A Novel Imaging Technique for Analyzing Condylar Movement During Mastication in Patients With Jaw Deformities: Four-Dimensional Computed Tomography.

OBJECTIVE: This study aimed to reveal characteristic condylar movements in patients with jaw deformities. STUDY DESIGN: Thirty patients with jaw deformities before surgery were enrolled and instructed to chew a cookie during 4-dimensional computed tomography (4DCT). The distance between the most anterior and posterior positions of the bilateral condyles on 4DCT images was measured and compared among patients with different skeletal classes. Correlations between the condylar protrusion and cephalometric values were also determined. RESULTS: The distances of condylar protrusion during mastication were significantly greater in the skeletal class II group than in the skeletal class III group ( P =0.0002). Significant correlations were found between the distances of condylar protrusion during mastication and the sella-nasion-B point angle ( r =-0.442, P =0.015), A point-nasion-B point angle ( r =0.516, P =0.004), sella-nasion plane to ramus plane angle ( r =0.464, P =0.01), sella-nasion plane to occlusal plane angle ( r =0.367, P =0.047), and condylion-gonion length ( r =-0.366, P =0.048). CONCLUSION: Motion analysis with 4DCT images revealed that condylar movement in patients with retrognathism was larger than in patients with mandibular prognathism. Skeletal structure was therefore correlated with condylar movement during mastication.

Nonsurgical orthodontic treatment for a patient with Sotos syndrome.

Sotos syndrome is a genetic disorder characterized by overgrowth in childhood, specific facial manifestations, advanced bone age, and mental retardation. The purpose of this article is to describe the nonsurgical orthodontic treatment of a 10-year-old boy with a skeletal mandibular protrusion, unilateral posterior crossbite, and Sotos syndrome. After maxillary lateral expansion, the skeletal Class III relationship with an anterior crossbite improved because of mandibular clockwise rotation, whereas the facemask had a marginal effect. After growth at 16 years, he had a skeletal Class I relationship, and thus, conventional orthodontic treatment with preadjusted edgewise appliances was initiated. After 41 months of multibracket treatment, acceptable occlusion with a functional Class I relationship was obtained. One year postretention, few changes in occlusion and facial features were observed. Our results demonstrate that considering the maxillofacial vertical growth during the peripubertal period associated with Sotos syndrome, more attention should be paid to the early orthopedic treatment with the facemask and/or chincap.

Osteoclasts enhance myeloma cell growth and survival via cell-cell contact: a vicious cycle between bone destruction and myeloma expansion.

Multiple myeloma (MM) expands in the bone marrow and causes devastating bone destruction by enhancing osteoclastic bone resorption in its vicinity, suggesting a close interaction between MM cells and osteoclasts (OCs). Here, we show that peripheral blood mononuclear cell-derived OCs enhanced growth and survival of primary MM cells as well as MM cell lines more potently than stromal cells, and that OCs protected MM cells from apoptosis induced by serum depletion or doxorubicin. OCs produced osteopontin (OPN) and interleukin 6 (IL-6), and adhesion of MM cells to OCs increased IL-6 production from OCs. In addition, IL-6 and OPN in combination enhanced MM cell growth and survival. However, the effects of OCs on MM cell growth and survival were only partially suppressed by a simultaneous addition of anti-IL-6 and anti-OPN antibodies and were completely abrogated by inhibition of cellular contact between MM cells and OCs. These results demonstrate that OCs enhance MM cell growth and survival through a cell-cell contact-mediated mechanism that is partially dependent on IL-6 and OPN. It is suggested that interactions of MM cells with OCs augment MM growth and survival and, thereby, form a vicious cycle, leading to extensive bone destruction and MM cell expansion.