The aim of this study is to clarify the traits of the Mongol's head, face and dental arch. In August to September of 1996, somatological measurements were taken of the head and face and plaster models of 175 Mongol young adults (88 males and 87 females), inhabitants of Hailaer City of China. Measured values of head and face, and of the dental arch were assessed by each item. Each value of the Mongol was compared with that of other East Asia tribes. Furthermore, the correlations between the measurements of head and face, and those of dental arches and palate height were examined. The results obtained were as follows : 1. Measurements of the head and face. 1) Head length : The mean value for the male is 176.0mm of the Short Type, and for the female 172.5mm of the Middle Type. 2) Head breadth : The mean value for the male is 154.1mm of the Middle Type, and for the female 150.7mm of the Wide Type. 3) Bizygomatic breadth : The mean value for the male is 123.8mm of the Very Narrow Type, and for the female 123.9mm of the Narrow Type. 4) Morphological facial height : The mean value for the male is 119.1mm of the Middle Type, and for the female 119.8mm of the High Type. 5) The head-type of the Mongol tribe belong to Hyperbrachycephalic Type. The face-type of the Mongol tribe belong to the Hyperleptoprosopic Type. 2. Measurements of the dental arch. The length of dental arch in Mongol tribe is longer than that of the Chaoxian tribe but shorter than that of the Hui tribe. The shape of dental arch in Mongol tribe is the similar to that of the Han tribe, the Man tribe and Japanese. 3. Correlation : No significant correlation was found in male. But in female significant positive correlation was shown between the bigonial breadth and upper dental arch length, and the bigonial breadth and lower dental arch length.

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Apoptosis is an important and well-controlled form of self-regulated cell death that differs from necrosis. This process has been recognized to be of major importance for embryonic development, tissue homeostasis, neurodegeneration, autoimmune disease, carcinogenesis, cancer progression, and the killing of cancer cells induced by chemotherapeutic drugs. Apoptosis is induced by radiation, heat, chemical agents, anti-cancer drugs, or some kinds of divalent metals. However, the effects of cobalt on cultured cells is still obscure. The role of cobalt in induction of apoptosis in cultured cells also is not known. To determine whether divalent metal compounds can affect apoptosis in Chinese hamster ovary cells (CHO cells), the effects of cobalt chloride and other metal compounds on cultured cells were examined. After reaching subconfluence, the CHO cells were exposed to varying concentrations of cobalt chloride. Cobalt chloride induced cytotoxicity and cell death in CHO cells in a dose-dependent manner up to the concentration of 1.0 mM as determined by WST-1 assay and by phase-contrast microscopy. By using the Hoechst 33342 staining, marked nuclear condensation and fragmentation of chromatin was observed in CHO cells. DNA ladder formation, a hallmark of apoptosis, also was detected in CHO cells by treatment with cobalt chloride. The induced-DNA fragmentation and DNA ladder formation were dose-dependent with maximal effect at concentrations of 0.5 mM cobalt chloride and were timedependent from 12 h to 48 h. Cobalt chloride also induced apoptosis in another human cell lines, MG63 cells, Saos-2 cells, SCC-25 cells, and HSG cells. However, cobalt chloride did not induce apoptosis in mouse cell line, 3T3-L1 cells. At the same concentration, the chloride compound of the other divalent metals including zinc, iron, nickel, and manganese and copper sulfate also induced apoptosis in CHO cells. However, magnesium chloride or calcium chloride did not induce apoptosis in CHO cells. Zinc chloride prevented cobalt chloride-induced apoptosis in CHO cells in a dose-dependent fashion up to 70μM as determined by phase-contrast microscopy, WST-1 assay, Hoechst staining and DNA ladder formation in agarose gel electrophoresis. The same concentrations of zinc chloride alone did not show any apoptotic features in the treated cells. The present results show that the pathway of the apoptosis in the cultured CHO cells is regulated with cobalt chloride and other divalent metals. The cobalt-induced apoptosis is prevented with zinc treatment. These findings indicate that apoptotic steps in CHO cells are related to the production of some kinds of proteases which are regulated by cobalt and zinc.

