Human Dental Structures Research Articles

Comparison of Mineral Density of Dental Structures of Ancient Human Skeletons from the Roman Period with Modern-Day Human Dental Structures

Comparison of maxillary, mandibular, dental crown and root mineral density in human skeletons identified in historical excavations with today's human maxillary, mandibular dental crown and root. After the skull images were obtained, four groups were created: maxilla 1, mandible 1 from the old period, maxilla 2 from the images taken from today's patients, and mandible 2 from the images taken from today's patients. Seventeen skeletons were previously classified as young age, middle age, and older age. Among the archive tomography images, 17 images from young (15-35), middle (36-56) and older (57 and over) age images were included in the study. HU value of the desired region was calculated automatically by the device using Region of interest (ROI). In this study, 34 jaws and 68 teeth were evaluated, including 7 mandibles and 10 maxillae from the late Roman period, and 8 mandibles and 9 maxillae from today's people. The average HU value of the crowns of mandibular anterior teeth from the late Roman period was measured as 2406.0. The average HU value of the crowns of maxillary anterior teeth was found to be 3383.8. In the posterior aspect, the average crown HU value measured in the maxilla was found to be higher than that in the mandible. The finding showed that the density of dental tissues of ancient people, such as enamel and dentin forming the crown, and cementum and dentin forming the root, was significantly higher than today's people.

Comparison of Preprocessing Techniques for Dental Image Analysis.

Various dental disorders, such as lesions, masses, carries, etc. may affect the human dental structure. Dental radiography is a technique, which passes X-rays through dental structures and records the radiographic images. These radiographic images are used to analyze the disorders present in the human teeth. Preprocessing is a primary step to enhance the radiographic images for further segmentation and classification of images. In this work, the preprocessing techniques such as unsharp masking using high pass filter, bi-level histogram equalization and hybrid metaheuristic have been utilized for dental radiographs. The performance measures of the preprocessing techniques were analyzed. Results demonstrate that a hybrid metaheuristic algorithm for dental radiographs achieves higher performance measures when compared to other enhancement methods. An average Peak Signal-to-Noise Ratio (PSNR) value of 21.6 was observed in the case of a hybrid metaheuristic technique for dental image enhancement.

Biofilm formation on different dental restorative materials in the oral cavity

BackgroundBacterial biofilms adhere to all tissues and surfaces in the oral cavity. Oral biofilms are responsible for the decay of human dental structures and the inflammatory degeneration of the alveolar bone. Moreover, oral biofilms on artificial materials influence the lifespan of dental prostheses and restoratives.MethodsTo investigate in vivo oral biofilm formation and growth, five different dental restorative materials were analyzed and compared to human enamel. The roughness of the materials and the human enamel control probe were measured at the start of the study. The dental restorative materials and the human enamel control probe were placed in dental splints and worn for 3 h, 24 h and 72 h.ResultsScanning electron microscopy (SEM) revealed major differences between oral biofilm formation and growth on the materials compared to those on human enamel. Microbiological analyses showed that bacterial strains differed between the materials. Significant differences were observed in the roughness of the dental materials.ConclusionsIt can be concluded that material roughness affects biofilm formation on dental surfaces and restoratives, but other factors, such as surface charge, surface energy and material composition, may also have an influence.

In vitro analysis of dental ceramics: evaluation of the radiopacity and chemical composition by raman spectroscopy

Objective: This study compared the radiopacity of different ceramic systems by means of digital radiographs and evaluate the chemical composition of the samples by Raman spectroscopy. Material and Methods: The hypothesis tested was that there was a difference in radiopacity among the tested materials. Specimens were prepared for each ceramic tested: FLD - VM7 (VITA Zahnfabrik), LD - IPS Empress e.max Press (IPS Empress), AL - In Ceram Alumina (VITA Zahnfabrik), ALYZ - In Ceram Zirconia (VITA Zahnfabrik), YZ - Lava All Ceram (3M/ESPE), and MYZ - Zirconzahn (Talladium Brazil). The specimens were radiographed and submitted to radiographic density readings using a histogram tool. The spectrometer coupled to a petrographic microscope was used for Raman spectroscopy measurements. Analysis of variance (ANOVA) and a Tukey post-hoc test were used to compare radiopacity of the different materials. Results: For all tested materials, the radiopacity showed statistically significant differences, except YZ and MYZ. Lava All Ceram and ZirkonZahn had high radiopacity values and VM7 and IPS Empress e.max Press showed lower radiopacity than human dental structures. Conclusion: It was possible to conclude that radiopacity is closely linked to ceramic chemical composition.KeywordsDental ceramics; Radiopacity; Raman spectroscopy test; Restorative dentistry.

