Bone modeling dynamics in acute otitis media

Objective: A number of middle ear diseases are associated with pathologic b one modeling, either formative or resorptive, As such, the pathogenesis of a sclerotic mastoid has been controversial for decades. Experimental studie s on acute middle ear infection have shown varying degrees of both osteores orption and osteoneogenesis, This study presents data on the dynamics of bo ne modeling in a rat model of acute pneumococcal otitis media, studied long itudinally from day 1 through 6 months after inoculation, Results: Qualitat ive, as well as quantitative histopathology revealed initial osteoresorptio n, followed by increasing apposition of new bone in the middle ear cavity, initiated at the outer periosteum, Measured bone thickness in four anatomic ally distinct locations peaked 3 months after inoculation, followed by some degree of normalization. However, bone thickness was still massively incre ased 6 months after the acute incident. Except in perilymphatic spaces of t he otic capsule, resorptive and formative activity were found in all bone t issue structures surrounding the middle ear cavity, including the bony exte rnal auditory canal and the ossicles, Conclusion: These findings may suppor t the existence of a perilymphatic barrier of specialized bone and suggest that even a single episode of acute infection may alter properties of ossic ular chain conduction, The authors conclude that acute otitis media is acco mpanied by massive and progressing net osteoneogenesis, already evident at 3 days and peaking 3 months after inoculation, followed by some degree of n ormalization. This is conceivably in support of the environmental theory of mastoid pneumatization, claiming inflammatory disease as the cause of a sc lerotic mastoid.