Related Experiment Videos
Microfissure between the round window niche and posterior canal ampulla
Abstract:
The microfissure between the round window niche and the posterior canal ampulla was examined in fetal, child, and adult human temporal bones. The communication which was filled with mesenchymal tissue and blood vessels extending from the middle ear, was observed between the round window niche and the posterior canal ampulla in 10 to 15-week human fetuses. The mesenchymal tissue in the communication was replaced by cartilage with advancing age of the fetus. No communication was observed at birth. From newborn to 12 months of age, no microfissure was observed. After one year of age, the microfissure was first observed and the frequency of the observation increased with increasing age of the patient. After six years of age, the microfissure was observed bilaterally in 100% of cases studied. The microfissure has its origin from the communication between the round window niche and the posterior canal ampulla in fetal life, and is a normal developmental and anatomical structure, and not a pathological finding.
Insights
A fetal communication near the round window develops into a microfissure in human temporal bones. This anatomical finding is a normal developmental structure, not a pathological condition.
Area of Science:
- Otolaryngology
- Human Anatomy
- Developmental Biology
Background:
- The round window niche and posterior canal ampulla are critical structures in the middle ear.
- Understanding their developmental relationship is key to interpreting anatomical variations.
Purpose of the Study:
- To investigate the developmental origin and prevalence of a microfissure between the round window niche and posterior canal ampulla.
- To determine if this microfissure represents a normal anatomical variation or a pathological finding.
Main Methods:
- Examination of human temporal bones from fetal, child, and adult stages.
- Histological analysis to identify and characterize the microfissure and associated tissues.
Main Results:
- A communication filled with mesenchymal tissue and blood vessels was observed between 10-15 week fetuses.
- This communication evolved into cartilage and later disappeared by birth, reappearing as a microfissure after one year of age.
- The microfissure was present bilaterally in 100% of individuals over six years old.
Conclusions:
- The microfissure originates from a fetal communication between the round window niche and posterior canal ampulla.
- It is a normal developmental and anatomical structure, not indicative of pathology.