Age Estimation by Forensic Odontology - Term Paper Example

Running Head: AGE ESTIMATION BY FORENSIC ODONTOLOGY Age estimation by forensic odontology Name Course Institution Date Age estimation by forensic odontology Introduction Modern science defines forensic odontology as a sub division of dentistry that deals with the appropriate examination and handling of dental evidence with the aim of presenting the findings in the interest of executing justice. Among the key functions of forensic odontology is age estimation. Age estimation is essentially imperative in forensic medicine since it not only assists in the identification process of deceased persons but it can also be applied in when dealing with cases of accidents and crimes. Age estimation is also a key factor that is employed especially when determining the identity of an individual. Estimating the age of an individual by using their teeth is a reliable method since teeth are natural and they can be preserved for long even after all the tissues and the bones of the body have disintegrated. This paper seeks to provide an incisive and comprehensive outlook of age estimation by forensic odontology. An incisive outlook of dental histology of age estimation will as well be addressed in this paper. Moreover, this paper will illustrate the concepts that revolve around dental age mineralization, crow completion, eruption, and root completion. This paper will also highlight the X ray factor, age estimation in bite mark area and then use of Aspartic acid racamezation such as L-amino and D amino acid in age estimation. Ultimately, this paper will give recommendations of what odontologists need to do with the findings in the pre and postmortem stages in reference to their dental records (Noble, 1976). Dental histology for age estimation According to the set standards in the field of forensic odontology, the methods or procedures of age estimation need to meet and follow specific requirements. For instance, these methods need to be inherently accurate. In cases whereby these methods are being applied in human beings who are still alive certain medical principles and ethics need to be put into account. The main features in the human dentine structures are dentinal tubules that are radiated from pulp of the dentine centum junction or the dentine enamel. Previous research studies have indicated that as an individual advances in age the size of their dental pulp cavity is minimized due to the deposits of the secondary dentine. Consequently, the measurements of the minimized pulp cavity are used to indicate the age of that individual. Moreover, in forensic dentistry the fundamental role of the odontologists involves age estimation through dental form. Dental identification comes in two major forms. Foremost, the examination that is commonly carried out entails a comparative identification that is in most cases used to establish the certainty of the vestiges of a decent corresponded by the antemortem. Secondly, in instances whereby the antemortem cannot be accessed a postmortem is verified by the forensic dentist thus suggesting that characteristics of the individual including their age (Rai, Dhatterwal & Anand, 2000). In the process of verifying the age of an individual’s forensic odontology involves the investigation of the teeth and long bones. Teeth and bones can be used in postmortems. Nevertheless, teeth can be evaluated in order to estimate age in some point in life. The maturation of teeth is inherently a unique process. The coronal base of a tooth is made up of the enamel. The enamel is considered as the hardest part of the human body. In reference to the physiological conditions the enamel does not portray any age- related changes consequent to its formation other than the loss of its permeability, a small level of wear and the increase of brittleness. On the other hand, behavioral habits and pathological conditions contribute to abrasion, erosion, caries and attrition. Over the course of time an irreversible loss of the enamel occurs. The other remaining part of the tooth is made of a cementum layer on the outward surface of root and the pulpodentinal complex (PDC). The pulpodentinal complex in most cases portrays age- related changes. According to research studies, the primary changes that occur in the pulpodentinal complex include the increase of mineralization in the dentin, the acceleration in the formation of the secondary dentine and the increase of calcification, fibers and infiltration. Moreover, a vital change that occurs in the pulpodentinal complex entails reduced circulation and the dental pulp innervation which is often times characterized by the reduction of cells. Dental age mineralization and eruption Dental structures can act as vital indictors of an individual's chronological age. The ages of young individuals such as the neonates and the foetuses can be identified through the analysis of the process of tooth development and thereafter a comparison within the frame of developmental charts is carried out. During the process of age estimation the conclusions or the results are in most cases to roughly ±1.5 years. The developmental charts are developed by experts in forensic odontology, the charts use graphics illustrate the formation of the dentition within a certain time range. For instance most charts range from 5 months in utero to 35 years thus giving illustrations on mixed, permanent and the deciduous dentitions. It is worth noting that in the process of determining the ages of sub-adult