Biomedical subjects

K Tanne

Publications and source records attributed to K Tanne.

At least 37 records · Page 2Linked to original sources

PubMed2003

Correlation between maximum bite force and craniofacial morphology of young adults in Indonesia.

The present study was conducted to evaluate the relationship between maximum bite force and craniofacial morphology. Sixty-four Indonesian female dental students aged 19-27 years with normal occlusion served as the subjects. The Dental Prescale System was used to measure the maximum bite force using a pressure sensitive sheets while craniofacial morphology measurements were determined from conventional lateral radiograms. The antero-posterior and right-left position of the occlusal load centre (the OLC) were measured also. Stepwise multiple regression analysis was performed to evaluate the relationship between bite force and craniofacial morphology while correlation analysis was used to evaluate the antero-posterior position of the OLC related to craniofacial morphology. Fifty-five per cent of the bite force could be explained by variations in the posterior facial height, gonial angle, antero-posterior size of the maxilla, and posterior length of the cranial base. The result showed a larger bite force implies a greater posterior facial height, smaller gonial angle, larger maxilla and straighter posterior length of the cranial base. This study suggests that among Indonesians, maximum bite force could be explained by craniofacial morphology as found in Caucasians. In addition, we proposed a clinical standard of the OLC for the comprehensive evaluation of occlusion.

Adult↗

PubMed2003

Effects of activator on masticatory muscle activity during daytime and sleep.

The purpose of this study was to investigate masticatory muscle activity with and without the use of an activator during daytime and sleep, and further to focus on the changes in muscle activity produced by the daytime use. The subjects in this study were 10 healthy males (mean age: 27.6 years). A portable electromyogram (EMG) recording device was used to record the activity from the right temporal, masseter and digastric muscles. After recording, the integrated EMG values (microV s) were measured. The muscle activity was lower during sleep than during daytime, irrespective of the use of the activator. In sleep-time, temporal and digastric muscle activity was significantly decreased, although masseter muscle activity presented no significant differences. With the activator in use, the digastric muscle activity tended to increase in comparison with the elevator muscles during daytime and sleep. Although the activity of both elevator muscles was diminished by use of the activator during sleep in all subjects, some subjects showed an increase during daytime. These results suggested that the activator should be used, if possible, not only during sleep, but also during daytime and clenched on consciously to obtain the adaptation and development of the masticatory muscles for the 're-training of the muscles' at a new favourable mandibular position.

Adult↗

PubMed2003

Association between condylar position, joint morphology and craniofacial morphology in orthodontic patients without temporomandibular joint disorders.

The present study investigated condylar position and joint morphology in adolescent patients and elucidated the possible association between the joint structure and condylar position, and craniofacial morphology. Sixty-five adolescent patients were selected as subjects and their tomograms and lateral cephalograms were analysed. No significant differences in joint spaces were found between the right and left temporomandibular joints. Both the condyles in this population were located slight anteriorly in the glenoid fossa. With respect to the association between condylar position, joint morphology and craniofacial morphology, the ramus plane angle also exhibited significant negative correlations with posterior, lateral and medial joint spaces. Furthermore, there was a significant negative correlation between the gonial angle and the anterior joint space. These findings imply that the condyle was likely to show more posterior position in the glenoid fossa when the mandible exhibited clockwise rotation. In conclusion, the condyle in the adolescent subjects showed a symmetrical anterior position relative to the glenoid fossa. In addition, the joint spaces and it ratios were significantly related to the craniofacial morphology associated with vertical dimension. It is suggested that the condylar position may be affected by craniofacial growth pattern.

Adolescent↗

PubMed2003

Association between craniofacial growth and urinary bone metabolic markers (pyridinoline, deoxypyridinoline) in growing rats.

Pyridinoline (Pyr) and deoxypyridinoline (Dpyr) are intermolecular cross-links of mature collagen and reflect the bone turnover. The purpose of this study was to elucidate the association between craniofacial growth and urinary Pyr and Dpyr levels. Lateral cephalograms and 24-hour urine were taken for 7 male rats from 5 to 20 wks old. The urinary Pyr and Dpyr were quantified by high-performance liquid chromatography. The neurocranium and upper viscerocranium exhibited significant increases in size, with the maximum rate at around 6 wks old. The mandible presented more substantial growth, with the maximum change at 8 wks old. The urinary Pyr and Dpyr levels gradually increased and reached the maximum at 8 wks old. No prominent association was found between neurocranial growth and urinary levels of pyridinium cross-links, whereas Pyr and Dpyr levels exhibited similar time-dependent metabolic changes to mandibular growth. In conclusion, it is shown that urinary pyridinium cross-links may be useful for the prediction of mandibular growth.

