The purposes of this study were to estimate Brdu positive and apoptotic cells dis tribution in co ndyl ar art icular and proliferative layer. and hi stopathological evaluat ion during one sided mas t icatory condition. 15 of 30 adults Sprague Dawley male rats were experimental group, and 15 rats were control group. Experime nta l group were gen t ly extracted on all lower and upper molar teeth to make unilateral mastication. Experimental gl'Oup were divided into two group as extracted side and nonextracted side condyle. Diluted bromodeoxyuridi ne(Brdu) solution(5mg/Kg) was injected in peri toneum before sacrifice at inte rval 1 week, 2 week, 4 week Streptoavidi n-Biotin method for Brdu was used to evaluate cellular proliferat ive activity, and fluorescent TUNEL method was used to estimate the a poptotic activity. The resul ts of this experiment were recorded about anterior and posteri or condyle sepa rately On anterior condyle, contl'Ol group was sustained increased proliferative activity th roughout experiment. whi le cel lu lar proliferative activity of extracted and nonextracted s ide condyle showed more decreased than control grou p ‘ On posteri or portion of condyle‘ control group and nonextracted group showed dramatically decreased cellular pr。 liferat ive activity during all expel‘ imental period. On anterior portion of condyle, control grollp s howed decreased a poptotic activity with time passed. bllt expel'imental gl'oup(both ext l'acted and nonextracted) exhibi ted incrcased a poptotic activity. Es pecia lly extracted grollp showed prominent increased apoptotic activity. On posteri or portion of condyle. extracted group showed dec reased apoptotic activity wi th time progress. but co ntrol and nonextracted group exhibi ted increased apoptotic activity with time progress. Conclllsively. antel'ior portion of condyle on ex t racted s ide expressed hypoplasia by low cellllJar prol iferative activity and increased apoptotic activity. and poste ri or portion on extracted side showed condylar surface hyperplasia by continious proliferative cell ular activity and low a poptotic activity. a nd t hllS unmasticatol'y condyle had anLeroposLel'iorly shorter mo rph이 ogy and verti ca11y longer morphology than masticatory and nOl'mal functioning condyle

The aims 0 1' t his study we re to evaluate proliferative and apoptotic cell distribution pattern in condylar articu lar and pl'oliferative layer as two types of diet(soft and ha rd) we1'e supplied to growing 1'a ts, 30 male Sprague Dawley g1'owing l'ats(twenty-one c1ays fl'om bi l'th) were c1ivided into two group, Each 15 rats were supplied by soft and hal'd di et , After c1 iluted Bl'du solution(5mg/ Kg)was injected into pel'itoneum befol'c sacrificc. rats wel'e sacl'i f iced at 1. 2. 3 week llltel'vals St1'eptoavidin-Biotin method for Brdu was used to evaluate celluJar proliferative activity. ancl fluol'escent TUNEL method was used to estima te the apoptotic activity, The results about this expe riment wel'e recorded about ante1'io1' and posterior condyle separateJy, In anteriol' portion of condyle, soft diet group showed inc1'eased p1'olife1'ative celluJar activity tha n hal'd diet group dw'ing 1, 2 week but decl'eased than hal'd diet g1'oup at 3 weeks. while hal'd diet group showed constant p1'oliferative cellular activity during all experimenta l period , ln posterior pOl'tion of condyl e、soft diet group showed increased activity than hard diet group at 3 weeks, while ha rd di et gl'oup showed constant proliferative cellular activity during exper‘ imental period , In a nterior pOl'tion of condyle‘ soft c1 iet group showed increased apoptotic activity with time progress, but hard diet group showed continuous low level of activity during experimental period , In posterio1' porti on 0 1' condyle, hard diet group showed cons tant low level apoptotic activity, plthough showed the lowes t leveJ at 1 week, On the con trary soft diet g1'oup showed c1ecl'eased apoptotic activity wi th time progress, ConcJusively, in soft diet group an teroposterior direction was reduced in condyJar morphologic dimension because of decreased prol iferative cellular and increased apoptotic activity on anterior portion and vertical dimension 0 1' condyle was increased because of increased proliferative cellular and decreased apoptotic activity on posterior portion. but in hard di et group proli ferative cellular and apoptotic activity were comparatively constant. and thus harcl diet group s howed antet'opos teriorJy broad and flat condylar morphoJogy