The mineralization values in the body of the artificially-demineralized caries-like lesion of human enamel, embedded with and without polyester resin, were analyzed on the transverse polished surfaces of 5 premolar teeth by energy-dispersive X-ray microanalysis (EDX) in SEM. In addition, the caries-like lesions were observed by backscattered electron (BSE) imaging and analyzed by wavelength-dispersive X-ray microanalysis (WDX). The resin-free samples had the caries-like body showing high BSE signals when compared with the rein-embedded samples. The high BSE-signal image will be caused by the ridges of the relatively-remineralized prism peripheries and the pits of the markedly-demineralized prism cores under mechanical grinding. The WDX line-profile of Ca-Kα in the resin-free samples was markedly decreased in the caries-like body when compared with that of the resin-embedded samples. The lower Ca content may be caused by the hollow of the caries-like body under mechanical grinding. In SEM-EDX, the caries-like body of the resin-free samples showed higher Ca values and tended to show higher P values than that of the resin-embedded samples. Such EDX data of the resin-free samples will be caused by porous structures in the caries-like body. In conclusion, when analyzed the natural caries and artificial caries-like lesions of enamel by SEM-EDX and WDX and also observed them by BSE, the samples should be embedded in infiltration resin in order to fill the porous structures and to form the smooth polished plane.

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The purpose of this study was to assess the clinical efficacy of guided tissue regeneration (GTR) surgery using polylactic acid membrane.
Twelve healthy patients with Class II furcation involvements or vertical defects, participated in this study. Probing pocket depth (PD) and clinical attachment level (CAL) measurements and dental radiographs were taken immediately before surgery and at 6 months after surgery.
Mean PD was reduced from 6.5±2.3mm to 2.8±0.6mm, with a mean reduction of 3.8±1.9mm.
Mean CAL was reduced from 7.5±2.1mm to 4.5±1.3mm, with a mean attachment gain of 3.1±1.8mm.
Radiographic improvement in the defect area was observed in six out of 12 patients.
No side effects were observed during the 6 months.
This study suggests that GTR surgery using polylactic acid membrane might be useful for periodontal tissue regeneration therapy.

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Three kinds of resin-modified glass ionomer (RMGI) cements (PF, LC, LCII) for restoration were evaluated by the observation of cement particles and measurement of mechanical properties. Especially, the influences of powder/liquid ratio on the mechanical properties of LCII were investigated.
SEM images of the RMGI cement particles showed that LCII improved cement particles, with consisting uniform fine particles as compared to particles of other RMGI cements. Hardness and compressive properties of LCII were significantly higher (p<<0.05) than those of other RMGI cements since these mechanical properties were enhanced by particle size. The change in powder/liquid ratio on LCII significantly influenced hardness (p<<0.05) but did not influence compressive properties. The evaluation of compressive yield ratio indicated that brittleness increased with the increases in the powder/liquid ratio. The bending strength of LCII was the lowest even when the elastic modulus was the highest. Moreover, that of LCII decreased with increases in powder/liquid ratio. These results suggest that the characteristics of RMGI cements were not only affected by the cement particle size and powder/liquid ratio conventionally important for GI cements, but also by the degree of ductility obtained from the relative resin content in the bulk.

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The orthodontic diagnosis in growing patients requires appropriate predictions of their future craniofacial morphology. The purpose of this study was to obtain basic information about skeletal Class III malocclusion, with body mass index (BMI), which is well correlated with amount of body fat, and to investigate the possibility of clinical application of this information.
The subjects, referred to as Class III group, included 105 males (mean age, 25.2±1.8 years; range, 15-38 years) and about 166 females (mean age, 24.9±1.9 years; range, 15-36 years) who presented with skeletal Class III malocclusion diagnosed as needing surgical orthodontic treatment. Data on the control group as normal Japanese population were obtained from the 1997 “Statistical Report on the School Health Survey” presented by the Ministry of Education, Japan, and 1998 “National Nutrition Survey” presented by the Ministry of Health and Welfare, Japan. That data included parameters such as growth phase of the whole body, BMI, height, and body weight.
The results were as follows :
1. Class III group male in their twenties and thirties, and Class III group female in their thirties showed significantly lower BMI than the BMI of the control group. More specifically, this tendency was most pronounced on males in their twenties.
2. The frequencies of obese and non-obese cases, respectively, were obtained. Class III group had lower frequencies of obesity, and tended to have a higher frequency of non-obesity, in all age subgroups of males and females in comparison with the control group.
3. In a comparison of the annual changes in BMI in subjects from the ages of 6 to 17 between Class III group and the control group, subjects in Class III group tended to have lower BMI. This tendency was stronger in males than in females. The greatest difference between Class III group and the control group was found in male and female subjects at the ages of 11 and 8, respectively.
4. Class III group was subdivided into non-obese and obese subgroups according to BMI, and the craniofacial morphology was compared between these two subgroups, using lateral cephalometric radiographs. The female obese subgroup showed a mandibular corpus length (POG'-GO) significantly shorter than that in females in the non-obese subgroup.
These results indicated that the BMI reflected growth phase in Class III group more accurately than did height and body weight.
Based on the relationship between amount of fat tissue and craniofacial morphology clarified in this study, it is considered that more detailed studies on the presence of fat tissue will further our understanding of growth phase in the craniofacial region, which will be useful for orthodontic practice.

