Comparative evaluation of bone microstructure in alveolar cleft repair by cone beam CT: influence of different autologous donor sites and additional application of β-tricalcium phosphate

Objectives This study used cone beam computed tomography (CBCT) images to comparatively evaluate the three-dimensional microstructural features of reconstructed bone bridge based on the bone harvesting site and the presence/absence of artificial bone material, as well as the features of regenerated bone tissue after bone harvesting from mandibular symphysis in secondary alveolar bone grafting (SABG) for patients with cleft lip, with or without cleft palate. Materials and methods Thirty-one patients were divided into three groups in which SABG was performed by autologous bone harvesting from iliac crest (IC), mandibular symphysis (MS), or MS combined with β-TCP granules (MS+TCP). The microstructural trabecular bone parameters (TBPs) and bone structure indexes (SIs) were analyzed using datasets of CBCT images taken before and after SABG. Results TBPs showed differences between IC and MS groups ( P < 0.05), resulting in greater values of bone volume density ( P < 0.05) and inferior value of TBPf ( P = 0.070) in IC group compared with MS group. Using MS+TCP or filling β-TCP granules into donor site significantly improved reconstructed or regenerated BV/TV and Tb.Th ( P < 0.05) compared with group without β-TCP. Conclusions Microstructural characteristics of reconstructed bone bridge were dependent on the donor site of bone harvesting; using an absorbable bone conductive material improved bone quality and increased bone volume density. Clinical relevance Application of β-TCP granules as a partial alternative with autologous bone from mandibular symphysis could obtain comparable outcomes in the microstructure of bone bridge to SABG with autologous iliac crest.