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Tamer  Mahmoud Ahmed
  • Arab Republic of Egypt
    Anthropology Department
    Institute of African Research and Studies
    Cairo University
    Giza
    P.BOX :12613
  • 00201140449054

Tamer Mahmoud Ahmed

One of the most important advantages of LIBS that make it suitable for the analysis of archeological materials is that it is a quasi-nondestructive technique. Archeological mandibles excavated from Qubbet el Hawa Cemetery, Aswan, were... more
One of the most important advantages of LIBS that make it suitable for the analysis of archeological materials is that it is a quasi-nondestructive technique. Archeological mandibles excavated from Qubbet el Hawa Cemetery, Aswan, were subjected to elemental analysis in order to reconstruct the dietary patterns of the middle class of the Aswan population throughout three successive eras: the First Intermediate Period (FIP), the Middle Kingdom (MK), and the Second Intermediate Period (SIP). The bone Sr/Ca and Ba/Ca ratios were significantly correlated, so the Sr/Ca ratios are considered to represent the ante-mortem values. It was suggested that the significantly low FIP Sr/Ca compared to that of both the MK and the SIP was attributed to the consumption of unusual sorts of food and imported cereals during years of famine, while the MK Sr/Ca was considered to represent the amelioration of climatic, social, economic, and political conditions in this era of state socialism. The SIP Sr/Ca, which is nearly the same as that of the MK, was considered to be the reflection of the continuity of the individualism respect and state socialism and a reflection of agriculture conditions amelioration under the reign of the 17th Dynasty in Upper Egypt.
Research Interests:
Background: Age estimation is an important factor in the identification of an individual in anthropology. The hard tissues of the human dentition are able to resist decay and degradation long after other tissues are lost. This resistance... more
Background: Age estimation is an important factor in the identification of an individual in anthropology. The hard tissues of the human dentition are able to resist decay and degradation long after other tissues are lost. This resistance has made teeth useful indicators for age calculation. Recent research indicates that tooth-cementum annulations (TCA) may be used more reliably than other morphological or histological traits of the adult skeleton to estimate age. while others reject it stating weak correlation between estimated and actual age. Objective: The aim of this study was to evaluate the use of incremental lines of dental root cementum for biological age determination and to examine the correlation between age and the number of incremental lines in human dental cementum in a sample of Egyptian adults Materials and Methods: Based on a known-age Egyptian adult sample, age estimates by TCA were conducted in a blind study involving 216 freshly extracted single rooted teeth. 616 undecalcified ground cross sections of approximately 90μm, were prepared, observed, photographed and measured. Images were enhanced by software and counts were made by one observer. The cementum bands were counted on the photomicrograph with the help of image analysis software and added to the average eruption time of individual tooth. The predicted age of the individual was thus obtained. Regression analysis was used to derive equations for age estimation. Results: It was found that age estimation based on the number of cementum lines strongly correlates with the chronological age (correlation coefficient r = 0.84 for men, r = 0.818 for women and r= 0.834 for the sex combined sample p<0.01). Factor of sex has no significant influence on the number of lines. Absolute average error for sex combined sample was 1.095± 7.735 years. Regression equations were derived for the Egyptians with a standard error of estimates is 2.1 years and mean square error of 6.63 years. Conclusions: The results of the current study demonstrate that TCA analysis may serve as an advantageous, quantitative method for age estimation. The accuracy is reflected in the error bounds obtained from the statistical analysis and regression analysis which were no more than 2.95 years. Digitalized system enhances the count and provides better results utilizing TCA technique.
Research Interests:
Dental caries still poses a large public health problem. Extensive caries can lead to large-scale suffering and reduction in quality of life both functionally and aesthetically. Evaluation of the various factors known to influence the... more
Dental caries still poses a large public health problem. Extensive caries can lead to large-scale suffering and reduction in quality of life both functionally and aesthetically. Evaluation of the various factors known to influence the severity and progression of disease is essential for health policy makers to promote oral health resources. Most studies that have assessed risk Factors for dental caries focused on non-modifiable risk factors such as previous caries experience and socioeconomic status. It is also important to investigate modifiable risk factors that can be used in developing guidelines for risk assessment and prevention as the Dietary habits. Objective: the aim of this study is to assess one dimensions of culture (Dietary habits) as an oral health determinant and it's relation to dental caries in children aging from 7-14 years living in Cairo compared to children with Nubian origins living in Aswan. Materials and Methods: This cross – sectional comparative study was performed on 200 children 7 to 14 years old. Examination was carried out by one examiner at different dental clinics in Cairo and Aswan (100 Egyptian Child and 100 Nubian child), with disposable mirror and explorer and under the light of dental unit. A researcher-administered questionnaire was used before the examination as regarding the child demographic data and information about the dietary habits. Analysis assessed risk factors for a 4-group primary dentition caries experience variable: the caries-free (reference group), the D1, the D2+F, and the D1D2+F groups. The dietary consumption frequencies for the children in the 4 caries groups were compared using multivariable multinomial regression analyses. Moreover, t-test was used for the comparison of both Egyptian and Nubian Groups Results: Lower Frequency of eating or drinking sugar-containing snacks in-between meals significantly increased the likelihood of being in the D1 group. Frequency of eating or drinking sugar containing snacks within one hour to bedtime significantly increased the likelihood of being in the D1D2+F group. Greater consumption frequency of added sugars at snacks significantly
Research Interests:
Estimation of adult skeletal age-at-death is not only one of the most important identifying features for an unknown individual but also one of the most difficult to achieve especially among old adults. The main source of the problem is... more
Estimation of adult skeletal age-at-death is not only one of the most important identifying features for an unknown individual but also one of the most difficult to achieve especially among old adults. The main source of the problem is the nature of human aging. This feature is characterized by an accumulation of metabolic disorders that show great variation in the level and the degree of change with increasing age both within and between populations. Moreover, individual aging is determined by the interplay of complex set of genetic, culture and environmental factors.

