Tooth acellular extrinsic fibre cementum incremental lines in humans are formed by parallel branched Sharpey's fibres and not by its mineral phase.

In humans, the growth pattern of the acellular extrinsic fibre cementum (AEFC) has been useful to estimate the age-at-death. However, the structural organization behind such a pattern remains poorly understood. In this study tooth cementum from seven individuals from a Mexican modern skeletal series were analyzed with the aim of unveiling the AEFC collagenous and mineral structure using multimodal imaging approaches. The organization of collagen fibres was first determined using: light microscopy, transmission electron microscopy (TEM), electron tomography, and plasma FIB scanning electron microscopy (PFIB-SEM) tomography. The mineral properties were then investigated using: synchrotron small-angle X-ray scattering (SAXS) for T-parameter (correlation length between mineral particles); synchrotron X-ray diffraction (XRD) for L-parameter (mineral crystalline domain size estimation), alignment parameter (crystals preferred orientation) and lattice parameters a and c; as well as synchrotron X-ray fluorescence for spatial distribution of calcium, phosphorus and zinc. Results show that Sharpey's fibres branched out fibres that cover and uncover other collagen bundles forming aligned arched structures that are joined by these same fibres but in a parallel fashion. The parallel fibres are not set as a continuum on the same plane and when they are superimposed project the AEFC incremental lines due to the collagen birefringence. The orientation of the apatite crystallites is subject to the arrangement of the collagen fibres, and the obtained parameter values along with the elemental distribution maps, revealed this mineral tissue as relatively homogeneous. Therefore, no intrinsic characteristics of the mineral phase could be associated with the alternating AEFC incremental pattern.

Variability in human tooth cementum thickness reflecting functional processes.

OBJECTIVE: The aim of this study was to investigate the thickness of acellular extrinsic fibre cementum (AEFC) at four root positions of anterior and posterior teeth with special focus on functional aspects. Furthermore, the correlations between cementum thickness and chronological age and sex are investigated. BACKGROUND: While numerous studies confirm continuous cementum apposition with age, masticatory forces as well as physiological and orthodontically induced tooth movements also have the potential to affect tooth cementum thickness. MATERIALS AND METHODS: Undecalcified teeth were embedded in resin and transverse-sectioned in the cervical third of the root. Two sections per root were selected, and digital images at four positions were obtained (mesial, distal, oral, and vestibular) using light microscopy. The AEFC thickness of 99 teeth (anterior = 66, posterior = 33, male = 54, female = 45) were measured in both sections. The differences in mean values between root positions and the association of root position variation with tooth type, age, sex, and subject as well as the overall effects of age and sex were analysed using a mixed model. RESULTS: First incisors and canines showed the greatest mean AFEC thickness, in contrast to premolars which had the lowest values. Differences were found across the four root positions, with a pattern varying considerably between anterior and posterior teeth and between maxilla and mandible in the anterior teeth. An interaction between root position and subject pointed to the existence of an individual component in the variation of AEFC thickness across the four root positions. There was an age trend with an almost linear increase in cementum thickness of 1 µm per year. Overall, females tended to exhibit a significantly lesser AEFC thickness compared to males. CONCLUSIONS: Distinct differences in the pattern of thickness values across the four root positions in anterior and posterior teeth support the assumption that the AEFC is strongly affected by functional processes. In addition to sex-specific differences and age-related trends, the root position variation of AEFC thickness varies from individual to individual.

Limitaciones Técnicas del Método de Conteo de Anulaciones del Cemento para Estimación de Edad. Hallazgos a Partir de Una Revisión con Búsqueda Sistemática / Technical Limitations of Cementum Annulation Count Method for age Estimation. Findings From A Scoping Review

