著者
Kazuhiko Hara Takahiro Shinozaki Akiko Okada-Ogawa Yumiko Matsukawa Ko Dezawa Yuka Nakaya Jui-Yen Chen Noboru Noma Shunichi Oka Koichi Iwata Yoshiki Imamura
出版者
Nihon University School of Dentistry
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.58, no.2, pp.195-204, 2016 (Released:2016-06-25)
参考文献数
44
被引用文献数
7 6

We investigated the temporal association between temporomandibular disorders (TMD)-related symptoms and headache during TMD treatment for patients who fulfilled the diagnostic criteria for headache attributed to TMD (HATMD) specified in the Diagnostic criteria for TMD (DC/TMD) and International classification of headache disorders (ICHD)-3 beta. The study enrolled 34 patients with HATMD induced by masticatory myofascial pain but not by temporomandibular arthralgia. Facial pain intensity, the pressure pain threshold of pericranial muscles, and maximum unassisted opening of the jaw were assessed at an initial examination and before and after physical therapy. The intensity and frequency of headache episodes and tooth contact ratio were also recorded before and after the intervention. Headache intensity and frequency significantly decreased, and these reductions were temporally related to improvements in facial pain intensity, maximum unassisted opening, and pressure pain threshold during TMD treatment. Linear regression analysis showed significant correlations between facial pain intensity and headache intensity and between tooth contact ratio and pressure pain threshold. Among patients who fulfilled the DC/TMD and ICHD-3 beta diagnostic criteria for HATMD, headache improved during TMD treatment, and the improvement was temporally related to amelioration of TMD symptoms. These findings suggest that sensitization in the central and peripheral nervous systems is responsible for HATMD. (J Oral Sci 58, 195-204, 2016)
著者
Noriko Tsubamoto-Sano Junji Ohtani Hiroshi Ueda Masato Kaku Kazuo Tanne Kotaro Tanimoto
出版者
Nihon University School of Dentistry
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.61, no.1, pp.119-124, 2019 (Released:2019-03-28)
参考文献数
34

This study was to investigate the influences of habitual mouth breathing on memory and learning ability during the growth period. At age 5 weeks, the experimental rats were subjected to surgery to close completely one side of the nasal cavity. An 8-arm radial maze was used to evaluate memory and learning ability at age 7, 11, and 15 weeks. Moreover, the brain was extracted at age 7, 11, and 15 weeks, and subjected to histomorphometric examination for the distribution and number of pyramidal cells in the hippocampal CA1 and CA3 regions after Nissl staining. The trial time to accomplish each task was significantly longer in the experimental group than in the control group throughout the experimental period. The number of pyramidal cells was significantly less in the experimental rats than in controls in both the CA1 and CA3 regions for the entire experimental period. Thus, the functional deterioration of the respiratory system during the growth phase exerts a substantial effect on the growth and development of the central nervous system.
著者
Keiko Fujii-Abe Masahiro Umino Hiroshi Kawahara Chika Terada Kazuhito Satomura Haruhisa Fukayama
出版者
Nihon University School of Dentistry
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.61, no.2, pp.364-369, 2019 (Released:2019-06-18)
参考文献数
31

Although in clinical dentistry the major method used for pain relief is oral administration of analgesics, alternative methods are available, such as transcutaneous electrical nerve stimulation (TENS), acupuncture, vibration and conditioned pain modulation (CPM), formerly termed diffuse noxious inhibitory control. The aim of the present study was to investigate the combined effects of non-noxious (TENS) and noxious (CPM) stimuli on postoperative pain after extraction of an impacted wisdom tooth. The study involved 44 patients who were scheduled to undergo impacted wisdom tooth extraction. The patients were randomly allocated into four groups: noxious stimuli, non-noxious stimuli, combined noxious and non-noxious stimuli, and a sham group. On the day after tooth extraction, stimulation procedures for pain relief were performed and changes in the level of perceived pain were scored using a visual analog scale (VAS). The combination of non-noxious and noxious stimuli decreased the VAS scores by 63.7%, indicating a more potent analgesic effect than that in the non-noxious, noxious, and sham groups. This method of analgesia using a combination of non-noxious and noxious stimuli can be applied to patients who are unable to tolerate analgesics, such as those with allergy, hypersensitivity or digestive disorders, and those who are pregnant.
著者
Kyozo Sasaki Mitsuru Motoyoshi Eri Horinuki Yoshinori Arai Noriyoshi Shimizu
出版者
日本大学歯学部
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.58, no.3, pp.415-422, 2016 (Released:2016-09-25)
参考文献数
31
被引用文献数
1

