No abstract available.

The purposes of this study were to clarify the effect of tooth size and arch size upon the crowding. 175 upper casts were measured and following conclusions were made. 1. Tooth size, intermolar width, 2nd premolar width of crowded group were not significantly different from those of noncrowded groups. 2. Intercanine width, arch length of noncrowded group were significantly larger than crowded group. 3. Multiple regression equations were derived by using tooth size, arch perimeter, arch length, intermolar width.
Bicuspid ; Crowding* ; Dental Arch* ; Statistics as Topic* ; Tooth*

No abstract available.
Diabetes Mellitus, Type 1* ; Echocardiography*

No abstract available.

No abstract available.

No abstract available.
Humans ; Nurseries*

The purpose of this study was to observe the tissue response to the orthodontic force applied immediately after buccal horizontal subapical osteotomy of maxilla. Five mongrel cats weighing about 2.5 Kg were used for this experiment. The left upper canine and premolar of each cat served as a experimental side and the right ones as a control side. On the experimental side, a 100gm orthodontic force was applied between the upper canine and premolar immediately after the osteotomy. On the control side, the same orthodontic force was applied without the osteotomy. After 7days, the experimental animals were sacrificed. The results were as follows: 1. In the pressure zones of the experimental group, significant increase of osteoclasts and direct resorption along the alveolar bone surface was observed as compared with those of the control group. 2. In the pressure zones of the experimental group, a less extensive hyalinized zone was observed than those of the control group. 3. In the pressure zones of both group, no root resorption was found. 4. In the tension zones of the experimental group, new bone deposition increased along the alveolar bone surface as compared with those of the control group. In conclusion, the results suggest the possibility that early orthodontic treatment after orthognathic surgery may have some benefits if the stability of the repositioned segment at surgery is secured.
Animals ; Bicuspid ; Cats ; Hyalin ; Maxilla* ; Orthognathic Surgery ; Osteoclasts ; Osteotomy* ; Root Resorption

As the result of the study concerning "bone inducibility of chitosan", 1. "BMP-2"was observed mainly through the test when the "osteoblast"is exposed to the "chitosan". The expression of BMP-2 was 542.63 times compared to control after 2 hours exposure and it was maintained 16.60 times till 24 hours. 2. The expression of BMP-4 was decreased compared to control during exposure. 3. The expression of BMP-7 revealed two peaks during exposure. 4. The expression of osteocalcin was increased in early phase, and then decreased. Although it is not clear whether the "chitosan"is clinically effective material as a "bone induction material", we could say that it has a function for bone induction. Further detailed study will be required.
Bone Morphogenetic Protein 7 ; Chitosan* ; Humans* ; Osteoblasts* ; Osteocalcin

There has been so much controversies about the position of upper and lower jaws, and their first permanent molars in normal occlusion and Angle's class I,II,III malocclusions. So, the purpose of this study is to compare the position of upper and lower jaws, and their first molars in normal occlusion and Angle's class IIIIII malocclusions by lateral cephalometric analysis. The sample consisted of one hundred and twenty girls(thirty in each group) who had completed growth. The findings of this study were as follows: 1. In class I malocclusion, both maxilla and mandible were slightly posterior position than normal occlusion, but they showed harmonious relationship. 2. In class II malocclusion, the mandible was greatly retruded, and the maxilla was also slightly retruded to the cranial base as compared with normal occlusion. 3. In class III malocclusion, the maxilla was significantly retruded to the cranial base, but no significant difference was found in mandibular position as compared with normal occlusion. 4. The maxillary first molar was located at posterior position in class II malocclusion, and anterior position in class III malocclusion to the cranium, so that the rotation of mandible was influenced by that. 5. The mandibular first molar showed constant relationship to the mandible in all four groups, but different position to the cranial base in direct proportion to the mandibular position. 6. On the treatment planning of class II malocclusion, it seems to be better to promote the mandibular horizontal growth by inhibiting the vertical growth of maxillary molar area, and on the treatment planning of class III malocclusion, it seems to be better to promote the antero-inferior growth of maxilla and to promote the mandibular vertical growth by inducing the vertical growth of maxillary molar area.
Jaw* ; Malocclusion* ; Mandible ; Maxilla ; Molar* ; Skull ; Skull Base

In order to improve the success rate of implants, various implant designs have been developed. Although there have been enough efforts to handle the surface of the implant with careful choice of material and mechanics so that the bone and the implant can be tightly joined together, they have still failed to play the role of periodontal ligaments of the natural teeth in the past. The role of periodontal ligaments is very important since it can improve the initial stability of implant by absorbing the impacts. The purpose of this study is, thus, to test the possibility of alleviating the impact when the surface of the implant was coated with chitosan, a natural polymer, and making sure that the coated material stayed on. Then, the condition of newly developed bone formation and the degree of inflammation in response was closely observed in the surface level. In the main experiment, Chitosan coated implant (3.3 mm X 7mm) was implanted on both the right and the left side of rabbit's femur. The animals were each sacrificed on the 1st, 2nd, 3rd, 7th, 14th, 21st and 28th day. The process was observed under an light microscope after the Toluidin Blue staining. From the experiment, it was found that the chitosan was evenly distributed on the surface of the screws, and the implant was adjoined with adjacent bone. There was a sign of inflammation on the 3rd day, but on the 14th day, the formation of woven bone and newly formed bones were noticed. Also, chitosan filled the gap was formed between the implant and the newly formed bone. The implant, the chitosan and the newly formed bone were forming one unit as a result. Therefore, it was found that chitosan coated implant could absorbe the impact in the initial stage of implant.
Animals ; Chitosan* ; Dental Implants* ; Femur ; Inflammation ; Mechanics ; Osteogenesis ; Periodontal Ligament ; Polymers ; Tooth