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

4

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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

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 10

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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

Yasuhiro NAMURA Yasuki UCHIDA Ryoichi SATO Noriyoshi SHIMIZU Mitsuru MOTOYOSHI Yusuke TSUTSUMI Takao HANAWA Takayuki YONEYAMA

出版者

The Japanese Society for Dental Materials and Devices

雑誌

Dental Materials Journal (ISSN:02874547)

巻号頁・発行日

pp.2019-023, (Released:2019-12-19)

参考文献数

21

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Chemical transitions after atmospheric pressure plasma irradiation were investigated by evaluating intermolecular attractions and atomic and molecular reactions. Gold, titanium and stainless-steel alloy samples were ground with #800 grit SiC waterproof paper and nitrogen gas atmospheric plasma irradiation was conducted. The surface free energies of the treated alloys were calculated and compared statistically. X-ray photoelectron spectroscopy analysis was performed.The surface free energies of all metal surfaces treated by plasma irradiation were 1.5-times higher than those of the untreated metals. The energy of the hydrogen bonding component increased, and all alloy surfaces were coated with metal oxide after only a short period of plasma irradiation. The surfaces oxidized by plasma exhibited a high active energy, mainly due to an increase in the hydrogen bonding component. Reactions with oxygen in the air were promoted on the clean surfaces with exposed reactive elements.

著者

Yasuyo Takahashi Kotoe Mayahara Rena Fushiki Rieko Matsuike Noriyoshi Shimizu

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.18-0001, (Released:2019-02-01)

参考文献数

24

被引用文献数

4

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High-magnitude mechanical strain inhibits bone nodule formation by reducing expression of bone morphogenetic protein-2 (BMP-2), Runt-related transcription factor 2 (Runx2), and muscle segment homeobox 2 (Msx2). Mechanical strain also induces production of proinflammatory factor prostaglandin E2 (PGE2) by osteoblasts. We measured the effect of mechanical strain-induced PGE2 production on bone nodule formation and expression levels of bone formation-related factors. Osteoblast-like cells isolated from fetal rat calvariae were loaded with 18% cyclic tension force (TF) for 48 h in the presence or absence of NS-398, a selective inhibitor of cyclooxygenase-2. To investigate the effect of TF-induced PGE2 on bone formation, bone nodule area on day 21 was measured by von Kossa staining. BMP-2, Runx2, and Msx2 expression levels were examined at 1 day after TF loading. Bone nodule formation was significantly inhibited by TF but was restored to control level by PGE2 inhibition. Furthermore, TF loading-induced reductions in expressions of these factors were restored to control level by PGE2 suppression. These results indicate that PGE2 production induced by high-magnitude mechanical strain inhibits bone nodule formation by reducing expression levels of bone formation-related factors.

著者

Michiko Ichinohe Mitsuru Motoyoshi Mizuki Inaba Yasuki Uchida Mari Kaneko Reiko Matsuike Noriyoshi Shimizu

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.17-0377, (Released:2018-10-26)

参考文献数

35

被引用文献数

19

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This study investigated the stability of mini-screws placed in the median palate. The study included 25 patients (7 males, 18 females; mean age, 23.4 ± 5.6 years; age range, 15.0-34.5 years) who had mini-screws placed during orthodontic treatment at Nihon University School of Dentistry Dental Hospital. Mini-screws (diameter, 2.0 mm; length, 9.0 mm) were placed in the median palatal region; the first screw was inserted mesiodistally at the distal contact of the maxillary first molar, and the second screw was placed 6-9 mm mesial to the first screw. Immediately after placement, the placement sites were carefully examined with cone-beam computed tomography and a Periotest device. Screw stability was not related to perforation of the nasal cavity, patient age, or patient sex. The success rate was significantly higher in patients with screw-suture distances of 1.5-2.7 mm than in those with distances of 0-1.4 mm. Moreover, mini-screws could be stabilized when palatal cortical bone thickness was ≥1.5 mm. The success rate was significantly higher in the group with insertion depths of ≥4.5 mm. These results indicate that primary stability of mini-screws requires sufficient cortical bone thickness, insertion depth, and screw-suture distance.

