Use of Micro-CT Imaging to Assess Ventral Mandibular Cortical Thickness and Volume in an Experimental Rodent Model With Chronic High-Phosphorus Intake

Adverse effects of high dietary phosphorus on bone health have been observed in both animal and human studies. The aim of the investigation was to examine chronic effects of high phosphorus diet on the apical mandibular cortical thickness and volume in a hystricomorph rodent (Octodon degus) using microcomputed tomography. Male degus were randomly divided into two groups fed by different mineral contents from the age of 12 weeks till the age of 17 months. The micro-CT scanning and wall thickness analysis were applied on the region of the mandible exactly under the apices of the 4th premolar tooth, first molar tooth, and second molar tooth in two animals from each group. General overview and mapping of the ventral mandibular bone thickness revealed pronounced bony mandibular protrusions in all the animals fed a high-phosphorus diet with obvious bone thinning apically to the 4th premolar and first and second molar tooth apices. Mandibular bone volume and thickness located apically to the premolar and molars were statistically significantly smaller/thinner in the group fed by a high phosphorus diet. The thinnest bone measured 0.004 mm, where the mandibular 4th premolar tooth almost perforated the mandibular cortex. Similar studies of metabolic bone disease and its influence on alveolar bone were also published in rats and mice. The influence of different environmental, infectious, or metabolic factors on the growing tooth, alveolar bone formation, and bone pathologies must be done experimentally on growing animals. In contrast, degus have continuously growing dentition, and the effect of any of the above listed factors can be studied in this animal model at any age and for longer time periods.

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The influence of dietary phosphorus and magnesium concentrations on the calcium content of heart and kidneys of DBA/2 and NMRI mice

Laboratory Animals ◽

10.1258/002367798780599758 ◽

1998 ◽

Vol 32 (4) ◽

pp. 483-491 ◽

Cited By ~ 26

Author(s):

F. A. R. van den Broek ◽

A. C. Beynen

Keyword(s):

Calcium Content ◽

Magnesium Content ◽

Nmri Mice ◽

Low Magnesium ◽

High Phosphorus ◽

Dietary Phosphorus ◽

Dietary Magnesium ◽

Plasma Magnesium ◽

High Phosphorus Diet ◽

Phosphorus Intake

Dystrophic cardiac calcification (DCC) is often found in DBA/2 mice, reportedly in association with low plasma magnesium levels in this mouse strain. It was hypothesized that high-phosphorus diets and low-magnesium diets that are known to lower plasma magnesium concentrations would promote the development of DCC. DBA/2 mice were fed diets with either low-magnesium (0.02%, w/w) or high-phosphorus (0.8%) concentrations or a combination of the two variables. NMRI mice were given either a low-(0.2%) or high-(0.6%) phosphorus diet. Female, but not male, NMRI mice accumulated calcium in the heart when fed the high-phosphorus diet; neither gender developed kidney calcification. DBA/2 mice with either a low-magnesium or a high-phosphorus intake developed marked cardiac calcifications. The combination of low-magnesium and high-phosphorus intake caused severe calcification of the heart, kidney and tongue'. Increasing the dietary magnesium content (0.08%) and reducing phosphorus (0.2%) did not fully prevent cardiac calcification, but reduced heart calcium concentrations in male DBA/2 mice. It is concluded that diets for DCC-susceptib1e mice should contain adequate amounts of magnesium and low, but sufficient amounts of phosphorus in order not to additionally stimulate cardiac calcification.