Age Factors↗

PubMed2003

Expression of vascular endothelial growth factor and the effects on bone remodeling during experimental tooth movement.

Vascular endothelial growth factor (VEGF) has an ability to induce functional osteoclasts as well as neovascularization. We recently reported that the number of osteoclasts was enhanced by the injection of recombinant human VEGF (rhVEGF) with the application of mechanical force for experimental tooth movement. In this study, the expression of VEGF was detected in osteoblasts on the tension side of the alveolar bone. Moreover, the rate of tooth movement was significantly increased in the rhVEGF injection groups compared with the controls. These results suggested that VEGF, highly expressed by mechanical stimuli, enhances the number of osteoclasts as a paracrine factor, and that the amount of tooth movement is accelerated by both endogenous VEGF and injected rhVEGF.

Analysis of Variance↗

PubMed2003

Dynamic shear properties of the temporomandibular joint disc.

Shear stress might be an important factor associated with fatigue failure and damage of the temporomandibular joint disc. Little information, however, is available on the dynamic behavior of the disc in shear. Since the disc is an anisotropic and viscoelastic structure, in the present study the dependency of the dynamic shear behavior on the direction and frequency of loading was examined. Ten porcine discs were used for dynamic shear tests. Shear stress was applied in both anteroposterior (A-P test) and mediolateral (M-L test) directions. The dynamic moduli increased as the loading frequency increased. The dynamic elasticity was significantly larger in the A-P test than in the M-L test, although the dynamic viscosity was similar in both tests. The present results suggest that non-linearities, compression/shear coupling, and intrinsic viscoelasticity affect the shear material behavior of the disc, which might have important implications for the transmission of load in the temporomandibular joint.

Animals↗

PubMed2002

RGD-CAP ((beta)ig-h3) is expressed in precartilage condensation and in prehypertrophic chondrocytes during cartilage development.

RGD-CAP ((beta)ig-h3), isolated from cartilage as a collagen-associated protein, was demonstrated to have a binding ability to collagen and to enhance the adhesion of chondrocytes via integrin alpha(1)beta(1). However, the role of this protein in cartilage development remains unclear. In this study, we investigated the expression of RGD-CAP ((beta)ig-h3) in chick embryos and cultured mesenchymal stem cells (MSCs) during the differentiation to chondrocytes. The effects of recombinant RGD-CAP on adhesion and DNA synthesis of MSCs and mineralization were also examined. Tissue sections from chick embryos at Hamburger-Hamilton (HH) stages 19-37 were immunostained with anti-chick RGD-CAP antibodies. The expression of RGD-CAP was slightest in chick embryos at HH stage 19, whereas a considerable expression of RGD-CAP was observed in the developing vertebrae and precartilage aggregate in the limb bud of chick embryos at HH stage 26. The expression of RGD-CAP was significantly reduced in vertebrae of chick embryo at HH stage 32. Reverse transcriptional polymerase chain reaction (RT-PCR) analysis showed that RGD-CAP was highly expressed in cultured MSCs and decreased by 4-day treatment with 10(-8) M dexamethasone when MSCs proliferated to adipocyte-like cells, whereas it was recovered by co-treatment with 3 ng/ml TGF-beta for 8-12 days when MSCs proliferated to hypertrophic chondrocyte-like cells. The adhesion and DNA synthesis of MSCs cultured on RGD-CAP-coated dishes increased significantly compared with the controls. RGD-CAP was distributed in the prehypertrophic zone in matured cartilage of the vertebrae of chick embryos at HH stage 37. Recombinant RGD-CAP inhibited the mineralization of hypertrophic chondrocytes. These results suggest that RGD-CAP ((beta)ig-h3) exerts an essential role in the early cartilage development by enhancing the adhesion and growth of the pre-chondrogenic cells, and functions as a negative regulator for mineralization at the terminal stage of the chondrogenic differentiation.

Animals↗

PubMed2002

Viscoelastic properties and residual strain in a tensile creep test on bovine temporomandibular articular discs.

