• International Journal of Oral Biology
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• v.38 no.3
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• pp.87-92
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• 2013

Periodontal inflammation increases the risk of tooth loss, particularly in cases where there is an associated loss of alveolar bone and periodontal ligament (PDL). Histological and morphometric evaluation of periodontal inflammation is difficult. Especially, the lengths of the periodontal ligament and interdental alveolar bone space have not been quantified. A quantitative imaging procedure applicable to an animal model would be an important clinical study. The purpose of this study was to quantify the loss of alveolar bone and periodontal ligament by evaluation with micro-computed tomography (micro-CT). Another purpose was to investigate differences in infections with systemic E. coli LPS and TNF-${\alpha}$ on E. coli lipopolysaccharide (LPS) in loss of alveolar bone and periodontal ligament model on mice. This study showed that linear measurements of alveolar bone loss were represented with an increasing trend of the periodontal ligament length and interdental alveolar process space. The effects of systemic E. coli LPS and TNF-${\alpha}$ on an E. coli LPS-induced periodontitis mice model were investigated in this research. Loss of periodontal ligament and alveolar bone were evaluated by micro-computed tomography (micro-CT) and calculated by the two- and three dimensional microstructure morphometric parameters. Also, there was a significantly increasing trend of the interdental alveolar process space in E. coli LPS and TNF-${\alpha}$ on E. coli LPS compared to PBS. And E. coli LPS and TNF-${\alpha}$ on E. coli LPS had a slightly increasing trend of the periodontal ligament length. The increasing trend of TNF-${\alpha}$ on the LPS-induced mice model in this experiment supports the previous studies on the contribution of periodontal diseases in the pathogenesis of systemic diseases. Also, our findings offer a unique model for the study of the role of LPS-induced TNF-${\alpha}$ in systemic and chronic local inflammatory processes and inflammatory diseases. In this study, we performed rapidly quantification of the periodontal inflammatory processes and periodontal bone loss using micro-computed tomography (micro-CT) in mice.

• Imaging Science in Dentistry
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• v.47 no.3
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• pp.199-207
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• 2017

Purpose: Evaluation of alveolar bone is important in the diagnosis of dental diseases. The periodontal ligament space is difficult to clearly depict in cone-beam computed tomography images because the reconstruction filter conditions during image processing cause image blurring, resulting in decreased spatial resolution. We examined different reconstruction filters to assess their ability to improve spatial resolution and allow for a clearer visualization of the periodontal ligament space. Materials and Methods: Cone-beam computed tomography projections of 2 skull phantoms were reconstructed using 6 reconstruction conditions and then compared using the Thurstone paired comparison method. Physical evaluations, including the modulation transfer function and the Wiener spectrum, as well as an assessment of space visibility, were undertaken using experimental phantoms. Results: Image reconstruction using a modified Shepp-Logan filter resulted in better sensory, physical, and quantitative evaluations. The reconstruction conditions substantially improved the spatial resolution and visualization of the periodontal ligament space. The difference in sensitivity was obtained by altering the reconstruction filter. Conclusion: Modifying the characteristics of a reconstruction filter can generate significant improvement in assessments of the periodontal ligament space. A high-frequency enhancement filter improves the visualization of thin structures and will be useful when accurate assessment of the periodontal ligament space is necessary.

• Imaging Science in Dentistry
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• v.46 no.4
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• pp.229-237
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• 2016

Purpose: The aim of this article is to review a group of lesions associated with periodontal ligament (PDL) widening. Materials and Methods: An electronic search was performed using specialized databases such as Google Scholar, PubMed, PubMed Central, Science Direct, and Scopus to find relevant studies by using keywords such as "periodontium", "periodontal ligament", "periodontal ligament space", "widened periodontal ligament", and "periodontal ligament widening". Results: Out of nearly 200 articles, about 60 were broadly relevant to the topic. Ultimately, 47 articles closely related to the topic of interest were reviewed. When the relevant data were compiled, the following 10 entities were identified: occlusal/orthodontic trauma, periodontal disease/periodontitis, pulpo-periapical lesions, osteosarcoma, chondrosarcoma, non-Hodgkin lymphoma, progressive systemic sclerosis, radiation-induced bone defect, bisphosphonate-related osteonecrosis, and osteomyelitis. Conclusion: Although PDL widening may be encountered by many dentists during their routine daily procedures, the clinician should consider some serious related conditions as well.