the dates of the teeth eruption are greatly variable and the concrete developmental phases of the teeth are even more accurate. The development of the third molar is often used by various forensic dentists to predict the age of young adults. However, there have been doubts regarding the accuracy of this method since the conclusion is solely established by the practitioners through their personal experience in the variability of the identified teeth. The forensic odontologists who advocate for the use of the third molar in age estimation claim that this method has an accuracy of about ±4 years. Research studies have shown that by using this method age estimation in the older adults and Middle-aged is to a large extent difficult. This is mainly due to the progression of periodontal disease, bone pathosis, excessive wear, complex restorative multiple restorations and extractions. By using the highly-variable markers the accuracy range is ±10-12 years. A number of odontologists advocate the use of aspartic acid racamezation in age estimation since they claim that this method has an accuracy of ±4 years. Age estimation using X-rays Over the course of time, in forensic odontology a number of dental methods of estimating age have been proposed. Most of these methods involve the extraction of microscopic section and direct measurements hence these techniques can be costly and time consuming. Furthermore, the approach of some of these methods provokes religious, ethical and cultural issues. Dental radiography has been the commonly used method in age estimation due to the fact that it involves simple techniques and it is non destructive. The initial methods generally involved both direct and indirect measurement of the dentine secondary deposits at the surface of the pulp. However, with time a refined technique was adapted this technique, unlike the other involved the direct measurement of the size of the root and the pulp by using the radiographs. Thereafter the ratios of both the root and pupal size are calculated. It was concluded that the multiple regression and principal component analysis of the measurements by using the dental radiographs is a non-invasive method of estimating age especially in adults (Hongwei, Jingtao &Cameron, 1991). Information obtained through X-ray transmissions are essential restricted to two dimensional information in low resolution in spite of this factor the information obtained is quite useful. The enhancement of X-ray transmission method is actualized through the use of X-ray micro focus computed tomography. This X-ray implement has an increased image resolution modality that enables non-destructive testing. The X-ray micro focus computed tomography uses similar principle like those that are used in medical computed tomography. However, the magnitude of the spatial resolution in the medical computed tomography is slightly higher. Over the past two decades, X-ray micro focus computed tomography has been used to give an analysis of the three dimensional composition of the root canal system which have extracted from the teeth prior and subsequent to endodontic instrumentation. It is evident that the use of the X-ray micro focus computed tomography is bound to develop forensic research as far as age estimation research is concerned. The integration of these methods and other appropriate software can bring about more precise and accurate formulas of estimating age on the basis of quantitative measurements of volumes (Clark, 1994). Age estimation using Aspartic Acid racamezation The estimation of age using aspartic acid which is one of the recommended methods to investigate forensic and legal issues in adult, adolescence and children. In adolescence and children radiological and morphological examination of skeleton and dental expansion are recommended. In adults the estimated age range is rather wide predictable and chronological ages frequently differ. Several changes take place in the amino acids which have protein molecules the changes that occur include, racamezation, oxidation and isomerisation. The first order of the chemical reactions is the process of racamezation. The living body consists of proteins which consist of the l-form of amino acid and peptides which are biologically synthesized through the D-form of amino acids. As age increases the L-form of amino acids is gradually converted to the D-form of amino acid this process is referred to as racamezation. This chemical reaction is influenced by factors such as PH, temperature and humidity among many other factors. Generally, racamezation occurs in bradytrophic and metabolic inactive tissues such as the eye, the brain and the teeth. The racamezation of aspartic acid is a continuous process that occurs in the life time of a living creature and even after their death. Recent research studies have indicated that high correlation exist between the racamezation ratio of aspartic acid and chronological age in comparison to amino acids in the dentin teeth. This correlation has been confirmed by several researchers. Moreover, it was reported that the racamezation process through the use of aspartic acid is able to estimate chronological age accurately as compared to other conventional methods. Currently, racamezation process through the use of aspartic acid is the considered as the most accurate method of age estimation. In the course of tooth eruption, the primary dentin develops, there exist gradient in age by several years from the crown region to the root region. The