Embryonic inhibition of colony-stimulating factor 1 receptor induces enlarged cartilaginous zone of the midpalatal suture in postnatal mice.

OBJECTIVES: The midpalatal suture acts as the growth centre of the maxilla. Colony-stimulating factor 1 receptor (CSF1R) is essential for osteoclastogenesis. Deletion of CSF1R, and its ligand, results in significant craniofacial phenotypes but has not been studied in detail in the midpalatal suture. MATERIALS AND METHODS: Pregnant ICR mice were treated with the CSF1R inhibitor PLX5622 at embryo Day 14.5 (E14.5) to E17.5. Pups at E18.5, postnatal Day 3 (P3) and P7 were collected for skeletal and histological staining. Osteoclasts were labelled using TRAP staining. PHH3 and TUNEL were employed to detect cell proliferation and apoptosis. Sox9, Ihh, and Col10a1 and Runx2, Col1a1, and DMP1 were used to detect chondrogenic differentiation and osteogenic differentiation, respectively. CD31, MMP9 and CTSK were utilized to assess vascular invasion and osteoclast secretion enzymes, respectively. RESULTS: Embryonic inhibition of CSF1R resulted in a depletion of TRAP-positive cells and an enlarged cartilage zone of the midpalatal suture of postnatal mice. Compared to those in the control group, Sox9, Ihh, Col10a1, Runx2 and Col1a1 were upregulated, whereas TUNEL and DMP1 were decreased in this zone. In the trabecular region, Col10a1 was upregulated, while TUNEL, Col1a1 and DMP1 were downregulated. Moreover, the expression of MMP9, CTSK and CD31 was decreased, and invasion into the cartilage zone was delayed. CONCLUSIONS: Embryonic inhibition of CSF1R led to an abnormally enlarged cartilaginous zone in the midpalatal suture, potentially due to delayed endochondral ossification caused by the depletion of osteoclasts. Additionally, we established a novel model of midpalatal suture dysplasia, offering prospects for future research.

Comparison of two preserved cartilage iliac crest cortical-cancellous bone blocks graft harvesting techniques in children: A prospective, double-blind, randomized clinical trial.

PURPOSE: To compare donor-site morbidity for alveolar bone grafting results following cartilage-preserving outer and inner cortico-cancellous iliac crest (OCIC and ICIC) bone block grafting in children. MATERIALS AND METHODS: Patients were randomly divided into two groups and prospectively reviewed. In the OCIC and ICIC groups, cortico-cancellous bone blocks were harvested at outer and inner iliac crest respectively. Patient characteristics and surgical parameters were compared; pain intensity and duration, lateral femoral cutaneous nerve (LFCN) injury, gait disturbance, scar and contour satisfaction were analysed postoperatively. RESULTS: Forty-nine consecutive patients (OCIC, 24; ICIC, 25) were included. There were no significant differences in patient characteristics or donor-site surgical parameters. The mean pain score on the first post-operative day was significantly lower in the OCIC group (3.75±1.70) than in the ICIC group (5.20±2.08) (p=0.012). The pain duration was similar in the two groups (median: 5 days). Temporary LFCN injury only occurred in 3 patients in the ICIC group. Postoperatively, the duck and circle gaits were observed in the OCIC and ICIC groups, respectively. There were no significant differences in the claudication duration, scar and contour satisfaction between the groups. CONCLUSION: OCIC bone graft harvesting is marginally advantageous in children due to less early postoperative donor-site pain and a lower risk of nerve damage.