We examined enzymic properties of alkaline phosphatase (ALPase) and its isozyme patterns using extract from the submandibular gland of senescence accelerated mice (SAM) at 7, 17, 27 and 37 weeks of age. Quantitative inhibition and thermostability studies on the separated fractions (peaks) that were obtained by ion exchange chromatography and agar electrophoresis, confirmed that most of the ALPase was the kidney type, while a small portion was the intestine type. There were agerelated changes in ALPase activity, with the peak being at 17 weeks of age. Shika Igaku (J Osaka Odontol Soc) 1997 Jun； 60(2)：105-114．

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I investigated the contribution of temporomandibular joint (TMJ) morphology to the development of temporomandibular joint disorder (TMD) in a retrospective study of the MR images of TMD patients and individuals free of clinical TMD symptoms. I examined retrospectively the axial MR images of 397 patients with clinical diagnosis of TMD, using 550 individuals without clinical symptoms as controls. The distance between the bilateral mandibular heads, and the horizontal angulation of the mandibular heads were measured for each subject. The average horizontal angulation of the mandibular heads in the TMD group was 20.1° in males and 18.4° in females, while the average in the controls was 18.2° and 19.3°, respectively. The average distance between the bilateral mandibular heads was 102.8 mm in males and 97.4 mm in females for the TMD group, compared with 106.6 mm and 101.8 mm for the controls, respectively. There was no statistical significance between the horizontal angulation and the distance between the bilateral heads at any age. However, there was a statistical difference of 100 mm in males and 95 mm in females for the distance between the bilateral heads of the TMD group and the controls.
These results indicate that this factor may be useful in discriminating between normal individuals and those with TMD, and further suggest that a narrow distance between the bilateral heads rather than horizontal angulation may contribute to the etiology of temporomandibular joint disorder. Shika Igaku (J Osaka Odontol Soc) 1997 Jun； 60(2)：115-122．

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Some strains of the anaerobic gram negative bacteria Prevotella intermedia isolated from oral infections show resistance to β-lactam antibiotics, and produce β-lactamase. We examined the induction of P. intermedia β-lactamase by various β-lactam antibiotics that are frequently administered for oral infections.
We studied P. intermedia MA 1 (MA 1, a low level β-lactamase producer) isolated from a closed dentoalveolar abscess, and P. intermedia MA 1-V 2 (MA 1-V 2, a high level β-lactamase producer) that was selected from MA 1 using ampicillin (ABPC). MA 1-V 2 β-lactamase activity for substrates cefazolin (CEZ) and ABPC was 0.227 and 0.042 U/mg protein, respectively, for 4h incubation, and 0.419 and 0.029 U/mg protein, respectively, for 15 h incubation after exposure without drugs (control). MA 1 β-lactamase activity for these substrates was 0.011 and 0.007 U/mg protein, respectively, for 15 h incubation in the control. After exposure to 1/128-1/8 MIC of ten β-lactam antibiotics for 4h, the enzyme activity of CEZ after treatment with latamoxef (LMOX) was increased to the value without drugs, and for 15 h, this activity of CEZ with exposure of piperacillin (PIPC), cephalexin (CEX), cefaclor, CEZ and imipenam (IPM) was higher than that of the control. Enzyme activity for ABPC was increased after exposure to penicillin G (PCG) and CEX for 4 h compared with no drug exposure, and for 15 h, this activity of ABPC after exposure to PCG, ABPC, CEX, CEZ, LMOX and aztreonum was also higher than that of the control. However, the amount of this enzyme induced by the various β-lactam antibiotics was very low. After exposure to 1/8-1/2 MIC of β-lactam antibiotics for 15 h, enzyme activity of ABPC with treatment of only PIPC and IPM was increased to the value without drugs.
These results suggest the possibility that P. intermedia β-lactamase was induced by β-lactam antibiotics other than cefmetazole. Shika Igaku (J Osaka Odontol Soc) 1997 Jun； 60(2)：123-130．

