Spectral characteristics of resonance disorders in submucosal type cleft palate patients

Hypernasality correlates with acoustics and aerodynamics

The Effect Of Tetracycline On TNF-alpha And Lipid Peroxidation In Sepsis Model Of Rat

The effects of estrogen on experimental tooth movement in ovariectomized rats / 대한치과교정학회지

The purpose of this study was to evaluate the effect of estrogen on the periodontium and alveolar bone tissue response during experimental tooth movement in ovariectomized rats. Eighty female rats, 250gm in body weight, were classified into four groups ; sham operated group(NN), ovariectomized group(ON), ovariectomized & estrogen injected group(OE), sham operated & estrogen injected injected group(NE), Rats were ovariectomized before 3 weeks to begin the experiment, which resulted in estrogen-deficient osteoporosis. In OE group & NE group, estrogen was injected 50microgramg/kg B.W. every other days. The left maxillary 1st molar was moved mesially with 60g force. Each four rats were sacrificed after 1, 3, 7, 15 days from application of orthodontic appliance and after additional 7 days from removal of orthodontic appliance. Histological findings on mesial roots of upper 1st molar in pressure and tension side are observed. The results were summarized as follows ; 1. In pressure side of alveolar bone, the number of osteoclasts and Howship's lacuna of ON group was significantly more than that of NN group from 1 day to 15 days(P0.05). The amount of tooth movement of ON group between 7 days and 15 days was significantly greater than those of other groups(P0.05).

A Static study on the orthognathic surgery via sagittal split ramal osteotomy

The immunohistochemical expression of collagens and the morphogenesis in the developing mandible of human embryos and fetuses / 대한치과교정학회지

Underlying malocclusions and dentofacial deformities are often related to variations in the craniofacial development. Type I and type II collagens are considered the major collagens of bone and cartilage respectively. Monitoring the patterns of those protein expressions during development will provide a basis for the understanding of normal and abnormal growths. This study was undertaken to investigate the morphogenetic changes and the expression patterns of type I and II collagen proteins involved in the developing mandible of human embryos and fetuses. 50 embryos and fetuses were studied with Hematoxylin and Eosin, Alcian blue-PAS, Masson Trichrome, and lmmunohistochemical stains. The results were as follows: 1. A 13.5 mm embryo showed the stomatodeum with dental lamina, maxillary and mandibular processes. Meckel's cartilage appeared in the mandibular arch of a 20.5 mm embryo. New bone formation was bilaterally initiated at the outer side of middle portion of Meckel's cartilage of 22-38mm embryos. 2. Meckel' cartilage was resorbed at the 15th week fetus. The endochondral ossification was observed where there was direct replacement of cartilage by bone. Meckel' cartilage disappeared and membraneous ossification were observed at the 25th week. 3. Before the appearance of Meckel's cartilage, the expression of type I collagen was moderate at the odontogenic epithelium of maxillary & mandibular process, but mild for the expression of type II collagen. 4. During the appearance of Meckel's cartilage and new bone formation, the immunoactivity of type II collagen was more expressed than type I collagen at the Meckel's cartilage and new bone. 5. During intramembranous bone formation, the expression of type II collagen was rare in the bony trabeculae. There was a switch for the expression of collagens from type II to type I during the appearance of Meckel's cartilage.