Bone Remodeling in the Human Otic Capsule: Some Morphological Findings

Abstract

Morphological aspects of normal bone remodeling were studied in 20 undecalcified human temporal bones of which 8 specimens contained secondary bone labeled with tetracycline during adult life. The results of microradiography, UV-microscopy and histochemical staining indicate that interglobular spaces and osseous globules of endochondral otic capsular bone are primary trabeculae formed exclusively during fetal endochondral ossification. This primary spongiosa while being subject to discrete osteonal remodeling could not be identified as a source of “osteocytic” remodeling. The lifelong persistence of capsular primary spongiosa is consistent with the unique spatial organization of perilabyrinthine bone tissue dynamics. Residual uncalcified cartilage was present only at the fissula ante fenestram and fossula post fenestram where newly formed osteonal bone was frequently found. The results suggest that capsular bone remodeling is exclusively quantum based.

Key Words:

• bone remodeling
• undecalcified processing
• microradiography
• fluorescent dyes
• temporal bone
• otic capsule
• fissula ante fenestram
• fossula post fenestram
• globuli ossei
• interglobular spaces