Epithelial rests of Malassez: from latent cells to active participation in orthodontic movement

ABSTRACT Introduction: The epithelial rests of Malassez (ERM) represent a group of cells in the periodontal ligament classically consisting of latent or quiescent structures associated with pathological processes. However, recent evidence shows that these structures cannot be considered only as cellular debris. The ERM is a major tissue structure, with functions in maintaining the homeostasis of periodontal tissue, including the maintenance of orthodontic movement. Objective: The present literature review aims at presenting the potential functions of ERM, with emphasis on orthodontic movement and the functional structure of the periodontium. Conclusion: ERM cells have a functional activity in modulation of orthodontic movement, trough their potential for differentiation, maintenance functions and the capacity of repairing periodontium.

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Autophagy facilitates type I collagen synthesis in periodontal ligament cells

Scientific Reports ◽

10.1038/s41598-020-80275-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tomomi Nakamura ◽

Motozo Yamashita ◽

Kuniko Ikegami ◽

Mio Suzuki ◽

Manabu Yanagita ◽

...

Keyword(s):

Periodontal Ligament ◽

Collagen Synthesis ◽

Type I Collagen ◽

Periodontal Diseases ◽

Polyacrylamide Gel Electrophoresis ◽

Sodium Dodecyl ◽

Physiological Role ◽

Type I ◽

Periodontal Tissue ◽

Pdl Cells

AbstractAutophagy is a lysosomal protein degradation system in which the cell self-digests its intracellular protein components and organelles. Defects in autophagy contribute to the pathogenesis of age-related chronic diseases, such as myocardial infarction and rheumatoid arthritis, through defects in the extracellular matrix (ECM). However, little is known about autophagy in periodontal diseases characterised by the breakdown of periodontal tissue. Tooth-supportive periodontal ligament (PDL) tissue contains PDL cells that produce various ECM proteins such as collagen to maintain homeostasis in periodontal tissue. In this study, we aimed to clarify the physiological role of autophagy in periodontal tissue. We found that autophagy regulated type I collagen synthesis by elimination of misfolded proteins in human PDL (HPDL) cells. Inhibition of autophagy by E-64d and pepstatin A (PSA) or siATG5 treatment suppressed collagen production in HPDL cells at mRNA and protein levels. Immunoelectron microscopy revealed collagen fragments in autolysosomes. Accumulation of misfolded collagen in HPDL cells was confirmed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis. E-64d and PSA treatment suppressed and rapamycin treatment accelerated the hard tissue-forming ability of HPDL cells. Our findings suggest that autophagy is a crucial regulatory process that facilitates type I collagen synthesis and partly regulates osteoblastic differentiation of PDL cells.

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STORAGE MEDIUM FOR AVULSED TEETH: A LITERATURE REVIEW

International Journal of Advanced Research ◽

10.21474/ijar01/13340 ◽

2021 ◽

Vol 9 (08) ◽

pp. 874-886

Author(s):

Navpreet Kaur ◽

Nikhil Srivastava ◽

Vivek Rana ◽

Noopur Kaushik ◽

Tushar Pruthi

Keyword(s):

Literature Review ◽

Periodontal Ligament ◽

Storage Medium ◽

Avulsion Injury ◽

Storage Media ◽

Pdl Cells ◽

Traumatic Dental Injuries ◽

Dental Injuries

Avulsion injury is one of the most severe types of traumatic dental injuries. Following avulsion, periodontal ligament tissues are injured and the vessels and nerves of the pulp rupture at the apical foramen which causes pulp necrosis. In studies it was reported that the key to retention of the knocked-out teeth was to maintain the viability of the periodontal ligament. Storage media plays an important role in preserving the viability of PDL cells during extra alveolar time. This article highlights the different storage medias available for avulsed teeth, along with their merits and demerits.

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Biomaterial-Based Approaches for Regeneration of Periodontal Ligament and Cementum Using 3D Platforms

International Journal of Molecular Sciences ◽

10.3390/ijms20184364 ◽

2019 ◽

Vol 20 (18) ◽

pp. 4364 ◽

Cited By ~ 5

Author(s):

Chan Ho Park

Keyword(s):

Tissue Engineering ◽

Tissue Regeneration ◽

Periodontal Ligament ◽

State Of The Art ◽

Tooth Root ◽

Tissue Formation ◽

Periodontal Tissue ◽

Periodontal Tissues ◽

Root Surfaces ◽

Periodontal Ligaments

Currently, various tissue engineering strategies have been developed for multiple tissue regeneration and integrative structure formations as well as single tissue formation in musculoskeletal complexes. In particular, the regeneration of periodontal tissues or tooth-supportive structures is still challenging to spatiotemporally compartmentalize PCL (poly-ε-caprolactone)-cementum constructs with micron-scaled interfaces, integrative tissue (or cementum) formations with optimal dimensions along the tooth-root surfaces, and specific orientations of engineered periodontal ligaments (PDLs). Here, we discuss current advanced approaches to spatiotemporally control PDL orientations with specific angulations and to regenerate cementum layers on the tooth-root surfaces with Sharpey’s fiber anchorages for state-of-the-art periodontal tissue engineering.

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