Modified bone density-dependent orthotropic material model of human mandibular bone

Background: Bone density, an important factor in functional bone quality, can affect the success of implant osteointegration or orthodontic treatment. A number of studies report that chonic periodontitis constitutes one risk factor of osteoporosis characterized by low bone mineral density and that the mandible is susceptible to osteoporosis. Purpose: The purpose of this study was to evaluate mandibular bone density in animal subjects suffering from chronic periodontitis. Methods: 40 male Wistar rats were divided into four chronic periodontitis groups and four control groups (each group n=5). As chronic periodontitis models, the subjects were injected with 2×109 CFU/ml of Porphyromonas gingivalis in the sulcular gingiva, whereas control group members were injected with normal saline. After 2, 3, 4 and 6-week injection periods, the subjects were sacrificed and radiographic examination of the mandibular bone subsequently performed. Mandibular bone density was evaluated by histometric analysis. Results: The mandibular bone density in members of the chronic periodontitis group was significantly lower than those of the control group (p<0.05). The reduced mandibular bone density in the chronic periodontitis group was in line with the protracted bouts of periodontitis. Conclusion: Reduced mandibular bone density was found in the chronic periodontitis model. The longer the duration of a bout of chronic periodontitis, the greater the reduction in mandibular bone density.

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Human Umbilical Cord Mesenchymal Stem-Cell Therapy to Increase the Density of Osteoporotic Mandibular Bone

European Journal of Dentistry ◽

10.1055/s-0039-1688527 ◽

2019 ◽

Vol 13 (01) ◽

pp. 058-063

Author(s):

Nike Hendrijantini ◽

Poedjo Hartono ◽

Muhammad Dimas Aditya Ari ◽

Fedik Abdul Rantan

Keyword(s):

Stem Cell ◽

Bone Density ◽

Mesenchymal Stem Cell ◽

Trabecular Bone ◽

Control Group ◽

Human Umbilical Cord ◽

Bone Area ◽

Mandibular Bone ◽

Trabecular Bone Area

Abstract Objective The aim of this study is to evaluate the feasibility of human umbilical cord mesenchymal stem-cell (hUCMSC) therapy in increasing osteoporotic mandibular bone density in a rat model by determining changes in alkaline phosphatase (ALP), osteocalcin, type 1 collagen, and trabecular bone area after treatment. Materials and Methods This research adopted an experimental posttest-only control group design. Thirty female Wistar rats were randomly divided into six groups, namely, a control group with rats postsham surgery (T1), osteoporotic model postovariectomy rats (T2), postovariectomy rats 4 weeks after gelatin injection (T3), postovariectomy rats 8 weeks after gelatin injection (T4), postovariectomy rats 4 weeks after hUCMSC injection (T5), and postovariectomy rats 8 weeks after hUCMSC injection (T6). The rats were all sacrificed for histological and immunohistochemical examinations of ALP, osteocalcin, type 1 collagen, and trabecular bone area. Results Increased expression of ALP, type 1 collagen, and osteocalcin, as well as increased trabecular bone area, was observed in the treatment groups compared with that in the osteoporotic groups. Conclusion hUCMSCs produce significant osteogenic effects and increase osteoporotic mandibular bone density in the animal model. Increases in bone density are demonstrated by the higher levels of ALP, osteocalcin, and type 1 collagen, as well as increases in the trabecular bone area.

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Increased Plasma Osteocalcin, Oral Disease, and Altered Mandibular Bone Density in Postmenopausal Women

International Journal of Dentistry ◽

10.1155/2019/3715127 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11

Author(s):

Supanee Thanakun ◽

Suchaya Pornprasertsuk-Damrongsri ◽

Chantida Pawaputanon Na Mahasarakham ◽

Suteera Techatanawat ◽

Yuichi Izumi

Keyword(s):