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Intraoral vertical ramus osteotomy of the mandible (IVRO) is a most frequently used method for correction of the facial asymmetry by lengthening the mandible vertically mandible. Postoperative relapse of elongated mandibular ramus following IVRO is more likely to result from excessive tension of the masseter-medial pterygoid muscle sling. It is also more likely to be lightened of such muscular tension in the case of extraoral vertical ramus osteotomy (EVRO) in which the masseter-medial pterygoid muscle sling is cut off. The purpose of the present study was to compare postoperative recovery process of masticatory motor function between the monkeys given IVRO and EVRO. Three adult Japanese monkeys were used. In two monkeys, the right mandibular rami were cut with IVRO, whereas the left ramus was cut with IVRO (IVRO Monkey) or with EVRO (EVRO Monkey). After splitting of the rami, metal splints were cemented to the left lower molars for the unilateral ramal elongation. In a Sham Monkey, the right and left rami were cut with IVRO and EVRO, respectively, and no treatment was given for the unilateral ramal elongation. In the Sham-and EVRO Monkeys, the masseter-medial pterygoid muscle sling was separated, and remained unsutured on the side received EVRO. The intermaxillary fixation was applied for three weeks in all monkeys. Concerning masticatory motor function such as natural chewing, producibility of a biting force of 20kg, and the Hoffman (H)-reflex activity in the masseter muscle, follow-up recordings were carried out bilaterally at an interval of about one month for more than one year postoperatively. The results obtained were as follows : 1. Voluntary chewing of raw sweet potato appeared 24 days postoperatively in the Sham Monkey, while the IVRO and EVRO Monkeys recovered it on the postoperative 64 and 68 days, respectively. 2. On the left side with EVRO and right side with IVRO in the Sham Monkey, forced chewing of a silicone tube started on the postoperative 24 and 66 days, respectively. 3. Recovery of 20 kg-biting force in the Sham Monkey occurred 35 and 167 days postoperatively on the left side with EVRO and right side with IVRO, respectively. On the other hand, recoveries of the biting force were observed 200 and 267 days postoperatively on both sides of the EVRO and IVRO Monkeys, respectively. 4. Masseteric H-reflex activity was first restored 66 days postoperatively on both sides of the Sham Monkey. In the EVRO Monkey, the left side with EVRO and right side with IVRO recovered on the postoperative 68 and 200 days, respectively. In the IVRO Monkey, the H-reflex was restored on neither sides over a year postoperatively. From these results, it is concluded that EVRO is superior in less operative invasion of the neuromuscular mechanisms to IVRO probably due to the former method eminent for the separation of the masseter-medial pterygoid muscle sling.

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The purpose of this study is to determine the use of panoramic radiography in observing the anatomical changes in the jaw bones as the result of aging. To study the effect of aging, the focus was the floor and posterior wall of the maxillary sinus, panoramic innominate line, pterygopalatine fossa, nasolacrimal duct, and ossification of the stylohyoid ligament and thickness of the mandibular cortical bone. Eight hundred panoramic radiographs, from routine radiological examinations at the Department of Dental Radiology, Kyushu Dental College Hospital, were used in this study. These were of both males and females ranging in age from 3 to 91 years old. The radiographs were classified by decade. Each decade consisted of 50 radiographs of males and 50 of females. The results obtained were as follows : 1. The maxillary sinus floors in the first decade of both males and females were not clearly observed. In the third decade, the maxillary sinus floors were clearly observed. However, by the fifth decade, the maxillary sinus floors were not noticeable. 2. The maxillary sinus posterior walls of both males and females were clearly observed in the second, third, and fifth decades. These maxillary sinus posterior walls were more evident in the females than in the males through all of the decades. 3. The panoramic innominate lines in the third decade in males and females were well observed. After the fourth decade, the panoramic innominate lines gradually decreased until the seventh decade. From the seventh to the eighth decades, the innominate lines did not change. 4. The pterygopalatine fossae of females were clearly observable in the first decade but in males, they were not seen until the second decade. After which both males and females continued the same. 5. The nasolacrimal ducts of males were clearly seen during the third decade, but in females, such occured during the second decade. In males and females, these gradually decreased by aging. 6. There was a high percentage of ossification of the stylohyoid ligament in males and females in the second decade. This reached its highest percentage in the seventh decade. 7. The thickness of the mandibular cortical bone in males and females increased rapidly during the second decade. However, in males it remained constant from the fourth until the eigth decade. In females, on the other hand, it then decreased in the eighth decade. It was apparent that there were differences (P<0.05) between males and females on the cortical bone thickness through the each decade. The thickness of the cortical bone in males remained constant during the second and eighth decades.

