[Comparison of skeletal structure of temporomandibular joint through cone-beam CT between Angle ClassⅠ, Ⅱ, Ⅱ, Ⅲ malocclusion patients with permanent dentition].

Purpose: To compare characteristics of temporomandibular joint and related structures according to gender and Angle Ⅰ, Ⅱ, Ⅱ and Ⅲ class.

Methods: Cone-beam CT (CBCT) was performed in 123 patients with malocclusion, and three-dimensional reconstruction was performed with Mimics 19.0 software.

[Effect of cyclic tensile stress on expression of type Ⅱ collagen and Sox9 in rat cranial base synchondrosis].

Purpose: To establish an in vitro mechanical stimulation model of cranial base synchondrosis chondrocytes, and to study the effect of cyclic tensile stress on the main extracellular matrix of rat cranial base synchondrosis.

Methods: Cyclic tensile stress was imposed to the second passage of cranial base synchondrosis chondrocytes for 3, 6, 12 and 24 hours respectively by using a Flexcell Strain Unit-5000T(10% surface elongation, 1 Hz). After mechanical loading, the total RNA of the cells harvested from six-well BioFlex was extracted.