Evaluation of secondary dentin formation for forensic age assessment by means of semi-automatic segmented ultrahigh field 9.4 T UTE MRI datasets

Abstract Dental methods are an important element of forensic age assessment of living persons. After the development of all the teeth, including third molars, is completed, degenerative characteristics can be used to assess age. The radiologically detectable reduction of the dental pulp cavity has been described as such a feature. We investigated the suitability of ultrahigh field 9.4 T ultrashort time echo (UTE) magnetic resonance imaging (MRI) for the evaluation of pulp cavity volume in relation to the total tooth volume in 4 extracted human teeth. The volume calculations were performed after semi-automatic segmentation by software AMIRA using the different intensities of the structures in the MRI dataset. The automatically selected intensity range was adjusted manually to the structures. The visual distinction of pulp and tooth structure was possible in all cases with in-plane resolution < 70 μm. Ratios of tooth/pulp volume were calculated, which could be suitable for age estimation procedures. Intensity shifts within the pulp were not always correctly assigned by the software in the course of segmentation. 9.4 T UTE-MRI technology is a forward-looking, radiation-free procedure that allows the volume of the dental pulp to be determined at high spatial resolution and is thus potentially a valuable instrument for the age assessment of living persons.

Download Full-text

Age-dependent decrease in dental pulp cavity volume as a feature for age assessment: a comparative in vitro study using 9.4-T UTE-MRI and CBCT 3D imaging

International Journal of Legal Medicine ◽

10.1007/s00414-021-02603-1 ◽

2021 ◽

Author(s):

Maximilian Timme ◽

Jens Borkert ◽

Nina Nagelmann ◽

Adam Streeter ◽

André Karch ◽

...

Keyword(s):

Dental Pulp ◽

Specific Reference ◽

Good Reliability ◽

Human Teeth ◽

Age Assessment ◽

Ultrashort Echo Time ◽

Pulp Cavity ◽

The Mean

AbstractEvaluation of secondary dentin formation is generally suitable for age assessment. We investigated the potential of modern magnetic resonance imaging (MRI) technology to visualize the dental pulp in direct comparison with cone beam computed tomography (CBCT). To this end, we examined 32 extracted human teeth (teeth 11–48 [FDI]) using 9.4-T ultrashort echo time (UTE)-MRI and CBCT (methods). 3D reconstruction was performed via both manual and semi-automatic segmentation (settings) for both methods in two runs by one examiner. Nine teeth were also examined by a second examiner. We evaluated the agreement between examiners, scan methods, and settings. CBCT was able to determine the pulp volume for all teeth. This was not possible for two teeth on MRI due to MRI artifacts. The mean pulp volume estimated by CBCT was consistently higher (~ 43%) with greater variability. With lower variability in its measurements, evaluation of pulp volume using the MRI method exhibited greater sensitivity to differences between settings (p = 0.016) and between examiners (p = 0.009). The interactions of single-rooted teeth and multi-rooted teeth and method or setting were not found to be significant. For examiner agreement, the mean pulp volumes were similar with overlapping measurements (ICC > 0.995). Suitable for use in age assessment is 9.4-T UTE-MRI with good reliability and lower variation than CBCT. For MRI, manual segmentation is necessary due to a more detailed representation of the interior of the pulp cavity. Since determination of pulp volume is expected to be systematically larger using CBCT, method-specific reference values are indispensable for practical age assessment procedures. The results should be verified under in vivo conditions in the future.

Download Full-text

Isolation and culture of dental pulp stem cells from permanent and deciduous teeth

Pakistan Journal of Medical Sciences ◽

10.12669/pjms.35.4.540 ◽

2019 ◽

Vol 35 (4) ◽

Cited By ~ 1

Author(s):

Shagufta Naz ◽

Farhan Raza Khan ◽

Raheela Rahmat Zohra ◽

Sahreena Salim Lakhundi ◽

Mehwish Sagheer Khan ◽

...