This study was designed to evaluate the creep characteristics and residual strain of bovine temporomandibular joint (TMJ) discs in tension. Twenty discs were divided into three specimens each: central, lateral and medial regions. Tension of 1.0 MPa was applied and sustained for 20 min to the specimens from 10 right-side discs, and tension of 1.5 MPa to specimens from 10 left-side discs. After the period of tension for creep, the specimens were removed from the tension devices and restoration observed for 20 min. Time-dependent creep curves showed a marked change in strain during the initial 5s. The essential time delay in strain ceased after 2 min, and strain reached an almost steady level after 3 min. At a tensile stress of 1.5 MPa, a strain of 14.5% on average was produced after 20 min creep in the central specimens; peripheral specimens showed strains of 12.4% on average. There were significant differences in strain between the central and peripheral specimens. The residual strain after 20 min restoration was 0.93% on average and there were no significant regional differences. This creep feature could be well represented by a generalized linear viscoelastic model. It was concluded that the regional differences in viscoelasticity might be caused by the complicated articulating functions of the TMJ, and that the residual strain caused by sustained stress could be an important factor in disc deformation.

Animals↗

PubMed2002

Biomechanical response of bovine temporomandibular joint disc to prolonged tensile stress.

This study was designed to evaluate the influence of prolonged tensile stress on the viscoelasticity of the temporomandibular joint (TMJ) disc. Twenty discs from 10, 3-year-old cattle were used. Tensile stress of 1.5 MPa was applied to specimens from the discs for 10, 20, 40 and 60 min. Following the prescribed period of tension for creep, the specimens were removed from the tension device and any recovery observed for 20 min. In all specimens, strain increased at the onset of stress application and reached almost steady conditions after 5 min. Although, the strain became slightly larger when the creep time was longer, no significant differences were found in the strains between any two tests with different periods of creep. The residual strain increased significantly with creep duration, and similarly the degree of recovery decreased significantly. In 10- and 20-min creep tests, the residual strains were 0.1 and 1.0%, the specimens in 40- and 60-min tests revealed irreversible changes in length. It was concluded that continuous loading for >40 min causes creep damage in bovine TMJ disc, and that prolonged sustained tension affects the recovery of joint homeostasis.

Animals↗

PubMed2002

The regional difference of viscoelastic property of bovine temporomandibular joint disc in compressive stress-relaxation.

An in vitro experimental technique was performed to measure the viscoelastic properties of the bovine disc. Thirteen TMJ discs from young cattle (3-year-old) were used. Each disc was divided into five specimens of anterior, central, posterior, lateral and medial regions, and they were used for compression tests. A series of stress-relaxation tests was conducted for each specimen from 5% strain up to 20% strain with 5% intervals. The stress-relaxation was monitored over a period of 5 min. Each region exhibited a different biomechanical behavior, which is presumably related to the organization and distribution of proteoglycans that indirectly modulate the stiffness of the collagen network. It is suggested that an improved understanding of the viscoelastic properties of the disc under function may guide consideration for design and selection of biomaterials for TMJ reconstruction.

Animals↗

PubMed2002

Differences in the fatigue of masticatory and neck muscles between male and female.

The purpose of this study was to investigate the nature of fatigue and recovery of masticatory and neck muscles and the differences between sexes in normal subjects during experimentally induced loading. Subjects consisted of eight males (mean age: 27.6 years) and eight females (mean age: 24.2 years) selected from the volunteers in the Faculty of Dentistry, Hiroshima University. The inclusion criteria for the subjects were as follows: (1) good general health, (2) normal horizontal and vertical skeletal relationships, (3) no severe malocclusions and (4) no complaints of temporomandibular disorders. Each subject was requested to bite an occlusal-force meter with 98, 196 and 294 N forces on the first molar region per side for 45 s. Activities of the masseter and sternocleidomastoid (SCM) muscles were recorded during these performances. Fatigue and recovery ratios were calculated with mean power frequency of power spectrum using a fast Fourier transform algorithm. Significant differences in the fatigue ratios between both sexes were found for the masseter muscle with 98, 196 and 294 N bite forces. Meanwhile, the SCM presented a significant difference between both sexes only at 98 N biting. Significant differences in the recovery ratios between both sexes were more prominent in the masseter muscle than in the SCM. These results suggest that the differences in muscle endurance between sexes may have some association with higher susceptibility of craniomandibular disorders in females than in males.

Adult↗

PubMed2002

Dynamic properties of bovine temporomandibular joint disks change with age.