Variation in the biological aging process has profound effects on age-t death assessment. The relationship between chronological age and skeletal age indicators is neither constant nor linear. The assumption that the underlying biological basis of the age-indicator relationship is constant across different populations is erroneous. Therefore, it is necessary to take into account that age changes are not uniform across populations.

It has been demonstrated that when applied an aging method to independent populations of known age at death, it proves less reliable than the results obtained when applying the method to samples from the population used to formulate the methods.

The purpose of the present study was to compare and evaluate two dental
macroscopic age estimation criteria. Namely root dentine translucency (RDT) and dental root color measured as a mean value of the red, blue, and green components of color (RGB). The sample consisted of 416 freshly extracted single rooted permanent teeth collected from 311 individuals referred to several dentists and dental clinics in Kom Ombou district, south Egypt in the Nubian resettlement area.

RDT and RGB were assessed using traditional (manual) and image analysis quantification techniques. Analysis reveals that there is high linear correlation between both RDT and RGB values with age, with r = 0.951 and –0.985 respectively. Regression analyses yields a new set of equations to estimate age among Egyptian Nubian population with high correlation values ranging from r = 0.90 to 0.97 and a standard error of the estimate ranging from ± 5.067 to ±2.996. The best estimates were obtained by combining both RGB and RDT. Additionally, the analysis has shown that sex of the individual don’t affect age assessment.

