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Emken S, Witzel C, Kierdorf U, Frölich K, Kierdorf H. Characterization of short-period and long-period incremental markings in porcine enamel and dentine-Results of a fluorochrome labelling study in wild boar and domestic pigs. J Anat 2021; 239:1207-1220. [PMID: 34240412 PMCID: PMC8546513 DOI: 10.1111/joa.13502] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/13/2021] [Accepted: 06/15/2021] [Indexed: 01/09/2023] Open
Abstract
Mammalian dental hard tissues exhibit incremental markings that reflect the periodic variation of appositional growth rates. In order to use these markings to characterize dental growth processes and to infer life‐history traits, an unequivocal identification of their periodicities is required. We performed a fluorochrome labelling study on forming enamel and dentine in molar teeth of wild boar and domestic pigs to establish the periodicity and temporal correspondence of incremental markings in enamel and dentine. The dominant incremental markings in enamel (laminations) and dentine (von Ebner lines) recorded in the pig teeth are of a daily nature. In addition, long‐period incremental markings with a periodicity of 2 days were recorded in enamel (striae of Retzius) and dentine (Andresen lines). The 2‐day growth rhythm was also expressed at the lateral crown surface, as evidenced by the pattern of perikymata. In enamel, also markings with a sub‐daily periodicity, representing an ultradian growth rhythm, were observed. Our study provides experimental evidence for the periodicity of incremental markings in porcine enamel and dentine. The findings correct previous misconceptions on incremental markings in dental hard tissues of pigs and other ungulates that had led to erroneous conclusions regarding crown formation parameters.
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Affiliation(s)
- Simon Emken
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Kai Frölich
- Department of Biology, University of Hildesheim, Hildesheim, Germany.,Tierpark Arche Warder e.V, Warder, Germany
| | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
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Melatonin effects on hard tissues: bone and tooth. Int J Mol Sci 2013; 14:10063-74. [PMID: 23665905 PMCID: PMC3676828 DOI: 10.3390/ijms140510063] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 04/29/2013] [Accepted: 05/02/2013] [Indexed: 11/16/2022] Open
Abstract
Melatonin is an endogenous hormone rhythmically produced in the pineal gland under the control of the suprachiasmatic nucleus (SCN) and the light/dark cycle. This indole plays an important role in many physiological processes including circadian entrainment, blood pressure regulation, seasonal reproduction, ovarian physiology, immune function, etc. Recently, the investigation and applications of melatonin in the hard tissues bone and tooth have received great attention. Melatonin has been investigated relative to bone remolding, osteoporosis, osseointegration of dental implants and dentine formation. In the present review, we discuss the large body of published evidence and review data of melatonin effects on hard tissues, specifically, bone and tooth.
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Liu J, Zhou H, Fan W, Dong W, Fu S, He H, Huang F. Melatonin influences proliferation and differentiation of rat dental papilla cells in vitro and dentine formation in vivo by altering mitochondrial activity. J Pineal Res 2013; 54:170-8. [PMID: 22946647 PMCID: PMC3597977 DOI: 10.1111/jpi.12002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 07/27/2012] [Indexed: 12/15/2022]
Abstract
Melatonin mediates a variety of biological processes ranging from the control of circadian rhythms to immune regulation. Melatonin also influences bone formation and osteointegration of dental implants. However, the effects of melatonin on dentine formation have not been examined. This study investigated the effects of melatonin on the proliferation and differentiation of rat dental papilla cells (rDPCs) in vitro and dentine formation in vivo. We found that melatonin (0, 10(-12) , 10(-10) ,10(-8) m) induced a dose-dependent reduction in rDPCs proliferation, increased alkaline phosphatase (ALP) activity, the expression of dentine sialoprotein (DSP), and mineralized matrix formation in vitro. In vivo melatonin (50 mg/kg, BW, i.p.) inhibited dentine formation. Melatonin (10(-8 ) m) suppressed the activity of complex I and IV in the basal medium (OS-) and enhanced the activity of complex I and complex IV in osteogenic medium (OS+). These results demonstrate that melatonin suppresses the proliferation and promotes differentiation of rDPCs, the mechanisms of which may be related to activity of mitochondrial complex I and complex IV.
