1. Graduate Student, Department of Prosthodontics, Graduate School, Chonnam National University, Gwangju, Korea.
2. Professor, Department of Prosthodontics, Graduate School, Chonnam National University, Gwangju, Korea.
3. Assistant professor, Department of Prosthodontics, Graduate School, Chonnam National University, Gwangju, Korea.
4. Part-time instructor, Department of Prosthodontics, Graduate School, Chonnam National University, Gwangju, Korea.