Dentinal Tubules
Definition
Microscopic channels running radially through dentine from the pulp cavity to the outer surface. They house odontoblast cell processes that can carry residual DNA. The tubule network creates a large surface area of protected biological material within the tooth.
- Structure
- Microscopic radial channels extending from the pulp cavity to the tooth surface, housing odontoblast cell processes.
- Forensic uses
- DNA recovery from degraded remains and species identification of ivory and other animal materials.
- Detection method
- Scanning electron microscopy reveals tubule arrangement, diameter, and density for comparative analysis.
Common questions
Why do forensic examiners care about dentinal tubules?+
Dentinal tubules house odontoblast cell processes that preserve DNA inside the tooth structure. This protected location makes teeth valuable sources of biological material for DNA extraction, especially when other remains are degraded or burned. The tubule network creates a large sheltered surface area that guards genetic material from environmental damage.
How do dentinal tubules help identify ivory species?+
Under scanning electron microscopy, the arrangement, diameter, and density of tubules differ among species. This microscopic signature works alongside other features like Schreger lines to distinguish elephant ivory from mammoth, walrus, or hippopotamus ivory, helping investigators track illegal wildlife trafficking.
What makes dentinal tubules different from other tooth features?+
Unlike visible tooth wear patterns or color, tubules are microscopic channels that run from the pulp cavity radially outward to the tooth surface. Their consistent structure and protected biological content make them reliable markers for both genetic analysis and comparative species identification.
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...
- Cryogenic Grinding
- The technique of freezing a tooth sample to cryogenic temperatures (liquid nitrogen, approximately -196°C) before mechanical pulverisation. Freezing prevents frictional heat generation...
- Mammoth Ivory Legality Gap
- Because Mammuthus primigenius is extinct and therefore not within CITES scope, its ivory is not internationally regulated. This legal gap is exploited...
- Mitochondrial DNA (mtDNA)
- DNA located in mitochondria rather than the cell nucleus. Present in hundreds to thousands of copies per cell, making it recoverable from...
- Pulp Cavity
- The hollow channel inside a tusk or tooth that in life contains blood vessels and nerves. In elephant tusks the pulp cavity...
- Pulp Extraction
- Accessing the soft tissue of the root canal (pulp) directly by cutting the tooth at the cementoenamel junction and removing the contents...
- Rhinoceros Horn Keratin Tubules
- Tightly packed melanin-pigmented keratin fibres, 50-80 micrometres in diameter, visible in a rhino horn cross-section under SEM. Distinguished from the keratinous sheath...
- Schreger Angle
- The acute angle formed at the intersection of two sets of dentinal tubule lines visible in the cross-section of a tusk. Values...
- Schreger Lines
- Crossing arc patterns in elephant and mammoth tusk cross-sections formed by the angles at which dentinal tubule bundles intersect. The acute angle...
- Short Tandem Repeat (STR) Profiling
- The amplification and typing of microsatellite loci where short DNA sequences are repeated a variable number of times. When applied to canine...
Explained in these topics
- Dental DNA, Tooth Sampling and Molecular IdentificationMicroscopic channels running radially through dentine from the pulp cavity to the outer surface. They house odontoblast cell processes that can carry residual...
- Ivory, Horn, and Tusk ExaminationMicroscopic channels running through ivory from the pulp cavity outward, carrying odontoblast processes in life. Their arrangement, diameter, and density under...