With the aid of questionnaires symptoms of mandibular dysfunction and some general and oral conditions were studied in a group of previous patients and in a randomly selected population sample. From the two materials answers were obtained from 82 persons (81 %) and 1.106 (91 %) respectively. The results confirmed that women are heavily overrepresented in patient materials. This differs from the fairly equal sex distribution found in population studies of mandibular dysfunction. The most frequent symptoms of mandibular dysfunction were TMJ-sounds which appeared in 39 and 79 % and pain on opening the mouth which appeared in 12 and 42 % of the population and patient samples respectively. All symptoms of mandibular dysfunction, headache, clenching of the teeth and unilateral chewing appeared significantly more often in the previous patients, but the number of natural teeth did not differ in the two samples. The general state of health was poorer and general joint—muscle symptoms were more common in the previous patients as well as in those of the population sample with symptoms of mandibular dysfunction. This finding suggests that functional disturbances of the masticatory system often may be related to impaired general health.