The aim of this study is to find out histomorphologic change and cellular activity of condyle resulted from unilateral mastication by comparison of cell proliferation and apoptosis activity. 30 adult rats were dived to 15 experimental group and 15 control group randomly. Right upper and l ower molars were gently extracted in experimental group, to make unilateral mastication environment. All subjects were sacrificed at 1 week, 2 weeks and 4 weeks by chloroform, and their tissues were prepare to observation. Streptovidin-biotin system for BrdU stanning, was used to determine cellular proliferative activity. TUNEL method was used to determine apoptotic activity. The result for cellular activity was recorded at both of anterior portion and posterior portion of condyle. Hematoxylin and Eosin stanning was used for histiomorphological change. The results were as follows. There were more change in superficial layer than deep layer of condyle in cellular activity. In anterior portion of condyle cartilage, cellular proliferative activity of experimental group was lower than control group and apoptotic activity of experimental group was higher than control group. And apoptotic activity of extracted side in experimental group is the most. In posterior portion of condyle cartilage, cellular proliferative activity of extracted side in experimental group was higher than non-extracted side and control group, And apoptotic activity of extracted side in experimental group was the low. As a result of histomorphological change, there was hyperplasia in posterior region o f extracted side c ondyle i n experimental g roup, but t here was n o change i n unextracted side i n experimental group. There was histomorphological hyperplasia in posterior condyle of experimental group as results of high cellular proliferative activity. There was mainly apoptotic change of anterior portion condyle in experimental group. But there was no histomorphologic change. In other words, there was hyperplasia by increasing of cellular proliferative activity in posterior portion of nonfunctional side condyle. In functional side condyle, there was no histomorphological change in functional condyle, but there was change in cellular activity.

Human gingival fibroblasts are necessary for oral homeostaslS These cells are fundamental in tissue healing and tissuc remodeling processes under a response to physiological actions such as mastication, Collagen and elastin, that are extracell ular glycoprotein of gingival fibroblast, are found in all animals, '1γpe 1 collagen is most dominant protein found in human gingival fibroblasts , Matrix metalloproteinase-1(MMP-1) has a role play in destruction of metabolism of extracellular matrix(ECM) and MMP-1 can destroy many ECMs as well as non-ECM molecules MMP-1’s local activation is conytolled by tissue inhibitor of metalloproteinase-1(TIMP-1) , Therefore, it is important to have a balance between in both s ituations MMPs and TIMPs of increased 0 1' decreased extracelluar matrix molecules, The purpose of trus study is to find out the effect of physical stimulus to human gingival fibroblast on mRNA, proteins of collagen 1, elastin, MMP-1, and TIMP-1 Healthy human gingival fibroblasts were separated and cultur때 in DMEM(Dulbeco’s Modified Eagle’s Medium) , When the sample reached to confluence state, it was separated with 0,25% t rypsin and 0‘ 53mM ethylendiaminetetraacetic aCld Separated cells were centrifuged in a cell culturing flask at 1000rpm for 30, 60, 120 mmutes Then it was forced by 35g/cm' continuously, The obtained results that expression of mRNA using histological study and Reverse Transcription Polymerase Chain Reaction (RT-PCR) , expression of protein using Enzyme-Linked Immunosorbent Assay(ELISA) for this study, At 30minutes after cen trifuging, there were s pindl e shaped gingival fibroblasts with long processes parallel to other cells in the control group , However the cell density was simil ar to compared group, At 60minutes after centrifuging, spindle shaped human gingival fibroblast with relatively long process, less densely packed, At 120minutes after centrifuging, cell processes were lengthened 2-3 times‘ and cell density was lower, At 30-60 minutes after centrifuging, it was increased by 1,3-1,7 times in expressoin of collagen 1 mRNA as compared with comparison group, However, there was no change in elastin, TIMP-l, and MMP-1, At 120 minutes after centrifuging, The revealed collagen 1 mRNA was increased 3 times as compared with comparison group, It was increased 2 times in elastin , 12 times in TIMP-1 as compared with comparison group, However, there was no change in MMP-l. At 30-60 minutes after centrifuging, it was increased by 1.1 times in revealing of protein revealing in collagen 1, TIMP-1 But there was no cha nge in elastin, MMP-1 At 120 minutes after centrifuging, it was increased by 1,2 times in revealing collagen 1 protein, 11 times in elastin, 12 times in TIMP-l, but there was no change in MMP-l. ln conclu s ion, it increased in revelation of collagen 1 ,elastin and TIMP-1 by continous stimulus in human gi ngival fibroblast, But there was no change in revelation of MMP-l Therefore, th is type of pressu re is one of the components for healing of gingiva l fibroblast