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Comparison of one versus two maxillary molars distalization with iPanda: a finite element analysis

Progress in Orthodontics ◽

10.1186/s40510-021-00356-6 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Kamontip Sujaritwanid ◽

Boonsiva Suzuki ◽

Eduardo Yugo Suzuki

Keyword(s):

Finite Element ◽

Stress Distribution ◽

Alveolar Bone ◽

Vertical Direction ◽

Minimal Amount ◽

Element Analysis ◽

Molar Distalization ◽

Second Molar ◽

Maxillary Molars ◽

Displacement Patterns

Abstract Background The purpose of this study was to compare the stress distribution and displacement patterns of the one versus two maxillary molars distalization with iPanda and to evaluate the biomechanical effect of distalization on the iPanda using the finite element method. Methods The finite element models of a maxillary arch with complete dentition, periodontal ligament, palatal and alveolar bone, and an iPanda connected to a pair of midpalatal miniscrews were created. Two models were created to simulate maxillary molar distalization. In the first model, the iPanda was connected to the second molar to simulate a single molar distalization. In the second model, the iPanda was connected to the first molar to simulate “en-masse” first and second molar distalization. A varying force from 50 to 200 g was applied. The stress distribution and displacement patterns were analyzed. Results For one molar, the stress was concentrated at the furcation and along the distal surface in all roots with a large amount of distalization and distobuccal crown tipping. For two molars, the stress in the first molar was 10 times higher than in the second molar with a great tendency for buccal tipping and a minimal amount of distalization. Moreover, the stress concentration on the distal miniscrew was six times higher than in the mesial miniscrew with an extrusive and intrusive vector, respectively. Conclusions Individual molar distalization provides the most effective stress distribution and displacement patterns with reduced force levels. In contrast, the en-masse distalization of two molars results in increased force levels with undesirable effects in the transverse and vertical direction.

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Assessment of the Retromolar Canal in Taiwan Subpopulation: A Cross-Sectional Cone-Beam Computed Tomography Study in a Medical Center

Tomography ◽

10.3390/tomography7020020 ◽

2021 ◽

Vol 7 (2) ◽

pp. 219-227

Author(s):

Yen-Wen Shen ◽

Wan-Chun Chang ◽

Heng-Li Huang ◽

Ming-Tzu Tsai ◽

Lih-Jyh Fuh ◽

...

Keyword(s):

Medical Center ◽

Third Molar ◽

Mandibular Canal ◽

Cone Beam ◽

Horizontal Distance ◽

Taiwanese Population ◽

Mandibular Bone ◽

Second Molar ◽

The Third ◽

Retromolar Canal

The retromolar canal is an anatomical variation that occurs in the mandibular bone. The retromolar canal typically originates in the mandibular canal on the distal side of the third molar and extends forward and upward to the retromolar foramen (RMF), which contains the neurovascular bundle. Accidentally damaging the neurovascular bundle in the retromolar canal during the extraction of the third molar, dental implant surgery, or maxillofacial orthognathic surgery may lead to subsequent complications such as incomplete local anesthesia, paresthesia, and bleeding during operation. The objective of this study was to investigate the prevalence of the RMF in the Taiwanese population in a medical center by using dental cone-beam computed tomography (CBCT) and to identify the position of the RMF in the mandibular bone. The dental CBCT images for the mandibular bone of 68 hemi-mandible were uploaded to the medical imaging software Mimics 15.1 to determine the prevalence of the RMF in the Taiwanese population and the three positional parameters of the RMF in the mandibular bone: (1) The diameter of the RMF, (2) the horizontal distance from the midpoint of the RMF to the distal cementoenamel junction of the second molar, and (3) the vertical distance from the midpoint of the RMF to the upper border of the mandibular canal. Seven RMFs were observed in the 68 hemi-mandibles. Thus, the RMF prevalence was 10.3%. In addition, the diameter of the RMF was 1.41 ± 0.30 mm (mean ± standard deviation), the horizontal distance from the midpoint of the RMF to the distal cementoenamel junction of the the second molar was 12.93 ± 2.87 mm, and the vertical distance from the midpoint of the RMF to the upper border of the mandibular canal below second molar was 13.62 ± 1.3487 mm. This study determined the prevalence of the RMF in the Taiwanese population in a medical center and its relative position in the mandibular bone. This information can provide clinicians with a reference for posterior mandible anesthesia and surgery to ensure medical safety.

