Histological evaluation of condylar hyperplasia model of rabbit following distraction osteogenesis of the condylar neck

Using orthodontic elastic traction during the active period of distraction osteogenesis to increase the effective vertical extension of hemifacial microsomia patients: A multi-center randomized clinical trial

In this study, the aim was to assess whether using elastic traction during the active period of distraction osteogenesis could effectively increase the vertical extension. Patients with Pruzansky-Kaban Type II mandibular deformity were recruited and randomly assigned into Elastic traction + Distraction Osteogenesis group or Distraction Osteogenesis group, respectively. During the active period, the experimental group received orthodontic elastic traction 3 days after distraction osteogenesis implantation, while the control group received no treatment. All the participants underwent computed tomography (CT) examination before surgery, at the end of the active period, 6 months and 2 years after distraction osteogenesis tractor implantation. The primary outcome was the effective vertical extension rate of the mandible from the baseline to the end of the active period after operations, and there were 7 secondary outcomes used. 70 patients were included. The effective vertical extension rates were 85.021% ± 7.432% (mean ± SD) and 68.811% ± 9.510% (mean ± SD) in the experimental and control groups, respectively (P = 0.001). The average distances between the lower middle incisor point to the sagittal plane at the end of the active period were 2.485 ± 1.411 mm and 3.938 ± 2.293 mm in the experimental and control groups, respectively (P = 0.026). At the end of the active period of distraction osteogenesis, the average values of the mandibular occlusal plane canting were -4.887 ± 3.126 mm and -0.177 ± 4.029 mm in the experimental and control groups, respectively (P = 0.026). Elastic traction-assisted distraction osteogenesis could improve traction efficiency and facial symmetry.

Cross-talk between synovial fibroblasts and chondrocytes in condylar hyperplasia: an in vitro pilot study

OBJECTIVE

Increasing evidence indicates an interaction between the synovium and the cartilage in the temporomandibular joint (TMJ) and other joints. We recently demonstrated that the expression of proangiogenic factors was enhanced and that of factors promoting matrix degradation was decreased in synovial fibroblasts in condylar hyperplasia (CH). The aim of this study was to explore whether CH chondrocytes can affect the expression of these factors of synovial fibroblasts in a co-culture system.

STUDY DESIGN

The expressions of vascular endothelial growth factor (VEGF), cluster of differentiation 34 (CD34), fibroblast growth factor 2 (FGF-2), and tissue inhibitor of metalloproteinase 1 (TIMP1) from CH condylar tissues were observed by using immunohistochemical methods. Synovial fibroblasts of control tissues were co-cultured with the chondrocytes of CH, and protein expressions of VEGF, FGF-2, thrombospondin 1 (TSP1), matrix metalloproteinase 3 (MMP3), and TIMP1 were examined by using Western blotting.

RESULTS

Positive staining for VEGF, CD34, FGF-2, and TIMP1 was found in the hypertrophic cartilage layer of CH condylar tissues. Protein expressions of VEGF, FGF-2, and TIMP1 were significantly increased in co-cultured synovial fibroblasts, but TSP1 and MMP3 expressions were decreased.

CONCLUSIONS

The angiogenic factors and matrix degradation-related factors in synovial fibroblasts co-cultured with CH chondrocytes showed the same trends as those in synovial fibroblasts from CH tissue, suggesting potential cross-talk between synovial fibroblasts and chondrocytes during CH progression.

Condylar and occlusal changes after high condylectomy and orthodontic treatment for condylar hyperplasia

Condylar hyperplasia (CH) of human temporomandibular joint (TMJ) often occurs unilaterally, and causes occlusal disturbance and facial asymmetry. The purpose of this study was to compare the effects of high condylectomy with and without postsurgical orthodontic treatment. Forty patients were diagnosed as having active CH and treated with high condylectomy. Patients in group A (n=24) took the postsurgical orthodontic therapy immediately after surgery, and those in group B (n=16) did not take orthodontic therapy. For both groups, the mandibular ramus height on the affected side was decreased significantly after surgery. Orthodontic treatment promoted maxillary alveolar remodeling significantly by depressing alveolar bone of the affected side and increasing alveolar bone of the nonaffected side. Better improvement for facial midline deviations was observed in group A than in group B. In both groups, the condylar remodeling was observed and manifested by the smoothening of condylar surface and returning of condyle to normal position in glenoid fossa. It was concluded that high condylectomy in the treatment of active CH of TMJ improved the functional occlusion and facial aesthetic. Postsurgical orthodontic therapy could more effectively enhance maxillary alveolar and condylar remodeling, and more rapidly and meticulously establish the stable occlusal and normal position of condyle than the spontaneous remodeling.