Unbiased Stereologic Estimation of the Spatial Distribution of Paget’s Disease in the Human Temporal Bone

BACKGROUND: It has been suggested that Paget's disease of bone and otosclerosis may share a myxoviral etiology. However, the association between virus infection and pathologic bone remodeling is still controversial. The aim of this study was to estimate the spatial distribution of pagetic bone remodeling around the inner ear space and to compare it with that of otosclerosis in a contemporary context of temporal bone dynamics. MATERIALS AND METHODS: From the temporal bone collection of Massachusetts Eye and Ear Infirmary, 15 of 29 temporal bones with Paget's disease were selected to obtain an independent sample. All volume distributions were obtained along the normal axis of capsular bone remodeling activity by the use of vector-based stereology. RESULTS: Pagetic bone remodeling was distributed centrifugally around the inner ear space at the individual and the general level. This pattern is similar to the normal distribution of perilabyrinthine bone remodeling but entirely different from the spatial location of otosclerosis, which are focal and centripetally distributed around the inner ear space. CONCLUSION: In Paget's disease, the antiresorptive barrier around the inner ear space becomes gradually overruled as pagetic bone resorption invades the otic capsule from the outside. However, in otosclerosis, this barrier has somehow failed locally inside the otic capsule. Although virus infections potentially may trigger osteoclastic activity additional pathogenetic factors are needed to explain the organ-specific nature and spatial properties of otosclerosis.