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Tooth crown traits of 19 members of the Manchu tribe of Xin-Bin, China, were examined and compared with those of 7 Northeast Asia populations in order to clarify the anthropological position of the Manchu tribe based on Turner's Mongoloid dental variation theory. Plaster models were taken from 104 male and 109 female students, 14 to 18 years of age, of the Manchu tribe middle high school in Xin-Bin. They were examined using the Arizona State University Dental Anthropology System. In the eight traits, considerable differences were shown between Sinodonty which is typical of Northeast Asia and Sundadonty which is typical of Southeast Asia. Winging (UI1^2) and 4-cusp (LM2) of Manchu were similar to those of Sundadonty. Shoveling (UI1), Double shoveling (UI1), Carabelli's trait (UM1), Deflecting wrinkle (LM1) and Y-groove pattern (LM2) of Manchu were similar to those of Sinodonty. Cusp 5 (UM1) of Manchu lie midway between Sinodonty and Sundadonty. Appearance rate of Double shoveling (UI1), Lingual cusp variation (LP2), Protostylid (LM1) and 4-cusp (LM2) were high in 7 Northeast Asia populations. Canine medial ridge (UC), Hypocone (UM2), Cusp5 (UM1), Carabelli's trait (UM1), Deflecting wrinkle (LM1), Distal trigonid crest (LM1) and Cusp7 (LM1) were middle, Winging (UI1^2), Shovelling (UI1), Interruption groove (UI2), Tuberculum dentale (UI2), Canine distal accessory ridge (UC), Odontome (UP, LP), Cusp6 (LM1) and Y-groove pattern (LM2) were low. In the eight traits, considerable differences were shown between Han trib and Manchu tribe. Double shoveling (UI1), Lingual cusp variation (LP2), Cusp 5 (UM1), Carabelli's trait (UM1), Protostylid (LM1) and 4-cusp (LM2) of Manchu were higher those of than Han. Tuberculum dentale (UI2) and Canine distal accessory ridge (UC) of Manchu were lower than those of Han.

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The aim of this study is to clarify the traits of the Dafurs's head, face and dental arch. In August and September of 1996, somatological measurements were taken of the head and face and plaster models of 190 Dafurs young adults (92 males and 98 females), inhabitants of Halaer City of China. Measured values of head and face, and of the dental arch were assessed by each item. Each value of the Dafurs was compared with that of other tribes living in north-east of China and Japanese. Furthermore, the correlations between the measurements of head and face, and those of dental arches and palate height were examined. The results obtained were as follows : 1. Measurements of the head and face. 1) Head length : The mean value for the male is 177.7 mm of the Short Type, and for the female 173.2 mm of the Middle Type. 2) Head breadth : The mean value for the male is 153.2 mm of the Middle Type, and for the female 150.0 mm of the Wide Type. 3) Bizygomatic breadth : The mean value for the male is 126.5 mm of the Very narrow Type, and for the female 125.3 mm of the Narrow Type. 4) Morphological facial height : The mean value for the male is 121.5 mm of the Middle Type, and for the female 118.9 mm of the High Type. 5) Cephalic index : The mean value for the male is 86.33, and for the fepale is 86.71, both of the Hyperbrachycephalic Type. 6) Morphological facial index : The mean value for the male is 96.11, and for the female is 95.04, both of the Hyperleptoprosopic Type. 2. Measurements of the dental arch. The shape of dental arch in Dafurs tribe is the similar to the Man tribe, the Mongol tribe and Japanese. 3. Correlation : In male significant positive correlation was shown between palate height and head height, palate height and physiognomical facial height, palate height and morphological facial height. In female significant positive correlation was only shown between the upper dental arch breadth and physiognomical facial height.