Bone Density ◽

Postmenopausal Women ◽

Panoramic Radiograph ◽

Oral Disease ◽

Enzyme Linked Immunosorbent Assay ◽

Elevated Plasma ◽

Missing Teeth ◽

Mandibular Bone ◽

Mucosal Disease ◽

Postmenopausal Status

An association between oral diseases and postmenopausal status has been recognized. However, the relationship between all oral disease, mandibular bone density, health status, and osteocalcin (OCN) bone markers in postmenopausal dental patients has not been reported. This study was therefore to verify the differences in plasma OCN levels, dental, periodontal, and oral mucosal disease, and mandibular bone density alterations from panoramic radiograph and systemic parameters in postmenopausal women, compared to premenopausal women. Oral, radiographic, and blood examination were performed in 92 females. Dental, periodontal, and oral mucosal statuses were recorded. Health profile parameters were collected from medical charts. Plasma OCN was evaluated by enzyme-linked immunosorbent assay. Forty-two (45.7%) participants were postmenopausal with a higher median age (55 (51, 62) years) than the premenopausal group (43 (38, 45) years). Overweight or obesity, hypercholesterolemia, and impaired fasting blood sugar were more prevalent in postmenopause. The average postmenopausal OCN level (425.62 ng/mL) was significantly higher than the premenopausal group (234.77 ng/mL, p<0.001). The average number of missing teeth, mean attachment loss, alveolar bone loss, periapical lesion count, and clinical oral dryness score were also significantly higher in postmenopause (p=0.008, <0.001, 0.031, 0.006, and 0.005, respectively). However, mandibular bone density determined by mandibular cortical index was lower in postmenopause (p<0.001). The panoramic mandibular index, mandibular cortical width, fractal dimension, and other oral mucosal disease did not differ between the groups. Postmenopause was associated with elevated plasma OCN (β = 0.504, p<0.001) when related covariates were adjusted. Elevated plasma OCN, oral mucosal dryness, high number of periapical radiolucencies and missing teeth, and lower mandibular bone density from panoramic radiograph were prevalent in postmenopausal women. Dentists should suspect an increased risk of low bone mineral density in postmenopausal patients who display these clinical and radiographic findings, and they should be referred for further examination. Plasma OCN may interconnect a relationship between postmenopausal status and the low mandibular bone density.

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Impact of Duffy antigen receptor for chemokine gene expression on mandibular bone density in menopausal women

International Journal of Oral and Maxillofacial Surgery ◽

10.1016/j.ijom.2012.07.007 ◽

2013 ◽

Vol 42 (3) ◽

pp. 411-416 ◽

Cited By ~ 1

Author(s):

W. Świątkowski ◽

M. Rahnama ◽

J. Kocki ◽

A. Światkowską

Keyword(s):

Gene Expression ◽

Bone Density ◽

Antigen Receptor ◽

Mandibular Bone ◽

Chemokine Gene ◽

Duffy Antigen ◽

Menopausal Women ◽

Chemokine Gene Expression

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Histological and Radiological Evaluation of Low-Intensity Pulsed Ultrasound Versus Whole Body Vibration on Healing of Mandibular Bone Defects in Rats

Medicina ◽

10.3390/medicina56090457 ◽

2020 ◽

Vol 56 (9) ◽

pp. 457

Author(s):

Milad Etemadi Sh ◽

Nan-Chen Hsieh ◽

Seyed Shahin Movahed Mohammadi ◽

Shahrooz Momeni ◽

Seyed Mohammad Razavi ◽

...

Keyword(s):

Bone Density ◽

Whole Body Vibration ◽

Bone Defects ◽

Whole Body ◽

Control Group ◽

Pulsed Ultrasound ◽

Mandibular Bone ◽

Body Vibration ◽

Low Intensity Pulsed Ultrasound ◽

Low Intensity

Background and Objectives: Mechanical stimulation can improve the structural properties of the fracture site and induce the differentiation of different cell types for bone regeneration. This study aimed to compare the effect of low-intensity pulsed ultrasound stimulation (LIPUS) versus whole body vibration (WBV) on healing of mandibular bone defects. Materials and Methods: A mandibular defect was created in 66 rats. The rats were randomly divided into two groups of rats. Each group was subdivided randomly by three groups (n = 11) as follows: (I) control group, (II) treatment with LIPUS, and (III) treatment with WBV. The radiographic changes in bone density, the ratio of lamellar bone to the entire bone volume, the ratio of the newly formed bone to the connective tissue and inflammation grade were evaluated after 1 and 2 months. Results: LIPUS significantly increased the radiographic bone density change compared to the control group at the first and second month postoperatively (p < 0.01). WBV only significantly increased the bone density compared to the control group at the second month after the surgery (p < 0.01). Conclusions: Application of LIPUS and WBV may enhance the regeneration of mandibular bone defects in rats. Although LIPUS and WBV are effective in mandibular bone healing, the effects of LIPUS are faster and greater than WBV.

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Analysis of Buffering Properties of Honeycomb Material

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.482-484.1146 ◽

2012 ◽

Vol 482-484 ◽

pp. 1146-1149

Author(s):

Ming Bo Yang ◽

Jin Bao Chen ◽

Fei Deng ◽

Meng Chen

Keyword(s):

Theoretical Analysis ◽

Material Properties ◽

Orthotropic Material ◽

Soil Mechanics ◽

Material Model ◽

Lunar Soil ◽

Equivalent Material ◽

User Material Model ◽

Honeycomb Material ◽

Equivalent Material Properties

The buffering properties of honeycomb material are analyzed in the presented work. Theoretical analysis based on energy method is first presented, the buffering process of honeycomb material can be divided into three phases, honeycomb material can be equivalent to orthotropic material and the equivalent material properties are given. Being good at soil mechanics, Abaqus can simulate lunar soil very well. Using a constitutive model for honeycomb material, which is a built-in user material model, the presented work developed a honeycomb material simulation model and verified with a practical example. Now we can analysis the entire landing buffer process in Abaqus, which is a complement to existing analysis processes.

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