• The korean journal of orthodontics
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• v.44 no.5
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• pp.263-267
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• 2014

Objective: To three-dimensionally elucidate the effects of occlusal hypofunction on the periodontal ligament and alveolar bone proper of rat molars by micro-computed tomography (micro-CT). Methods: Occlusal function in the molar area was restricted by attaching an anterior bite plate on the maxillary incisors and a metal cap on the mandibular incisors of 5-week-old male Wistar rats for 1 week. The periodontal ligament space and alveolar bone proper around roots of the mandibular first molar were assessed by histology and micro-CT. Results: The periodontal ligament space was narrower and the alveolar bone proper was sparser and less continuous in the hypofunction group than in the control group. Further, both the volume of the periodontal ligament and the volumetric ratio of the alveolar bone proper to the total tissue in the region of interest were significantly lower in the hypofunction group (p < 0.05). Conclusions: Occlusal hypofunction induces atrophic changes in the periodontal ligament and alveolar bone proper of rat molars.

• The korean journal of orthodontics
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• v.18 no.2
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• pp.311-327
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• 1988

Vascular changes in the periodontal ligament of the rat incisors following application of experimental orthodontic forces were examined by the India ink perfusion method. 57 rats were used for this experiment. The rats were divided into experimental group (54 rats) and control group (3 rats). 54 experimental rats were divided into group I (27 rats) and group II (27 rats). The right and left upper incisors of group. I and group II rats were separated distally with forces of 20gm, 70gm respectively. The vascular changes of periodontal ligament were observed histologically by means of light microscope after 1, 2 and 3 days of tooth movement and 1,3,5,8,14, and 21 days after removal of orthodontic force. The results were as follows; 1. After one day of tooth movement, occlusion of blood vessels, hyalinization of periodontal ligament and resorption of alveolar bone adjacent to the alveolar crest on pressure side were observed. Above the tissue changes on the pressure side of group II were more severe than those of group I. Especially, septal bone of group II was separated after 2 days of tooth movement. 2. In tension zones, periodontal space was widened and periodontal fibers were orientated in the direction of puil. The blood vessels of periodontal ligament were distended. New bone deposition was seen along the inner surface of the alveolus after 2 days of tooth movement. 3. After 3 days of tooth movement, deposition of new bone was seen along the periosteal surface of alveolar bone on pressure side, progressing with increasing after removal of orthodontic force. Remodelling of the new bone was occurred 5 days after removal of orthodontic force. 4. 3 days after removal of orthodontic force, invasion of blood vessels into the marginal periodontal ligament on pressure side was observed clearly and the vessels below the epithelial attachment were increased. 5. After removal of orthodontic force, hyalinized structures disappeared concomittantly with an invasion of blood vessels from the neighboring periodontal ligament. 14 days after removal of orthodontic force, the vessels in the periodontal ligament of group I were finished the vascular rearrangement. 21 days after removal of orthodontic force, the vessels in the periodontal ligament of group II were finished the vascular rearrangement.

• The Journal of the Korean dental association
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• v.27 no.8 s.243
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• pp.687-687
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• 1989

• Imaging Science in Dentistry
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• v.48 no.2
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• pp.79-86
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• 2018

Purpose: This study aimed to carry out a systematic review of studies in the literature comparing conventional imaging techniques with cone-beam computed tomography in terms of the role of these techniques for assessing any of the following periodontal conditions and parameters: infrabony defects, furcation involvement, height of the alveolar bone crest, and the periodontal ligament space. Materials and Methods: Interventional and observational studies comparing conventional imaging techniques with cone-beam computed tomography were considered eligible for inclusion. The MEDLINE and Embase databases were searched for articles published through 2017. The PRISMA statement was followed during data assessment and extraction. Results: The search strategy yielded 351 publications. An initial screening of the publications was performed using abstracts and key words, and after the application of exclusion criteria, 13 studies were finally identified as eligible for review. Conclusion: These studies revealed cone-beam computed tomography to be the best imaging technique to assess infrabony defects, furcation lesions, the height of the alveolar bone crest, and the periodontal ligament space.