Keyword(s):

Stem Cells ◽

Dental Pulp ◽

Dental Pulp Stem Cells ◽

Permanent Teeth ◽

Deciduous Teeth ◽

Tooth Pulp ◽

Human Teeth ◽

Creative Commons ◽

Calcified Tissue

Objective: To isolate dental pulp mesenchymal stem cells (MSCs) from non-infected human permanent and deciduous teeth. Methods: It was an in-vitro experimental study. Human teeth were collected from 13 apparently healthy subjects including nine adults and four children. After decoronation dental pulps were extirpated from teeth and cultured via explant method in a stem cell defined media. Data was analyzed by descriptive statistics. Results: As above MSCs emerged exhibiting fibroblast-like morphology. In vitro culture was positive for 100% (9/9) and 75% (3/4) of the permanent and deciduous teeth respectively. First cell appeared from deciduous teeth pulp in 10±6.2 days while permanent teeth pulp took 12.4±3.7 days. Together, 26.6±3.6 and 24.5±3.5 days were required for permanent and deciduous tooth pulp stem cells to be ready for further assays. Conclusions: The protocol we developed is easy and consistent and can be used to generate reliable source of MScs for engineering of calcified and non-calcified tissue for regenerative medicine approaches. doi: https://doi.org/10.12669/pjms.35.4.540 How to cite this:Naz S, Khan FR, Zohra RR, Lakhundi SS, Khan MS, Mohammed N, et al. Isolation and culture of dental pulp stem cells from permanent and deciduous teeth. Pak J Med Sci. 2019;35(4):---------. doi: https://doi.org/10.12669/pjms.35.4.540 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Download Full-text

Midkine Promotes Odontoblast-like Differentiation and Tertiary Dentin Formation

Journal of Dental Research ◽

10.1177/0022034520925427 ◽

2020 ◽

Vol 99 (9) ◽

pp. 1082-1091 ◽

Cited By ~ 1

Author(s):

Y.H. Park ◽

Y.S. Lee ◽

Y.M. Seo ◽

H. Seo ◽

J.S. Park ◽

...

Keyword(s):

Cell Differentiation ◽

Dental Pulp ◽

Expression Patterns ◽

Exposure Model ◽

Tooth Pulp ◽

Dental Pulp Cells ◽

Tertiary Dentin ◽

Pulp Cells ◽

Dentin Formation

Autophagy is an intracellular self-degradation process that is essential for tissue development, cell differentiation, and survival. Nevertheless, the role of autophagy in tooth development has not been definitively identified. The goal of this study was to investigate how autophagy is involved in midkine (MK)–mediated odontoblast-like differentiation, mineralization, and tertiary dentin formation in a mouse tooth pulp exposure model. In vitro studies show that MK and LC3 have similar expression patterns during odontoblast-like cell differentiation. Odontoblast-like cell differentiation is promoted through MK-mediated autophagy, which leads to increased mineralized nodule formation. Subcutaneous transplantation of hydroxyapatite/tricalcium phosphate with rMK-treated human dental pulp cells led to dentin pulp–like tissue formation through MK-mediated autophagy. Furthermore, MK-mediated autophagy induces differentiation of dental pulp cells into odontoblast-like cells that form DSP-positive tertiary dentin in vivo. Our findings may provide 1) novel insight into the role of MK in regulating odontoblast-like differentiation and dentin formation in particular via autophagy and 2) potential application of MK in vital pulp therapy.

Download Full-text

A deep learning method for automatic segmentation of the bony orbit in MRI and CT images

Scientific Reports ◽

10.1038/s41598-021-93227-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jared Hamwood ◽

Beat Schmutz ◽

Michael J. Collins ◽

Mark C. Allenby ◽

David Alonso-Caneiro

Keyword(s):