著者

Kyoko Mukaida Kotoe Mayahara Rina Sanuki-Suzuki Takahiko Tamura Noriyoshi Shimizu

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.60, no.2, pp.316-319, 2018 (Released:2018-06-20)

参考文献数

7

被引用文献数

3

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For treatment of severe bimaxillary protrusion in adults, a condition known to be among the most difficult to manage, both the maxillary and mandibular anterior teeth must be fully retracted using all the extraction space available. This article reports the treatment of an adult with severe high-angle bimaxillary protrusion. To correct the protrusion of the anterior teeth, orthodontic anchor screws (OASs) were used to provide absolute anchorage during anterior retraction. Acceptable occlusion, facial profile, and balance were achieved. OASs appear to be very useful for treatment of severe bimaxillary protrusion in adults.

著者

Moeko Kato Yasuhiro Namura Takayuki Yoneyama Noriyoshi Shimizu

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.17-0356, (Released:2018-05-31)

参考文献数

23

被引用文献数

5

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This study investigated the effect of the vertical position of the canine on changes in the frictional/orthodontic (F/O) force ratio of nickel-titanium (Ni-Ti) archwires during the initial levelling phase of orthodontic treatment. Frictional and orthodontic forces were measured by using low-friction brackets and Ni-Ti archwires with three different cross-sectional sizes and force types. To simulate canine malocclusion (first premolar extraction case), the upper right canine was displaced gingivally by 1 to 3 mm and the inter-bracket distance between the upper right lateral incisor and second premolar was set at 15 mm or 20 mm. A three-point bending test was performed to measure the orthodontic force of each Ni-Ti archwire. Frictional forces were measured with a universal testing machine and dental arch models by pulling parallel to the end of the archwire at a crosshead speed of 0.5 mm/min. F/O force ratio was calculated and analysed statistically. At a displacement of 3 mm, few archwires had F/O force ratios of less than 1.0, at which orthodontic force overcame frictional force, thus ensuring extrusion of the canine. For effective tooth movement, orthodontists should use Ni-Ti archwires with an F/O force ratio of less than 1.0.

著者

Wakako Miyama Yasuki Uchida Mitsuru Motoyoshi Keiko Motozawa Moeko Kato Noriyoshi Shimizu

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

vol.60, no.1, pp.147-153, 2018 (Released:2018-03-24)

参考文献数

28

被引用文献数

3

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This study examined the relationship of vertical and horizontal changes in the alveolar bone crest with upper incisor movement after orthodontic treatment. Tooth movement was measured on lateral cephalograms. Vertical and horizontal changes in the median alveolar crest and distance from the cementoenamel junction and anterior nasal spine to the alveolar crest were measured with cone-beam computed tomography. The incisal edge moved distally, and the cervical point intruded significantly and moved distally. The median alveolar crest decreased by 3.80 ± 2.05 mm. The distance from the labial cementoenamel increased significantly, by 0.35 ± 0.38 mm. The vertical distance from the anterior nasal spine decreased significantly, and the alveolar crest moved distally. Vertical tooth movement was positively associated with change in the distance from the labial cementoenamel junction and inversely associated with vertical change in the distance from the anterior nasal spine on the labial and palatal sides. Lingual tooth movement was positively and negatively correlated with horizontal changes in the labial and palatal alveolar crest and vertical change in the palatal alveolar crest. The lingual movement of incisors was related to labial bone resorption. Greater lingual and extrusive movement of incisors led to a greater decrease in the alveolar bone crest.

