Page 77 - Veritas

FEATURE ARTICLES

the teeth to show sexual dimorphism in the teeth have been widely used

in the past few years for sex determination. However, to date, the pres-
ence of sex chromatin or Barr bodies in the pulp of the teeth (according

to the method devised by Barr and Bertram) has been adopted as a more
reliable and accurate method for sex determination. Further, studies have

also been carried out to extract DNA from the pulp as well as dentine and
use it for sex determination through biochemical assays. Another interest-

ing fact is the presence of a unique protein Amelogenin or AMEL, a major
protein found in the enamel of teeth. The uniqueness of AMEL is that it

has a different pattern of nucleotide sequence in the enamels of males
and females. Two different AMEL genes, one located on chromosome X

and one on the Y chromosome are found in males. However, females have

two identical AMEL genes located on the X chromosome.

The determination of race by examination of the morphological features
of the teeth remains debatable. Unique features such as shovelling or

scooping of the upper incisor (most common among Mongoloids), chis-
el-shaped incisors (most common among African) can be used to deter-

mine the ethnicity of the individual. Dental restorations may indicate the
ethnicity of the individual. Sometimes methods of restorations used in

certain regions may be unique and may not be used at any other place.

At the same time, every tooth possesses a set of unique characteristics

called ‘tooth individual characteristics’, which form the basis of its unique
identification. Dental anomalies and variation such as microdontia (small-

er teeth than normal) and macrodontia (larger teeth than normal); dis-
turbances in the number of teeth such as anodontia (congenital absence

of teeth), polydontia or hyperdontia (having extra teeth); disturbances in
the eruption of teeth such as impacted teeth (failed to erupt and remain

buried in the alveolar bone) and ectopic eruption (when a tooth cannot

complete its eruption because it is blocked by an adjacent tooth or by a
misplaced orthodontic band--usually on a first molar tooth) defines the
individual character of teeth.

Such anomalies help a forensic odontologist to analyze the exhibit and

62 VERITAS