3D Cone Beam Computed Tomography Volumetric Outcomes of rhBMP-2/demineralized bone matrix vs Iliac Crest Bone Graft for Alveolar Cleft Reconstruction.

BACKGROUND: Recent studies indicate that recombinant human bone morphogenetic protein (rhBMP-2) in a demineralized bone matrix scaffold (MS) is a comparable alternative to iliac bone autograft in the setting of secondary alveolar cleft repair. Post-reconstruction occlusal radiographs demonstrate improved bone stock when rhBMP-2/MS is used, but lack the capacity to evaluate bone growth in three dimensions. This study uses cone beam computed tomography (CBCT) to provide the first clinical evaluation of volumetric and density comparisons between these two treatment modalities.

METHODS: A prospective study was conducted with 31 patients and 35 repairs of the alveolar cleft over a two-year period. Twenty-one repairs utilized rhBMP-2/MS while 14 repairs utilized iliac bone grafting. Postoperatively, occlusal radiographs were obtained at 3 months to evaluate bone fill; CBCT images were obtained at 6-9 months to compare volumetric and density data.

RESULTS: At 3 months, postoperative occlusal radiographs demonstrate that 67% of patients receiving rhBMP-2/MS had complete bone fill of the alveolus, vs 56% of patients in the autologous group. In contrast, CBCT data shows 31.6% (95% CI: 24.2- 38.5%) fill in the rhBMP-2/MS group compared with 32.5% (95% CI: 22.1-42.9%) in the autologous population. Density analysis demonstrated identical average values between the rhBMP-2/MS and iliac bone crest group (1.38g/cc).

CONCLUSIONS: These data demonstrate comparable bone regrowth and density values following secondary alveolar cleft repair using rhBMP-2/MS vs. autologous iliac bone graft. CBCT provides a more nuanced understanding of true bone regeneration within the alveolar cleft that may contribute to the information provided by occlusal radiographs alone.