Effect of estrogen on growth hormone receptor expression of human periodontal ligament cell line / 대한치과교정학회지

The present studies were performed to investigate the interaction of 17beta-estradiol and human growth hormone(hGH) on the proliferation of human periodontal ligament(hPDL) cell. The independent effects of 17beta-estradiol and hGH on hPDL cell proliferation were investigated and the effects of hGH on hPDL cell proliferation after 17beta-estradiol pre-treatment were also investigated. Lastly, the change of hGH receptor expression in hPDL cell after 17beta-estradiol pre-treatment were investigated The obtained results were as follows; 1. The treatment of 17beta-estradiol or hGH had no significant effects on hPDL cell proliferation. 2. After pre-treatment of 17beta-estradiol, hGH stimulated the proliferation of the hPDL cell, regardless of hHG concentration. 3. Although there was not hGH receptor in the hPDL cell, hGH receptors were expressed in hPDL cell after more than 6 hours pre-treatment cf 17beta-estradiol. 4. The effect of hGH on hPDL, cell proliferation was related to the hGH receptor expression. 17beta-estradiol pre-treatment contributed to the hGH effects on the hPDL cell by stimulating hGHR expression.

Eperimental study on the effects of ovariectomy and estrogen on the bone pattern of mandible in rats / 대한치과교정학회지

The purpose of this study was to evaluate the changes of cancellous and cortical bone and the effect of estrogen in ovariectomized rats. Fifty female rats, 250gm in body weight, were divided into three groups : ovariectomized group(OVE), ovariectomized and estrogen-injected group(OVE-EST), and sham operated and estrogen-injected group(EST), Bilateral ovariectomy was performed at the onset of the experiment. In OVE-EST group and EST group, estrogen was injected 50microgram/kg B.W. every other days from 3 weeks after surgery to sacrifice Each five rats were sacrificed after 5, 6, 7 weeks. One side of mandibular body was radiographed with a soft x-ray apparatus (Hitex Co., Ltd., Japan). Thereafter the obtained microradiographs were used for the morphometric analysis using a Image analyzer. The morphometric analysis was performed for parameters such as total bone area, cortex bone area and medullary one area. The other side of the mandibular bone was decalcified and embedded in paraffin as using a general method. The specimens were sectioned and stained with Mallory`s anilline blue and observed light microscopically. The results were as follows. 1. In all groups, the proportion of cortex to total bone area was not significantly different. 2. In ovarietomized(OVE) group, the proportion of marrow cavity to medullary bone area increased significantly from 5 to 7 weeks(p<0.05). In ovariectomized and estrogen-injected (OVE-EST) group, it decreased significantly at 7 weeks, and in estrogen-injected(EST) group, it decreased significantly from 6 week(p<0.05). 3. Microradiogram and histopathologic findings revealed that marrow cavity was enlarged and osteoclasts were observed around irregular bone surface in OVE group. In OVE-EST group, the size of marrow cavity at 7 weeks was similar to that of control group, as dense trabecular bone increased from 5 to 7 weeks, marrow cavity decreased.

Posteroanterior cephalometric characteristics in skeletal Class III malocclusion / 대한치과교정학회지

In proper diagnosis of skeletal Class III malocclusion, it was important to know the pattern of three dimensional skeletal & facial disharmony. The purpose of this study was to obtain P-A cephalometric characteristics in skeletal Class III malocclusion comparing with normal occlusion. The samples were consisted of 120 subjects, divided into four groups : Male normal occlusion, Female normal occlusion, Male skeletal Class III malocclusion, Female skeletal Class III malocclusion. Posteroanterior and lateral cephalogram were taken from the subjects with a x-ray apparatus (ASHAI CX90SP, Japan) and traced on acetate pater with routine manner. The transverse and vertical values from posteroanterior cephalometry, the sagittal values from lateral cephalmetry and their ratio were obtained. The results were as follows : 1. The anteroposterior discrepancy in skeletal Class III group was not due to short maxillary length(Cd-A), but to longer mandibular length(Cd-Gn) than normal occlusion group. 2. The faces of skeletal Class III group were longer than normal occlusion group. It was not due to increase of upper face height (Cg-ANS) but to increase of the lower face height(ANS-NE) especially mandibular height(Cd-Me). 3. There was no difference in the facial width values between normal occlusion group and skeletal Class III group, except upper molar width(U6-U6), lower molar width(L6-L6) and mandibular width(Ag-Ag) of female skeletal Class III group which were larger than normal occlusion group. 4. The increase of mandibular length of skeletal Class III group was reflected in the increase of lower facial height but did not have an effect on the mandibular width.

Condylar ankylosis: Unilateral posttraumatic condylar pseudoankylosis / 대한치과교정학회지

The ankylosis of temporomandibular joint occured by several causes directly developes TM joint disfunction, In cases with prolonged condylar ankylosis, especially at growing age the condylar ankylosis evokes malfunction of growth center area, and then develops the abnormal facial morphology and malocclusion. Therefore it must be cured. Almost authors have agreed to the necessity of surgical correction of the TMJ anlylosis. but they did not decide the one surgical method to get the best result. The Tx. method suggested by many authors are the using interposition after resection of condyle to remain a lever of 3rd class in Mn. kinetics, the autogenous condylar graft and the alloplastic condylar graft. Some authors have got the satisfied results only with the condylectomy of the involved TMJ. This study also operated only the detachment of fibrous adhesion on ankylosed condylar side and then established occlusion in the case with the unilateral TMJ ankylosis and fibrous joint adhesion and facial asymmetry evoked after the fracture of condylar head at early age. This study got a improved mouth opening and a stable postsurgical result after I year. Also, this study reviewed many author's study about the chanracteristics, etiology, diagnosis and Tx. method for the ankylosis of TMJ.