It is not yet clear to know how normal human osteoblasts(NHost) from oral and maxillofacial area deposit, stabilize, and configure their extracellular matrix on dental biomaterial surfaces. Therefore it is necessary to design biomaterials with improved biocompatibility that will promote earlier bone differentiation and mineralization. There is now increasing evidence that TGase 2 may play a role in the initiation and regulation of the mineralization processes and serves to cross-link osteocalcin and osteopontin, which are predominant substrates for TGase 2 expressed during bone mineralization. But it is still unclear as to which TGase 2 is expressed by NHost in vitro bone formation. The purpose of this s tudy was t o determine the level of TGase 2 expression associated with collagen I , osteopontin and osteocalcin in NHost cell lines from oral and maxillofacial area in vitro. We will investigate whether TGase 2 has an active role in the biocompatibility of dental biomaterials during differentiation and mineralization of NHost. NHost cell lines were cultured under DMEM with 10% FBS at 37ﾟC and 5% CO2. Collagen quantification, mineralization and calcium assay, ALP activity assay, and RT-PCR analysis during bone differentiation and mineralization were done. ALP levels showed higher activity under AA+hGP t han under AA. I nhibition o f T Gase 2 by cystamine showed d ecreased Ca++ concentration, c ollagen I deposition and ALP level during 11 days of differentiation. TGase 2 mRNA expression of NHost was constant during mineralization stage. TGase 2 enzyme activity was increased during differentiation. Osteopontin mRNA expression during mineralization was higher than that of osteocalcin and collagen I . It suggested that TGase 2 associated with collagen I, osteocalcin and osteonectin might play a role in the differentiation of NHost from oral and maxillofacial area, but a little involved in mineralization.

A possible rapid biodegradation of abandoned livestock was tested by using the dead pig and chicken. The dead pig (36 ㎏) was completely decomposed after 23 days of placement in the open field during June 2007. When the door of a cage in which a dead chicken (3.4 ㎏) was placed was opened, a lot of flies were attracted to the chicken and layed eggs on the chicken. As the result the chicken was decomposed down to 0.6 ㎏ after 6 days of placement in the open field, On the other hand when the door was closed, the decomposition was very slow. The chicken weighed 3.0 ㎏ even after 6 days. An experiment conducted during October 2007 showed that decomposition speed depended on the number of inoculated flies. When 50 pairs of Lucilia sericata flies were inoculated to 3.2 ㎏ chicken, it was decomposed down to 1.0 ㎏ after 22 days in the field. However, when 200 female and 100 male flies were inoculated, the 3.4 ㎏ chicken was decomposed to 0.8 ㎏ after 11 days in the field. A 10,858 pupae (371.2 g) was produced from the latter chicken. These pupae may possibly be used as a feed for fish and fowl. From these results it is considered that further research is needed to commercialize the blow flies for the rapid decomposition of an abandoned livestock of diverse size under diverse environment.

Odontomas are the most common benign tumors of odontogenic origin characterized by their‘ slow growth, and a re cons ider ed to be developmental a nomalIes They consist of enamel, dentine, cementum and pulpal tissue and cons titue about 22% of all odontogeni c tumors The purpose of this study was to value clinicopathologic features of this kind 01 tumors‘ and to apply these results to make a pa ln of diagnosis and treatment in future, The 20 cases of odontomas between 1991 a nd 2004 subrn.i tted to Dept , of Oral Pathology of Dankook Univ, Dental Hos pital were used We analyzed theil‘ prev a lence‘ di s tributi on in gender , age of the pat ients , anatornic location. clinical manifestations and histopa thologic fea rtures Cli nical symptoms s howed delayed eruption(n=3) of either the deciduous or permanent tooth‘ mtra- 01 extraoral swelli ng(n =9). pain(n =2) , Of a ll the odontomas, 45% in the Mn & 55% in the Mx was seen There were 55% in the anter iosuperier sector & 25% i n the pos ter ioi nferior zone. while the rest in the upper molar region, COO showed 18,5 year s(r ange 6,4) , 60% 0[' diagnosed odontomas, incisor / canine area of mx, smaller(5-30mm) & unilocular. and mu l tip le radiopaque mini teeth s urroun따d by defined radiolucency, whi le CXO showed 30, 1 years(range 14 , 5) ‘ 40% of diagnosed odon tomas ‘ 1s t and 2nd molar of the mn, la rger(1O-60mrn) & unilocular undistinguished radiopaque mass and surrounded by ra di 이 uc e nt zo ne & a di s tin ct ra di opaque border, Both showed reduced enamel epithelium, enamel. dentin and cementum‘ di s play ing s ph eri al calcificat ions. and fibrous capsule as background , A.nd ghost cells were seen in 2 cases COO s howed hig hly orga nization & differenti ation, resembling a minitooth Each tooth was contained with co n nective tissuc sac CXO s howed haphazard organization, and was domi nated by dentin , displaying no resemblance a tooth, Through the definitive diagnos is of odonotmas on the basis of the clinicopath이 ogi c results, we should establish a plan in diagnosis and t rea tment of odontomas