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The purpose of this study was to investigate the changes of symphysis concerned with labial movement of the lower incisors. The subjects consisted of 20 patients, adult female skeletal class III with mandibular osteotomy treated at Showa University Dental Hospital. The materials consisted of latelal cephalograms at the beginning of orthodontic treatment and the end of preoperative orthodontic treatment. The results were as follows :
1. Significant changes in the cephalogram angle analysis were the labial movement of ∠L1 to the mandibular plane and reduction of ∠FMIA.
2. Significant changes in symphysis were the reduction of B′-Me and Ap′-Me.
3. There was correlation between SNB and ∠L1 to the mandibular plane at the beginning of orthodontic treatment, and between ∠SNB and ∠FMIA, and ∠ANB and ∠FMIA at the end of operative orthodontic treatment.
4. There was correlation between the amount of change in B'-Me and the amount of Ap'-Me.
5. There was no correlation between the cephalogram angle analysis data (∠SNB, ∠ANB, ∠L1 to the mandibular plane and ∠FMIA) at the beginning and the treated changes in symphysis.
These results suggest that the changes in symphysis were found to affect the lower incisor to labial movement, and it also suggested that the change of point Ap for lingually was related to the change of point B as well.

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Our previous study indicated that resin-modified glass ionomer cements (RMGIC) were recognized to have less bond strength as compared to other conventional resin materials for bracket bonding. Therefore, it is important to understand the morphology, structure and component of the bracket bases greatly affecting the bond strength to select suitable brackets for those RMGIC. However, there are many kinds of brackets commercially available and information on the structures of especially bracket bases bonding to the teeth, especially, is lacking.
In this study, the morphology, structure and component of commercially available orthodontic bracket bases with three different bracket materials (metals, ceramics and plastics) were investigated. The bracket bases were observed by two different SEM (secondary electron and backscattered electron) images. Element analysis was also performed by EDX and FT-IR spectrum. All metal brackets were made of stainless steel except the titanium bracket. One particular metal bracket was coated with gold-silver alloy. The shape of the metal bracket bases were divided into two types : bonded mesh wire and with the assembled small rhombus prominent. Both types of metal bracket seemed to have more mechanical retention than the ceramic and plastic brackets. The base of the ceramic brackets, consisting of alumina or zirconia, was structurally simple. Ceramic brackets had the lowest mechanical retention on the bracket base. Three plastic brackets consisting of polycarbonate were used as engineering plastics. Four plastic brackets were reinforced by glass fibers or ultra-fine particles.
The present study indicated that each bracket differed morphologically, structurally as well as materially. This finding suggests that much attention should be paid to the selection of orthodontic bonding brackets when RMGIC are applied as bonding materials.

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The case of a 16-year-old female patient with the complaint of facial asymmetry and unilateral posterior crossbite was reported before and after two-jaw surgery to evaluate facial cosmetics and occlusion. A pre-surgical orthodontic appliance was inserted immediately after the first examination because her growth was completed. Her mandible was deformed to the left side and lateral crossbite was recognized with a slight clinical symptom of TMD on the left side. Her maxillary first premolars were extracted to correct the axial inclination of the incisors, and her mandibular first premolars were also extracted to eliminate crowding. After 28 months of pre-surgical orthodontics, mandibular set-back surgery (SSRO) and Le Fort I surgery were performed simultaneously. Maxillary deformation was corrected by decreasing the right molar height and by increasing the left molar height. Stable occlusion and successful facial symmetry were achieved, and the fixed appliance was removed 6 months after surgery.
Data of the pressure sensitive occlusal sheet (Dental Prescale®) indicated that the occlusal contact area, occlusal force and occlusal balance improved between the beginning and end of active treatment, and during 1-year retention. The data suggests that improvement was successful, both morphologically and functionally.

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Osseointegrated dental implants have been used to help regain of masticatory function after treatment of oral diseases.
In this report, a 28-years old patient with re-recurrence of ameloblastoma was treated by reconstruction with vascularized bone graft after mandibulectomy, and three dental implants in the grafted mandible for supporting a partial overdenture were placed. This partial overdenture was compose of a gold bar, a titanium framework and magnet attachments. This type of an overdenture was designed to fulfill the patient's requirements concerning esthetics, masticatory function and easy care of implant posts.
Magnetic attachments can be made it possible to do easy when the patient had to insert his prosthesis and seated in exactly the right position.
His masticatory function after a mandibulectomy was evaluated by occlusal balance and Sato's chart of masticatory efficiency. Fifteen months after wearing the prosthesis, occlusal surfaces were reconstructed; as a result, the center of occlusal forces moved more center.
Oral hygiene is considerably easier to perform than with implant-bone fixed bridgework. This is particularly advantageous with reconstructed patient. Prosthetic treatment using a partial overdenture for this case established masticatory recovery of the patient and esthetics.

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The purpose of this study was to investigate the actual condition of outpatients at the Pediatric Dentistry Clinic of Showa University. The findings were as follows; 1) The number of new outpatients in a year (1999) was 750.2) New outpatients were classified into 547 normal children, 111 disabled children and 92 cleft of the lip, alveolus and palate children. 3) The average age of normal children was 5 years 8 months. The average age of the disabled children was 6 years 5 months. And that of children with cleft of the lip, alveolus and palate was 2 years 3 months. 4) The number of new outpatients of every month was the most in June, secondly in April and then in July. 5) Among days of the week, the outpatients were concentrated on Monday. 6) The number of the outpatients who lived in area of this around Hospital (Showa University Dental Hospital) was more than 70 percent. 7) Concerning chief complaints, most outpatients request the caries treatment, a few did the care of malocclusion and the traumatic teeth. 8) As to the average decayed teeth and filled teeth (df-t) index of a normal child 4 year old children were the highest according to the age. The index was 6.25. 9) 60 percent of normal children who were 5 years old or less have never had dental treatment. 10) 70 percent of outpatients underwent regularly examination after they finished the dental treatment. As compared with the preceding reports the features of the trend were as follows; the disabled children increased. The chief complaints were diversified.

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