Functional disorders of the temporomamdibular joint and masticatory system were investigated in 209 men and 110 women, ranging form 20 to 30 years old, with a method devised by Agerberg and Carlsson. The investigated persons were dental students of the School of Dentistry, Seoul National University and student nurses of the School of Medicine, Seoul National University. The obtained results were as follows : 1. Facial pain and headache were reported by 32%. 2. Pain on gaping was localized mainly to the temporomandibular area and was noted in 8%. 3. Chicking of the temporomandibular joints was reported by 26%, somewhat more often by males. 4. Clenching of the teeth was relatively common in men and biting of the lip was comman in women. 5. Prevalence of mandibular dysfunction was found in 53%.