20 and that of radicular dentin was 12.29±2.47. The amide II area intensity of coronal dentin was 0.84±0.25 and that of radicular dentin was 1.94±0.45. The amide III area intensity of coronal dentin was 0.17±0.03 and that of radicular dentin was 0.50±0.10. Additionally, the phosphate area intensity of coronal dentin was 24.45±9.23 and that of radicular dentin was 42.05±3.67. All of the area intensities of coronal dentin were lower than those of radicular dentin.

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Although the casting technique is popular in laboratory work, industrial waste is created in the form of mold materials. The purpose of this study was to develop reusable investments to reduce this waste. Glass powder was milled from broken measuring instruments. Five kinds of experimental glass-bonded investments (Code: G-0, G-5, G-10, G-15, G-20) were coordinated according to the additional glass powder weight for cristobalite. The thermal expansion up to 900°C and compressive strength after firing were measured by mixing with water at a ratio of 0.3. Moreover, platetype specimens and MOD crowns were cast from G-0, G-10, G-20, and surface roughness and fit were evaluated. As the control, commercial gypsum-bonded investment was selected. Experimental investments were reused by milling.
Glass powder liquefied at about 800°C. This phenomenon was also verified by contraction while measuring the thermal expansion. With the increase of glass, thermal expansion was decreased. However, their values were greater than that of the control. Fired strength was increased as the amount of glass increased. From fundamental results, casting experiments were performed using G-0, G-10 and G-20. The surface roughness value from G-0 was larger than those from others. In the case of fit, castings from G-10 and G-20 had large gaps. When removing the MOD cap, fit was obviously improved. Therefore these gaps were caused from excess or expansion. The fit of G-10 was better than that of G-20 because of large expansion. In conclusion, experimental glass-bonded investments were possible to reuse and G-10 was considered to be effective in laboratory use within the limits of this study.

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It had been reported that the orthodontic treatment of skeletal Class III openbite with tongue thrusting were very difficult and complexity, by reasons of difficulty vertical tooth movement and occlusal stability in retention period.
We experienced the treatment above patient who was a 16-year-5-month old-female at the first examination with skeletal class III, unilateral congenital missing tooth (upper left side second bicuspid) and openbite with tongue thrusting. We planed appliances were multi-bracket system, expansion appliance and non-extraction method that is expanded maxillary arch in order to reduction of tongue thrusting, myofunctional theraphy (MFT) and non-extraction treatment were placed.
As a results of that, we obtained a favorable occlusion and still maintained in 2 years retention terms.
In this experience, it was suggested that the evasion of excessive oral capacity reduction for tongue thrusting and asymmetric molar occlusal relationship might be beneficial treatment ideas.

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Growth prediction is important in orthodontic treatment during the growth period. In this case, a patient in a growth period displayed signs of skeletal maxillary protrusion at the age of 11 years and 5 months. To treat this skeletal maxillary protrusion, the right and left maxillary first premolars were removed at another dental clinic, and orthodontic treatment with a multi-bracket device was initiated. Dynamic treatment was completed after 2 years and 5 months of its implementation, when the patient reached the age of 13 years and 10 months. During a follow-up for retainer use after the completion of treatment, change of jaw position in response to growth was observed, and the patient was referred this hospital where an examination was conducted.
The initial diagnosis from this department was skeletal mandibular protrusion with deviation in the left direction, as well as deformity of the left side of the mandibular neck deviating inward and the mandibular head.
The treatment approach was based upon surgical orthodontic treatment, with follow-ups implemented until the completion of jaw growth. After the growth follow-ups were completed, we employed surgical orthodontic treatment to correct the occlusion without maxillomandibular tooth extraction. The rationale behind this selection of treatment was that the maxillary teeth were already extracted with congenital missing of the mandibular canines on both sides.
We would like to report on the consideration of the change observed in this case during the growth period and dynamic treatment, as well as the occlusion maintenance during the retention period.

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The patient was a female aged 18 years and 6 months. Her complaints were a convex profile and unesthetic appearance of her anterior teeth. She was diagnosed as having severe bi-maxillary protrusion with moderate upper and lower crowding. Treatment was carried out using edgewise orthodontic appliances with upper and lower first premolar and additional upper first molar extraction. Premolar extraction and molar distalization sometimes becomes necessary in bimaxillary protrusion with crowding cases because of the need to correct the crowding and the axial inclination of both anteriors.
In this case, the upper right first molar, for which an inappropriate root canal treatment had been conducted, and the upper left first molar were diagnosed as secondary caries. Therefore, the upper first molars were extracted, and the third molars were aligned to compensate for the first molars owing to consideration of a long-term prognosis, correction of the crowding, tooth axial, and achieving a straight profile without reinforced anchorage.

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[in Japanese]

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[in Japanese]

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