Benign fibro-osseous lesions of the jaw include a spectrum of developmental, reactive or neoplastic lesions characterized by replacement of normal bone with fibrous tissue that, over time, is infiltrated by osteoid or cementoid
Since the most external aspect of cementum is covered by a layer of cementoblasts over a zone of non-mineralized cementoid
, a surface that provides satisfactory conditions for osteoclast binding (RGD-peptides that are bound to calcium salt crystals on mineralized surfaces) is not present.
Damage that follows involves cementoblasts and cementoid
(paracement), covering cell cement which becomes vulnerable to the action of osteoclasts.
Less commonly, the woven bone may be deposited either in sclerotic, interconnected lamellae, cementoid
bodies, or in orderly and parallel spicules.
Of note, the basophilic cementoid bodies around the core of some of the bony trabeculae were surrounded by osteoblastic cells.
(10) COFs contain thin bony trabeculae, ovoid cementoid deposits, a storiform stroma (which sometimes includes giant cells), a blood-free area defining the specimen's borders, and dense collagen fibers mixed with a cellular stroma.
The other difference between these two variants is the presence of foci of calcifications of the collagenous materials in the WHO type which are described as cementoid
, osteoid, and dysplastic dentin by several authors.
The ossifying and cementifying lesions should not be differentiated as it is speculated that the fibro-osseous lesions might represent stages in the evolution of a single disease process, passing through the stages of fibrous dysplasia to ossifying fibroma to cementoid
(10) The mineralized portion may be osteoid, cementoid
, or dystrophic.
Irregular masses of osseous tissues (Figure 9,10) and number of tiny sphericular areas of darkly stained cementoid
tissue were also seen (Figure11).