Overview and definition
A bone graft is a post-treatment finding, not a pathologic lesion: it is biomaterial deliberately placed to replace or augment deficient alveolar or facial bone and to provide a scaffold for new bone formation and remodeling.[1][2] In oral and maxillofacial practice, grafts are classified by origin as autografts (patient's own bone, the osteogenic gold standard), allografts (processed human donor bone, e.g., FDBA and DFDBA), xenografts (animal-derived), and alloplastic/synthetic materials such as hydroxyapatite and β-tricalcium phosphate.[1][2][3] They are supplied as particulate or block forms.[3] Common indications include alveolar ridge preservation and augmentation before implant placement, sinus floor elevation, periodontal intrabony defects, and secondary alveolar bone grafting in cleft lip and palate.[4][5] Recognizing a graft as an expected post-surgical state—rather than disease—avoids misinterpretation as a mass or sequestrum.[6]
Radiographic findings
Recognition. On panoramic, periapical, or occlusal films, a recent graft appears as a radiopaque region superimposed on or adjacent to native bone, often with discernible borders between graft and host in the early phase.[7] Mineralized particulate allograft, xenograft and many synthetics appear as granular medium-to-high opacity filling the defect, whereas block autograft resembles a discrete osseous fragment that on CT matches adjacent cortical bone.[6] Demineralized allograft is initially radiolucent, and xenograft granules may remain distinguishable for years.
Location. Appearance follows the indication: crestal/ridge augmentation sites, the maxillary sinus floor after elevation, and the alveolar cleft in CLP patients.[7][8][9] Maxillary grafts (e.g., sinus lift) are evaluated against sinus anatomy and mucosal thickening, which can blur density contrast; mandibular onlay/ridge grafts are assessed against the native cortex.[9][10]
Normal evolution and mimics. With incorporation, radiodensity increases and a trabecular pattern develops, and the graft–host interface becomes progressively indistinct—an expected maturation finding, not pathology.[7] Key discriminators: 2D radiographs systematically overestimate bone fill and cannot capture buccopalatal volume, so apparent "success" may mask resorption; CBCT/CT provides accurate volumetric assessment.[9][11][12] Mimics to avoid misreading include residual/recurrent disease versus graft material, and graft particles versus sequestra.[6]
Management and prognosis
Interpretation should correlate imaging with the surgical history and timeline, since density and interface change physiologically during incorporation.[7] Graft resorption is expected to some degree and is the principal determinant of outcome, best quantified with 3D imaging when precision matters.[8][9] Red flags warranting clinical correlation and referral include graft or membrane exposure (the most common complication), postoperative infection, persistent pain, hemorrhage, neurosensory disturbance, or a discrete lucency/sequestrum suggesting failure.[13] Impaired healing is more likely in smokers and in poorly controlled diabetes.[13] Routine postoperative review assesses incorporation before implant placement; suspected failure or inadequate volume may require revision grafting.[11]