Enamel
Definition
The outermost layer of the tooth crown, formed by ameloblasts before tooth eruption. Composed of approximately 96% hydroxyapatite mineral by weight. Acellular after eruption: no living cells remain within mature enamel, which means it cannot be used for nuclear DNA profiling but can be sampled for isotope analysis.
- Location
- Outermost layer of the tooth crown
- Formed by
- Ameloblasts, before tooth eruption
- Mineral content
- About 96% hydroxyapatite by weight
- Cellular status
- Acellular after eruption
Common questions
Why can enamel not be used for nuclear DNA profiling?+
Once a tooth erupts, enamel loses all living cells, so there is no nuclear DNA to recover from it. Forensic odontologists instead sample dentin or pulp tissue, which retain cells, for STR typing.
What can enamel still be used for in forensic identification?+
Its mineral structure locks in isotope ratios from childhood diet and geography, so enamel is sampled for stable isotope analysis to estimate a person's region of origin or approximate age at tooth formation.
Related terms
- Cementum
- A thin, bone-like mineralised tissue that covers the external surface of the tooth root. Deposited incrementally throughout life in alternating translucent and...
- Dentine
- The mineralised tissue forming the bulk of the tooth, surrounding the pulp chamber and root canal. Contains a network of dentinal tubules,...
- Cementum Annuli
- Incremental growth layers in cementum, deposited at a rate of approximately one pair of translucent and opaque bands per year throughout adult...
- Crown
- The visible portion of a tooth above the gum line, covered by enamel. In forensic charting, crown morphology, restorations, and wear patterns...
- Deciduous Dentition
- The first set of 20 teeth, also called primary or milk teeth, that erupt from approximately six months and are progressively replaced...
- Occlusion
- The way upper and lower teeth meet when the jaw closes. Occlusal wear patterns, class I/II/III relationships, and individual facets on specific...
- Odontoblast
- A specialised cell of neural crest origin that forms dentine. The cell body sits at the pulp-dentine junction while a long cellular...
- Stable Isotope Analysis
- A technique that measures the ratio of stable (non-radioactive) isotopes of elements such as strontium, oxygen, and carbon in a biological sample....
Explained in these topics
- Dental Anatomy: Morphology, Tissues and the ArchesThe outermost tissue of the crown, composed of approximately 96 percent hydroxyapatite. It is the hardest substance produced by the human body and the main rea...
- Dental Tissue and Its Forensic Applications