Biphasic Calcium Phosphate Microparticles Mixed With Autologous Blood: Application for the Reconstruction of a Large Mandibular Bone Defect in a Dog.

Large mandibular bone defects can be difficult to treat in dogs, with a high risk of mal or nonunion due to instability and risk of infection. This case report describes the use of autologous clotted blood mixed with biphasic calcium phosphate microparticles to fill a defect in a nonunion fracture and promote bone regeneration in a dog using a 2-stage surgical approach. This new method was designed and tried in a dog with a chronic, unstable mandibular fracture associated with a large sequestrum. Initial treatment involved debridement of the lesion, then the oral wound and oral vestibule were reconstructed in 2 layers. Four weeks later a second stage surgery allowed placement of a pre-contoured maxillofacial plate to bridge the defect, which was filled with a blood/biphasic calcium phosphate compound implant. Cone-beam computed tomography was used prior to the initial surgery for preoperative planning and 3-D printing of a mandibular template for plate contouring. CT was subsequently used to document the healing process, using a bone density measurement tool to assess bone regeneration. Radiographic evidence suggestive of osseointegration was observed within 6 months with effective filling of the defect and restoration of alveolar ridge continuity. A return to normal and atraumatic occlusion was considered excellent. Cone-beam computed tomography was found useful to document radiographic evidence of osseointegration, bone regrowth and remodeling. This case report is to serve as a proof-of-concept study and should be followed by a prospective evaluation.

The Use of Biphasic Calcium Phosphate Substitute (BCP) in Mandibular Defects in Dogs: Use of CBCT to Evaluate Bone Healing.

This study aimed to assess the use of cone beam computed tomography (CBCT) to follow-up bone healing of mandibular bone defects in dogs, filled with a combination of autologous blood and millimetric BCP granules. CBCT was performed ≥4 weeks postoperatively. CBCT gray-scale values were measured from multiplanar reconstructions of the defects and compared to that of normal contralateral mandibular bone and to pure BCP/blood composite time 0 (T0) value. Other parameters, determined by affecting grades according to specific criteria included: bone ridge margin restoration; biomaterial homogeneity; bone-biomaterial interface. Results: 8 dogs with 14 defects were included. Median age was 7.2 years (1-15 years). Follow-up CBCT was performed 1 to 7.5 months postoperatively (mean 3.3 months). Defect CBCT gray-scale values at follow-up were significantly greater than T0 (p < 0.05). Ratios of maximum and minimum densities of the defects to contralateral mandibular bone followed a linear correlation with time (p < 0.05). The bone ridge margin was adequately restored in all the defects and significantly correlated with time (p = 0.03). Biomaterial homogeneity was fair to good in 11 defects and significantly correlated with the bone ridge margin parameter (p = 0.05) and time (p = 0.006). There was no significant correlation with the bone-material interface. The latter was satisfactory in 12 defects and significantly correlated with time (p = 0.01) but not with the other parameters. The biomaterial was more homogeneous in smaller defects and with increasing time. CBCT allowed effective assessment of bone healing via the measurement of CBCT gray-scale values and assessment of multiple radiological variables.