En la última década, la odontología forense se ha enfocado en el desarrollo de metodologías para la estimación de edad (EE) debido a la gran demanda en procesos identificatorios. Entre esas técnicas, el conteo de anulaciones del cemento dental (TCA) ha ofrecido resultados promisorios, pero también contradictorios que han generado dudas sobre su precisión y confiabilidad. El objetivo de este trabajo fue caracterizar, establecer alcances, e identificar las limitaciones del conteo de TCA según los actuales estándares normativos y metodológicos. Se realizó una revisión con búsqueda sistemática del método de conteo de TCA para EE incluyendo estudios experimentales y notas técnicas en las bases PubMed/Medline, Scopus, Web of Science (WoS) y Embase. Se emplearon los términos "estimation", "age" y "cementum", con búsqueda manual complementaria en Google Scholar. Se excluyeron revisiones, estudios en colecciones arqueológicas, estudios radiológicos y cartas al editor. La búsqueda arrojó un total de 273 artículos, seleccionándose 27 que cumplieron con los criterios de inclusión. La mayoría de los estudios fueron publicados en Asia, particularmente en India (n=21). Sólo 6 artículos declararon el número total de individuos, tipos de diente y de cortes histológicos, siendo el premolar el más estudiado. Apenas dos artículos evaluaron la calidad de la muestra a analizar mediante legibilidad de los cortes obtenidos. El test más empleado para evaluar la precisión del método fue el coeficiente de correlación de Pearson (n=21). Estos hallazgos exponen la alta heterogeneidad reportada en las metodologías de EE mediante conteo por TCA, por lo que aún no existe un proceso estandarizado que abarque todas sus etapas y entregue resultados confiables siguiendo los estándares jurídicos actuales para la evidencia científica. Un mayor control de las limitaciones técnicas detectadas aumentará el valor como prueba en un contexto identificatorio legal o forense.

SUMMARY: In the last decade, forensic odontology has focused on the development of age estimation (AE) methodologies due to the great request in identification processes. Among these techniques, the tooth cementum annulation (TCA) count method has offered promising but also contradictory results, raising questions about its accuracy and reliability. The aim of this work was to characterize, establish the scope, and identify the limitations of the TCA count method according to the current normative and methodological standards. A scoping review was carried out for TCA count methods for AE, including experimental studies and technical notes in the PubMed/Medline, Scopus, Web of Science (WoS) and Embase databases. The terms "estimation", "age" and "cementum" were used, with a complementary manual search in Google Scholar. Reviews, studies in archaeological collections, radiological studies and letters to the editor were excluded. The search yielded a total of 273 articles, selecting 27 of them that met the inclusion criteria. Most of the studies were published in Asia, particularly India (n=21). Only 6 articles declared the total number of individuals, types of teeth, and histological sections, with the premolar being the most studied. Only two articles evaluated the quality of the sample to be analyzed through the legibility of the cuts obtained. The most widely used test to assess the precision of the method was the Pearson correlation coefficient (n=21). These findings expose the high heterogeneity reported in EE methodologies by counting TCA, so there is still no standardized process that covers in all its stages and delivers reliable results following current legal standards for scientific evidence. More control of the detected technical limitations will increase the value as evidence in a legal or forensic identification context.

A case of congenital multiple epiphyseal dysplasia from the Late Migration Period graveyard in Drnholec (Czech Republic).

OBJECTIVE: To contribute to differential diagnosis of multiple epiphyseal dysplasia (MED) in archeological and clinical contexts. MATERIALS: A skeleton of a 30- to 45-year-old male (grave no. 806) from the Late Migration Period graveyard in Drnholec-Pod sýpkou (Czech Republic), radio-carbon dated to AD 492-530. METHODS: Morphological and metric analyses. RESULTS: Significant pathological changes were noted on ossa coxae and proximal ends of the femora, which appear similar to changes associated with Legg-Calvé-Perthes disease. X-ray examination made it possible to rule out pseudoachondroplasia, rickets and metabolic bone diseases. CONCLUSIONS: The finding was evaluated as a probable case of congenital multiple epiphyseal dysplasia. SIGNIFICANCE: This case will contribute to the construction of estimates of the occurrence of this disease in historical populations and can be instructive for diagnostics in current medical practice. LIMITATIONS: The final diagnosis is limited by the lack of genetic analysis. SUGGESTION FOR THE FUTURE RESEARCH: Further clarification leading to diagnosis will benefit from genetic analysis and evaluation of skeletal remains throughout Europe.

Age estimation using tooth cementum annulations: bias and sources of inaccuracy.

BACKGROUND: Counting the tooth cementum annulations (TCA) is a method for estimating the age at death of adults by sections of their tooth root. The objective of this study was to assess the precision of counting the cementum incremental lines and the congruence between known age and age estimates. Possible factors affecting the accuracy of the estimate were also analyzed. METHODS: A sample of 67 permanent teeth extracted from individuals with known age (18-84 years) and sex was analyzed to calculate the dental age. RESULTS: Results demonstrate an excellent inter- and intra-observer reliability of annuli counting, with dissimilarities within the limits of agreement. A moderate positive correlation was found between chronological age and TCA. Our results showed that age congruence rates differed across age groups (85% congruence in individuals ≤30 years; 75% in individuals aged 31-60 years; 60% in the over 60s). Considering the bias, this method showed a clear tendency to underestimate age in specimens from old people. After age 43, the TCA estimate is highly inaccurate exceeding the underestimation of 10 years, on average, in comparison to the chronological age. Both chronological age and dental arch seem to influence the accuracy of estimates, unlike sex and the tooth root number. CONCLUSIONS: TCA analysis is characterized by high precision and low accuracy, decreasing with age. Therefore, its applicability is limited in elderly subjects. The choice of methods for age estimation in adult skeletal remains should take into account the particular age range of individuals. We recommend using different age estimation methods to verify the reliability of the performed assessments.