This study examined the effects of a bite-jumping appliance combined with low-intensity pulsed ultrasound (LIPUS) stimulation on the mandibular condyle of growing rats using micro CT (mCT) and histological examinations. Twelve Wistar rats were divided into three groups of four individuals each: Group 1 was an untreated control group, Group 2 received bite-jumping appliances, and Group 3 received bite-jumping appliances and LIPUS stimulation (15 min/day, 2 weeks) to the temporomandibular region. We measured the length and three-dimensional bone volume of each rat’s mandibular condyle using mCT. The condylar cartilage was observed after the rats had been sacrificed. There was no significant difference in condylar sagittal width among the groups. The bite-jumping appliance combined with LIPUS stimulation increased the condylar major axis, mandibular sagittal length and condylar bone volume to a greater degree than use of the bite-jumping appliance alone. Histological examination demonstrated hypertrophy of the condylar cartilage layers, the fibrous layer and hypertrophic cell layer of the rats treated with bite-jumping appliances combined with LIPUS stimulation in comparison to rats treated with bite-jumping appliances alone. (J Oral Sci 58, 415-422, 2016)
著者
Satoko Iwasa Hirotaka Ota Kensuke Nishio Mariko Ohtsu Masafumi Kusunoki Takahiro Gojoubori Tetsuo Shirakawa Masatake Asano
出版者
日本大学歯学部
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.58, no.3, pp.317-323, 2016 (Released:2016-09-25)
参考文献数
25
被引用文献数
2

Toll-like receptors (TLR) recognize microbe-associated molecular patterns and induce the innate immune response. Among them, TLR5 recognizes the Gram-negative bacterial component flagellin. The aim of this study was to examine the expression of TLR5 in mouse salivary gland (SG). The SG was excised from 8- to 10-week-old female C57BL/6 mice. Salivary gland epithelial cells (SGECs) were purified and subjected to reverse transcription polymerase chain reaction (RT-PCR). Western blotting was performed to detect TLR5 expression at the protein level in several organs. The localization of TLR5 in SG was examined using immunohistochemical staining. The responsiveness of SGECs to flagellin was further examined by evaluating the induction of CXCL1 by real-time PCR and immunoprecipitation followed by Western blotting. TLR5 expression in SG was confirmed at the gene and protein levels. Immunohistochemical staining detected TLR5 in both acinic and ductal cells of the sublingual gland, but not in serous acinic cells of the submandibular gland. Although TLR5 was detected throughout the cytoplasm in ductal cells, positive staining was observed on the basal side of the mucous acinic cells. The purified SGECs responded to flagellin and induced the production of CXCL1. These findings suggest that TLR5 is functionally expressed in the SG and responds to its cognate ligand flagellin. (J Oral Sci 58, 317-323, 2016)
著者
Balwant Rai Jasdeep Kaur Reinhilde Jacobs Jaipaul Singh
出版者
日本大学歯学部
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.52, no.2, pp.251-256, 2010 (Released:2010-06-25)
参考文献数
25
被引用文献数
33 55

