Abstract:

Objective:The purpose of this study was to compare the morphological character between immortalized mandibular condylar chondrocyte (IMCC) and primarily cultured mandibular condylar chondrocyte (MCC).Methods:The phase contrast microscope, photomicroscope and transmission electron microscope were used to observe the morphological character of IMCC and MCC. The highresolution pathological image and word report system-1000 (HPIAS-1000) was used to compare the size of IMCC and MCC. Results:The phase contrast micrography showed thatMCCs in primary culture underwent distinct morphological changes with re- spect to shape, size, and density of the cells. The majority of MCCs were in polygonal shape earlier in culture, while more fusiform and spindle-shaped cellswere found after 4-5 passages. While IMCCswere polygonal-shaped, similar toMCCs. Subcul- ture, freezing and recovering had no effect on cellular shape of IMCC. Transmission electron microscopy indicated thatMCC had chondrocyte-like phenotype, while IMCC looked like prechondroblast or immature chondrocyte. Some of IMCCs had irregular nu- cleus, and the proportion of nucleus/cytoplasm changed. By analysis of HPIAS-1000, the diameter and area of IMCCwere obvi- ous smaller than those of MCC (P<0.01).Conclusion:IMCC retain the main morphological character of MCC, and also keep a stable phenotype, which belong to immature chondrocytes, similar to cells in the proliferative zone.

Key words: condyle, chondrocytes, immortalization, ultrastructure, morphology