Deep Learning ◽

Human Performance ◽

Automatic Segmentation ◽

Ct Images ◽

Human Observer ◽

In Series ◽

Magnetic Resonance Imaging Mri ◽

High Degree ◽

Orbital Region ◽

Ct And Mri

AbstractThis paper proposes a fully automatic method to segment the inner boundary of the bony orbit in two different image modalities: magnetic resonance imaging (MRI) and computed tomography (CT). The method, based on a deep learning architecture, uses two fully convolutional neural networks in series followed by a graph-search method to generate a boundary for the orbit. When compared to human performance for segmentation of both CT and MRI data, the proposed method achieves high Dice coefficients on both orbit and background, with scores of 0.813 and 0.975 in CT images and 0.930 and 0.995 in MRI images, showing a high degree of agreement with a manual segmentation by a human expert. Given the volumetric characteristics of these imaging modalities and the complexity and time-consuming nature of the segmentation of the orbital region in the human skull, it is often impractical to manually segment these images. Thus, the proposed method provides a valid clinical and research tool that performs similarly to the human observer.

Download Full-text

Dental Pulp-Derived Mesenchymal Stem Cells for Modeling Genetic Disorders

International Journal of Molecular Sciences ◽

10.3390/ijms22052269 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2269

Author(s):

Keiji Masuda ◽

Xu Han ◽

Hiroki Kato ◽

Hiroshi Sato ◽

Yu Zhang ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Dental Pulp ◽

Genetic Disorders ◽

In Vitro Models ◽

High Plasticity ◽

Human Teeth ◽

Clinical Diagnoses ◽

Models Of Disease

A subpopulation of mesenchymal stem cells, developmentally derived from multipotent neural crest cells that form multiple facial tissues, resides within the dental pulp of human teeth. These stem cells show high proliferative capacity in vitro and are multipotent, including adipogenic, myogenic, osteogenic, chondrogenic, and neurogenic potential. Teeth containing viable cells are harvested via minimally invasive procedures, based on various clinical diagnoses, but then usually discarded as medical waste, indicating the relatively low ethical considerations to reuse these cells for medical applications. Previous studies have demonstrated that stem cells derived from healthy subjects are an excellent source for cell-based medicine, tissue regeneration, and bioengineering. Furthermore, stem cells donated by patients affected by genetic disorders can serve as in vitro models of disease-specific genetic variants, indicating additional applications of these stem cells with high plasticity. This review discusses the benefits, limitations, and perspectives of patient-derived dental pulp stem cells as alternatives that may complement other excellent, yet incomplete stem cell models, such as induced pluripotent stem cells, together with our recent data.

Download Full-text

Lithium Chloride Exerts Differential Effects on Dentinogenesis and Osteogenesis in Primary Pulp Cultures

Frontiers in Dental Medicine ◽

10.3389/fdmed.2021.649500 ◽

2021 ◽

Vol 2 ◽

Author(s):

Anushree Vijaykumar ◽

Mina Mina

Keyword(s):

Dental Pulp ◽

Osteoblast Differentiation ◽

Prolonged Treatment ◽

Odontoblast Differentiation ◽

Positive Effects ◽

Reparative Dentin ◽

Dentin Formation ◽

Reparative Dentin Formation

Wnt/β-catenin signaling is known to play essential roles in odontoblast differentiation and reparative dentin formation. Various Wnt activators including LiCl have been increasingly studied for their effectiveness to induce repair of the dentin-pulp complex. LiCl is a simple salt thought to activate Wnt/β-catenin signaling by inhibiting GSK3β. Previous in vitro and in vivo studies showed that LiCl increased odontoblast differentiation and enhanced reparative dentin formation. However, the underlying molecular and cellular mechanisms by which LiCl regulates odontoblast and osteoblast differentiation during reparative dentinogenesis are not well-understood. Our in vitro studies show that exposure of early dental pulp progenitors to LiCl increased the survival and the pool of αSMA+ progenitors, leading to enhanced odontoblast and osteoblast differentiation. The positive effects of LiCl in the differentiation of osteoblasts and odontoblasts from αSMA+ progenitors are mediated by Wnt/β-catenin signaling. Our results also showed that continuous and late exposure of dental pulp cells to LiCl increased the expression of odontoblast markers through Wnt/β-catenin signaling, and the number of odontoblasts expressing DMP1-Cherry and DSPP-Cerulean transgenes. However, unlike the early treatment, both continuous and late treatments decreased the expression of Bsp and the expression of BSP-GFPtpz transgene. These observations suggest that prolonged treatment with LiCl in more mature cells of the dental pulp has an inhibitory effect on osteoblast differentiation. The inhibitory effects of LiCl on osteogenesis and Bsp were not mediated through Wnt/β-catenin signaling. These observations suggest that the effects of LiCl, and GSK3β antagonists on reparative dentinogenesis involve multiple pathways and are not specific to Wnt/β-catenin signaling.