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In the chemotherapy for head and neck cancers, cisplatin (CDDP) has exellent antitumor effects and is necessary for combination therapy. At the same time, this anticancer drug has various side effects. In an attempt to minimize the side effects of CDDP and to enhance antitumor effects, CDDP is combined with non-anticancer drugs and administered. For the cultivated cancer cells, KB cells were used and cultivated for a fixed period. Then, CDDP is combined with Caffeine (Caff) or synthetic eel calcitonin (ECT) and administered to the cells. Their effects on the KB cells were investigated in terms of growth conditions and morphology. The results were as follows : 1. No significant antitumor effect in terms of growth condition was found in the CDDP alone (1μg/ml) group (group B1), as compared with the control group. However, between the CDDP alone (2μg/ml) group (group B2) and the control group, significant antitumor effect in terms of growth condition and cytomorphologic changes were found. 2. Between the Caff alone (100μg/ml, or 200μg/ml) groups (group C1, C2) and the control group, no significant genesistasis nor marked cytomorphologic changes were shown. 3. Between the ECT alone (1/50U/ml, or 1/100U/ml) groups (group D1, D2) and the control group, no significant difeerences in genesistasis nor in cytomorphologic changes were shown. 4. Between the CDDP-Caff combined groups (group E1, E2) and control goup, significant differences in genesistasis (p<0.01) and marked cytomorphologic changes were shown. However, between group E1 and group E2, each of 2- and 3-day groups did not show significant genesistasis. 5. The CDDP-ECT combined groups (group F1, F2) showed significant genesistasis (p<0.01) and marked cytomorphologic chainges as compared with the control group. However, between group F1 and group F2, no significant genesistasis was shown. 6. On the basis of the foregoing results, the combined application of CDDP and Caff or ECT enhanced antitumor effect several times. The present experiment results gave considerable suggestions for the clinical aspect, although many further experimental studies need to be made.

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The Selection of the retainer in partial dentures is very important for the prognosis of the abutment tooth. In order to minimize the damage to periodontal tissues supporting the abutment tooth, numerous studies on the abutment tooth behavior with partial prostheses have been undertaken in various methods ; strain gauge, photoelastic, mandibular kinesiograph, CCD camera, and finite element methods. However, the effect of the clasp design on the behavior of the abutment teeth is unclear yet. In this study, the original analysis system in six degrees of freedom was developed to measure the movement of the abutment tooth of the removable denture. The measuring device of this system is composed of only three position sensitive detectors (PSD) and a laser oscillation device. Therefore high accuracy, light weight and small body were accomplished. The experimental denture was prepared on a simulation model of Kennedy Class II which is partially edentulous. The alveolar ridge, and the root of the abutment tooth were covered with silicone material for simulating the mucosa and the periodontal membrane. The experimental denture was designed to allow replacement of five types of clasp (Aker's Clasp ; As, Aker's Clasp With Proximal plane ; Ap, Back action clasp ; Ba, Krol's RPI retainer ; Kr, Kratochvil's RPI retainor ; Kt). The load was applied on central fossa of the artificial first molar on the experimental denture by compressive machine. The load was increased gradually (1 mm/min) to 7N. The measurements were performed three times for each clasp. The results were as follows : 1. The original analysis system in six degrees of freedom was very useful to determine the movement of abutment tooth of the partial denture. Since this system is small size, light weight and high accuracy, the application for live tooth is expected. 2. Inclination, rotation, bodily movement of the abutment tooth with the Ap and the As were the largest among the clasps. The movement of the tooth with Kt was the smallest as compared with other clasps. 3. With the use of the Ba, the inclination and sinking of the abutment tooth were considerably small. But the bodily movements of the tooth in horizontal direction were large. It seems that this type of clasp does not affect the abutment tooth harmfully. 4. With the Kr, the directions of the abutment tooth movement were changed in the bucco-lingual movement, mesio-distal movement and rotation. It seems that the proximal plate slipped from the proximal plane of the abutment tooth at approximately 3N.

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The purpose of this study was to evaluate the impression techniques for polyvinyl siloxane impression materials in terms of the accuracy of the resultant stone casts. An acrylic resin maxillary model with nature dentition was prepared as the original model. Four impression techniques with or without undercut blockout were selected to make the impressions, using stock tray only, custom tray only, custom tray with resin copings for abutment teeth and custom tray with bridge copings. The dimensional changes of the anterior bridge area and posterior bridge area of stone casts were compared. The results obtained were as follows : 1. The effect of undercut blockout on the accuracy of stone cast was more significant in the anterior bridge area than in the posterior bridge area. 2. The dimensional changes of the anterior abutment teeth were more significantly affected by the impression techniques than those of the posterior. 3. It would appear from this study that the impressions made by custom tray with bridge coping were superior to those by the other techniques in terms of the dimensional accuracy and stability of the stone casts.