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High‐phosphorus diet controlled for sodium elevates blood pressure in healthy adults via volume expansion

Journal of Clinical Hypertension ◽

10.1111/jch.14182 ◽

2021 ◽

Author(s):

Jia‐ying Zhang ◽

Huai‐zhou You ◽

Meng‐jing Wang ◽

Qian Zhang ◽

Xin‐yu Dong ◽

...

Keyword(s):

Blood Pressure ◽

Volume Expansion ◽

Healthy Adults ◽

High Phosphorus ◽

High Phosphorus Diet

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Osteoclastic effects of mBMMSCs under compressive pressure during orthodontic tooth movement

Stem Cell Research & Therapy ◽

10.1186/s13287-021-02220-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jing Wang ◽

Delong Jiao ◽

Xiaofeng Huang ◽

Yuxing Bai

Keyword(s):

Stem Cells ◽

Bone Marrow ◽

Normal Saline ◽

Periodontal Ligament ◽

Alveolar Bone ◽

Tooth Movement ◽

Orthodontic Tooth Movement ◽

Mouse Bone Marrow ◽

Micro Ct ◽

Tail Vein

Abstract Background During orthodontic tooth movement (OTM), alveolar bone remodelling is closely related to mechanical force. It is unclear whether stem cells can affect osteoclastogenesis to promote OTM. This study aimed to investigate the role of mouse bone marrow mesenchymal stem cells (mBMMSCs) under compression load in OTM. Methods A mouse OTM model was established, and GFP-labelled mBMMSCs and normal saline were injected into different groups of mice by tail vein injection. OTM distance was measured using tissue specimens and micro-computed tomography (micro-CT). The locations of mBMMSCs were traced using GFP immunohistochemistry. Haematoxylin-eosin staining, tartrate-resistant acid phosphate (TRAP) staining and immunohistochemistry of Runx2 and lipoprotein lipase were used to assess changes in the periodontal ligament during OTM. mBMMSCs under compression were co-cultured with mouse bone marrow-derived macrophages (mBMMs), and the gene expression levels of Rankl, Mmp-9, TRAP, Ctsk, Alp, Runx2, Ocn and Osterix were determined by RT-PCR. Results Ten days after mBMMSCs were injected into the tail vein of mice, the OTM distance increased from 176 (normal saline) to 298.4 μm, as determined by tissue specimen observation, and 174.2 to 302.6 μm, as determined by micro-CT metrological analysis. GFP-labelled mBMMSCs were mostly located on the compressed side of the periodontal ligament. Compared to the saline group, the number of osteoclasts in the alveolar bone increased significantly (P < 0.01) on the compressed side in the mBMMSC group. Three days after mBMMSC injection, the number of Runx2-GFP double-positive cells on the tension side was significantly higher than that on the compression side. After applying compressive force on the mBMMSCs in vitro for 2 days, RANKL expression was significantly higher than in the non-compression cells, but expression of Alp, Runx2, Ocn and Osterix was significantly decreased (P < 0.05). The numbers of osteoclasts differentiated in response to mBMMs co-cultured with mBMMSCs under pressure load and expression of osteoclast differentiation marker genes (Mmp-9, TRAP and Ctsk) were significantly higher than those in mBMMs stimulated by M-CSF alone (P < 0.05). Conclusions mBMMSCs are not only recruited to the compressed side of the periodontal ligament but can also promote osteoclastogenesis by expressing Rankl, improving the efficiency of OTM.

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Mandibular Bone and Soft Tissues Necrosis Caused by an Arsenical Endodontic Preparation Treated with Piezoelectric Device

Case Reports in Dentistry ◽

10.1155/2013/723753 ◽

2013 ◽

Vol 2013 ◽

pp. 1-4 ◽

Cited By ~ 2

Author(s):

A. Giudice ◽

M. G. Cristofaro ◽

I. Barca ◽

D. Novembre ◽

M. Giudice

Keyword(s):

Soft Tissues ◽

Mandibular Bone ◽

Bone Necrosis ◽

Second Molar ◽

Piezoelectric Device ◽

The Right

This paper describes a case of wide mandibular bone necrosis associated with significant soft tissues injury after using an arsenical endodontic preparation in the right lower second molar for endodontic purpose. Authors debate about the hazardous effects of the arsenic paste and the usefulness of piezosurgery for treatment of this drug related bone necrosis.

