Chapter-2---Human-Osteology-and-Odontology_2014_Forensic-Anthropology

2.1 Principles of Human Osteology and Odontology

Forensic anthropology relies heavily on human osteology (study of bones) and odontology (study of teeth).
The skeleton is a mineralized connective tissue framework supporting muscles, tendons, and ligaments, while protecting vital organs (e.g., brain, heart).
Functions of bones:
- Support and structure for the body.
- Facilitating movement through a system of levers operated by muscles.
- Protection of vital organs.
- Blood cell production and mineral storage.
Teeth play a critical role in mastication (chewing) and articulation for speech.
A forensic anthropologist must recognize both complete bones and fragmentary remains, understanding normal bone biology and variants to differentiate between individuals and groups.

Composition of bone:
- Organic component: Mainly collagen, giving bones flexibility.
- Inorganic component: Hydroxyapatite (Ca10(PO4)6(OH)2) provides strength and rigidity.
Bone cells:
- Osteoblasts: Forming cells that synthesize and deposit bone.
- Osteoclasts: Resorptive cells that remove bone tissue.
- Osteocytes: Mature bone cells that maintain bone tissue.
Microstructure: Bone is organized into Haversian systems (osteons) that house blood and nerve supplies essential for nourishment.
- **Components of osteon: **
  - Haversian canal (central canal for blood/nerves).
  - Lamellae (concentric rings).
  - Volkmann's canals (link vessels).
  - Lacunae (contain osteocytes).
  - Canaliculi (channels connecting osteocytes).
Bone growth:
- Occurs via osteogenesis, which is intramembranous or endochondral ossification.
- Bone shapes modulate through modeling (growth) and remodeling (replacing old bone) influenced by mechanical stress.

Osteogenesis: Bone matrix is deposited on existing surfaces or precursors.
Types of ossification:
- Intramembranous: Occurs in cranial bones.
- Endochondral: Occurs in most other bones by ossifying cartilage.
Cartilage models develop into mature bones through organized centers of ossification.
Factors affecting growth: Age can be determined through ossification centers appearing at predictable times.

The adult human skeleton contains 206 bones divided into:
- Cranial skeleton (skull bones): protected brain and supports face.
- Postcranial skeleton:
  - Axial skeleton: bones near the body’s midline (skull, thorax).
  - Appendicular skeleton: bones of limbs.
Directional terms: used in anatomy to describe positions relative to standard anatomical positions (standing, facing forward).

Comprises the teeth of the cranium and mandible, developing through odontogenesis in the jaws.
Two types of dentition:
- Deciduous dentition: 20 baby teeth that are eventually replaced.
- Permanent dentition: 32 adult teeth categorized as incisors, canines, premolars, and molars. The dental formula is 2123 for permanent teeth.
Structure of teeth:
- Crown: Visible portion above the gumline, covered with enamel.
- Root: Anchors teeth in alveoli below gumline.
Specific functions related to tooth types:
- Incisors: Cutting.
- Canines: Grabbing.
- Premolars: Transitional function.
- Molars: Grinding.
Dental formula depicts arrangement and number of tooth types.

Knowledge in osteology and odontology is crucial for forensic assessment.
Understanding bone composition and structure leads to insights in forensic anthropology.
Adult skeletons—approximately 206 bones—serve vital functions & development indicators.
Teeth consist of dentin, enamel, and cementum, erupting in sequential sets affecting growth and identification.