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ABSTRACT: To investigate dental pulp healing after tooth replantation in rats using nestin as an odontoblastic marker for immunohistochemical analysis.
Twenty-five maxillary right first molars from 25 female Sprague-Dawley rats, aged 4 weeks post-natally, were extracted and immediately repositioned in the original socket within 5 s. Five rats each were later killed on days 3, 5 and weeks 1, 2 and 4. The maxillae were removed en bloc and the tissue samples containing the maxillary right first molars were decalcified, sectioned, mounted and stained with anti-nestin antibody to be observed under a light microscope.
At 3 days after replantation, there was a localized inflammatory reaction, but pulp revascularization and healing had begun in the root area. At 5 days after replantation, odontoblast-like cells were observed. Reparative dentine deposition was observed beneath the pulp-dentine border from 1 week after replantation, and gradually increased until 2 weeks after replantation. The presence of odontoblast-like cells and the formation of reparative dentine continued from the first week throughout the experimental period. At week four, deposition of osteodentine and cementum-like tissues were observed.
Pulpal mineralization after replantation initially occurred via the deposition of reparative dentine, followed by the deposition of osteodentine and cementum-like tissues in rat teeth.
International Endodontic Journal 02/2012; 45(7):652-9. · 2.18 Impact Factor
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ABSTRACT: The purpose of this study was to evaluate the effect of alendronates on healing of extraction sockets and healing around implants in the maxilla of rats.
Twenty-four Sprague-Dawley rats were used. The rats in bisphosphonate group were subcutaneously injected with alendronate (5.0 mg kg(--1)) three times a week for 4 weeks. Both sides of the maxillary first molars were extracted, and customized titanium implants (Ø1.5 × 2.0 mm) were placed immediately into one side. Rats were killed at 3, 7, 14, or 28 days following surgery.
New bone formation in extraction sockets, bone area around the implant site, and bone-implant contact were not delayed in the bisphosphonate group. The tartrate-resistant acid phosphatase positive cell count did not differ between bisphosphonate and control groups; however, empty lacunae were observed significantly more in bisphosphonate group. The differences in empty lacunae were shown at different time points between the implant sites and extraction sites: at 7 days after extraction, and at 14 and 28 days after implantation.
Alendronates seemed to decrease bone resorption but not to decrease bone formation. Empty lacunae were observed significantly more at later time points in implant sites compared to extraction sockets.
Oral Diseases 06/2011; 17(7):705-11. · 2.49 Impact Factor
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ABSTRACT: Botulinum toxin type A (BTX-A) reduces the muscular contractions by temporarily inhibiting the release of acetylcholine at the neuromuscular junction. The purpose of this study was to investigate the effects of the BTX-A injected into the masseter muscle of a developing rat mandible.
Four-week-old male (no. 80) Sprague-Dawley rats were divided into four groups: control group, saline group, BTX-A group and baseline control group. Rats of baseline group were sacrificed at 0 day to provide baseline values of the mandibular measurements. The masseter muscle of rats in the saline and the BTX-A group were administered with saline and BTX-A solutions respectively. Experimental animals were sacrificed after 4 weeks.
The BTX-A group demonstrated smaller mandibular dimension compared with the other groups (P < 0.05). Their condylar cartilages showed increased apoptosis at the proliferation stage of the reserve zone and masseter muscle fibers demonstrated atrophic changes.
The result demonstrated BTX-A influence on inhibitory action of the developing mandible because of apoptosis at the proliferation stage of the reserve zone of the condylar cartilage in developing rat mandible.
Oral Diseases 04/2008; 14(7):626-32. · 2.49 Impact Factor
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ABSTRACT: Survival of periodontal ligament cells is crucial issue after tooth replantation. To understand this matter, we introduced MTT assay, which can be used as a tool for measuring the viability of periodontal ligament cells from extracted rat molars.
The maxillary molars of 4-week-old Sprague-Dawley white female rats were used. Ten teeth of each immediate, 1 h Viaspan and 1 h dry were processed for MTT evaluation. Another 10 teeth from each group were treated in the same manner as above, but were replanted into their original socket. After 2 weeks, the animals were killed and the prevalence of resorption pits was evaluated.
