Mandibular periostitis ossificans in immature large breed dogs: 5 cases (1999-2006).

This case series describes clinical, radiographic, and histopathological features of mandibular swellings in 5 immature, large breed dogs. The dogs originated from different regions of the United States. In each case, intraoral dental radiography of the jaw swelling revealed a two-layered (double) ventral mandibular cortex. Biopsy was performed in 4 of the 5 puppies, revealing periosteal new bone formation. Resolution of the mandibular swelling was spontaneous in the 4 dogs available for follow-up examination. The authors postulate that the clinical, radiographic, and histopathological presentation of mandibular swelling in these 5 dogs is a distinct pathological entity consistent with an inflammatory condition of the maturing human mandible known as periostitis ossificans.