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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Forensic dentistry | 6/7 | https://en.wikipedia.org/wiki/Forensic_dentistry | reference | science, encyclopedia | 2026-05-05T09:19:59.890392+00:00 | kb-cron |
== Sex estimation == The determination of sex is important in the identification of unknown individuals in both forensic and archaeological contexts. The preferred anatomical methods for sex determination are based on pelvic and cranio-facial morphology. Using these parts of the skeleton, males and females can be correctly classified with over 90% accuracy. However, these skeletal elements are sometimes recovered in a fragmentary state, rendering sex estimation difficult. Moreover, there is currently no reliable method of sex determination of juvenile or sub-adult remains from cranial or post-cranial skeletal elements since dimorphic traits only become apparent after puberty, and this represents a fundamental problem in forensic investigations. In such situations, teeth are potentially useful in sex determination. Due to their hardness, they are highly resistant to taphonomic processes and are much more likely to be recovered than other parts of the fact, the enamel present on teeth is the hardest biological substance in the human body; therefore making them extremely sustainable analytical evidence in a forensic context. Moreover, teeth may be particularly useful for sexing immature skeletal remains since both primary and permanent sets of teeth develop before puberty. For several decades research has been conducted into human dental sexual dimorphism, looking at different tooth classes, and using various techniques and measurements, to try to establish the extent of any dimorphism and find criteria or patterns that might enable accurate sexing of unknown individuals. Most of these studies have focused on sexual dimorphism in crown-size dimensions. This research has established that human teeth are sexually dimorphic and, although males and females exhibit overlapping dimensions, there are significant differences in mean values. Sexual dimorphism has been observed in both deciduous and permanent dentition, although it is much less in deciduous teeth. On average, male teeth are slightly larger than female teeth, with the greatest difference observed in the canine teeth. Research using microtomographic scans to look at internal dental tissues has also shown that male teeth consist of significantly greater quantities of dentine than female teeth. This results in female teeth having thicker enamel, on average. Researchers have attempted to use statistical techniques such as discriminant functions or logistic regression equations based on these sex differences to estimate the usefulness of such formulae is uncertain because sexual dimorphism in teeth may vary between populations. The advanced methods which amplify the DNA by using Polymerase chain reaction (PCR) give 100% success in sex determination. Sex estimation based on dentition remains experimental and has yet to gain widespread acceptance. Nevertheless, it offers potentially useful additional techniques that could be used alongside more established methods.
== Identification methods ==
=== Radiograph comparison === The comparison of antemortem and post-mortem radiographic records can be done to attain a positive identification of an individual. Teeth are used since they are very durable and resistant to extreme conditions. The radiographs can present dental restorations as well as unique morphology for each individual. Dental patterns are unique due to the variety of treatments as well as growth for each individual, which creates a benefit in using them for human identification Post-mortem radiographs can be taken at the scene or in a laboratory, the antemortem records are collected from dentists’ existing files and are used for comparison with the radiographs taken from the deceased unknown individual. It is important that dentists keep all radiographs stored properly since the original dental records will be used during this comparison. The antemortem and post-mortem radiographs will both be analyzed and transcribed onto Victim Identification forms and loaded into a computer database in order to compare many different antemortem records to the post-mortem in order to obtain a match. Radiograph comparison is often a method used in mass fatalities for example natural disasters but It can be used in any case.
=== DNA extraction === Teeth contain a great source of DNA since they are very chemically and physically resistant to extreme conditions. This method is especially useful in cases where other DNA sources are not accessible, for example in burned victims. Teeth can be used to create a DNA profile in order to identify unknown deceased individuals. Dentin and enamel provide a resistant and protective surface that houses the dental pulp which is located under the enamel and dentin layers in the center of the tooth, which contains the nerves and blood supply as well. Within the pulp is where genomic and mitochondrial DNA can be extracted. The teeth should not be completely destroyed using DNA analysis alone, it should be compared with other techniques as well before damaging techniques are used.
=== Smile photographs comparison === In cases where the body is in an advanced stage of decomposition, such as in cases of skeletal remains and charring, and considering the difficulties or impossibility of using fingerprint analysis and the high cost of DNA testing, forensic dentistry can play an important role in identification. The most common means used for ante-mortem comparison are X-rays, dental models, and dental records. However, there are cases where the presumed victim never visited a dentist or the family cannot obtain the aforementioned sources, complicating the odontolegal identification of the victim. Another source of comparison can be photographs of the presumed victim's smile (ante-mortem) compared to photographs of the deceased person's smile (post-mortem), which can highlight the dental characteristics present and, if consistent, confirm the victim's identification. However, it is important to pay attention to details that are important in the process, such as the techniques that will be used for the comparison. Two main techniques are generally employed (both of which require the forensic dentist to take photographs of the deceased person's smile, which can then be compared to the ante-mortem photographs):