In vivo MTT assay corresponded with the histological results of the resorption pits (P <or= 0.05). The polarizing and optical microscopic findings were consistent with the in vivo MTT assay results.
In vivo MTT measurements were consistent with the histologic observations and suggest that the in vivo MTT assay could be a tool for evaluating the viability of periodontal ligament cells directly from the extracted root surface. The advantages are shorter analysis time compared with animal or cell culture experiments, easy manipulation, clear quantification and immediate identification of the vital cells.
Oral Diseases 10/2007; 13(5):495-9. · 2.49 Impact Factor
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ABSTRACT: Cortical activation is one of the procedures to accelerate tooth movement by manipulating the cortical bone. In this study, the effect of cortical activation on orthodontic tooth movement was investigated clinically and histologically in the surrounding bony tissue.
In the lower and upper jaws of two beagle dogs, cortical activation was applied to the buccal and lingual side of the alveolar bone in the right jaw where 12 holes were made on each cortical plate 4 weeks after the extraction of all the second bicuspids while under deep anesthesia. All third bicuspids on both jaws were forced to move forward by a 150-g force using NiTi coil spring with/without guiding wire. The tooth movement was measured and the animals were killed after tooth movement.
Rapid initial tooth movement was apparent after cortical activation. However, after 6 months of cortical activation, the cell number and cellular activity of the surrounding periodontal tissue were decreased.
This experiment showed that rapid initial tooth movement was apparent following the application of orthodontic force after cortical activation but the cellular activity and fibroblast structure were abnormal in the surrounding periodontal tissue.
Oral Diseases 06/2007; 13(3):314-9. · 2.49 Impact Factor
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ABSTRACT: Temporomandibular disorder (TMD) includes a number of clinical conditions involving the masticatory musculature or the temporomandibular joint (TMJ) and associated structures. Previous studies have shown the presence of high-affinity estrogen receptors in the TMJ articular cartilage. The aim of this study was to evaluate the developmental changes in mouse TMJ under estrogen deficiency.
Four-month-old ovariectomized mice were killed after certain weeks. We examined the significant alterations of the expression patterns of bone morphogenetic protein (BMP)-4, Runx2, and bone sialoprotein (BSP) after ovariectomy. Results: In the control group, BMP-4, Runx2, and BSP expressions showed no definite difference at any stage. In the ovariectomy group, the intensity of BMP-4 and Runx2 expression increased after ovariectomy. BSP immunoreactivity, however, increased slightly at 2 weeks but then decreased gradually.
Estrogen plays important roles in the metabolism and maintenance of TMJ via regulations of signaling molecules such as BMP-4, Runx2, and BSP. Our results suggest that estrogen deficiency is a candidate cause of TMD. This study revealed further osteogenetic properties of estrogen that may be useful in the clinical treatment and prevention of TMD.
Oral Diseases 04/2007; 13(2):220-7. · 2.49 Impact Factor
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ABSTRACT: For the successful organ transplantation, immune rejection has to be considered. Autogenic transplantation of human teeth is generally carried out free of clinical difficulty because of the lack of immune reaction, whereas allogenic tooth transplantations easily induce host immune rejection to donor tissues. The aim of the present study was to evaluate the replacement of donor tissue by host cells after allogenic tooth transplantation.
First molars extracted from lacZ transgenic ROSA26 mice were transplanted into the alveolar socket and the tongue of host wildtype mice, where the first molar had existed.
Donor cells from lacZ transgenic mice were not detected in the periodontal ligament space, but rather in the pulp chamber of the donor tooth. Furthermore, if the pulp chamber was widely open to an affluent blood supply, odontoblasts and fibroblasts in the donor tissue survived in the dental pulp.
Our experimental models using lacZ transgenic ROSA26 mice clearly demonstrate that donor periodontal tissue cells are replaced by host cells and that periodontal tissue can regenerate after allogenic tooth transplantation. Furthermore, our models suggest that donor pulpal cells can survive if the vascular supply into the pulp chamber is sufficient.
