[Condylar morphological changes before and after orthodontic treatment for angle Class I malocclusion adult patients].

PURPOSE: To evaluate the condylar morphological changes in adult Angle Class I malocclusionpatients before and after orthodontic treatment using a cone-beam CT (CBCT). METHODS: Images of 25 adult Angle Class I patients (5 males, 20 females) who had no temporomandibular joint disorder symptom were involved in this study, and Mimics 10.01 software was used to reconstruct the three-dimensional condyle and measure the height of condyle, the area and bone density of the largest cross sectional plane and sagittal plane, and the volume and bone density of the whole and upper three-dimensional condyle before and after orthodontic treatment. Paired t test was used for comparison between pre- and post-treatment condylar metric analysis with SPSS 19.0 software package. RESULTS: After treatment, the area and bone density of the largest cross sectional plane and sagittal plane were reduced significantly(P<0.05). The volume and bone density of the whole three-dimensional condyle and bone density of the upper three-dimensional condyle were reduced significantly(P<0.05). CONCLUSIONS: Adaptive bone remodeling of the condyle may occur due to alternation of occlusion by orthodontic treatment in adult Angle Class I malocclusion patients.

[The expression of VEGF-C in the condylar cartilage after anterior disc displacement and its clinical significance].

PURPOSE: To investigate the expression and significance of vascular endothelial growth factor-C in the condylar cartilage after anterior disc displacement of temporomandibular joint. METHODS: Sixty healthy adult Japanese rabbits were used in this study. Forty-eight rabbits were subjected to surgical anterior disc displacement in the right TMJs, every 12 rabbits were sacrificed 1, 2, 4, 8 weeks post-operation, 12 rabbits without operation were used as normal control.The gene expression and distribution of VEGF-C in condylar cartilage were studied by gene chip, real-time quantitative PCR and SP immunohistochemical methods. Paired t test was used for analysis with SPSS19.0 software package. RESULTS: After anterior disc displacement, the expression of VEGF-C in the 2nd week reached to a minimum level, there was a significant difference (P<0.05), and increased in the 8th week. VEGF-C was expressed by cells of articular cartilage in the proliferative zone, hypertrophic zone and calcified cartilage zone. The expression in 1-week group was mainly found in the deep proliferative zone and hypertrophic zone, while the expression mainly found in the hypertrophic zone in 2-and 4-week group; calcified cartilage gradually enhanced, and there was significant difference (P<0.05) between 8-week group and control group. CONCLUSIONS: VEGF-C gene transcription and expression may be involved in the remodeling of the condylar cartilage after anterior disc displacement.