Pengaruh Penambahan Hidroksiapatit dari Cangkang Telur Ayam Terhadap Kekerasan Permukaan GIC

Hydroxyapatite (HA) is a bioceramic with excellentbiocompatible properties, and composition and crystal structure similar to apatite in the human dental structure and skeletal system. A number of researchers have attempted to evaluate the effect of the addition of HA powders to increasemechanical properties of restorative dental materials. In this study, HA was synthesized using chicken eggshell as calcium source for synthesizing HA by using precipitation technique. The aim of this study was to determine the effect of incorporation of eggshell-derived HA on the surface hardness GIC (Fuji IX GP). Specimens were divided into two groups: group GIC without incorporation of HA as control group (n = 16) and group GIC with incorporation of 5% HA as experimental group (n = 16). Total of specimens were 32 cylinders 5mm diameter and 2mm height. Surface hardness GIC was measured with vickers microhardness tester. Data wasanalyzed by unpaired T-test. The mean of surface hardness for GIC control group was 51.37 ± 1,63VHN and the experimental group was 56.60 ± 1,22HVN. The results T-test showed a significant difference between groups (p<0.05). It can be concluded thatincorporation of eggshell-derivedHA could increasesurface hardness of GIC.

The recognition, recovery and preservation of the human dentition and dental structures following high temperature incineration

One of the roles of the forensic odontologist during Phase 1 (scene) of a disaster victim indentification (DVI) incident involves the recognition and recovery of all human dental structures. This not only involves the recognition of teeth fragments and skeletal elements of the skull and mandible, but also involves recognising human from non-human elements. The recovery, preservation and successful transportation of the remains assists in the success of Phase 2 (mortuary/PM data) and, ultimately, scientific identification. This part of the workshop will examine the techniques forensic odontologists use to recognise, recover and preserve dental structures when dealing with cases following high temperature incineration.

In vitro comparison of the radiopacity of cavity lining materials with human dental structures

Aim:To compare the optical densities (OD) of calcium hydroxide (CH) and glass ionomer cement with the same thicknesses of the dental structures.Materials and Methods:Eighteen specimens of each material, with thicknesses of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm were made in a Teflon matrix. To compare the radiopacity of the materials with the dental structures, dental cuts of the first molars, increasing in thickness from 0.5 to 3.0 mm, were obtained. To standardize the radiographs, a transparent acrylic matrix (Standardizing Device) was developed and used. Thirty radiographs were taken, five for each tested material.Results:Statistical analysis (Two-way ANOVA - Bonferroni, P < 0.05) demonstrated that when the materials were compared, there was statistically significant difference between the ODs, only for the thickness of 1.0 mm (P < 0.05).Conclusion:The thickness of the material contributed to its radiopacity, and these materials had to be used in a thickness between 1.5 and 2.0 mm.

Effect ofStreptococcus mutanson mechanical properties of human dental structures

In this study, the mechanical properties of human dental structures have been investigated by using instrumented nanoindentation. Immersion in solutions containingStreptococcus mutans, which is the principal cause of dental caries, was applied to tooth specimens to clarify its effect on the microstructure and mechanical properties of the dental structures. With an extended time of up to 16 h, the pH value of theS. mutanssolutions dropped from 7.3 to 5.8. Therefore, after immersion in theS. mutanssolutions for 16 h, slight erosions of the dental structures began; after 64 h, severe tooth decay occurred with obviously etched dental features. After 128 h, the elastic modulus of enamel and dentine dropped to 85 and 67%, respectively, of the original values of untreated specimens, and the hardness dropped to 88 and 55%, respectively.

Effects of incorporation of hydroxyapatite and fluoroapatite nanobioceramics into conventional glass ionomer cements (GIC)