Download Full-text

Dental pulp stem cells from human teeth with deep caries displayed an enhanced angiogenesis potential in vitro

Journal of Dental Sciences ◽

10.1016/j.jds.2020.03.007 ◽

2021 ◽

Vol 16 (1) ◽

pp. 318-326

Author(s):

Yan Chen ◽

Xinzhu Li ◽

Jingyi Wu ◽

Wanyu Lu ◽

Wenan Xu ◽

...

Keyword(s):

Stem Cells ◽

Dental Pulp ◽

Dental Pulp Stem Cells ◽

Human Teeth

Download Full-text

Automatic Segmentation of the Dorsal Claustrum in Humans Using in vivo High-Resolution MRI

Cerebral Cortex Communications ◽

10.1093/texcom/tgaa062 ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Shai Berman ◽

Roey Schurr ◽

Gal Atlan ◽

Ami Citri ◽

Aviv A Mezer

Keyword(s):

High Resolution ◽

Automatic Segmentation ◽

Thin Sheet ◽

Brain Regions ◽

Reproducible Research ◽

Human Connectome Project ◽

High Resolution Mri ◽

Magnetic Resonance Imaging Mri ◽

And Function

Abstract The claustrum is a thin sheet of neurons enclosed by white matter and situated between the insula and the putamen. It is highly interconnected with sensory, frontal, and subcortical regions. The deep location of the claustrum, with its fine structure, has limited the degree to which it could be studied in vivo. Particularly in humans, identifying the claustrum using magnetic resonance imaging (MRI) is extremely challenging, even manually. Therefore, automatic segmentation of the claustrum is an invaluable step toward enabling extensive and reproducible research of the anatomy and function of the human claustrum. In this study, we developed an automatic algorithm for segmenting the human dorsal claustrum in vivo using high-resolution MRI. Using this algorithm, we segmented the dorsal claustrum bilaterally in 1068 subjects of the Human Connectome Project Young Adult dataset, a publicly available high-resolution MRI dataset. We found good agreement between the automatic and manual segmentations performed by 2 observers in 10 subjects. We demonstrate the use of the segmentation in analyzing the covariation of the dorsal claustrum with other brain regions, in terms of macro- and microstructure. We identified several covariance networks associated with the dorsal claustrum. We provide an online repository of 1068 bilateral dorsal claustrum segmentations.

Download Full-text

Automatic Segmentation of the Skull in MRI Sequences Using Level Set Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.58-60.2370 ◽

2011 ◽

Vol 58-60 ◽

pp. 2370-2375

Author(s):

Wei Li Ding ◽

Feng Jiang ◽

Jia Qing Yan

Keyword(s):

Level Set ◽

Medical Image ◽

Automatic Segmentation ◽

Image Sequences ◽

Initial Contour ◽

Single Image ◽

Mri Sequences ◽

Magnetic Resonance Imaging Mri ◽

Mri Image

Magnetic Resonance Imaging (MRI) has been widely used in clinical diagnose. Segmentation of these images obtained by MRI is a necessary procedure in medical image processing. In this paper, an improved level set algorithm was proposed to optimize the segmentation of MRI image sequences based on article [1]. Firstly, we add an area term and the edge indicator function to the total energy function for single image segmentation. Secondly, we presented a new method which uses the circumscribed polygon of the previous segmentation result as the initial contour of the next image to achieve automatic segmentation of image sequences. The algorithm was tested on MRI image sequences provided by Chuiyanliu Hospital, Chaoyang District of Beijing; the results have indicated that the proposed algorithm can effectively enhance the segmentation speed and quality of MRI sequences.

Download Full-text