This study was carried out to determine statistical information concerning the crowns and the fixed partial dentures (total number, types and rate of crowns, number of vital or non-vital abutment teeth, etc.) which were placed in the outpatients in the Department of Fixed Prosthodontics at Showa University Dental Hospital from April 1994 to March 1995.
The following results were obtained :
(1) The total number of crowns and fixed partial dentures produced were 1,357 ; among them, crowns totaled 1,163 (85.7%) and the fixed partial dentures, 194 (14.3%).
(2) Most of the crowns were full cast crowns (592, 50.9%); The second most commonly produced was porcelain fused to metal crowns (303, 26.1%), the third was resin faced cast crowns (193, 16.6%).
(3) Porcelain fused to metal crowns and resin faced cast crowns were most commonly used for the anterior teeth ; full cast crowns and porcelain fused to metal crowns, for the premolar teeth ; full cast crowns, for the molar teeth.
(4) Fixed partial dentures located in the posterior region were about 60% ; those in the anterior and the antero-posterior regions were about 20% each.
(5) With regard to the relationship between the missing teeth and the abutment teeth of the fixed partial denture, the three-unit fixed partial dentures (one missing tooth with two abutment teeth) were most frequently treated in all regions.
(6) The crowns covered by the insurance dental service were 67.5% ; the fixed partial dentures were 64.9%.
(7) Concerning the abutment teeth of the crowns, non-vital teeth were 90.1%, implant abutments were 1.0% ; non-vital teeth of the fixed partial dentures were 72.5%.

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Enamel lamellae in first and second molar teeth of rat mandibles, 4 weeks after birth, were observed by scanning electron microscopy with EDTA-treated samples. The lamellae succeeding to organic pellicles were occasionally seen in the buccal and lingual regions of the mid-coronal to cervical enamel, and the mesial and distal regions of the fissure walls of the cuspal-side enamel. However, the lamellae were always found throughout the fissure floors buccolingually, where fissure caries is apt to occur.

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Hand to mouth coordination is one of the important behaviors when eating. However, some people with feeding disorders are unable to coordinate well the mouth with the hand when feeding themselves, causing fatigue and aspiration. The subjects were 20 healthy volunteers aged 22 to 35 with normal upper limb function and normal dental occlusion. The food item used was a very small, round bite-sized cookie (“bolo” in Japanese). The process of finger feeding was video-taped by two CCD cameras. The picture was recorded to a Motion Grabber, an image processing system established by Ouyou Keisoku Corporation. The movements were broken down into 1/60 seconds and the following segments were analyzed : 1. From picking up the food to placing it on the lip (P-I), 2. from picking up the food to opening of the mouth (P-O), 3. from opening the mouth to placing the food on the lip (O-I), 4. from picking up the food to pointing the food and the index finger perpendicular to the lip (P-V), and 5. from pointing the food and the index finger perpendicular to the lip to placing the food on the lip (V-I). The results obtained were as follows :
1. There were statistically significant differences in length of movement, time length and speed between P-V and V-I.
2. The subjects could be classified into the following 3 groups :
Group 1) the length of movement for P-V is longer than P-O (13 subjects); Group 2) the length of movement for P-O is longer than P-V (2 subjects); and Group 3) the length of movement for P-V and P-O was changed by food locations (5 subjects).
3. Time length and speed for P-I in Group 2 were significantly longer and slower than those in Group 1.

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The purpose of this study was to know the actual conditions of oral states and eating habits of children on the early stage of mixed dentition. We examined oral conditions and made questionnaire about eating habits to 90 children (male 49, female 41), whose upper permanent incisors had erupted and were managed at Pedodontics Department in Showa University Dental Hospital. The subjects were divided into 3 groups at eruption grade. The results were as follows. 1) Oral conditions; 5 children (5.9%) had caries on permanent incisors. Adhesive levels of plaque on the upper incisors were high and lateral incisors showed higher score than central incisors, but average plaque score was low at group 3 compaired with group 1, 2. Caries activity showed high score at group 3 and there was a significant difference between group 3 and other groups. With the space between permanent incisors, the rate of closed type had a tendency to increase and the rate of irregularity of dental arch have a tendency to decrease in accompany with incisors eruption. 2) Eating habits; they had a tendency to take meals and between meals regularly and favor sweet taste. Then, they had a tendency to leave for management of between meals from parents with incisors eruption. 3) Relationship between oral conditions and eating habits; The children who replied to take between meals irregulary, more times and add sugar to their drink had a tendency to show high score at plaque score and Cariostat score. There was no relationship between G.I. score and eating habits.