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Effects of different force magnitudes on corticotomy-assisted orthodontic tooth movement in rats

The Angle Orthodontist ◽

10.2319/103117-736.1 ◽

2018 ◽

Vol 88 (5) ◽

pp. 632-637 ◽

Cited By ~ 4

Author(s):

Kriangkrai Kraiwattanapong ◽

Bancha Samruajbenjakun

Keyword(s):

Alveolar Bone ◽

Tooth Movement ◽

Root Resorption ◽

Volume Fraction ◽

Micro Ct ◽

Histomorphometric Analysis ◽

Bone Volume Fraction ◽

Bone Response ◽

Significant Difference ◽

Light Force

ABSTRACT Objectives: To investigate the effects of light and heavy forces with corticotomy on tooth movement rate, alveolar bone response, and root resorption in a rat model. Materials and Methods: The right and left sides of 40 male Wistar rats were randomly assigned using the split-mouth design to two groups: light force with corticotomy (LF) and heavy force with corticotomy (HF). Tooth movement was performed on the maxillary first molars using a nickel-titanium closed-coil spring delivering either 10 g (light force) or 50 g (heavy force). Tooth movement and alveolar bone response were assessed by micro–computed tomography (micro-CT) at day 0 as the baseline and on days 7, 14, 21, and 28. Root resorption was examined by histomorphometric analysis at day 28. Results: Micro-CT analysis showed a significantly greater tooth movement in the HF group at days 7 and 14 but no difference in bone volume fraction at any of the observed periods. Histomorphometric analysis found no significant difference in root resorption between the LF and HF groups at day 28. Conclusions: Heavy force with corticotomy increased tooth movement at days 7 and 14 but did not show any difference in alveolar bone change or root resorption.

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Glucagon-Like Peptide-1 Receptor Agonist Liraglutide Ameliorates the Development of Periodontitis

Journal of Diabetes Research ◽

10.1155/2020/8843310 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Noritaka Sawada ◽

Kei Adachi ◽

Nobuhisa Nakamura ◽

Megumi Miyabe ◽

Mizuho Ito ◽

...

Keyword(s):

Receptor Agonist ◽

Alveolar Bone ◽

Diabetic Patients ◽

High Morbidity ◽

Sprague Dawley ◽

Gene Expressions ◽

Second Molar ◽

Sd Rats ◽

Glucagon Like Peptide ◽

Glucagon Like Peptide 1

Periodontitis is one of the diabetic complications due to its high morbidity and severity in patients with diabetes. The prevention of periodontitis is especially important in diabetic patients because the relationship between diabetes and periodontitis is bidirectional. Here, we evaluated the impacts of glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide on the amelioration of periodontitis. Five-wk-old Male Sprague–Dawley (SD) rats ( n = 30 ) were divided into 3 groups: normal, periodontitis, and periodontitis with liraglutide treatment groups. Periodontitis was induced by ligature around the maxillary second molar in SD rats. Half of the rats were administered liraglutide for 2 weeks. Periodontitis was evaluated by histological staining, gene expressions of inflammatory cytokines in gingiva, and microcomputed tomography. Periodontitis increased inflammatory cell infiltration, macrophage accumulation, and gene expressions of tumor necrosis factor-α and inducible nitric oxide synthase in the gingiva, all of which were ameliorated by liraglutide. Liraglutide decreased M1 macrophages but did not affect M2 macrophages in periodontitis. Moreover, ligature-induced alveolar bone resorption was ameliorated by liraglutide. Liraglutide treatment also reduced osteoclasts on the alveolar bone surface. These results highlight the beyond glucose-lowering effects of liraglutide on the treatment of periodontitis.

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