Oral Diseases 08/2006; 12(4):395-401. · 2.49 Impact Factor
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ABSTRACT: Apoptosis plays important roles in various stages of organogenesis. In this study, we hypothesized that apoptosis would play an important role in tooth morphogenesis. We examined the role of apoptosis in early tooth development by using a caspase inhibitor, z-VAD-fmk, concomitant with in vitro organ culture and tooth germ transplantation into the kidney capsule. Inhibition of apoptosis at the early cap stage did not disrupt the cell proliferation level when compared with controls. However, the macroscopic morphology of mice molar teeth exhibited dramatic alterations after the inhibition of apoptosis. Crown height was reduced, and mesiodistal diameter was increased in a concentration-dependent manner with z-VAD-fmk treatment. Overall, apoptosis in the enamel knot would be necessary for the proper formation of molar teeth, including appropriate shape and size.
Journal of Dental Research 07/2006; 85(6):530-5. · 3.49 Impact Factor
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ABSTRACT: Hertwig's epithelial root sheath (HERS) plays an important role in tooth root formation. In this study, we examined root formation of the first molar in mice, focusing on cell proliferation, cell death, cell migration, and the expression patterns of the signaling molecules, including glycoproteins and proteoglycans between PN8 and PN26. The number of HERS cells decreased during root formation, although HERS retained total length until PN15. The migration of HERS cells did not occur during root formation. Moreover, the immunopositive reaction of laminin beta-3 and syndecan-1 in HERS indicates that both cell adhesion and cell proliferation are essential for HERS development. Bmp-2, Bmp-4, and Msx-2 were expressed in HERS cells during root formation. We also developed an in vitro culture system for investigating the periodontium and suggest that this system provides an excellent vehicle for full exploration, and hence improved understanding, of the development and regeneration of the periodontium. Together, our results provide a comprehensive model describing the morphogenesis of early root development in vertebrates.
Journal of Dental Research 10/2004; 83(9):688-92. · 3.49 Impact Factor
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ABSTRACT: According to some reports, movement of the malleus, resulting from anterior hypertension on the discomallear ligament (DML), could produce aural symptoms related with damage to middle ear structures. The aim of this study was to examine the topographic relationship of the DML and the anterior ligament of malleus (ALM). Four fetuses and 16 adult hemi-sectioned heads were used to determine the anatomic-clinical relevance of DML and ALM in temporomandibular disorder. In fetal specimens, the DML was distinctly interposed between the malleus and the disc of the temporomandibular joint (TMJ), and the ALM had a structure apparently composed of the superior and inferior lamellae, running anteriorly in continuation with the sphenomandibular ligament (SML) through the future petrotympanic fissure (PTF). In all adult specimens, the DML was inserted into the malleus, and it expanded broadly toward the disc and capsular region of the TMJ in a triangular shape and inserted into the disc and capsule of the TMJ. The two-lamellae structure of the ALM was not distinguishable in adult specimens. The overstretched ALM resulted in movement of the malleus in five cases, but similar tension applied to the DML did not cause any movement of the malleus. This result provides an indication of the clinical significance of the ALM, a ligamentous structure continuous with the SML. It is apparent that the ALM has the potential to cause aural symptoms as a result of damage to the middle ear structure.
Surgical and Radiologic Anatomy 03/2004; 26(1):39-45. · 1.06 Impact Factor
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ABSTRACT: According to some reports, movement of the malleus, resulting from anterior hypertension on the discomallear ligament (DML), could produce aural symptoms related with damage to middle ear structures. The aim of this study was to examine the topographic relationship of the DML and the anterior ligament of malleus (ALM). Four fetuses and 16 adult hemi-sectioned heads were used to determine the anatomic-clinical relevance of DML and ALM in temporomandibular disorder. In fetal specimens, the DML was distinctly interposed between the malleus and the disc of the temporomandibular joint (TMJ), and the ALM had a structure apparently composed of the superior and inferior lamellae, running anteriorly in continuation with the sphenomandibular ligament (SML) through the future petrotympanic fissure (PTF). In all adult specimens, the DML was inserted into the malleus, and it expanded broadly toward the disc and capsular region of the TMJ in a triangular shape and inserted into the disc and capsule of the TMJ. The two-lamellae structure of the ALM was not distinguishable in adult specimens. The overstretched ALM resulted in movement of the malleus in five cases, but similar tension applied to the DML did not cause any movement of the malleus. This result provides an indication of the clinical significance of the ALM, a ligamentous structure continuous with the SML. It is apparent that the ALM has the potential to cause aural symptoms as a result of damage to the middle ear structure.
