Subjects: French adults over the 22, ranging up to 90 years of age.
Parameters:
(1) periodontosis (gingival regression): Associated with degeneration of the soft tissues surrounding the tooth.
(2) transparency of the dental root: This is caused by deposition of hydroxyapatite into the dentin tubuli and never appears before the age of 20.
(3) root height
Measurement of periodontosis:
(1) This is a smooth and yellowish area below the enamel. It is darker than the enamel but clearer than the rest of the root.
(2) The value is the maximum distance between the cementoenamel junction and the line of soft tissues attachment.
Measurement of transparency of dental root:
(1) This is performed on a powerful lightbox.
(2) Along the labial surface of the tooth (point where maximal) the distance from the apex of the root to the maximum height of transparency is measured.
Measurement of root height: The distance from the apex of the root to the cementoenamel junction along the labial surface.
periodontosis factor =
= (height of periodontosis in mm) * 100 / (root height in mm)
transparency factor =
= (height of transparency in mm) * 100 / (root height in mm)
age in years =
= (0.18 * (periodontosis factor)) + (0.42 * (transparency factor)) + 25.53
Performance:
• The measurements must be precise and the points measured well standardized.
• The mean error between the actual and estimated age was +/- 10 years for the working sample and +/- 8.4 years in a control sample.
Modifications of Prince and Ubelaker: These authors tested the method using the Terry collection at the Smithsonian's Museum of Natural History. They found that the mean error could be reduced by using equations specific for gender and race as follows:
age in years for black females =
= (1.63 * (root height in mm)) + (0.48 * (periodontosis factor)) + (0.48 * (transparency factor)) – 8.41
age in years for black males =
= (1.04 * (root height in mm)) + (0.31 * (periodontosis factor)) + (0.47 * (transparency factor)) + 1.70
age in years for white females =
= (1.10 * (root height in mm)) + (0.31 * (periodontosis factor)) + (0.39 * (transparency factor)) + 11.82
age in years for white males =
= (0.15 * (root height in mm)) + (0.29 * (periodontosis factor)) + (0.39 * (transparency factor)) + 23.17