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Affiliation(s)
- Jie Liu
- Department of pediatric dentistry, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen UniversityGuangzhou, China
- Department of Oral Anatomy and Physiology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen UniversityGuangzhou, China
| | - Hongyu Zhou
- Department of pediatric dentistry, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen UniversityGuangzhou, China
- Department of Oral Anatomy and Physiology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen UniversityGuangzhou, China
| | - Wenguo Fan
- Department of Oral Anatomy and Physiology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen UniversityGuangzhou, China
- Guangdong Provincial Key Laboratory of StomatologyGuangzhou, China
| | - Weiguo Dong
- Department of Oral Anatomy and Physiology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen UniversityGuangzhou, China
- Guangdong Provincial Key Laboratory of StomatologyGuangzhou, China
| | - Shenli Fu
- Department of pediatric dentistry, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen UniversityGuangzhou, China
- Department of Oral Anatomy and Physiology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen UniversityGuangzhou, China
| | - Hongwen He
- Department of Oral Anatomy and Physiology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen UniversityGuangzhou, China
- Guangdong Provincial Key Laboratory of StomatologyGuangzhou, China
| | - Fang Huang
- Department of pediatric dentistry, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen UniversityGuangzhou, China
- Department of Oral Anatomy and Physiology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen UniversityGuangzhou, China
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Sakai VT, Cordeiro MM, Dong Z, Zhang Z, Zeitlin BD, Nör JE. Tooth slice/scaffold model of dental pulp tissue engineering. Adv Dent Res 2011; 23:325-32. [PMID: 21677087 DOI: 10.1177/0022034511405325] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Multipotency is a defining characteristic of post-natal stem cells. The human dental pulp contains a small subpopulation of stem cells that exhibit multipotency, as demonstrated by their ability to differentiate into odontoblasts, neural cells, and vascular endothelial cells. These discoveries highlight the fundamental role of stem cells in the biology of the dental pulp and suggest that these cells are uniquely suited for dental pulp tissue-engineering purposes. The availability of experimental approaches specifically designed for studies of the differentiation potential of dental pulp stem cells has played an important role in these discoveries. The objective of this review is to describe the development and characterization of the Tooth Slice/Scaffold Model of Dental Pulp Tissue Engineering. In addition, we discuss the multipotency of dental pulp stem cells, focusing on the differentiation of these cells into functional odontoblasts and into vascular endothelial cells.
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Affiliation(s)
- V T Sakai
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, Ann Arbor, 48109-1078, USA
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Iinuma YM, Tanaka S, Kawasaki K, Kuwajima T, Nomura H, Suzuki M, Ohtaishi N. Dental Incremental Lines in Sika Deer (Cervus nippon); Polarized Light and Fluorescence Microscopy of Ground Sections. J Vet Med Sci 2004; 66:665-9. [PMID: 15240941 DOI: 10.1292/jvms.66.665] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Periodic growth incremental lines are found universally in dental hard tissues. This periodicity theoretically allows for estimation of age, even in days, which would be useful in studies of wild animals. In the present study, enamel and dentin increments of the sika deer (Cervus nippon) were observed in ground sections with a polarized light microscope, and their periodicity was examined by the use of a chronological labeling method with fluorochromes. Enamel increments occurred at a mean interval of 10.6 (SD=1.5) microm, and mean spacing of dentin increments was 17.3 (SD=1.8) microm. Fluorochromic marking revealed that incremental lines form each day in enamel and almost every second day in dentin. The fluorescence-labeled lines suggest that enamel formation of the first molar is complete by the age of 5 months. Due to its longer interval of incremental lines and longer term of formation, we conclude that dentin is more suitable than enamel for day-age estimation in sika deer. Experimental confirmation of incremental growth periodicity in various species can improve the reliability of use of tooth increments for age estimation and life history reconstruction.
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Affiliation(s)
- Yasuko M Iinuma
- Laboratory of Wildlife Biology, Graduate School of Veterinary Medicine, Hokkaido University, Japan
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