Extensive research within the past half-century has indicated that curcumin (diferuloylmethane), a yellow pigment in curry powder, exhibits anti-oxidant, anti-inflammatory, and pro-apoptotic activities. We investigated whether the anti-pre-cancer activities assigned to curcumin are mediated through an anti-oxidant and DNA-protecting mechanism. Patients with oral leukoplakia, oral submucous fibrosis or lichen planus, and healthy individuals (n = 25 for each group) aged 17-50 years were selected. Salivary and serum oxidative markers such as malonaldehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), vitamins C and E were measured just prior to the intake of curcumin, after one week of curcumin intake and following clinical cure of precancerous lesions. Serum and salivary vitamins C and E showed increases, while MDA and 8-OHdG levels showed decreases in patients with oral leukoplakia, submucous fibrosis and lichen planus after intake of curcumin for all categories of precancerous lesions. The changes in these values were observed to be statistically significant after clinical cure of the disease (P < 0.05). The five-point rating scale for pain, as well as lesion size in oral leukoplakia, submucous fibrosis and lichen planus, improved significantly (P < 0.05). In addition, in submucous fibrosis, mouth opening (P < 0.05) recovered significantly. In oral leukoplakia, submucous fibrosis and lichen planus, the levels of serum and salivary vitamins C and E increased significantly, while MDA and 8-OHdG levels decreased after 131(15), 211(17), and 191(18) days, respectively. Values for serum and salivary vitamins C and E showed a significant decrease in oral leukoplakia, submucous fibrosis and lichen planus, in contrast to healthy individuals, but increased significantly in all groups subsequent to curcumin administration after clinical cure of lesions. Based on these results, we can conclude that curcumin mediates its anti-pre-cancer activities by increasing levels of vitamins C and E, and preventing lipid peroxidation and DNA damage. (J Oral Sci 52, 251-256, 2010)
著者
Hiroshi Kobayashi Masaru Yamaoka Makoto Hayashi Bunnai Ogiso
出版者
日本大学歯学部
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.58, no.1, pp.93-99, 2016 (Released:2016-03-26)
参考文献数
27
被引用文献数
1 2

A non-contact electromagnetic vibration device (NEVD) was previously developed to monitor the condition of periodontal tissues by assessing mechanical parameters. This system requires placement of an accelerometer on the target tooth, to detect vibration. Using experimental tooth models, we evaluated the performance of an NEVD system with a laser displacement sensor (LDS), which does not need an accelerometer. Simulated teeth (polyacetal rods) were submerged at various depths in simulated bone (polyurethane or polyurethane foam) containing simulated periodontal ligament (tissue conditioner). Then, mechanical parameters (resonant frequency, elastic modulus, and viscosity coefficient) were assessed using the NEVD with the following detection methods: Group 1, measurement with an accelerometer; Group 2, measurement with an LDS in the presence of the accelerometer; and Group 3, measurement with an LDS in the absence of the accelerometer. Statistical analyses were performed using nonparametric methods (n = 5) (P < 0.05). The three mechanical parameters significantly increased with increasing depth. In addition, the mechanical parameters significantly differed between the polyurethane and polyurethane foam models. Although Groups 1 and 2 did not significantly differ, most all mechanical parameters in Group 3 were significantly larger and more distinguishable than those in Groups 1 and 2. The LDS was more accurate in measuring mechanical parameters and better able to differentiate periodontal tissue conditions. (J Oral Sci 58, 93-99, 2016)
著者
Kensuke Nishio Keiko Motozawa Daisuke Omagari Takahiro Gojoubori Takayuki Ikeda Masatake Asano Nobuhito Gionhaku
出版者
日本大学歯学部
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.58, no.1, pp.59-65, 2016 (Released:2016-03-26)
参考文献数
39
被引用文献数
7