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Rough surfaced substrates made by different methods have been shown to increase osteoblastic differentiation ; however, it has not been clear whether roughness itself was responsible for this increase. In this study, we examined the effect of roughened substrates, by excluding the factors other than roughness, on osteoblastic proliferation and diferentiation. Rat calvarial cells were cultured on plastic cover strips having varied degrees of roughness by the treatment with four kinds of grinding papers with different particle size. The proliferation and alkaline phosphatase (ALP) expression of calvarial cells increased on the rough surfaced cover strips. The proliferation and the expression increased in response to the increase in the degree of surface roughness upto approximately 0.8μm of average roughness, and then decreased thereafter. These results indicate that surface roughness by itself causes increases in osteoblastic proliferation and the differentiation in cell culture.

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成長発育期の特に思春期のカルシウム不足により虚弱骨を惹起した場合, 直ちにバランスのとれた食餌療法を長期間継続することにより, 骨基質形成が回復するかを明らかにすることを目的に検討した.生後8週齢(ヒトの思春期に相当)のWistar系雄ラット30匹を使用した.対照群(標準食群)は, ラット標準A配合飼料と水道水で3週間飼育した.カルシウム欠乏食群は, A食変型カルシウム欠乏飼料と蒸留水で3週間飼育した.低カルシウム食群は, A食変型30%低カルシウム飼料と水道水で3週飼育した.脛骨骨幹皮質骨における骨基質形成について検索し, 以下の結果を得た.小児期の中でも生体組織が最も大きく変化する時期は思春期, いわゆる第二次性徴期であることはいうまでもない.この時期では小児にとって低年齢児で日常の食生活を学習し, 高年齢児で一つの習慣として規則正しい食生活へと自己の管理をする時期でもある.このような流れの中で成長期の若年期には骨の内部構造はある程度の骨塩量を保っていることになる.従って, 低年齢児と異なり, バランスのとれた食生活を長期間にわたって行うことにより, 骨の変換は活発になり回復することが考えられる.このことは当教室の一連の研究から骨構築状態は低年齢児と大きく異なった所見である.ヒトの思春期に相当する時期での低カルシウム食群は乳児期, 幼児期, 学童期に至る食生活のカルシウムを十分摂取しておくことにより予防は十分可能であることが示唆された.

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Porphyromonas gingivalis is an oral anaerobic rod-shaped bacterium, involved in periodontal diseases. The cell division gene, ftsZ, has been cloned from P. gingivalis 381. This gene encoded a protein of 458 amino acids with a deduced molecular weight of 50.3kDa, as confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Like other eubacterial homologues, P. gingivalis FtsZ possesses a putative GTP binding motif and a GTP hydrolyzing region. Although P. gingivalis ftsZ could not complement an Escherichia coli ftsZ mutant, overproduction of P. gingivalis FtsZ in E. coli resulted in the formation of long filamentous cells. To assess P. gingivalis FtsZ function as a GTPase, the FtsZ proteins were partly purified, examined GTPase activity using 2-amino-6-mercapto-7-methylpurine ribonucleoside (MESG)/phosphorylase system, and determined a GTPase activity. This was suggested that P. gingivalis FtsZ may be also shared universal characteristics among FtsZs.

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There is a large body of evidence supporting the involvement of active oxygens in smoking-related diseases such as lung cancer and other respiratory diseases. Hydrogen peroxide (H_2O_2), one of active oxygens, has been reported to be generated from cigarette smoke. Furthermore, in the mouth, H_2O_2 is not only formed by bacteria colonizing the mucous membranes but also by the cells of the salivary glands. These reports suggest that in the mouth, there is a special need for defense against H_2O_2. In the present study, the effect of cigarette smoking on H_2O_2-degrading enzyme (catalase and peroxidase) activities in human saliva was studied. Cigarette smoking resulted in a dramatic decrease of catalase activity in the saliva. This decrease was found to be attributed to a decrease in catalase protein. On the other hand, cigarette smoking resulted also in a dramatic decrease of peroxidase activity. These results suggest that a decrease of salivary catalase and peroxidase by cigarette smoking leads to the accumulation of H_2O_2 in the saliva and then H_2O_2 attacks mucosal cells lining the oral cavity.