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We studied the purification and function of the outer membrane (OM) protein (OMP) of anaerobic gram negative bacteria which permeate antibacterial agents. OMs of Prevotella intermedia ATCC 25611 (P. i 25611) and P. nigrescens ATCC 33563 (P. n 33563) were solubilized by 14 detergents. SDS solubilized these bacterial OMs best among detergents used, followed by n-heptyl-β-D-thioglucoside (HTG). OMPs of P. i 25611 and P. n 33563 were extracted using Tris-HCl buffer with 48 mM HTG and 1 mM EDTA (pH 7.9), after cell membranes of these bacterial cell envelopes (including OM, peptidoglycan layer and cell membrane) were solubilized by 1% salcosyl treatment.
These bacterial OMPs were purified using TSKgel DEAE-5 PW ion-exchange chromatography and Sephacryl S-100 HR or S-200 HR gel filtration. The β-lactam antibiotic permeability of purified OMPs was detected using proteoliposomes which were reconstituted with OMPs, phosphatidylcholine and dicetylphosphate (93 : 3), and cephalosporinase. β-Lactams including cefazolin, cefaclor, cephaloridine, and cephalothin (CET) penetrated the proteoliposomes reconstituted first with 35 kDa and then with 120 kDa OMP of P. n 33563. The permeability of CET was the highest among β-lactams used. These β-lactam antibiotics penetrated the proteoliposomes reconstituted first with 20 kDa and then with 42 kDa OMP of P. i 25611. The permeability of the 35 kDa and 120 kDa OMPs of P. n 33563 were higher than those of the 20 kDa and 42 kDa OMPs of P. n 25611.
These results suggest that purified OMPs of these bacteria have porin that permeate antibacterial agents. Shika Igaku (J Osaka Odontol Soc) 1997 Jun； 60(2)：131-140．

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We recorded electromyograms at basic jaw positions at the superior and inferior heads of the lateral pterygoid muscle, the anterior belly of the digastric muscle, the temporal muscle, the masseter muscle and the sternocleidomastoid muscle, together with incisal movements, in 8 healthy controls and 9 persons with their mandibles in closed lock. In the healthy subjects, the superior head showed powerful activity during intercuspal clenching, and displayed reciprocal activity with the inferior head during tapping, protrusion and lateral movement. Persons with closed lock had decreased activity of the superior and inferior heads. They also had spontaneous activity of the temporal muscle, and activity of the sternocleidomastoid muscle during opening. The superior and inferior heads often displayed inconsistent patterns during various jaw movements These results suggest that electromyographic examination of the lateral pterygoid muscle and other masticatory muscles in various jaw positions may be useful in the diagnosis of closed lock. Shika Igaku (J Osaka Odontol Soc) 1997 Jun； 60(2)：141-151．

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To examine the role of Fusobacterium nucleatum (F. nucleatum) in closed dentoalveolar abscesses of endodontic origin, we studied the susceptibility of bacteria to antimicrobial agents and β-lactamase productivity. The subjects were one case of predominantly Fusobacterium (case A) and two cases where it was not predominant (cases B and C). Fifty-five strains of Fusobacterium were isolated in case A, one strain in case B and two strains in case C. All Fusobacterium were identified for F. nucleatum. The predominant speciles of case B was Prevotella intermedia (P. intermedia) and 52 strains were isolated. The predominant species of case C was Bacteroides pneumossintes, and 55 strains were isolated. β-lactamase production was detected in 64% of the species of case B. Of the Fusobacterium examined, none produced β-lactamase. In case MICs against F. nucleatum were higher than Prevotella sp. or Porphyromonas gingivalis. However, in cases B and C, MICs againstF. nucleatum were equal to or less than those against the predominant strains.
These results suggest that when the infectious ability of F. nucleatum is greater than that of P. intermedia, F. nucleatum becomes predominant. Shika Igaku (J Osaka Odontol Soc) 1997 Jun； 60(2)：152-158．