Comparative hard x-ray tomography for virtual histology of zebrafish larva, human tooth cementum, and porcine nerve.

Purpose: Synchrotron radiation-based tomography yields microanatomical features in human and animal tissues without physical slicing. Recent advances in instrumentation have made laboratory-based phase tomography feasible. We compared the performance of three cutting-edge laboratory systems benchmarked by synchrotron radiation-based tomography for three specimens. As an additional criterion, the user-friendliness of the three microtomography systems was considered. Approach: The three tomography systems-SkyScan 2214 (Bruker-microCT, Kontich, Belgium), Exciscope prototype (Stockholm, Sweden), and Xradia 620 Versa (Zeiss, Oberkochen, Germany)-were given 36 h to measure three medically relevant specimens, namely, zebrafish larva, archaeological human tooth, and porcine nerve. The obtained datasets were registered to the benchmark synchrotron radiation-based tomography from the same specimens and selected ones to the SkyScan 1275 and phoenix nanotom m® laboratory systems to characterize development over the last decade. Results: Next-generation laboratory-based microtomography almost reached the quality achieved by synchrotron-radiation facilities with respect to spatial and density resolution, as indicated by the visualization of the medically relevant microanatomical features. The SkyScan 2214 system and the Exciscope prototype demonstrated the complementarity of phase information by imaging the eyes of the zebrafish larva. The 3 - µ m thin annual layers in the tooth cementum were identified using Xradia 620 Versa. Conclusions: SkyScan 2214 was the simplest system and was well-suited to visualizing the wealth of anatomical features in the zebrafish larva. Data from the Exciscope prototype with the high photon flux from the liquid metal source showed the spiral nature of the myelin sheaths in the porcine nerve. Xradia 620 Versa, with detector optics as typically installed for synchrotron tomography beamlines, enabled the three-dimensional visualization of the zebrafish larva with comparable quality to the synchrotron data and the annual layers in the tooth cementum.

Effects of Intraligamentary Injection of Osteogenic-Induced Gingival Fibroblasts on Cementum Thickness in the Dog Model of Tooth Root Resorption.

Tooth root resorption is an unwanted result of orthodontic tooth movement, and it can be expressed by a reduction in cementum thickness. The aim of this experimental study was to evaluate the effect of intraligamentary injection of osteogenic-induced gingival fibroblasts (OIGF) on cellular and acellular tooth root cementum thickness in modeled orthodontic tooth movement. Six beagle dogs were used in the study. All the upper and lower third and fourth premolars were subjected to mechanical loading for 4 weeks, which induced orthodontic tooth movement. Fifteen premolars were assigned to the OIGF group, which received a single OIGF injection through the periodontal ligament near the root apex (n = 7 teeth), and to the control group, which received a single injection of Dulbecco's modified eagle's medium in the periapical area (n = 8 teeth). The evaluation of histomorphometry was performed to assess the thicknesses of cellular and acellular cementum at the root apex and four bilateral sites distal to the apex. We found no statistically significant enhancing effects of gingival fibroblasts on either cellular or acellular cementum thicknesses when compared with the control group. We conclude that a single intraligamentary injection of OIGF does not stimulate the formation of tooth root cementum in the dog model of orthodontic tooth movement. Thus, OIGF is unlikely to prevent orthodontic-induced tooth root resorption.

CXXC5 orchestrates Stat3/Erk/Akt signaling networks to modulate P. gingivalis-elicited autophagy in cementoblasts.

