HISTORICALLY, teeth have been used for identification in forensic science investigations. It is among the sturdiest parts of the human body and they are often the best-preserved part of human remains. There is no registered dental database of human teeth made readily available for identification purposes unlike the national fingerprint identification data systems. So police and forensic investigators use dental records to identify human remains found without any identification papers. There are several different ways of using teeth to identify a person; the DNA from the pulp chamber can be extracted and used to cross match and identify a victim. People can also be identified by their bite mark, which is the pattern their teeth make when they come together or occlude. Criminals have been identified from the bite mark they may have left on a victim or the bite marks that the victims have left on their body during a struggle. Another option is simple dental records. Tooth enamel (the outer layer of teeth) is harder than any other substance in the human body, which is why teeth remain long after all other parts have decayed. Victims of fires are often identified by their teeth which can withstand temperatures of more than 2,000 degrees Fahrenheit (1,093 degrees Celsius). Teeth that have been through especially intense heat are very fragile and may shrink but they can be preserved with lacquer and used for identification as long as they are handled very carefully. Dental implants, such as a partial or gold crown, will be distorted by fire but can still aid in identification. Every individual has a unique dental imprint and identification by dental records is useful to identify crime victims or victims of large scale natural disasters.