formation of the secondary and tertiary dentine take place throughout the life time of the living being however their age is lower than that of the primary dentine. The development of the dentine follows a certain pattern and it differs from one personal to the other. Foremost, the first molar develops, followed by the central incisive, the canine and then the first and second premolar. Finally the second molar develops. In the different types of teeth the degree of aspartic acid racamezation varies. The teeth that develop first tend to have a high degree of racamezation thus the first molar has a high degree as compared to other teeth (Yekkala& Willlems, 2006). The kind of tooth chosen as the test tooth determines the result attained since the rate of racamezation varies in the different regions of the teeth. In the process of age estimation the dentine region that is to be analyzed from the test tooth needs to be clearly defined and prepared in accordance to the set standards and protocols so as to enable quality assurance in the laboratories. In order for accuracy to be realized in the process of age estimation it is recommended that in the process of studying the test tooth a minimum of four control teeth should be tested. The four control teeth to be tested should be of known ages of homonymous teeth from the same jaw as the test tooth. Moreover, recent research studies have proved that in the process of age estimation the control tooth can be substituted with specimens that are prepared from the components of the D and L forms of aspartic acid. Age estimation is commonly calculated using the linear regression equation from the least squares procedure using the standards teeth. It is also possible to carry out a series of experiments by using the known age of the teeth to the extent of standard errors within + or – 3 prior to the application of the evaluation procedure. On the other hand, varying results can be reached using the racamezation methods. This can be attributed to the different dentin specimen and the difference in the analytical settings used in analytical techniques such as gas chromatography. The rate of racamezation is greatly affected by the change in temperature. Despite of the fact that most of the conducted investigations are conducted by using dentin specimens it essential that the entire dentine is used form the lingual-labial sagittal sections so that the degree of racamezation can be determined accurately. The incisor and the molar are recommended during age estimation since they are small in size, they a have a single root and the required amount of dentine can be attained easily (Ogino & Nagy, 1985). Bite Mark Areas Subsequent to the assortment of dental evidence, odontologists compare and analyze bite marks. Several factors could impinge on the accuracy of the identification process of bite marks. These factors include changes that are dependant on time, the effects of the bite marks, dents on the soft tissues and measurements. Additionally, poor photography affects the accuracy of the identification process of bite marks. In most cases the analysis of bite marks areas involves the use of pigskins since it can be directly compared to the human skin. Biting a human being is also considered as unethical. The limitations experienced during the analysis of bite marks include, variations in the pigskin properties and the techniques used when simulated pressure in the bite marks areas. Postmortem bites that occur in non-human skin portray different patterns as compared to those that are seen in the antemortem bite marks. Researchers in the field of forensic odontology recommend that there is need to standardize the pressure that is applied in the modeling skin in order to come up with experimental bite marks. This should be done instead of using the manual model of putting pressure on the pigskin models (Nunn, Shaw & Smith, 1996). There exist direct and indirect procedures of bite mark analysis. The direct method of bite mark of analysis entails a comparison between the presented dental models either in the form of photographs or fingerprint powder. The indirect method of analyzing bite marks involves the utilization of transparent overlays in the documentation of the edges in the suspect‘s bite mark areas. Over the course of time, new methods of analyzing bite marks have adopted these methods involve the use of 2D polyline procedure which entail the sketching straight lines amid two set points in the arch that lies between the incisal edges to designate the tooth width. The other method is the painting method. This method involves coating the edges of the incisors in the reference to the dental model. The incisors are coated with a red glossy paint thereafter, the Adobe Photoshop is used to create measurements on the image. About 13 variables are used in the analysis process. The identification process in the two methods is usually based the distance from canine-to-canine (1 variable), the width of the incisor (4 variables), and angles of rotational in the incisors (8 variables). The 2D polyline procedure greatly relies on accurate measurements, whereas the painting procedure relies on the specific overlaying of the presented images. Generally, both methods are reliable but the 2D polyline method provides more objective and efficient result. Postmortem in Age estimation by forensic odontology In the absence of antemortem dental records and other methods of age estimation cannot be used, the odontologist intervenes by limiting the