Matrix metalloproteinases (MMPs) and tumor-associated macrophages (TAMs) play important roles in tumor growth. The present study investigated the expression levels of MMP2 and MMP9 in relation to the distribution of TAMs in the primary and metastatic regions of oral squamous cell carcinoma. Twenty-nine cases of oral squamous cell carcinoma (OSCC) with regional lymph node metastasis were selected from available documents in the archives of the Department of Pathology, Nihon University School of Dentistry. Four-micrometer-thick sections were prepared from the primary and metastatic regions. Each section was subjected to immunohistochemical staining using anti-MMP2, anti-MMP9, and anti-CD68 antibodies. The distribution and localization of MMPs and TAMs were compared between primary and metastatic regions. The expression levels of both MMPs were higher in the metastatic regions of lingual and gingival cancers. Statistically significant differences were observed in both T1 and T2 cases. In contrast to the higher expression of MMPs in metastatic regions, a higher number of TAMs were distributed in the primary regions. From these results, MMP expression levels and the numbers of TAMs were expected to have an inverse relationship between the primary and metastatic regions of OSCC. (J Oral Sci 58, 59-65, 2016)
著者
Kiyomi Kohinata Kunihito Matsumoto Toshihiro Suzuki Mari Tsunoda Yusuke Hayashi Masao Araki Koji Hashimoto Kazuya Honda
出版者
日本大学歯学部
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.58, no.1, pp.29-34, 2016 (Released:2016-03-26)
参考文献数
22
被引用文献数
1 1

As part of our ongoing investigation of risk and predictive factors associated with temporomandibular disorders, we used magnetic resonance imaging (MRI) to identify risk factors for sideways disk displacement of the temporomandibular joint in 26 patients with MRI-confirmed unilateral pure sideways disk displacement (medial or lateral disk displacement) and normal positioning of the contralateral temporomandibular joint. Coronal morphologic harmonization between the condyle and fossa, angle between the axis of the ramus and condyle, and angle between the lateral pterygoid muscle (LPM) and condyle were evaluated. Only angle of the LPM related to the condyle was significantly correlated with mediolateral disk position; the angles of joints with medial, normal, and lateral disk positions were 70.2°, 66.7°, and 60.1°, respectively. These results suggest that a greater angle of the inferior head of the LPM to the axis of the condyle on axial MRI images may cause medial disk displacement, while a smaller angle may result in lateral disk displacement. (J Oral Sci 58, 29-34, 2016)
著者
Tamotsu Tsurumachi
出版者
日本大学歯学部
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.55, no.4, pp.267-273, 2013 (Released:2013-12-18)
参考文献数
71
被引用文献数
1 5

Periradicular surgery is often used as a last resort to save an endodontically treated tooth with a persistent periapical lesion. The introduction of surgical microscopes, ultrasonics, and compatible root-end filling materials has made periradicular surgery a much more predictable treatment. The advantages of modern periradicular surgery include easier identification of root apices, smaller osteotomines, shallower resection angles, and tight sealing within the prepared root-end cavity. Modern periradicular surgical thus has a much higher success rate than traditional periradicular surgery. (J Oral Sci 55, 267-273, 2013)
著者
Fernando O. Costa Luís O. M. Cota Eugênio J. P. Lages Renata M. Cyrino Alcione M. S. D. Oliveira Peterson A. D. Oliveira José R. Cortelli
出版者
日本大学歯学部
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.55, no.3, pp.245-253, 2013 (Released:2013-09-13)
参考文献数
46
被引用文献数
4 8

This cross-sectional study investigated associations of cumulative smoking exposure and duration of smoking cessation with periodontitis and evaluated the effects of biological, behavioral, and social risk variables on these associations. The sample comprised 705 adults of both sexes (age, 35-65 years) who underwent a full-mouth periodontal examination. Subjects were classified according to smoking status as nonsmokers, former smokers, and current smokers, and univariate and multivariate analysis was used to evaluate associations between periodontitis prevalence and potential risk variables. The rates of periodontitis among nonsmokers, former smokers, and current smokers were 25.6%, 29.3%, and 45.1% respectively. After adjusting for other periodontal risk variables the odds ratio (95% confidence interval) for periodontitis was 3.09 (1.98-4.92) for former smokers and 5.24 (2.61-8.97) for current smokers. A significant dose-response relationship between pack-years of smoking and periodontitis prevalence was observed, as was a significant decrease in the risk of periodontitis as years of smoking cessation increased. Cumulative smoking exposure and duration of smoking cessation were significantly associated with periodontitis. (J Oral Sci 55, 245-253, 2013)
著者
Mari Namura Mitsuru Motoyoshi Yasuhiro Namura Noriyoshi Shimizu
出版者
日本大学歯学部
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.50, no.1, pp.45-51, 2008 (Released:2008-04-11)
参考文献数
28
被引用文献数
4 5

