294 Forensic dentistryall or part of a tooth exists. In those cases, aspartic acid racemization analysis
or^14 C analysis may be performed.
The same radiographic and visual procedures used for living individuals
can be used for the deceased. In addition to those methods, and with per-
mission from coroners or medical examiners, teeth can be removed for age
estimation studies. All of the methods that consider postformation changes in
teeth can be used. Tooth cementum annulation (TCA) analysis is becoming
relatively common for age estimation with other mammals. With proper con-
sideration of the limitations of the technique, there is no reason that it could
not be routinely used in human age estimation. Although work remains
to be performed to validate the determination of the ratios in amino acid
racemization, that method is a promising technique for improving dental age
estimation in all age groups. Both tooth cementum annulation and aspartic
acid racemization can be used, with associated limitations, for individuals of
any age. Radioactive^14 C analysis from tooth enamel is a new and promising
technique, potentially offering the most accurate and precise information on
estimated date of birth for those individuals born after 1943.
Using human teeth for age estimation is well established in past and
recent literature. Multiple studies have demonstrated varying accuracy, reli-
ability, and precision. Reproducible and reliable results are possible when
the appropriate techniques for a given situation are properly understood
and applied. Soomer et al. correctly stated in their 2003 paper that “forensic
odontologists should evaluate each age estimation case and, in addition to
their visual age assessment, choose one or more methods that would best
serve their particular case, keeping in mind that accuracy and precision are
the main requirements.”^14 Willems et al. in 2002 concluded that “an impor-
tant aspect in dental age estimation is that the investigator should apply a
number of different techniques available and perform repetitive measure-
ments and calculations in order to improve reproducibility and reliability of
the age estimation.”^173
Linear regression, confidence levels, and standard deviations relate to
means for the populations studied. Specific individuals within a population
may live at either end of the range or fall outside the normal limits. Error
exists in every system of age estimation. The limitations of current methods
and the paucity of population data available mean those methods are not
adequate to allow precise age estimation results for every case. Age estima-
tion reports must clearly convey that the data reported are based on mean
ages derived from the features studied for a specific population and should
include realistic ranges. Specific casework may require combining methods
to arrive at the most accurate conclusions.
When possible, more than one dental technique or a combination of
dental and skeletal or other techniques should be used. Since research into
age estimation is ongoing, forensic dentists performing age estimation must