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An anthropological study of the oral cavity in various areas of Japan and neighboring countries has been conducted to clarify racial lineages. The aim of this study is to clarify the oral traits of Amami population. Plaster models were taken from 131 males and 111 females ages 15 to 18, and then measured. Each measurement of the dental arches and palates of the Amami population was compared between males and females. Each measurement of the Amami population was also compared with that of the Japanese (Ishigakijima, Okinawa, Tanegashima, Kitakyushu population, Iki), Taiwanese, Taiwan Aboriginals (Ami, Bunun, Paiwan, Rukai tribes), Central American Indian Jicaques and Balinese. Dental arch lengths were significantly greater in the Amami than in the Taiwan Aboriginals and the Jicaques. Dental arch breadths were smaller in the Amami than in the Jicaques. Lengths of the dental arch were greater in the Amami than in the Okinawans, the Ami, the Bunun, the Paiwan and the Balinese. Palatal heights were significantly higher in the Amami than in the Taiwanese, the people from Iki and the Jicaques, and lower than in the Paiwan and the Rukai. Length of the sutura palatina mediana was shorter in the Amami than in the people from Ishigakijima, the Okinawans, the Balinese, and longer than in the Paiwan. Palatal arch lengths were narrower in the Amami than in the Balinese. Palatal breadths were smaller in the Amami than in the people from Ishigakijima, the Taiwanese, the Taiwan Aboriginals, the Jicaques and the Balinese. Mandibular alveolar breadths were smaller in the Amami than in the people from Ishigakijima and Tanegashima, the Taiwanese, the Taiwan Aboriginals and the Jicaques. These findings and the results of a cluster analysis and neighbor-joining method, and multi dimensional scaling (MDS) suggest that oral traits of the Amami population differ from those of the Taiwan Aboriginals and the Jicaques, and are similar to the Japanese, and was related to the Taiwanese.

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Porphyromonas gingivalis is one of major etiologic agents of progressive periodontal disease and has several proteolytic enzymes implicated in invasion, tissue destruction and evasion of host antibacterial defenses. The aim in our laboratory is to fully clarify the role of enzymes in relation to pathogenesis of this bacterium. In the previous study, we determined the nucleotide sequence of clone pAL2 obtained from P. gingivalis 381 (Microbiology 141 : 2047-2052, 1995), which appeared to contain a DNA fragment encoding a proteolytic enzyme. An approximate 3.8kb DNA fragment (pAL2) was sequenced, the DNA sequence analysis revealed one complete ORF (pepO) and two incomplete ORFs in this fragment. ORF (pepO) encoded a protein (P. gingivalis PepO) of 690 amino acids with a calculated molecular weight of 78, 796. A comparison of the amino acid sequence of P. gingivalis PepO with other proteins in the SWISS-PROT database revealed a 31.7% identity with Endothelin-Converting Enzyme 1 (ECE 1), one of the NEP families. Polymerase chain reaction (PCR) was performed for amplification of pepO, and the PCR fragment was cloned into pET-3a in order to overexpress P. gingivalis PepO in E. coli BL21 (DE3). Furthemore, the overexpressed P. gingivalis PepO was purified to apparent homogeneity by ion-exchange chromatography and gel filtration. The optimal pH of the purified enzyme was between 6.8 and 7.2, and the optimal temperature range was between 40℃ and 50℃. The activity was strongly inhibited by the NEP inhibitor phosphoramidon, but only slightly by the NEP inhibitor thiorphan, like ECE 1. The purified enzyme hydrolyzed metenkephalin, bradykinin and substance P, which were physiological peptides, like NEP from Lactococcus lactis. And the enzyme cleaved big endothelin (ET)-1 big ET-2 and big ET-3, so that generated ET1, ET2 and ET3. The ECE 1 is a key enzyme during processing for generating ET1 which acts as a mitogen as well as a vasoconstrictor for vascular smooth muscle cells. Therefore, these results suggest that P. gingivalis PepO might operate as a virulence factor of not only periodontitis but cardiovascular diseases.

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The purpose of the study was to investigate whether tooth mobility affected on response of periodontal pockets following non-surgical periodontal therapy. Twenty patients with moderate to advanced periodontitis were selected. The following clinical parameters were recorded by five examiners ; probing pocket depth (PPD), probing attachment level (PAL), tooth mobility and bleeding on probing (BOP). Non-surgical treatment consisted of plaque control, scaling and root planing was performed. All teeth were divided into two groups of slight mobility group (Miller's Index : 0, 1) and severe mobility group (Miller's Index : 2, 3). Furthermore, for each groups, all sites were classified into three severity categories according with initial PPD : PPD≦3mm, 3mm<PPD≦6mm, 6mm<PPD The amount of change of PPD and PAL for each pockets were compared between two groups. The results showed that the slight mobility group, compared with severe mobility group exhibited significantly greater amount of reduction of PPD and gain of PAL. It was suggested that tooth mobility affected on healing response of periodontal pockets following non-surgical treatment.