Surgical and Radiologic Anatomy 01/2004; 26(1):39-45. · 1.06 Impact Factor
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ABSTRACT: The purpose of this study was to evaluate the topography of the nerve distribution on the two heads of the lateral pterygoid and to clarify their morphological-functional correlations. The nerve distribution on the lateral pterygoid was studied in 24 hemi-sectioned heads. Both heads of the lateral pterygoid were innervated from the mandibular nerve branches, but with various nerve distribution patterns. The nerves innervating the superior head of the lateral pterygoid originated from the buccal nerve only in 45.8% of cases. In contrast, the nerves innervating the inferior head of the lateral pterygoid originated from both the buccal and mandibular nerve trunk in 58.3% of cases. In the seven distribution categories of the mandibular nerve branches, both the superior and inferior heads of the lateral pterygoid had a common source of nerve innervation in only 20.8% of cases, the buccal nerve. In contrast, in 45.9% of cases, additional nerve twigs from the mandibular nerve trunk were distributed on the inferior head of the lateral pterygoid. In summary, besides the buccal nerve described in anatomy textbooks, the nerve branches that originated directly from the mandibular nerve trunk innervated the lateral pterygoid.
International Journal of Oral and Maxillofacial Surgery 09/2003; 32(4):408-13. · 1.51 Impact Factor
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ABSTRACT: In this paper, we complete our investigations of mean convergence of Lagrange interpolation for fast decaying even and smooth exponential weights on the line. In doing so, we also present a summary of recent related work on the line and [–1,1] by the authors, Szabados, Vertesi, Lubinsky and Matjila. We also emphasize the important and fundamental ideas, applied in our proofs, that were developed by Erds, Turan, Askey, Freud, Nevai, Szabados, Vrtesi and their students and collaborators. These methods include forward quadrature estimates, orthogonal expansions, Hilbert transforms, bounds on Lebesgue functions and the uniform boundedness principle.
Acta Applicandae Mathematicae 01/2003; 76(1):17-36. · 0.90 Impact Factor
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ABSTRACT: Given a continuous real-valued function f which vanishes outside a fixed finite interval, we establish necessary conditions for weighted mean convergence of Lagrange interpolation for a general class of even weights w which are of exponential decay on the real line or at the endpoints of (−1,1).
Journal of Computational and Applied Mathematics.
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ABSTRACT: Commonly, the nerve branches from the anterior mandibular nerve trunk pass between the roof of infratemporal fossa and the superior head of lateral pterygoid. However, varied courses of the mandibular nerve branches can be frequently observed. The purpose of this study was to clarify the positional relationships and the clinical relevance of the course variations of the branches of the anterior mandibular nerve trunk with reference to the surrounding anatomical structures. Thirty-six hemi-sectioned heads were studied in detail. In 20 cases, the posterior deep temporal nerve had a common trunk with the masseteric nerve and was then divided anteriorly (15 cases) or posteriorly (five cases). In 16 cases, the posterior deep temporal nerve arose from the mandibular nerve trunk independently. Based on the branching patterns of the middle deep temporal nerve, type A (one twig of the middle deep temporal nerve) was most frequent and occurred in 41.7%. Similarly, type B (two twigs), type C (three twigs) and type D (four twigs) were observed in 36.1%, 16.7%, and 5.5%, respectively. The twigs of the middle deep temporal nerve, which pierced the muscle fibers of the superior head of lateral pterygoid, were found in 21 cases (58.3%). Cases in which the middle deep temporal nerve pierced through all areas of the superior head were most frequent (56.5%). These results suggest that the piercing patterns of the middle deep temporal nerve show there is a possibility that it may be compressed during the actions of the superior head of lateral pterygoid.
Surgical and Radiologic Anatomy 25(5-6):393-9. · 1.06 Impact Factor
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Journal of Computational and Applied Mathematics 137(1):71-76. · 1.11 Impact Factor
