Epiphyseal Fusion
Definition
The obliteration of the cartilaginous growth plate and bony union of the epiphysis with the diaphysis. Fusion sequence and timing form the basis of sub-adult skeletal age estimation. Sex differences (females 1-2 years earlier) and population differences (South Asian populations 1-2 years later on some elements) are documented.
- Age range
- Adolescence through mid-twenties
- Sex difference
- Females complete fusion 1-2 years earlier than males
- Population variation
- South Asian populations show 1-2 year delays on some skeletal elements compared to other groups
Common questions
What is epiphyseal fusion?+
Epiphyseal fusion is when the growth plate cartilage between the epiphysis (end cap) and diaphysis (shaft) of a long bone hardens into bone, permanently joining the two pieces. This process stops the bone from growing any longer.
When does epiphyseal fusion happen?+
Fusion occurs across a wide range of skeletal elements through adolescence and into the mid-twenties. The timing varies by bone and is predictable enough to estimate age. Females typically fuse 1-2 years earlier than males.
Why does epiphyseal fusion matter in forensic investigations?+
In skeleton-based age estimation, the pattern of which bones have fused and which have not gives a reliable age range for young adults and adolescents. Unfused epiphyses signal sub-adult age. Forensic anthropologists use the sequence and timing of fusion as a primary tool to narrow a person's age.
Related terms
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- The reference system for developmental skeletal age estimation published by Louise Scheuer and Sue Black in 'Developmental Juvenile Osteology' (Academic Press, 2000)....
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- Appendicular Skeleton
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- Axial Skeleton
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- Commingled Remains
- Skeletal material from more than one individual mixed together, as commonly recovered from mass graves, transportation disasters, or fire scenes. Sorting commingled...
- Demirjian Stages
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- The process by which bone replaces a cartilage precursor. All long bones, the vertebrae, the ribs, and the cranial base form by...
- Forensic Anthropology
- The laboratory and scene-side discipline concerned with the analysis of skeletal and decomposed remains to establish biological profile, manner of death, trauma,...
Explained in these topics
- DVI from the Osteology Angle: MNI, MNE and the Commingled-Remains ProblemThe process by which the cartilaginous growth plate between the epiphysis and diaphysis ossifies and the two portions fuse. The presence of unfused epiphyses i...
- Skeletal Remains: Species, Sex, Age, Stature and IdentificationUnion of the epiphysis with the diaphysis at a growing long bone, sealing the epiphyseal plate; the timing of fusion at named joints is the backbone of age est...
- Sub-Adult Age from Dental Eruption and Epiphyseal FusionThe replacement of growth plate cartilage between the epiphysis and diaphysis by bone, ending longitudinal growth. Fusion timing is the basis of skeletal age e...
- The Human Skeleton: Axial, Appendicular and the Ossification TimelineThe obliteration of the cartilaginous growth plate and bony union of the epiphysis with the diaphysis. Fusion sequence and timing form the basis of sub-adult s...