The keystone pathogen Porphyromonas gingivalis (P. gingivalis) elicits inflammation and autophagy in periodontal tissues. Transcription factor CXXC-type zinc finger protein 5 (CXXC5) and various signals are sensitive to P. gingivalis invasion. Herein, we investigated the P. gingivalis-elicited autophagy activity, the contribution of CXXC5, and the involvement of signals in cementoblasts, tooth root surface cells crucial in periodontal and periapical regions. After coculture with P. gingivalis, cementoblasts exhibited inflammatory cytokine increase, light chain 3(LC3)-I/II conversion, autophagosome activation, and CXXC5 reduction. Cementoblasts with loss and gain of CXXC5 were developed. CXXC5 silencing suppressed autophagy and inflammation, thereby partially compensating for the effects of P. gingivalis, and vice versa. We then screened potential signals and verified the positive participation of Stat3/Akt/Erk networks through specific inhibitor employment. P. gingivalis and CXXC5 induced autophagy through Beclin1 and Atg5 activation. Intriguingly, Annexin V/PI assay and EdU detection revealed that P. gingivalis promoted apoptosis and repressed cell proliferation. In sum, coculture with P. gingivalis enhanced autophagy activity in cementoblasts, which was partially suppressed by CXXC5 downregulation and mediated by Jak/Stat3, PI3K-Akt, and Erk1/2 signaling. This process probably influenced cell apoptosis and proliferation.

Measuring incremental line width and appearance in the tooth cementum of recent and archaeological human teeth to identify irregularities: First insights using a standardized protocol.

OBJECTIVE: Irregular incremental lines (ILs) in the tooth cementum were previously associated with pregnancy and certain diseases. This study aims to identify irregular ILs and assess their patterns and reproducibility. MATERIALS: 24 recent and 32 archaeological teeth from the nineteenth century with known birth history. METHODS: Histological sections of tooth roots were microscopically assessed. The width and appearance of 16,605 ILs were measured according to a standardized protocol. RESULTS: Irregular appearing ILs were present in earlier deposited ILs, which correspond to younger years in life. Irregular appearances decreased as the IL number increased, whereas irregular width was spread evenly across all ILs. Within-section reproducibility was relatively high for irregular appearance (intra class correlation close to 0.70 in recent and archaeological teeth) and irregular width (intra class correlation: recent: 0.49; archaeological: 0.58), whereas the across-section reproducibility was moderate. CONCLUSIONS: Irregular width and appearance in ILs were identified successfully with within-section reproducibility. The moderate reproducibility across sections needs to be addressed in further studies by more systematic sampling of sections. SIGNIFICANCE: The proposed protocol identifies irregularities in a reproducible manner and may suggest that irregular ILs could be used in paleopathology to identify pregnancies and diseases. LIMITATIONS: The correlation between the identified irregular ILs and known pregnancies has not been assessed as part of this study. SUGGESTIONS FOR FURTHER RESEARCH: The identified irregular ILs need to be validated by correlating them with known life history data.

Age estimation by cemental annulation rings.

CONTEXT: Tooth plays a pivotal role in the identification of a person when all other remains are ruined by natural or unnatural causes. Dental evidence can contribute to age estimation in forensic dentistry. Estimating the age of an individual with the help of a tooth for identification proves beneficial. Alternating light and dark bands seen on the cementum have been shown to be proportionate to the age of the patient in number. This was done to evaluate the cementum annulation in age determination. AIMS: This study aimed to determine the age of an individual using tooth cementum annulation. MATERIALS AND METHODS: In this study, twenty extracted teeth were collected and all the clinical details of the patient such as age, sex, and chief complaint were recorded. The collected teeth was preserved in formalin overnight and then washed under tap water before they were sectioned. The area selected for counting was observed under 10 × objective of light microscope, and photomicrographs were taken for the counting of the lines. At the time of analysis, the age of the patient was not disclosed to the observer. STATISTICAL ANALYSIS USED: Student's t-test was used for statistical analysis. RESULTS: This study showed the correlation between the actual age of the individual and the estimated age using tooth cementum annulation method and showed significant statistical value. CONCLUSION: Incremental lines found in cementum can be used for age estimation in forensic dentistry.

Differences between biological and chronological age-at-death in human skeletal remains: A change of perspective.

