Evaluation of jawbone calcification in osteopetrotic (op/op) mice using computed tomography

The study was conducted to evaluate the degree of calcification in the jawbones of 3 pairs of 4-week-old male op/op mice and littermates using computed tomography (CT) numbers. The mean CT numbers for op/op mice (n = 3) were 251.3 HU (range, 226 to 278) in the maxillary bone and 353.7 HU (range, 320 to 398) in the mandibular bone. The mean CT numbers for littermates were 336.7 HU (range, 324 to 350) and 596.6 HU (range, 580 to 604), respectively. The CT numbers of littermates were higher than in op/op mice for both maxillary and mandibular bones. These results indicated that the degree of bony calcification in littermates was higher than that in 4-week-old op/op mice in both the maxillary and mandibular bones. CT is able to demonstrate the degree of bony calcification in the jawbones of op/op mice using CT numbers, and it is suggested that CT is an extremely effective tool for examining the conditions of bone in vivo. This study also shows that op/op mice are useful for investigation of bone calcification or maturation.