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In order to establish a model for observing the periodontal tissue changes caused by increased occlusal stress in teeth adjacent to an extraction site in rats, we examined the tissue 4, 7, 12, 24 and 48 weeks after the extraction. Examination was carried out macroscopically, with light microscopy and by confocal laser scanning microscopy (LSM). The rats were divided into two groups. In group A, the mandibular left first molars were extracted under anesthesia. The same treatment was done on the animals in group B, and in addition the crown of the mandibular left second molar was removed. In order to carry out LSM observation, the rats were injected subcutaneously with 0.16% calcein solution every day for 10 days before euthanasia. Both groups were fixed perfusively with 10% buffered formalin solution before removal of the mandibles.
There was a daily reduction in the width of the cortical bone and a decrease in the amount of cancellous bone trabeculae. However, the trabeculae increased at 48 weeks after the first molar extraction and removal of the second molar crown. Although it was not easy to observe the trabeculae of the rat alveolar bone with light microscopy, it was possible with LSM. These results suggest that rats may be used as a model for investigating changes in the periodontal tissues caused by increased occlusal stress in teeth adjacent to an extraction site when suitable observation methods are used. Shika Igaku (J Osaka Odontol Soc) 1997 Jun； 60(2)：159-164．

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We studied the difference between three-dimensional CT (3 D-CT) imaging and cephalograms. The dimensions of the 3 D-CT image were very accurate and differed from those of the dry skull by less than 1 mm. The cephalogram was radially enlarged, with the position of landmarks differing by the scale of the enlargement. We concluded that 3 D-CT imaging is more accurate than cephalograms, and is appropriate for morphological analysis or the maxillofacial region.

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When porcelain is fused to pure titanium, certain problems arise with the coarseness of oxidative adhesion and strong oxidation of the metal surface. We compared marginal distortion of metal frame during the firing of porcelain on pure titanium, precious alloy, semi-precious alloy and non-precious alloy. In addition, we studied how the oxidation heat temperature affected bonding strength. Marginal distortion of the pure titanium metal frame was considerably less than that of the other three metals after degassing, and was relatively small and constant during firing. Oxidation for three minutes at 500 to 800℃, created a high bond strength and produced the lowest coefficient of variation with a stable bond.

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The maxillofacial region is a highly complex osseous and muscular anatomical structure. Comprehension of the three-dimensional structures in this region is very important in the successful surgical management of dento-facial deformities. We designed a simple offline system for the three-dimensional reconstruction of these structures. Data processing by our system is comparable to a dedicated work station, enabling the user to observe a patient from any given angle. We described an outline of this system and examples of its application.

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We collected synovial fluid from temporomandibular joints with internal derangement and pain. Glycosaminoglycans were liberated by digestion with pronase E, and precipitated with 5% cetylpyridinium chloride and 95% ethanol. Unsaturated disaccharide isomers of chondroitin sulfate, obtained following chondroitinase ACII digestion, were analyzed by high-performance liquid chromatography. We found ΔDi-0 S and ΔDi-6 S in the chondroitin sulfate of the fluid from most of the diseased joints. There were significant differences in the amount of ΔDi-0 S (p<0.01) and ΔDDi-6 S (p<0.05) in the synovial fluid of the diseased and healthy joints. These results suggest that chondroitin sulfate in the synovial fluid provides a useful indicator of the degree of temporomandibular joint disease.

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Although necrosis is passive cell death due to cell injury, apoptosis is a form of programmed or physiological cell death. Apoptosis plays a role in removal of unnecessary cells during embryonic development and normal tissue turnover. We attempted to elucidate how apoptosis is responsible for cell turnover in epithelium of the cystic wall. We used formalin-fixed, paraffin-embedded sections of biopsy or excisional specimens from various cystic lesions. Apoptosis was detected using the method of terminal deoxynucleotidyl transferase (TdT)-mediated dUTPdigoxigenin nick end labeling, and studied its distribution in the epithelium. We found that apoptotic cells predominated in the inner layer of the cystic wall, indicating that the cells in this layer exfoliate.

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