Although orthodontic treatment improves dentoalveolar problems, the facial profile seldom changes because the perioral muscles do not easily adapt to the new morphological circumstances. We employed proprioceptive neuromuscular facilitation (PNF), which is training with added resisted movement to motions such as lifting the upper lip, lowering the lower lip, and sticking out the tongue, to adapt the perioral muscles to the new morphological circumstances. The subjects were 40 adults with an average age of 29.6 years. A series of PNF exercises was performed three times per day for 1 month. Lateral facial photographs were taken using a digital camera before training (T0), after training (T1), and 1 month after the end of training (T2). The nasolabial (NL), mentolabial (ML), and mentocervical (MC) angles were measured, and linear measurements were taken to verify the change of each measurement point. In the test group, the NL and ML angles significantly increased (P < 0.05), and the MC angle significantly decreased after the PNF exercise. From T1 to T2, the NL and ML angles decreased significantly, while the MC angle increased significantly. No significant differences were observed in these angles when the values measured at T0 and T2 were compared. Although the training appeared to be effective for sharpening the mouth and submandibular region, continued training is necessary to avoid relapse. (J. Oral Sci. 50, 45-51, 2008)
著者
Yoshiki Imamura Akiko Okada-Ogawa Noboru Noma Takahiro Shinozaki Kosuke Watanabe Ryutaro Kohashi Masamichi Shinoda Akihiko Wada Osamu Abe Koichi Iwata
出版者
Nihon University School of Dentistry
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
pp.19-0459, (Released:2020-03-11)
参考文献数
87

Burning mouth syndrome (BMS) is one of the most frequently seen idiopathic pain conditions in a dental setting. Peri- and postmenopausal women are most frequently affected, and patients who experience BMS complain of persistent burning pain mainly at the tip and the bilateral border of the tongue. Recent studies have assessed whether BMS is a neuropathic pain condition, based on morphologic changes in biopsied tongue specimens, and whether there are abnormal pain responses in patients with this disease. Somatosensory studies have reported some abnormal findings in sensory and pain detection thresholds with inconsistency; however, the most distinct finding was exaggerated responses to painful stimuli. Imaging and electrophysiologic studies have suggested the possibility of dysregulation of the pain-modulating system in the central nervous system, which may explain the enhanced pain responses despite the lack of typical responses toward quantitative sensory tests. Basic studies have suggested the possible involvement of neuroprotective steroids, although the underlying mechanisms of this condition have not been elucidated. Experimental studies are looking for preferable supportive therapies for BMS patients despite the obscure pathogenesis.
著者
Shinji Usami Yosuke Yamazaki Maki Yuguchi Yuichi Namba Hirofumi Kanazawa Keitaro Isokawa
出版者
Nihon University School of Dentistry
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
pp.19-0297, (Released:2020-03-11)
参考文献数
27

The morphogenesis of long bones is a multistep process that generates a variety of genetically defined forms. The tarsometatarsal (TMT) long bone morphology in birds develops through lateral fusion of three initially independent periosteal bone cylinders (BCs). Previous studies have clarified the histological details and chronology of the changes occurring during development. The present study investigated the temporospatial distribution of osteogenic and osteoclastic cells in the embryonic chicken using histochemistry for alkaline phosphatase and tartrate-resistant acid phosphatase, with particular reference to the radial growth of BCs and their subsequent fusion process. Osteogenic cells were localized preferentially in the periosteum of radially growing BCs, leaving open cancellous spaces in the BC wall. Osteoclasts observed later than embryonic day 10 were localized preferentially in the endosteal surface, and therefore the radial growth of BCs resulting from osteoblast activity was accompanied by endosteal resorption by osteoclasts, with progressive enlargement of the bone marrow spaces. During BC fusion, trabecular bridges were formed by periosteal osteogenic cells, with removal of the bone septum by endosteal osteoclasts. These findings suggest that fusion of BCs in the embryonic chicken is mediated by cellular events constituting ordinary long bone development, and not through a defined mechanism specific for fusion.
著者
Masamichi Shinoda Yoshinori Hayashi Asako Kubo Koichi Iwata
出版者
Nihon University School of Dentistry
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
pp.19-0373, (Released:2020-03-04)
参考文献数
86

