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Human temporal bone study on the postnatal ossification process of auditory ossicles
T Yokoyama1, Y Iino, K Kakizaki
1Department of Otolaryngology, Teikyo University School of Medicine, Tokyo, Japan.
The Laryngoscope
|June 16, 1999
Summary
Ossification of the malleus and incus is complete by 25 months of age in children. Congenital anomalies did not influence the timing of this crucial bone development process.
Area of Science:
- Otolaryngology
- Developmental Biology
- Anatomy
Background:
- The malleus and incus initially contain bone marrow in infancy.
- This bone marrow is gradually replaced by bone and vascular channels with age.
Purpose of the Study:
- To determine the age of complete ossification of the malleus and incus.
- To investigate factors influencing the ossification process in pediatric temporal bones.
Main Methods:
- Analysis of human temporal bone sections from 32 infants and children (1 day to 9 years).
- Computer-aided digital image processing to quantify bone marrow area in the malleus and incus.
- Correlation of ossification completion age with congenital anomalies and middle ear mesenchyme.
Main Results:
- Bone marrow was present in the malleus and incus up to 25 months of age.
- Ossification appeared to complete earlier in the malleus than the incus.
- No correlation found between ossification timing and congenital anomalies or residual mesenchyme.
Conclusions:
- Ossification of middle ear ossicles is a continuous process from fetal life through infancy.
- The clinical significance of residual postnatal bone marrow in ossicles is unknown but may serve a hematopoietic function.