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Various kinds of space maintainers are used to prevent the space loss and support the succedaneous teeth eruption when premature loss of primary teeth is caused at the stage of primary or mixed dentition.
We investigated the actual condition of space maintainers used to outpatients at the Pedodontic Clinic of Showa University Dental Hospital from April 1977 to March 1995.
The subjects who were adopted for space maintainers were 1030 children and 1494 maintainers were inserted.
The results were as follows : 1) Dental caries was the most popular cause of premature loss, but recently loss by trauma tended to increase. 2) 6 year-old children represented a large percentage of space maintainers inserted cases. 3) Loss regions of the primary teeth were mostly unilateral posterior of the lower, and anterior or unilateral posterior of the upper. 4) Among total 1494 cases, rate of removable space maintainers was 48.6%, Crown-loop and Band-loop 35.0%, and Lingual Arch 13. 4%. 5) Troubles occurred mostly within 5 months after space maintainers insertion.

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The purpose of this study was to investigate the factors affecting the bonding of Silicoater MD (SMD) system for resin veneering to cp titanium.
Cp titanium plates were sandblasted according to the instruction of the system followed by the pre-heat treatment at 300 to 600°C. Specimens for the bond strength were prepared with different heating time for Sililink and the opaque resin was cured by two light exposure units. Post-cure heat treatment of the opaque and resin composites was performed at 100°C for 15 to 60 minutes. The bond strength was determined by a tensile shear test after storing the specimen in deionized water at 37°C for one day and also after thermal cycling at 5°C and 55°C for 16.5 days (20,000 cycles). Contact angles of cp titanium plates with pre-heat treatment was measured. SEM observation of the surface of the sandblasted cp titanium plate on the cross section was performed.
Pre-heat treatments for titanium didn't enhance bond strengths significantly, though contact angle had a tendency to decrease with the increase of temperature and treating time. Heating time of Sililink influenced the bond strength which was an important step to prepare Si-Ox layer for a chemical bond. The light exposure unit influenced the bond strengths because of the temperature rising of the opaque resin. The post-cure heat treatment had little effects on the bond strengths.
The handling properties of the SMD system was very easy but was still technically sensitive. We suggest the 2 minutes heating for Sililink and the use of Triad II for the curing of opaque resin to increase the bond between titanium and resin for the current system.

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The purpose of this study was to establish an esthetic goal for the lower incisors after orthodontic treatment. The subjects consisted of 88 individuals who had received orthodontic treatment at Showa University. They were divided into two groups based on whether or not their final appearance was esthetically balanced, and also classified as either Mesiofacial type, Brachyofacial type or Dolicofacial type. We examined the angle of lower incisors formed with the A-Pog line using lateral cephalometrics. We found that 1. the lower lips were in a forward position in the unbalanced group : 2. there was a correlation between the anterior-posterior position of the lower incisors and the lips : and 3. the distance between the lower incisal edge and the A-Pog line was 3.7±1.4 mm in the Mesiofacial type, 3.6±1.6 mm in the Brachyofacial type and 4.7±2.0 mm in the Dolicofacial type. There were no differences among the three groups in the angle between the lower incisors and the A-Pog line.
These results indicate that we must consider the facial pattern when establishing a treatment goal. In particular, we must set the lower incisors in a forward position in Dolicofacial-type patients.

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Tongue movement during articulation is difficult to be measured without disruption of natural speaking patterns of the subject.
However, this difficulty was overcome with the use of ultrasonography which has the capability to measure internal movement indirectly without the necessity of physical contact with the structures involved.
In addition, this study utilized the standardized scanning method to maintain the transducer at the proper angle and location under the mandible.
With this technique, we were able to clearly observe and analyse the tongue surface movements at the coronal plane by B/M mode.
The sonographic study was performed in 13 healthy adult volunteers, between the ages of 19 and 33 years, who have normal oral morphology and speech. Phonetic transcriptions from the Japanese language [ka], [ta], [ra] were selected as speech models for observation.
The results were as follows.
1) [ka], [ta] and [ra] produced the bilaterally symmetrical movements of the tongue.
2) During the articulation of [ka] the middle part of the tongue moved significantly longer than the right and left lateral tongue margins.
3) During the articulation of [ta] and [ra] the anterior part of the tongue moved significantly longer than the posterior region.
4) Tongue movements of two subjects showed different pattern from the others during the articulation of [ta] and [ra].
It appears that real time ultrasound scanning can provide a reliable method for investigating tongue movements during actual speech.
Further research will need to focus on comparing normal and defective articulatory patterns with the goal of both establishing a clinical technique for patient evaluation and developing biofeedback training system, especially those who have lateral articulation disorders.

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A case of Angle Class II division 1 with excessive overjet and gummy smile is reported in this paper, in the patient which was operated by Le Fort I osteotomy on upper jaw, and sagittal split osteotomy on lower jaw.
After preoperative orthodontic treatment, a Le Fort I osteotomy was performed by using the extraction space of the upper second molars on upper arch.
As a result, it was possible to set back of the upper jaw, at central incisor's cutting margin, 7.0 mm upward and 5.0 mm backward, and at mesial dental cusp of first molars, 4.5 mm upward and 7.0 mm backward.
Advancement of the mandible was accomplished by mandibular sagittal split osteotomy, and angle of ANB was improved from 7.0 degree to 3.9 degree.
We report the treatment procedures and results of this case, and discuss significant future problems.

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