Histological analysis of rhbmp-2 alveolar bone graft in individuals with cleft lip and palate

This study histologically evaluated bone and soft tissues removed from the region of rhBMP-2grafted alveolar cleft in individuals with unilateral cleft lip with or withoutcleft palate (UCL+P), 6 months to 4 years after graft surgery.The experimental group consisted of 13 individuals with UCL+Pwith impacted canines in the rhBMP-2 (Infuse®) grafted alveolar region. The control group comprised six individuals with UCL+Pwith impacted canines in the noncleft side, near the ungrafted cleft or in the area grafted with autogenous iliac crest bone. At the time of surgical canine exposure, 6 to 46 months after secondary bone graft, biopsies of bone and soft tissues were obtained and submitted to histological analysis with hematoxylin and eosin.Microscopic sections of the experimental group showed fragments of viable bone tissue with normal osteocytes in lacunae, osteoblasts on the bone surface and medullary spaces filled by fibrous connective tissue and blood vessels. The bone tissue biopsies obtained 6 to 9 months after grafting showed more disorganized bone trabeculae, without lamellar formations and with greater osteocyte density per area, indicating lower degree of bone maturity. Biopsies taken 2 to 4 years after bone grafting were composed only of mature lamellar bone tissue containing incremental lines and osteocyte lacunae. Soft tissue sections revealed fragments of oral mucosa consisting of para-keratinized stratified squamous epithelium with underlying dense connective tissue.Fragments of bone and soft tissues removed from the rhBMP-2 grafted cleft area showed normal histological morphology, resembling the tissue characteristics of the control group.