It was concluded that RDT and RGB can be used to assess age at death
with high accuracy. Moreover, this technique can form a basis of practical
application in establishing age at death both in forensics and paleodemographic
aspects.
The correlation between the reduction of the coronal pulp cavity and the chronological age was examined in a sample of 532 intact mandibular second premolar from 266 Individuals of known age and sex. A panoramic radiographic examination... more
The correlation between the reduction of the coronal pulp cavity and the chronological age was examined in a sample of 532 intact mandibular second premolar from 266 Individuals of known age and sex. A panoramic radiographic examination was conducted on the selected individuals. Panoramic radiography was used to measure the length (mm) of the tooth crown (CL=coronal length) and the length (mm) of the coronal pulp cavity (CPCL=coronal pulp cavity length). The tooth-coronal index (TCI) after Ikeda et al. (1985) was calibrated with the computer software for accuracy and precision for each tooth. The values obtained were then subjected to regression analysis to derive equations for age estimation. The results were calculated and correlated with the chronologic age for evaluation. The correlation coefficients between chronological age and tooth coronal index ranged from -0.963 to -0.925. Regression equations derived for age estimation utilizing TCI for Egyptian population showed coefficient of determination (r2) ranging from 0.843 to 0.862 .This study shows the potential value of tooth coronal index aging method, which can be easily used to estimate age.
Together with the determination of age, ethnicity and stature, the identification of sex from human skeletal remains is an important element in anthropological and forensic assessments. Loth & Henneberg (1996) described a simple... more
Together with the determination of age, ethnicity and stature, the identification of sex from human skeletal remains is an important element in anthropological and forensic assessments. Loth & Henneberg (1996) described a simple morphological feature for sex determination by observing the flexure of the posterior margin of the mandibular ramus, at the level of the occlusal plane and claimed 99% prediction accuracy. To date, reliability of this method in assessing sex in an Egyptian sample has not yet been reported upon. Therefore, the purpose of this study is to evaluate the sex diagnostic power of the method among the adult Egyptians. Orthopantomographic assessment of mandibular posterior ramus flexure as a single sex indicator in 100 adult Egyptians revealed accuracy of 82% for males and 84 % for females and an overall accuracy of 83%. These results differ from those published by Loth & Henneberg (1996). However, they are in agreement with the conclusions reached by several other scholars. It is concluded that, using ramus flexure alone for sex assessment does not provide a high level of confidence and should be used in conjunction with other dimorphic traits.
The purpose of the present study was to evaluate two dental macroscopic age estimation criteria. Namely root dentine translucency (RDT) and dental root color measured as a mean value of the red, blue, and green components of color (RGB).... more
The purpose of the present study was to evaluate two dental macroscopic age estimation criteria. Namely root dentine translucency (RDT) and dental root color measured as a mean value of the red, blue, and green components of color (RGB). The sample consisted of 416 freshly extracted single rooted permanent teeth collected from 311 individual referred to several dentists and dental clinics in Kom Ombou district, south Egypt in the Nubian resettlement area. RDT and RGB were assessed using image analysis quantification techniques.
Analysis reveals that there is high linear correlation between both RDT and RGB values with age, with r = 0.951 and –0.985 respectively. Regression analyses yields a  new set of equations  to estimate age among Egyptian Nubian population with high correlation values ranging from r = 0.90 to 0.97 and a standard error of estimated ranging from ± 5.067 to ±2.996.  The best estimates were obtained by combining both RGB and RDT.
From the results it is concluded that RDT and RGB can be used to assess an accurate estimate of age and this technique can form a basis of practical application in establishing age both in forensics and paleodemographic aspects.
Background & Objectives: Bioanthropological research must be built upon a foundation of accurate age and sex estimates. Age and sex estimation from dental radiographs is a non-destructive, simple method to obtain information. The... more
Background & Objectives: Bioanthropological research must be built upon a foundation of accurate age and sex estimates. Age and sex estimation from dental radiographs is a non-destructive, simple method to obtain information. The objectives of the present dissertation were to analyze six
dental age and sex estimation methods regarding their comparative validity and practical implementation using 600 digital orthopantograms. Furthermore, a purpose of the investigation was to supplement the literature with data on dental age and sex estimation in Egyptians and Tunisians
individuals.
Methods: The orthopantomograms were selected based on the
inclusion and exclusion criteria set forth for the study. Aging and sexing of modern Egyptian and Tunisian populations as follows: Sex assessment using discriminant Function analysis of mandibular measurements, mandibular ramus flexure and of mandibular canine index, The estimated gender was
then compared with the known gender and percentage accuracy of determination was calculated, while age was assessed using orthopantomographic indices of the pulp of mandibular canine namely coronal pulp cavity index, pulp-tooth area index and linear measurement of
the pulp cavity
Results: The results showed that the mandibular ramus flexure, mandibular canine index and discriminant function analysis for sex determination among the study populations using digital orthopantomogrms can be used to diagnose sex with an average accuracy up to 86%. Similarly the pulp tooth area, the coronal pulp cavity index and linear measurement of pulp  were used for age estimation using mandibular canines, statistically significant correlation between age and the study variables was revealed. This work revealed no significant difference between chronological and estimated
ages. Different equations for age estimation in the resent research yielded an error of age estimation about 2.5 years as a mean value for both the Egyptians and Tunisians which is much lower than most that of anthropological methods
Moreover, it was shown that a combination of variables potentially leads to increases of the predictive power beyond the capabilities of each method alone for both age and sex estimation. A new function for sex determination for the Egyptians and Tunisian was derived as population specific method for sex determination that yielded a more accurate sex estimate.
Conclusion: Consequently, it was concluded that, this research showed promising results for dental age and sex estimation in a non-invasive manner using dental digital orthopantomograms of Egyptian and Tunisians populations. Moreover, population-specific equations were introduced to
enhance the accuracy of the estimates.
Research Interests: