Three-dimensional evaluation of condylar morphology after orthodontic treatment in adult patients with Class II malocclusion by cone-beam computed tomography.

BACKGROUND: The aim of this study was to evaluate the condylar morphological changes after orthodontic treatment in adult patients with Class II malocclusion using a Cone-beam computed tomography (CBCT). METHODS: Images of twenty-eight adult patients with Class II malocclusion who have no temporomandibular symptoms were involved in this study. To analyze the post-treatment changes in condylar morphology, mimics 17.0 software was used to measure several values and reconstruct the three-dimensional condyle, including height of the condyle, area and bone mineral density of the maximum axial and sagittal section, volume and bone mineral density of the three-dimensional condyle and condylar head before and after orthodontic treatment. Using SPSS 19.0 software package Paired t-test was applied for comparison of condylar morphology analysis between pre-treatment and post-treatment. RESULTS: Height of condylar head increase significant (P < .05). Bone mineral density showed a decrease in the maximum axial and sagittal section, three-dimensional condyle and condylar head (P < .01). Evaluation of volume revealed that volume of both condyle and condylar head decrease considerably (P < .05). No significant difference was detected in other values ((P > .05). CONCLUSION: Condylar volume decreased and height of condylar head have changed, so we speculated that adaptive bone remodeling of the condyle occurs.

[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.

[Research on condylar morphology in patients with prolonged unilateral posterior teeth loss with cone beam computed tomography].

OBJECTIVE: This study aimed at using cone beam computed tomography (CBCT) to study the influence ofprolonged unilateral posterior teeth loss on bilateral condylar morphology. METHODS: The CBCT images of 30 patients withprolonged unilateral posterior teeth loss and 30 healthy people as controls were corrected. Mimics 15.0 software was used tomeasure volume, area, distance, and bone density of condyle. The results were statistically analyzed. RESULTS: The volumeand bone density of condylar head and the entire condyle on missing teeth side were less than the contralateral side (P<0.05).The area and bone density of condylar transverse plane were greater than the contralateral side (P<0.05). CONCLUSION: After prolonged unilateral posterior teeth loss, adaptive reconstruction occurs in the bilateral condyles, and condyle of missing teethside is smaller than the contralateral side.