area in which the object under investigation belongs thus increasing the likelihood of tracing the antemortem dental records. This method is referred to as postmortem dental profiling. The information that is derived from this process enables the odontologists to embark on a more elaborate investigation on the antemortem records. A postmortem dental profile essentially gives information on the age of the individual or the object under investigation. In some cases it is possible for the postmortem dental profile to give additional information on their dental diseases, habitual behaviors and systemic diseases. Forensic anthropologists in most instances give details of the conducted osteological studies. On the other hand, forensic dentists intervene or give assistance during these processes. The investigation of the ancestry background or the sex can not only be evaluated by analyzing the shape or the form of the skull but also the analysis of the teeth. Basically, from the appearance of skull, the forensic dentists are able to determine and categorize the origin of the object under observation into three groups namely the Mongoloid, Caucasoid, and Negroid. Other characteristics that can assist in the identification process include the cusps of Carabelli, multi-cusped premolars and the shovel-shaped incisors. These factors can as well assist in age estimation (Hongwei, Jingtao &Cameron, 1991). Subsequent to the completion of the postmortem record, a systematic and methodical comparison is conducted. The comparison entails the evaluation of each tooth and the immediate surrounding structures. Dental restorations is inherently significant in the process of identification nonetheless, several other oral features are evaluated. These additional features are very vital especially in individuals with minimal restorations. Due to the continuous decrease in dental caries, non-restorative cases are bound to increase during the process of age estimation. It is quite imperative that during the process of comparison the discrepancies and similarities. The discrepancies that should be noted include those that are explainable and the unexplainable. Explainable discrepancies refer to the time difference between the postmortem reports and the antemortem reports. For instance, this pertains to the extraction or restoration of teeth and the placement or the enlargement of teeth. In an unexplainable discrepancy the tooth absent on the antemortem record however it can be found in the postmortem record. In such cases exclusion needs to be made. A number of conclusions can be made in the process of reporting a dental identification. According to the American Board of Forensic Odontology it is recommended that the conclusion should be limited to four scopes namely, positive identification, possible identification, insufficient evidence and exclusion. Positive identification occurs when the antemortem and postmortem data are supported by sufficient details and they do not have unexplainable discrepancies. Possible identification occurs under the condition that both the antemortem and postmortem data have features that are consistent. However, due to the quality of the two data either the postmortem or the antemortem is taken up as the real evidence. In this case it is impossible to determine the identity positively. Insufficient evidence during age estimation is established when the given information given is not enough to support the conclusion. Exclusion occurs when the data presented is evidently inconsistent. It is worth noting that for positive estimation to occur there are no required features or concordant points. Similarly, a full series of radiographs cannot give sufficient data to so as to make a positive conclusion. The discretion of age estimation greatly depends on the odontologists who in needs to verify the conclusions before an authoritative body (Solheim, 1993). Conclusion. Forensic odontology as a sub division of dentistry that deals with the appropriate examination and handling of dental evidence with the aim of presenting the findings in the interest of executing justice. . Estimating the age of an individual by using their teeth is a reliable method since teeth are natural and they can be preserved for long even after all the tissues and the bones of the body have disintegrated. According to the set standards in the field of forensic odontology, the methods or procedures of age estimation need to meet and follow specific requirements. For instance, these methods need to be inherently accurate. In cases whereby these methods are being applied in human beings who are still alive certain medical principles and ethics need to be put into account. References Noble, H(1976). The estimation of age from the dentition: Dental identification and forensic odontology.New York: Henry Kimptom Publisher 1976: 28-34 Rai B, Dhatterwal K& Anand .C. (2000).Five markers of the changes in teeth: an estimating of age. Internet Journal of Forensic Science, Vol. 1, No. 2. (s) Yekkala, R & Willlems, G. (2006). Racamezation of aspartic acid from dentin in the estimation of chronological age. Journal of forensic science. 159S: 89-94. Beilen, D, Willlems, G & Peirs, A. (2004). Age calculation using X-ray micro focus computed Tomographical scanning of the teeth: A pilot study. Journal of forensic science. Vol 49:4. Solheim, T, T. (1993). A new method for dental age estimation in adults. Forensic science international. 1993:59:137-147. 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