Nociceptive stimuli to the orofacial region are typically received by the peripheral terminal of trigeminal ganglion (TG) neurons, and noxious orofacial information is subsequently conveyed to the trigeminal spinal subnucleus caudalis and the upper cervical spinal cord (C1-C2). This information is further transmitted to the cortical somatosensory regions and limbic system via the thalamus, which then leads to the perception of pain. It is a well-established fact that the presence of abnormal pain in the orofacial region is etiologically associated with neuroplastic changes that may occur at any point in the pain transmission pathway from the peripheral to the central nervous system (CNS). Recently, several studies have reported that functional plastic changes in a large number of cells, including TG neurons, glial cells (satellite cells, microglia, and astrocytes), and immune cells (macrophages and neutrophils), contribute to the sensitization and disinhibition of neurons in the peripheral and CNS, which results in orofacial pain hypersensitivity.
著者
Masayuki Kobayashi Yuka Nakaya
出版者
Nihon University School of Dentistry
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
pp.19-0386, (Released:2020-02-27)
参考文献数
59

Corticofugal projections to neurons in the medullary dorsal horn, i.e., the trigeminal spinal subnucleus caudalis (Sp5C), are thought to play a critical role in regulating nociceptive information processing in the trigeminal nervous system. The Sp5C consists of 5 layers, each of which exhibits its own characteristic features of cellular organization. Therefore, the layers receiving corticofugal projections must be identified when discussing the role of the cerebral cortex in nociception arising from the trigeminal nerve. It is also necessary to discriminate between layers of the Sp5C where corticofugal projections terminate, because the Sp5C involves glutamatergic neurons and GABAergic/glycinergic neurons, which correspond to excitatory and inhibitory neurons, respectively. This review summarizes descending projections from the cerebral cortex, including the primary and secondary somatosensory and insular cortices, to the Sp5C.
著者
Arati S. Panchbhai Shirish S. Degwekar Rahul R. Bhowte
出版者
Nihon University School of Dentistry
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.52, no.3, pp.359-368, 2010 (Released:2010-09-24)
参考文献数
45
被引用文献数
30 31

Diabetes is known to influence salivary composition and function, eventually affecting the oral cavity. We thus evaluated saliva samples for levels of glucose, amylase and total protein, and assessed salivary flow rate in diabetics and healthy non-diabetics. We also analyzed these parameters with regard to duration and type of diabetes mellitus and gender, and aimed to assess the interrelationships among the variables included in the study. A total of 120 age- and sex-matched participants were divided into 3 groups of 40 each; the uncontrolled diabetic group, the controlled diabetic group and the healthy non-diabetic group. Salivary investigations were performed using unstimulated whole saliva. Mean salivary glucose levels were found to be significantly elevated in both uncontrolled and controlled diabetics, as compared to healthy non-diabetics. There were significant decreases in mean salivary amylase levels in controlled diabetics when compared to healthy non-diabetics. Other than salivary glucose, no other parameters were found to be markedly affected in diabetes mellitus. Further research is needed to explore the clinical implications of these study results. (J Oral Sci 52, 359-368, 2010)
著者
Kunihito Matsumoto Toshihiko Amemiya Motohiro Ito Yusuke Hayashi Kenichiro Watanabe Ko Dezawa Yoshinori Arai Kazuya Honda
出版者
Nihon University School of Dentistry
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.62, no.1, pp.62-66, 2020 (Released:2020-01-29)
参考文献数
35