The temporomandibular joint disk exhibits morphological and biochemical age-related changes. However, the possible age-related changes of the dynamic viscoelasticity in the disk are unclear. We tested the hypothesis that the dynamic viscoelastic properties of the disk change with age. Thirty-six disks from young-adult, adult, and mature-adult cattle were used for dynamic tensile tests. In all disks, the magnitudes of the complex modulus, the storage modulus, and the loss modulus increased as the frequency increased. The mature-adult disks had higher values of these moduli than did the younger disks. The loss tangent ranged from 0.1 to 0.3, which means that the disk has relatively large elasticity and relatively small viscosity. It was concluded that both the elasticity and viscosity of the disk increase with age. This may reflect age-related changes in biochemical composition.

Aging↗

PubMed2002

RGD-CAP (betaig-h3) exerts a negative regulatory function on mineralization in the human periodontal ligament.

In our previous studies, RGD-CAP/betaig-h3 was isolated from a fiber-rich fraction of cartilage and was found to have a negative function on mineralization of hypertrophic chondrocytes. However, the expression and biological function of RGD-CAP in the periodontal ligament (PDL) are not known. We hypothesized that RGD-CAP could be expressed in the PDL and regulate its mineralization. To test this, we investigated the expression of RGD-CAP in human PDL and the effects of RGD-CAP on mineralization of cultured PDL cells. RGD-CAP was detected in the human PDL as multimeric proteins greater than 200 kDa. The RGD-CAP mRNA level decreased in cultured PDL cells exposed to 10(-8) M dexamethasone or 10(-8) M 1alpha,25-dihydroxyvitamin D(3) when these steroids increased alkaline phosphatase (ALP) activity. Furthermore, exogenous RGD-CAP suppressed the ALP activity and bone nodule formation of cultured PDL cells. These findings suggest that RGD-CAP in the PDL modulates the mineralization which affects adjacent alveolar bone metabolism.

Alkaline Phosphatase↗

PubMed2002

Early detection of dens evaginatus appearing on the premolars and clinical management: histological study.

A review of the methods for the prevention of central cusp fracture is presented, with a case of central cusp protection of a premolar by self-curing acrylic resin by early detection. The anomalous tooth was extracted for histological observation. Closure of the pulpal horn, could be accomplished by early detection and adequate treatment for the central cusp fracture of premolars. In this case, if the gradual attrition of a central cusp were not possible, a protecting the cusp using a self-curing acrylic resin would be an effective form of treatment.

Acrylic Resins↗

PubMed2001

Molecular cloning of rabbit hyaluronic acid synthases and their expression patterns in synovial membrane and articular cartilage.

cDNAs for hyaluronic acid synthases (HAS2 and HAS3) were cloned from a cDNA library of cultured rabbit synovial membrane cells. The cDNA encoding the open reading frame of rabbit HAS2 and HAS3 was 1659 nucleotides in length with a predicted molecular mass of about 63 kDa. The amino acid sequence showed that the rabbit HAS2 was 98.7 and 98.4%, and HAS3 was 98.2 and 97.5% identical with human and mouse forms of the proteins, respectively. The predicted sequences for hyaluronic acid (HA) binding motifs and the catalytic domains related to beta 1-4 and beta 1-3 linkages, essential for HA synthesis, were almost conserved in both rabbit HAS2 and HAS3, similarly to human and mouse HASs. RT-PCR analysis and in situ hybridization revealed that the mRNA of HAS2 was highly expressed in the synovial membrane and articular cartilage, whereas the expression of HAS3 mRNA was slightest in these tissues. Thus, it is demonstrated that rabbit HASs are highly conserved in sequence content as compared to the human and mouse homologues described previously, and that HAS2 is predominantly expressed in the synovial membrane and articular cartilage, but HAS3 is not.

Amino Acid Sequence↗

PubMed2001

Influence of oestrogen and androgen on modelling of the mandibular condylar bone in ovariectomized and orchiectomized growing mice.