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The main purpose of the present study was to compare tooth displacement under small loading between the same teeth in healthy state and in experimental periodontitis. Five mongrel dogs served as the subjects. High accuracy laser displacement transducer was used in this study. At all tested sites, probing depth (PD), clinical attachment level (CAL), gingival crevicular fuluid (GCF) and tooth mobility (Periotest value) were recorded. The tooth displacement was studied by using 1-100g of vertical loading. Each load was suddenly applied, maintained for 30 seconds, and then suddenly removed. The experimental tooth was unloaded for 5 minutes before the application of a further load. The time between each sampling was set as 0.05 second. The results obtained were as follows : 1. The two-stage intrusion pattern was observed in experimental periodontitis teeth, as shown in healthy teeth. 2. In experimental teeth the two-stage tooth displacement was observed from 1g of loading which was not observed in healthy tooth. 3. The tooth displacement distance both in 1st-stage and 2nd-stage significantly increased on tooth which was affected with periodontitis. 4. A significant correlation was observed between intrusion distance of phase1 (loading of 10-50g) and tooth mobility. The change in mobility of tooth displacement may have the possible role in pathological tooth movement which was observed in severe periodotits.

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The present study was carried out to evaluate the effects of the change in occlusal area and region on nocturnal masseter muscle activity. The subjects were 8 adult males with normal masticatory function. The maximum occlusal force and occlusal contact area of each subject were tested by using Dental Prescale. The subjects were classified into two groups from the following two different criteria : the maximum occlusal force and the proportion of right-hand and left-hand occlusal forces. On the basis of the data obtained from the above-mentioned occlusal forces, three biteplates were designed. Partial contact biteplate having a contact area on a tooth of lateral side, bilateral contact biteplate having two contact areas on the respective teeth of bilateral side, and full contact biteplate contacting with whole teeth. Using a long-term EMG recording nocturnal EMG was recorded with application of a biteplate. The EMG at maximum clenching was also recorded in the beginning of the recording and 7 reference levels, namely 75, 50, 40, 30, 20, 10 and 5% of the maximum clenching, were determined to evaluate the nocturnal EMG. The duration and frequency of muscle activities in 7 reference levels were analyzed. The following results were obtained. 1. Significant relationship was found between maximum occlusal force and occlusal contact area. But no significant relationship was found between these numerical values and the electric potentials at maximum clenching. 2. No significant differences were found among the three types of biteplates through whole subjects. 3. In the masseter muscle activity of the group indicating strong occlusal force, significant decrease was found in application of all three types of biteplate, compared with that in control, but no significant differences were found among any three types of biteplate. In the masseter muscle activity of the group indicating weak occlusal force, significant decrease was found only in application of partial contact biteplate at low clenching levels. 4. In the masseter muscle activity of the group indicating disproportion in right-hand and left-hand occlusal forces, significant decrease was found in application of partial contact biteplates at low clenching levels, compared with that in control. In the masseter muscle activity of the group indicating proportion in right-hand and left-hand occlusal forces, significant decrease was found in application of all three types of biteplate, compared with that in control, but no significant differences were found among any three types of biteplate. Those findings suggest that the nocturnal masseter muscle activity be decreased when given occlusal contact on one side. But when given occlusal contact on lateral sides, the decrease of nocturnal masseter muscle activity is related to maximum occlusal force and the proportion of occlusion, but has no relation to the change of the occlusal area.

