This study was designed to clarify the three dimensional features of naso-maxillary complex in cleft lip and palate (CLP) by using computed tomography (CT) and to examine its change following an upper dental arch expansion. Sequential CT images with 2mm-thickness were obtained for 11 unilateral CLP boys (UCLP), 6 bilateral CLP boys (BCLP) and 4 boys without cleft (non-cleft) . Additionally, two serial sets of upper dental cast before and after dental arch expansion coupled with CT images in UCLP were used to evaluate the effect of dental arch expansion on the naso-maxillary complex. UCLP demonstrated a remarkable naso-maxillary deformity characterized by a decreased volume of maxillary sinus in comparison with the non-cleft patients. Both the volume and shape of nasal cavity were significantly different between the cleft and non cleft side. Naso-maxillary morphology of BCLP, however, was similar to that of the non cleft except for the decreased volume of alveolar arch. Comparative study of UCLP and BCLP showed a significant difference in naso-maxillary morphology. There were some significant correlations between the dental arch expansion and change of each naso-maxillary component, suggesting the effect of expansion stress on the naso-maxillary complex in UCLP. However, deformation caused by expansion stress varied, depending on each component of the naso-maxillary complex.
To understand the precise mechanism of bone formation induced by bone morphogeneticproteins (BMPs), it is important to elucidate the receptor system of BMPs. In this study, expression of mRNAs for serine/threonine kinase receptors, including BMP receptors, duringectopic bone formation induced by BMP, was investigated, and also the molecular cloning of rat BMP type IA receptor (BMPR-IA) was performed. Polymerase chain reaction (PCR) -based analysis revealed that mRNAs for BMP type IA and type IB receptors were expressed in the BMP-induced bone forming tissues throughout thestages tested and that mRNA for activin type IA receptor, which was shown to serve as areceptor for BMP as well, was also expressed. These results suggest that these three receptorsplay important roles for the ectopic bone formation induced by BMP. In addition, expression of mRNAs for TGF-βtype I and type II receptors and activin type IB and type II receptors wasalso detected in the BMP-implanted tissues, which suggested the possible involvement of TGF-βs and activins as ligands in the ectopic bone formation. The comparison of the rat BMPR-IA with the human and mouse counterparts showed highconservation among species. This finding suggests that BMPs may exert their effects through highly conserved pathway among species.
Production and characterization of hemidesmosome-specific mouse monoclonal antibodies 3A1 and 8A12 raised against the oral Squamous carcinoma line cells were previously reported. In this study, further investigations were carried out to characterize these antigens using those cells. Immunoaffinity-purified 3A1 antigen was identified as a 180kD glycoprotein [205kD under reduced conditions] . Acetate membrane electrophoresis of disaccharides originating from this antigen digested by chondroitinase ABC showed that this protein was associated with hyaluronate. Immunoprecipitates by 3A1 and 8A 12 antibodies were composed of two bands: 180kD and 140kD [205kD and 125kD by reduction], and were similar to integrin α6β4 precipitated by monoclonal anti-α6 subunit antibody. Immunoprecipitation-Western Blot analysis showed that the 140kD [125kD] protein precipitated by 3A1 and 8A12 was α6 subunit and that the 180kD [205kD] β4 subunit. After the α6 subunit was immunodepleted, only the 180kD [205kD] band was immunoprecipitated by 3A1 or 8A12. Both 3A1 and 8A12 blocked the adhesion of LMF5 cells to laminin. These data indicated that 3A1 and 8A12 recognized integrin β4 subunit and that integrin α6β4 functioned as a laminin receptor on these cells. It was suggested that hyaluronan detected in the 3A1 antigen was associated with two putative hyaluronan-binding motifs in the extracel-lular domain of the integrin β4 subunit.
