Patients with systemic lupus erythematosus (SLE), a chronic inflammatory disease characterized by loss of T- and B-cell tolerance to autoantigens, are at increased risk for osteoporosis and fractures. Mice deficient in Fc gamma receptor IIb (FcγRIIB) exhibit spontaneous SLE and its restoration rescues the disease. To determine whether deleting FcγRIIB affects cortical bone mass and mechanical properties, we analyzed cortical bone phenotype of FcγRIIB knockouts at different ages. FACS analysis revealed that 6-month-old FcγRIIB mice had increased B220CD138 cells, markers of plasma cells, indicating active SLE disease. In contrast, 3-month-old FcγRIIB mice did not develop the active SLE disease. µCT analysis indicated that FcγRIIB deletion did not affect cortical bone in 3-month-old mutants. However, 6- and 10-month-old FcγRIIB males and females had osteopenic cortical bone and the severity of bone loss increased with disease duration. FcγRIIB deletion decreased cross-sectional area, cortical area, and marrow area in 6-month-old males. Cortical area and cortical thickness were decreased in 10-month-old FcγRIIB males. Lack of FcγRIIB decreased cortical thickness without affecting cortical area in females. However, deletion of a single FcγRIIB allele was insufficient to induce cortical bone loss. The bending strength was decreased in 6- and 10-month-old FcγRIIB-deficient males compared to WT controls. A microindentation analysis demonstrated significantly decreased hardness in both 10-month-old FcγRIIB males and females. Our data indicate that FcγRIIB contributes to the regulation of cortical bone homeostasis subsequent to SLE development and that deletion of FcγRIIB in mice leads to SLE-like disease associated with cortical bone loss and decreased bending strength and hardness.

Using a computer-aided, three-dimensional surgical simulation planning program, soft-tissue planning can help achieve adequate facial esthetics and patient satisfaction after orthognathic surgery. This study aimed to assess the Simplant O&O software’s soft tissue prediction accuracy. Fourteen skeletal type III patients who underwent orthognathic surgery by the same surgeons were included in this prospective study, and they were separated into two groups: the one-jaw (n = 5) and two-jaw (n = 9) groups. The software was used to analyze the preoperative (T0) and 4-month postoperative computed tomography data (T1), as well as intraoral scans. Data from cone-beam computed tomography and stereolithography from a scanned dental cast were used to reconstruct a composite skull model. Based on the presurgical CT data, the program generated a predicted soft tissue image (TP), which was then superimposed on the T1. The distances between seven T1 and TP landmarks were measured and evaluated using a one-sample t-test. In the one-jaw group, the mean error for all linear measurements was 1.73 ± 1.14 mm, whereas the mean error of the two-jaw group was 1.03 ± 0.83 mm, and both measurements were within clinically acceptable limits. Pronasele had the best correlation (mean error of 0.63 ± 0.45 mm) while soft tissue pogonion and soft tissue point B had the worst correlations (mean error of 2.87 ± 2.22 mm and 1.31 ± 0.98 mm, respectively). Even though there were some limitations, it was possible to conclude that the ability to accurately predict soft tissue changes using Simplant O&O for skeletal type III patients makes it adequate for use in clinical practice.