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Serotoninergic (5-HT) neuron is well known as a potent inflammatory mediator which leads to pain behaviour. However, which 5-HT receptor subtypes are involved in peripheral sensitization has not been understood. Sarpogrelate HC1 (MCI) is a newly produced compound and that affects 5-HTergic neurons. No data examined the effect of MCI on inflammatory pain response in relation to activation of selective subtype of 5-HT receptors. The present study was designed to evaluate the modulating effect of systemic or local administration of MCI on the instances of flinching behavior after formalin injection into the rat paw. The effects were compared with those of ketanserine, 5-HT_<2A> antagonist. Male Sprague-Dawley rats were subjected to formalin testing. During 60 min period after injection pain behaviour expressed as flinches of the injected hind paw was counted in 5 min intervals. Rats were divided into two series of study ; 1) i.p. or 2) s.c. drug administration. 1) MCI in a dose of 1, 3, 10mg/kg, given i.p. 30 min prior to formalin injection significantly and dose-dependently attenuated biphasic increases in flinching behavior ; phase 1 (max. 10 flinches/min at 1 min) and phase 2 (max. 17 flinches/min at 35-50 min). The ED50 calculated is 3.5mg/kg for the phase 1 and 3.5mg/kg for the phase 2, respectively. This attenuating effect was reversed by the coadministration of α-methyl-5-HT, 5mg/kg, i.p., 5-HT_<2A> agonist. Ketanserine 10mg/kg, i.p., 5-HT_<2A> antagonist similary attenuated flinches during both phase 1 and 2 periods. 2) MCI in a dose of 5μg given s.c. attenuated biphasic increases in flinching behavior and this effect was attenuated by giving α-methyl-5-HT, 5μg while it did not affect by giving 8-OH-DPAT 5μg, s.c., 5-HT_<1A> agonist. Ketanserine 5μg given s.c., attenuated flinches during both phase 1 and 2 periods. Although the formalin test reflects, as does any acute injury state, a surprisingly complex series of events, the initial afferent barrage generates an augmented state of spinal processing, as well as a subsequent phase in which the ongoing afferent input evokes peripheral tissue inflammation. The present results demonstrate that systemic or local MCI administration provokes antinociceptive effect on formalin-produced inflammatory pain behaiour and this effect was reversed by 5-HT_<2A> receptor agonist. The results confirm that Ketanserin, 5-HT_<2A> receptor antagonist, also attenuated formalin-evoked pain behaviour. It is suggested that MCI has a beneficial effect on developing inflammatory pain behaviour via inhibiting selective 5-HT_<2A> receptor.

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Peripheral nerve injury often leads to pathological pain processes including hyperalgesia and allodynia in animals and humans. Although peripheral neuronal mechanisms contribute to these pathological pain state, recent investigation shows that changes in central neuronal function, such as glutamatergic nerve activation and disinhibition of inhibitory neurons in the spinal cord, may play a pivotal role. Therefore, it is reasonable to determine whether apoptosis develops resulting from glutamatergic activation via acceleration of intracellular and nuclear signalling processes. The aim of the present study was to investigate the histopathological changes in relation to response to thermal stimulation with time in rats with chronic constriction injury (CCI). Male Sprague-Dawley rats were anesthetized with pentobarbital (50mg/kg, I.P.) and left sciatic nerve were ligated. Sham rats were performed skin incision only. Paw withdrawal latency times (PWL) of response to thermal stimulation were measured in these rats by using the plantar test equipment at the 6 th to 10 th postoperative days (POD). Immunohistochemical analysis for apoptosis (TUNEL stain) and neuronal degeneration (NAUTA stain) in the laminae I-II, III-VI and VII-IX in spinal cord (L3-5) in rats was performed with light microscope (40 and 400 times) at the 6 th, 7 th and 10 th POD, respectively. TUNEL stain score was obtained as 0 : no positive neuron to 3 : more than 10% neurons show positive, and NAUTA stain score was also obtained as 0 : normal neuron to 3 : more than 50% somato-dendritic argyrophyllic neurons. In the sham group, any remarkable change in the pain behaviour throughout period measured. While in the CCI rat, PWL decreased at the ipsilateral side after operation. In TUNEL stain, positive neurons developed in the ipsilateral laminae I-II at the 6th and 7th day and then became to less at the 10th day after CCI. In contrast, positive neurons of NAUTA stain were developed in the ipsilateral laminae III-VI after CCI (7th<10th day). The present results demonstrate that apoptosis development was firstly found in the superficial layer of spinal cord in rats with early state of hyperalgesia evoked by sciatic nerve ligation. This may suggest that sciatic nerve injury leads to increased ascending inputs or glutamatergic nerve activation followed by derangement of intracellular signalling-intranuclear process (c-fos expression) in the spinal cord which causes apoptosis leading to pain behaviour. It is also suggested that the delayed appearance of neuronal degeneration in the laminae III-VI causes dysfunction of inhibitory interneurons located in this region and this neuronal damage is sufficient to develop the sustained pain behaviour.

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