Hydroxyapatite (HA) has excellent biological behavior, and its composition and crystal structure are similar to the apatite in the human dental structure and skeletal system; a number of researchers have attempted to evaluate the effect of the addition of HA powders to restorative dental materials. In this study, nanohydroxy and fluoroapatite were synthesized using an ethanol based sol–gel technique. The synthesized nanoceramic particles were incorporated into commercial glass ionomer powder (Fuji II GC) and were characterized using Fourier transform infrared and Raman spectroscopy, X-ray diffraction and scanning electron microscopy. Compressive, diametral tensile and biaxial flexural strengths of the modified glass ionomer cements were evaluated. The effect of nanohydroxyapatite and fluoroapatite on the bond strength of glass ionomer cement to dentin was also investigated. Results showed that after 1 and 7 days of setting, the nanohydroxyapatite/fluoroapatite added cements exhibited higher compressive strength (177–179 MPa), higher diametral tensile strength (19–20 MPa) and higher biaxial flexural strength (26–28 MPa) as compared with the control group (160 MPa in CS, 14 MPa in DTS and 18 MPa in biaxial flexural strength). The experimental cements also exhibited higher bond strength to dentin after 7 and 30 days of storage in distilled water. It was concluded that glass ionomer cements containing nanobioceramics are promising restorative dental materials with both improved mechanical properties and improved bond strength to dentin.

Immunocytochemical analysis of dentin: a double-labeling technique.

Immunocytochemical analysis is a fundamental and selective technique for identifying different molecular components of human dental structure. The hypothesis tested here is that the application of different etching solutions on dentin does not hinder collagen fibrils and proteoglycans from maintaining their immunochemical antigenicity. Human dentin disks were treated with 0.5M of EDTA, citric acid, maleic acid, or phosphoric acid (for 15 or 30 s). A double-immunolabeling technique was performed to identify, simultaneously, collagen fibrils and chondroitin sulfate. The use of different acids resulted in different degrees of labeling. Maleic and citric acids revealed a diffuse and intense labeling for both collagen fibrils and proteoglycans. The use of phosphoric acid on dentin showed a massive coagulation of the proteoglycans (15 s) or very low labeling (30 s). These data clarify that the use of acids on dentin components is able to modify their antigenicity. Moreover, the double-labeling immunocytochemical technique allows understanding of the spatial relationships between the collagen fibrils and proteoglycans of the dentin matrix.

The distribution pattern of the hyaluronan receptor CD44 during human tooth development

The aim was to investigate the expression pattern of the major cell-surface hyaluronan receptor CD44, as there are no existing data on its presence or absence in human dental structures at different developmental stages. Immunohistochemical localization of CD44 was studied using a monoclonal antibody, H3, that specifically recognizes an epitope in the common backbone of all CD44 isoforms. The dental lamina displayed a strong CD44 signal; the external enamel epithelium was negative. In the coronal region of the tooth germ the presecretory ameloblasts showed an intense reaction whereas the less differentiated inner enamel epithelial cells showed no signal at the cervical loop where they meet the external enamel epithelium. In the stellate reticulum a moderate reaction was detected. The secretory ameloblasts and the stratum intermedium showed a strong cell-surface CD44 signal. A strong signal was also observed on the odontoblasts and their processes. In the pulp, close to the odontoblastic layer, weak labelling was seen in the walls of capillary vessels. The distribution of CD44 in the human tooth germ corresponds to that of hyaluronan in most locations, suggesting that during tooth development this transmembrane protein plays an important part in hyaluronan-mediated events.

Hominoid dental maturation

Traditional analyses of dental eruption pattern and enamel attrition suggested that the South African australopithecines exhibited a human-like or delayed maturation rate. Recent work has challenged this view by proposing that early hominids matured at a rate more like extant apes. We show that relative growth rates of ape and human dental structures are essentially similar, and that pattern differences in calcification stem from hominid incisor and canine reduction with concomitant facial reorganization. Pattern of dental development alone cannot be used to infer rates of somatic maturation.

Post-pleistocene reductions in human dental structure: a reappraisal in terms of increasing population density

This paper discusses the well-documented acceleration which occurred in the reduction of human dental structure during the post-Pleistocene. It suggests that the process can be explained in terms of different but related factors inherent in a transition from late-Pleistocene hunting and gathering conditions to ones involving a sedentary life in larger groups. It is postulated that directional selective forces acting during Upper Paleolithic to maintain large tooth size had only a poor influence and that the new techniques in food preparation had little or no effect. The phenomenon is seen as a possible side-effect of a more complex overall reduction in body size, of which dental reduction only represents a small but demonstrable part. It is also suggested that stresses may have played an important role in producing a transitory reduced dimensional expression of the genetic background. An interaction between the variables directly or indirectly affecting body mass is shown in the model proposed which relates to post-Pleistocene. An increase in population density is indicated as being the most decisive biological factor in determining the acceleration in the trend towards reduction.