Oestrogen and androgen exert a substantial influence on bone metabolism, but any differences in their influence on modelling of the condyle, a mandibular growth site, have not been fully clarified. The purpose here was to examine histological and histochemical differences in the condyle of ovariectomized (OVX) or orchiectomized (ORX) mice given injections of oestrogen (E(2), 17 beta-oestradiol) or non-aromatizable androgen (DHT, 5 alpha-dihydrotestosterone). Eight-week-old C57BL/6J mice (n=170) were used: they were divided equally into six experimental groups (OVX, ORX, OVX+E(2), ORX+E(2), OVX+DHT, ORX+DHT), and non-treatment male and female control groups. In each experimental group, five mice were killed 2,4,8 and 12 weeks after OVX and ORX. Oestrogen or androgen were given daily after the surgery by subcutaneous injection of E(2) or DHT. Increases in the number of tartrate-resistant acid phosphatase-positive cells induced in the OVX and ORX mice from 4 to 12 weeks after surgery were obviously suppressed by E(2) and DHT. The trabecular bone volume in the OVX and ORX mice treated with DHT had only increased at 12 weeks after surgery, whereas the E(2) injected mice exhibited a substantial increase from 4 to 12 weeks after surgery. E(2) injected into the OVX and ORX mice increased the trabecular bone volume earlier than did DHT, and both E(2) and DHT suppressed osteoclast differentiation similarly during the same period. These results suggest that metabolic responses of osteoclasts and osteoblasts to E(2) and DHT may be different, producing somewhat different patterns of bone modelling in males and females.

Acid Phosphatase↗

PubMed2001

Regulation of hyaluronan synthase gene expression in human periodontal ligament cells by tumour necrosis factor-alpha, interleukin-1beta and interferon-gamma.

Accumulation and fragmentation of hyaluronic (HA) accompanies the inflammatory changes in the periodontium and gingival crevicular fluid are involved in periodontitis, but the mechanism for this is unknown. Recently, three human hyaluronan-synthase (HAS1, 2, and 3) genes have been cloned and characterised as synthesising hyaluronans of different molecular weights. Both HAS1 and HAS2 synthesise high molecular-weight HA, whereas HAS3 produces lower molecular weight HA. In the present study the regulation of HAS genes by cytokines in cultured human periodontal ligament (PDL) cells was investigated using a novel real-time fluorescence polymerase chain reaction detection system. Human PDL cells derived from premolars were cultured with or without tumour necrosing factor (TNF)-alpha (1-100 ng/ml), interleukin (IL)-1beta (0.1-10 ng/ml) and interferon (IFN)-gamma (1-100 ng/ml). Expression of HAS mRNA was assessed in cultured cells treated with these cytokines for 0-24 h. The expression of HAS2 mRNA was enhanced about 4.5- and 2.2-fold at maximum after 3-h stimulation with 10 ng/ml TNF-alpha and 1 ng/ml IL-1beta, respectively, whereas IFN-gamma exerted little effect on HAS2 or HAS3 mRNA expression during the experiment. Expression of HAS3 mRNA was increased by about 14- and 10-fold after 3-h stimulation with 10 ng/ml TNF-alpha and 1 ng/ml IL-1beta, respectively. These results suggest that TNF-alpha and IL-1beta regulate HAS expression, and consequently may result in an accumulation of HA and an increase in HA of a lower molecular-weight.

Cells, Cultured↗

PubMed2001

Biomechanical behaviour of bovine temporomandibular articular discs with age.

The purpose was to evaluate age-associated changes in the creep and restoration properties of bovine temporomandibular joint (TMJ) discs under and after sustained tensile stress. Forty discs were obtained from 7- and 10-year-old cattle, referred to as the adult and mature adult groups, respectively. Tension of 1.0 MPa was applied and sustained for 20 min to specimens from ten right discs and of 1.5 MPa to specimens from ten left discs. After the period of tension for the study of creep, the specimens were removed from the tension devices and their restoration observed for 20 min. For comparative purposes the relevant results for a young adult group were recruited from data on 3-year-old bovine TMJ discs reported in a previous study on viscoelastic properties. In all the specimens the time-dependent creep curves showed a marked change in strain during the initial 5 s, but the elastic moduli at the onset of stress were significantly larger in the mature adult group than in the other groups. After 20-min creep, the strains were decreased in relation to the age of the specimen and were significantly smaller in the mature adult than in the young adult. With regard to regional differences, the medial specimens exhibited significantly smaller strains than the central ones in all three age groups. Furthermore, the residual strains after 20-min restoration also decreased slightly with age. It is concluded that the bovine TMJ disc becomes stiff and acquires the capacity to recover from continuous deformation during growth and maturation. These findings suggest that the TMJ disc can modify its viscoelasticity in order to withstand extrinsic functional stresses.

Aging↗