著者

Niina Tsurumachi Daisuke Akita Koichiro Kano Taro Matsumoto Taku Toriumi Tomohiko Kazama Yoshinao Oki Yoko Saito-Tamura Morio Tonogi Noriyoshi Shimizu Masaki Honda

出版者

Nihon University School of Dentistry

雑誌

Journal of Oral Science (ISSN:13434934)

巻号頁・発行日

pp.16-0786, (Released:2018-02-26)

参考文献数

38

被引用文献数

4

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Dedifferentiated fat (DFAT) cells were isolated from mature adipocytes using the ceiling culture method. Recently, we successfully isolated DFAT cells from adipocytes with a relatively small size (<40 μm). DFAT cells have a higher osteogenic potential than that of medium adipocytes. Therefore, the objective of this study was to determine the optimal concentration of collagenase solution for isolating small adipocytes from human buccal fat pads (BFPs). Four concentrations of collagenase solution (0.01%, 0.02%, 0.1%, and 0.5%) were used, and their effectiveness was assessed by the number of small adipocytes and DFAT cells isolated. The total number of floating adipocytes that dissociated with 0.02% collagenase was 2.5 times of that dissociated with 0.1% collagenase. The number of floating adipocytes with a diameter of ≤29 μm that dissociated with 0.02% collagenase was thrice of those dissociated with 0.1% and 0.5% collagenase. The number of DFAT cells that dissociated with 0.02% collagenase was 1.5 times of that dissociated with 0.1% collagenase. In addition, DFAT cells that dissociated with 0.02% collagenase had a higher osteogenic differentiation potential than those that dissociated with 0.1% collagenase. These results suggest that 0.02% is the optimal collagenase concentration for isolating small adipocytes from BFPs.

著者

Tomoyasu Kiyokawa Mitsuru Motoyoshi Mizuki Inaba Remi Sano Akari Saiki Go Torigoe Masatake Asano 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.59, no.3, pp.447-451, 2017 (Released:2017-09-14)

参考文献数

22

被引用文献数

2

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The purpose of this experiment was to investigate whether low-intensity pulsed ultrasound (LIPUS) irradiation can inhibit dentoalveolar ankylosis in transplanted rat teeth. LIPUS irradiation (the pulsed ultrasound signal had a frequency of 3.0 MHz, a spatial average intensity of 30 mW/cm2, and a pulse ratio of 1:4) was performed on the face over the re-planted teeth of rats for 4 weeks. After the rats were euthanized, we measured mobility (Periotest value [PTV]) of the transplanted and control teeth using a Periotest. Finally, we performed histological evaluation to detect ankylosis. PTVs tended to be significantly lower for re-planted teeth than for control teeth. Histological evaluation revealed that the roots of all re-planted teeth were coalescent with alveolar bone. Furthermore, no ankylosis was observed in three-fifths of the re-planted teeth following LIPUS irradiation. These results indicate the potential efficacy of LIPUS to inhibit dentoalveolar ankylosis.

著者

Yasuki Uchida 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.59, no.2, pp.257-262, 2017 (Released:2017-06-22)

参考文献数

29

被引用文献数

5

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This study investigated guidelines for placement of monocortical screws in the mandible, particularly the mandibular canal. In this study of 35 patients, we used cone-beam computed tomography to determine the distance from the alveolar crest to the superior border of the mandibular canal (DMC) and the shortest distance from the buccal and lingual cortex to the mandibular canal (attaining distance) in the areas between premolars (premolar area), between the second premolar and first molar (middle area), and between the first and second molars (molar area). The DMC values for these areas were 16.55, 18.94, and 16.58 mm, respectively, and were similar in adults and adolescents. When the attaining distance was 8 mm, the heights on the buccal and lingual sides of the areas were 9 and 16.6 mm, 13.7 and 14.7 mm, and 15.3 and 12 mm, respectively. Risk of proximity to the mandibular canal should be considered at above heights or greater when an orthodontic anchorage device (OAD) 8 mm in length is placed. Careful attention is needed for placements on lingual side in adolescents. By reducing the OAD length to 6 mm, placement safety increases in all areas except the premolar area, especially on the buccal side.