Deciduous Tooth Size and Subsistence Change in Prehistoric Georgia Coast Populations

Previous articleNext article No AccessResearch ConclusionsDeciduous Tooth Size and Subsistence Change in Prehistoric Georgia Coast PopulationsClark Spencer LarsenClark Spencer Larsen Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Current Anthropology Volume 24, Number 2Apr., 1983 Sponsored by the Wenner-Gren Foundation for Anthropological Research Article DOIhttps://doi.org/10.1086/202970 Views: 5Total views on this site Citations: 14Citations are reported from Crossref Copyright 1983 The Wenner-Gren Foundation for Anthropological ResearchPDF download Crossref reports the following articles citing this article:Sujitha P, R. Bhavyaa, Muthu M S, Latha Nirmal, Sneha S. Patil Crown dimensions of primary teeth—A systematic review and meta‐analysis, Journal of Forensic Sciences 67, no.44 (Mar 2022): 1348–1356.https://doi.org/10.1111/1556-4029.15015Christopher M. Stojanowski, Kathleen S. Paul, Andrew C. Seidel, William N. Duncan, Debbie Guatelli-Steinberg Heritability and genetic integration of tooth size in the South Carolina Gullah, American Journal of Physical Anthropology 164, no.33 (Aug 2017): 505–521.https://doi.org/10.1002/ajpa.23290Christopher M. Stojanowski, Clark S. Larsen, Tiffiny A. Tung, Bonnie G. McEwan Biological structure and health implications from tooth size at Mission San Luis de Apalachee, American Journal of Physical Anthropology 132, no.22 (Feb 2007): 207–222.https://doi.org/10.1002/ajpa.20489Christopher M. Stojanowski, Michael A. Schillaci Phenotypic approaches for understanding patterns of intracemetery biological variation, American Journal of Physical Anthropology 131, no.S43S43 (Jan 2006): 49–88.https://doi.org/10.1002/ajpa.20517R. Macchiarelli, L. Bondioli, S. Caropreso, A. Mazurier, G. Merceron, E. L. Piana The oldest human remains from the Beagle Channel region, Tierra del Fuego, International Journal of Osteoarchaeology 16, no.44 (Jan 2006): 328–337.https://doi.org/10.1002/oa.828Edward F. Harris, Loren R. Lease Mesiodistal tooth crown dimensions of the primary dentition: A worldwide survey, American Journal of Physical Anthropology 128, no.33 (Nov 2005): 593–607.https://doi.org/10.1002/ajpa.20162Ryan M. Tubbs, Jodie A. O’Gorman Assessing Oneota Diet And Health: A Community And Lifeway Perspective, Midcontinental Journal of Archaeology 30, no.11 (Feb 2014): 119–163.https://doi.org/10.1179/mca.2005.004Paul W. Sciulli Evolution of dentition in prehistoric Ohio Valley Native Americans III. Metrics of deciduous dentition, American Journal of Physical Anthropology 116, no.22 (Jan 2001): 140–153.https://doi.org/10.1002/ajpa.1107 Determining What Our Ancestors Ate, (Dec 2000): 11–12.https://doi.org/10.1017/CHOL9780521402149.003Clark Spencer Larsen Dietary Reconstruction and Nutritional Assessment of Past Peoples: The Bioanthropological Record, (Dec 2000): 13–34.https://doi.org/10.1017/CHOL9780521402149.004Roberto Macchiarelli Prehistoric “fish-eaters” along the eastern Arabian coasts: Dental variation, morphology, and oral health in the Ra's al-Hamra community (Qurum, Sultanate of Oman, 5th-4th millennia BC), American Journal of Physical Anthropology 78, no.44 (Apr 1989): 575–594.https://doi.org/10.1002/ajpa.1330780411Gloria y'Edynak Yugoslav Mesolithic dental reduction, American Journal of Physical Anthropology 78, no.11 (Jan 1989): 17–36.https://doi.org/10.1002/ajpa.1330780105CLARK SPENCER LARSEN Bioarchaeological Interpretations of Subsistence Economy and Behavior from Human Skeletal Remains, (Jan 1987): 339–445.https://doi.org/10.1016/B978-0-12-003110-8.50009-8R. Macchiarelli, L. Bondioli Post-pleistocene reductions in human dental structure: a reappraisal in terms of increasing population density, Human Evolution 1, no.55 (Oct 1986): 405–417.https://doi.org/10.1007/BF02436617

Skeletal and Dental Adaptations to the Shift to Agriculture on the Georgia Coast

Skeletal and Dental Adaptations to the Shift to Agriculture on the Georgia Coast

The Probable Mutation Effect

The Probable Mutation Effect