In order to attain joining the super-elastic Ti-Ni alloy wire to the Co-Cr alloy wire and be able to maintain the super-elasticity of the Ti-Ni alloy wire, a new soldering method was devised. The silver solder was first molten on the 0.016×0.022 inch Co-Cr alloy wire (Co-Cr) and then flowed onto the 0.016×0.022 inch super-elastic Ti-Ni alloy wire (Ti-Ni) to form soldering. The specimens of soldered Ti-Ni to Co-Cr butt joint, TN-CC, were examined for its super-elasticity, torsional strength, tensile strength and the metallographic structure of the soldered joint. The findings were as follows: 1. TN-CC still maintained its super-elasticity. 2. The torsional strength of TN-CC was equal to that of Ti-Ni. The tensile strength of TN-CC was 73% of that of Ti-Ni. 3. The tensile strength of TN-CC immersed in 1%NaCl solution at 37°C for 30 days was considered to be still strong enough for clinical use. 4. During the tensile strength test, the breakage of TN-CC occurred at the area of merger of the solder and Ti-Ni. As the reason for this breakage, it suggested that Ti-Ni was stretched and narrowed at the soldered area and that the Sn-rich phase in the solder was induced along Ti-Ni. 5. This new soldering method was shown to be useful in clinical cases, and the fabrication of new orthodontic appliance using two distinct types of wire, one to independently move teeth and the other to be the anchorage, has already been developed.
The purpose of this study is to investigate the translucent sensory measurement as a basic study for developing the translucent sensory scale (Haze Guide) of tooth crowns. Seven subjects with normal visual sensation were examined to search for the translucent sensory interval of uncertainty using methods of limits, and 3 panels were selected from this result and prepared for further experiments. Fact-findings of the translucent senses were performed on these 3 panels using the magnitude estimation method and the absolute judgement method. With these methods we were able to construct the translucent sensory measurement and to establish the ranges of Haze scores and magnitude of each step and a permitted limit of each Haze tab, which should be possessed with the tooth crown translucent sensory scale. The results were as follows 1. The translucent senses were well adapted to the Stevens power law of modality characteristic exponent. The exponent was 1.74. 2. Standard light translucent sensory guide for tooth crowns were in the range between 25. 2% and 91.9% at Haze values. Eighteen steps were arranged within this range, and when the Haze difference was taken larger at lower Haze values and the difference was taken smaller accordingly at higher values, the visual sensation came to achieve an equally appearing interval of translucency.
Transferrin receptor (TfR) is expressed in the proliferating cells. The author performed an immunohistochemical investigation with TfR and an analysis of TfR protein and mRNA in several cell-lines and examined the relationship between the TfR content and the proliferative activity of the tumor cells. Immunohistochemical examination revealed a strong reaction of the TfR was found in the cell membrane of the epithelial malignant tumors and the non-epithelial malignant tumors showed diffuse staining in the cytoplasm. TfR was almost regulated by the cellular density in the culture dishes. A confluent phase growth led to a low level of TfR. And among the several cell-lines, a higher level of TfR was seen in the cell of the short-doubling time than that of the long-doubling time. In vivo, similarly the rapid growth tumor indicated a high level of TfR rather than the slow growth one. Thus, the level of TfR indicates the degree of the proliferative activity of the tumor cells, so the examination of TfR content is helpful for the determination of the degree of malignancy in each tumor case.
Although much is known about the hormonal regulation of hard tissue development, much less is known about the nuclear regulatory molecules that affect the process. Homeobox-containing genes are thought to encode DNA-binding transcriptional factors which control the expression of other genes. In this study, molecular cloning of Msx homeobox-containing genes from a bovine odontoblast library and a human dental pulp-derived cells library was performed, and also the expression of mRNAs for Hox and Msx homeobox-containing genes during ectopic bone formation induced by BMP was investigated. Screening of a bovine odontoblast cDNA library and a human dental pulp-derived cells library with murine Msx-1 and Msx-2 cDNA probes led to the isolation of several positive clones. All of the clones from a bovine odontoblast library encoded the bovine counterpart for human MSX-1. All of the clones from a human dental pulp-derived cells library encoded the human counterpart for murine Msx-2. Northern blot analysis probed with a human MSX-2 cDNA indicated the expression of 2.2kb and 1.2kb mRNA in human dental pulp-derived cells. Polymerase chain reaction (PCR) -based analysis in the BMP-implanted tissue revealed that nine rat homologues of Hox homeobox-containing genes were expressed in the early cell migration stage and that two Msx genes were expressed in the cartilage and bone differentiation stages. The PCR study provided evidence of dynamic changes in the BMP-induced homeobox gene expression.