OBJECTIVES: This analysis seeks to determine whether differences between real and estimated chronological age (CA) with biological age (BA) in skeletal individuals reflect variability in aging. MATERIAL AND METHODS: A total of 87 individuals of two samples, ranging from 20 to 94 years old, were analyzed. One, partially documented, belongs to a Mexican skeletal collection dating to the 20th century; the other is an assemblage of prehispanic individuals from different archaeological sites. In all specimens, the tooth annulation method (TCA) was applied to estimate CA, while-excluding individuals older than 80 years-auricular surface (AS) and pubic symphysis (PS) methods were used to estimate BA. Statistical analyses were conducted to identify correlations and significance of the differences between CA vs. TCA, CA vs. AS/PS, TCA vs. AS/PS. Sex of individuals was assessed for its influence in aging. RESULTS: The use of TCA to estimate CA was successful for most individuals. A strong correlation was found between CA vs. TCA, CA vs. AS/PS, TCA vs. AS/PS and their differences were significant but variation in these were found when assessed by separate age groups. Sex did not influence such differences. DISCUSSION: TCA can be used to estimate CA and its differences with BA, being less than 10 years, are similar to those found in living populations. Differences between CA and BA are due to intra-population variability, which could be the consequence of individual differences in aging. More research is needed to have confidence that under- and overestimations of BA are indicators of aging variability at the level of the individual.

Using dental cementum increment analysis to estimate age and season of death in African Americans from an historical cemetery in Missouri.

The Missouri River in Callaway County, Missouri, flooded in 1993, necessitating salvage excavations at old Shiloh Cemetery, which yielded 11 mostly complete skeletons of African American adolescents and 7 other individuals who died during the mid to late 1800s. The skeletons exhibit evidence of stress normal for the period but no indications of cause of death. The individuals' unusual age distribution and proximity to one another raise the question of how they died. It is possible these individuals died from trauma or chronic or acute disease. Among the possible causes of death is one of the epidemics that swept across Missouri during the 1800s. In this study we counted tooth cementum annulations (TCA) to verify the skeletal age-at-death estimates and conducted dental cementum increment analysis (DCIA) to determine the season of death as a first step in understanding the history of the cemetery. TCA results confirmed that the 11 African-American individuals examined were teenagers. DCIA demonstrated that all of the individuals died between April and September. The burials, therefore, represent a section of a mixed-race cemetery, which included African American teenagers who died during the same season. Future research will attempt to identify whether this burial cohort died of chronic or acute disease, possibly of an epidemic of infectious disease.

Periapical cemento-osseous dysplasia: case report

Introduction: Periapical cemento-osseous dysplasia is a pathologic entity resulting from bone and cementum reactional process which affects the periapical region of the anterior mandible. Its etiology is not fully understood, but possibly it is related to an unusual bone and cementum response to some local factor. Objective: The aim of this study is to present a case of periapical cemento-osseous dysplasia. Case report: A 50 years-old female patient sought for dental care due to pain in the lower right premolar region. The panoramic radiography revealed the presence of an extensive radiolucent lesion with radiopaque areas located between the roots of the teeth #43 and #35. Teeth presented vitality and it was not observed any changes involving the periodontal ligament. Periapical cemento-osseous dysplasia diagnosis was established through clinical and radiographic features. Periapical cemento-osseous dysplasia does not require any treatment unless complications occur. Patient's complaint of discomfort was related to occlusal imbalance and was solved after the occlusion reestablishment. The patient was radiographically followed-up for 12 months and the lesion exhibits satisfactory signs of healing. Conclusion: The dentists need to be aware of asymptomatic intra-osseous lesions affecting the anterior region of mandible not to misconduct the diagnosis that could compromise the patient's oral health.

Demography of straw-colored fruit bats in Ghana.

Eidolon helvum is widely distributed across sub-Saharan Africa where it forms large, dense colonies. The species is migratory and satellite telemetry studies have demonstrated that individuals can migrate over 2,500 km. It is a common source of bush meat in West Africa and evidence of infection with potentially zoonotic viruses has been found in West African colonies. The species, therefore, is of interest to both ecologists and those interested in public health. Despite this, demographic parameters of the species are unknown. We focused our study primarily on a colony of up to 1,000,000 bats that roost in trees in Accra, Ghana to obtain estimates of birth rate and survival probability. Aging of bats by examination of tooth cementum annuli allowed use of life tables to indicate an annual survival probability for juveniles of 0.43 (95% confidence interval [CI] 0.16-0.77) and for adults of 0.83 (95% CI 0.73-0.93). Additionally, an annual adult survival probability of 0.63 (95% CI 0.27-0.88) was estimated by following 98 radiocollared bats over a year; capture-recapture data were analyzed using multistate models to address the confounding factor of emigration. True survival probabilities may be in between the 2 estimates, because permanent emigration may lead to underestimation in the capture-recapture study, and population decline may lead to overestimation in the life table analysis. Birth rates (0.96 young per female per year, 95% CI 0.92-0.98) and colony size changes were also estimated. Estimation of these key parameters will allow future analyses of both infection dynamics within, and harvest sustainability of, E. helvum populations.