This study was performed to develop a new rat model of reduced masticatory activity in order to assess the effect of this reduction on the morphology of the temporomandibular joint (TMJ) over time. Female rats were used, and ovariectomy was performed to simulate aged/postmenopausal status. Twenty-four SD rats aged 6 weeks were divided into four groups: ovariectomy/sham procedure (Ov/S); ovariectomy/reduced masticatory activity (Ov/RMA); non-Ov/S (NO/S); and non-Ov/RMA (NO/RMA). The RMA procedure involved grinding down the edges of the upper and mandibular incisors by about 3 mm and supplying the rats with a powdered diet. The bilateral TMJ was examined by micro-computed tomography at 0, 1, 2, 4, 6, and 8 weeks after the start of RMA. Condylar width was greater in the NO/S group than in the Ov/S group after the 2nd week, showing that ovariectomy reduced the width of the condyle. After the 2nd week, significant differences in condylar width were apparent between the NO/S and NO/RMA groups, and between the Ov/S and Ov/RMA groups. This RMA procedure appeared to provide a good model of reduced masticatory activity. The present findings in female rats suggest that reduction of appropriate mastication activity in the growth period results in poor growth of the mandibular condyle and immediately induces atrophy of the mandibular condyle under conditions simulating aged/postmenopausal status.
著者
Yasuhiro Namura Toshiki Takamizawa Yasuki Uchida Mizuki Inaba Daichi Noma Tomoko Takemoto Masashi Miyazaki Mitsuru Motoyoshi
出版者
Nihon University School of Dentistry
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.62, no.1, pp.48-51, 2020 (Released:2020-01-29)
参考文献数
20

Although there have been improvements in bracket systems precoated with adhesive, removal of adhesive remnants continues to be problematic. This study compared the hardness and maintainability of precoated adhesive with other commercial adhesives. Knoop hardness values were measured after light- or chemical-induced initial curing, immersion in distilled water at 37°C for 24 h and 1,000 and 10,000 thermal cycles after 24 h. Additionally, the forces required to move brackets by 0.5 mm were measured during bracket positioning, and brackets bonded to bovine enamel were examined by field-emission scanning electron microscopy. The Knoop hardness values of the precoated adhesives were lower than those of commercial resin composite adhesives, and hardness was dependent on the amount of filler in the resin matrix. The ability to maintain the device position may depend on the resin matrix composition. Precoated adhesives with less filler and more matrix material are light curable, and remnant resin may be easily removed.
著者
Sayaka Maruyama Hirofumi Tsutsumi Hikaru Izawa Toshinobu Komuro
出版者
Nihon University School of Dentistry
雑誌
Journal of Oral Science (ISSN:13434934)
巻号頁・発行日
vol.62, no.1, pp.28-31, 2020 (Released:2020-01-29)
参考文献数
11

This study attempted to determine the minimum number of cells required to conduct DNA analyses effectively. Oral mucosal cells obtained from eight persons were suspended and individually collected by using micromanipulation technique. DNA was extracted and amplified by whole-genome amplification (WGA). Nuclear DNA was extracted to evaluate the feasibility of autosomal short tandem repeat (STR) polymorphism and Y-chromosomal STR polymorphism analyses. Tests were conducted with 20 and 30 cells, to determine the minimum number of cells required for each DNA analysis. Tests with 20 cells were repeated 5 times, to examine reproducibility. When five or 10 cells were used, loci could not be identified for most alleles. Furthermore, DNA polymorphism analyses of a single cell transferred directly to a polymerase chain reaction solution were unsuccessful. The present findings suggest that, in forensic identification, 20 or more cells are required in order to obtain clear results from autosomal and Y-chromosomal STR polymorphism analyses. Furthermore, the feasibility of sample preservation and reexamination was also confirmed by DNA amplification with WGA.