A 57 years old female complained of severe pain on the right temporomandibular joint (TMJ) area. Her right condyle had been partly resected under surgical operation 13 years ago due to condyle hypertrophy, thereafter she felt dull pain on TMJ area and recently the lesion became severely swelled and painful leading to cancer phobia. The present radiological views showed slightly enlarged and sclerosed condyle with increased radiopacity, but its articular sliding function was almost disable during mouth opening. The patient’s TMJ lesion was carefully managed with conservative physiotherapy and pain treatment. The microsection of condyle head obtained from the previous operation was re-evaluated histologically, and it was finally diagnosed as osteochondrosis dissecans (OCD), exhibiting hyperplastic proliferation of cartilage in condyle head and marked vascular dilatation in epiphyseal zone. This abnormal cartilage tissue was distinguishable from normal cartilage tissue found in the peripheral cartilaginous cap of the same microsection. The involved cartilage cap showed thick hypertrophic chondrocyte zone with horizontal and vertical clefts accompanying diffuse hyaline degeneration. The superficial fibrous zone of cartilage cap was thickened and frequently peeled off, while lower hypertrophic zone of cartilage cap was highly cellular and proliferative. Consequently, the endochondral ossification became aberrant and resulted pre-mature apoptosis of many hypertrophic chondrocytes, followed by diffuse and mild inflammatory reaction in the underlying marrow tissue. Therefore, it was suggested that this hypertrophic condyle lesion, OCD, be differentiated depending on radiological and histological features from ordinary condyle hyperplasia, osteochondroma, and osteoarthritis, and that the pathological confirmation of OCD may provide a reliable modality for dental and medical treatment of chronic and painful TMJ lesion.

Osteochondroma is one of the most common benign tumors of the bone. Although osteochondroma is rarely seen in the facial region, it was reported that the cases occured in the mandibular region, especially around the condyle. Patients complain about malocclusion, temporomandibular disorders and facial asymmetry. The treatments of these cases include total condylectomy or local resection of the lesion. A 48-year-old man visited our hospital. His chief complaints were pain in the left temporomandibular joint (TMJ) and deviation of mandible during mouth opening. Panoramic radiograph showed an enlarged left condyle. A bony proliferation with benign sign was also observed in the computed tomography. Surgical treatment was done by removing the bony mass. Histologically, biopsy result was an osteochondroma. After surgery, there was reduced pain and normal mouth opening. Deviation of the mandible was also observed. We report a case of osteochondroma on the mandibular condyle and a review of literature about the surgical treatment.

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.

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