• Journal of Oral Medicine and Pain
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• v.42 no.3
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• pp.85-88
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• 2017

Burkitt's lymphoma is a malignant monoclonal proliferation of early B-lymphocyte. Since Burkitt's lymphoma is a highly aggressive disease, early detection is a crucial. This disease often involves jaw and mandibular mass or swelling may also be seen, but in the early phase of Burkitt's lymphoma these symptoms cannot be observed. A rare case of Burkitt's lymphoma without any mandibular mass and the general symptoms was present. The excruciating toothache led the patient to visit the dental clinic and misdiagnosis of chronic periodontal abscess was made initially. Dentists should consider the oral manifestations of systemic disease when the multiple periodontal ligament space widening is observed and the dental treatment for mimicking odontogenic pain has no effect.

• The korean journal of orthodontics
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• v.32 no.6 s.95
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• pp.455-466
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• 2002

The objective of this study was to evaluate the changes that occurred over time in the distracted periodontal ligament space following the rapid retraction of a tooth by periodontal distraction after bone undermining surgery had been conducted in the dogs. The upper second premolars were extracted on the left and right side in 4 male beagle dogs. Immediately after extraction, the interseptal bone distal to the upper first premolar was thinned and undermined by grooving to decrease the bone resistance. Activating an individualized distraction appliance at the rate of 0.225mm twice a day, the upper first premolar was retracted rapidly toward the extraction socket. Periodontal distractions were performed for 5, 10, and 20 days, and 20-day-distraction cases were followed by maintenance periods of 0, 14, 28, and 56 days. After 20 days of rapid retraction, the average distal movement of the upper first premolar was 5.02mm, and the average mesial movement of the upper third premolars serving as an anchorage unit was 0.18 mm. On histological examination, the regeneration of bone occurred in a highly organized pattern. Distracted periodontal ligament space was filled with newly formed bone oriented in the direction of the distraction, and this was followed by extensive bone remodeling. This result was similar to those observed in other bones after distraction osteogenesis. In the periodontal ligament, the relationship between collagen fibers and cementum began to be restored 2 weeks after the distraction was completed, and showed almost normal features 8weeks after the completion of the periodontal distraction. However, on the alveolar side, the new bone formation was still in process and collagen fiber bundles and Sharpey's fibers were not present 8 weeks after the completion of the periodontal distraction. Reactions in the periodontal ligament of the anchorage tooth represented bone resorption on the compressed side and new bone deposition on the tension side as occurred in conventional orthodontic tooth movement. In conclusion, the results of this study showed that periodontal structures on the distracted side of the periodontal ligament were regenerated well histologically following rapid tooth movement.

• The korean journal of orthodontics
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• v.34 no.6 s.107
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• pp.506-513
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• 2004

Osteoclast action is necessary for alveolar bone remodeling in orthodontic tooth movement. The nervous system has also been reported to be associated with bone remodeling. This study was aimed to investigate the changes of osteoclasts in the periodontal ligament (PDL) space after surgical resection of the inferior alveolar nerve (IAN). Experimental rats were divided into young and adult groups. A surgical resection procedure of the IAN was carried out in the left side of the mandible and a sham operation in the right side of the mandible. The number of osteoclasts on the bundle bone surface and the resorption activity of the osteoclasts were histomorphometrically measured. The changes in distribution of substance P (SP) immunoreactive (IR) nerve fiber were evaluated in the PDL and pulp. SP-IR nerve fiber was depleted in both the PDL and pulp of the IAN resection side in both groups, which confirmed the resection of IAN to be successfully conducted. The number of osteoclasts in the IAN resection side was significantly reduced in both the young and adult groups (p<0.01 and p<0.05), whereas the resorption activity of osteoclasts did not show any significant difference between the IAN resection side and the sham operation side in both groups (p>0.05 and p<0.05). The adult group showed that the number of osteoclasts reduced significantly (p<0.01) and the resorption activity didn't change in comparison with the young group (p>0.05). These results suggest that surgical resection of the IAN and aging reduce the population of the recruited osteoclasts within the PDL, but don't affect on the osteoclastic resorption activity.