1. Department of Preventive Dentistry, School of Dentistry, Kyungpook National University, Daegu, Korea.
2. Department of Physical Medicine and Rehabilitation, Yeungnam University College of Medicine, Daegu, Korea.
3. Department of Preventive Medicine and Public Health, Yeungnam University College of Medicine, Daegu, Korea.
4. Department of Medical Science, Graduate School, Yeungnam University, Daegu, Korea.
5. Department of Neurosurgery, Yeungnam University College of Medicine, Daegu, Korea.
6. Department of Dentistry, Yeungnam University College of Medicine, Daegu, Korea.