The aims of this study were first to investigate, by means of a mail questionnaire, variables from three domains: (i) socio-economic attributes; (ii) general and oral health; and (iii) dental attitudes and behaviours in a large sample of 50- and 60-year-old subjects, and second to compare subjects with or without reported temporomandibular joint (TMJ) pain with respect to these variables. In 2002, a questionnaire was mailed to all 50- and 60-year-old subjects in two Swedish counties, Orebro and Ostergötland (n = 17,138; n50 = 8878; n60 = 8260). Individuals not responding within 2 weeks were given a reminder. If still not answering, a new questionnaire was sent. The final response rate was 72.8% (n = 12,468). The reported responses to questions regarding 'pain in the TMJ region' and 'difficulty to open the mouth wide' were dichotomized into two groups: (i) no temporomandibular disorders (TMD) symptoms; and (ii) some, rather great or severe TMD symptoms. Striking differences in demographic, occupational, general and oral health conditions were found between the groups with and without TMD symptoms. The strongest risk indicator for both pain and dysfunction was reported bruxism. Women, younger subjects (50 years old) and blue-collar workers were significantly more prevalent in the TMD symptom groups. Variables related to impaired general and oral health were more common in the groups with reported TMD problems, whereas satisfaction with received dental care and with teeth was lower. Individuals with reported TMD symptoms differed significantly from those without TMD symptoms in socio-economic attributes, general and oral health symptoms, dental conditions and satisfaction with their teeth.

In 1992 a questionnaire was sent to 50-year-olds in two Swedish counties. These self-report data were compared with clinical observations with regard to number of teeth, removable dentures, caries, and periodontitis. Complete information from both data sources was obtained for 1041 persons. The relevant questionnaire item explained 71% of the missing tooth variance. An agreement of 0.91 (Cohen's kappa) was obtained for removable dentures. A question about problems in opening the mouth differentiated clearly with regard to measured mouth opening ability. Toothache and tooth sensitivity were reported with 95% probability when having 22 decayed teeth and with 46% when there were no decayed teeth (58% correctly predicted). Two teeth with pockets > or = 6 mm gave 5% probability and 22 such teeth gave 39% probability of reporting migration of front teeth. The main conclusion from this study is that there is good correspondence between subjective self-reports and clinical findings, especially for those conditions that are relatively easy for the patient to observe, such as the number of teeth and the presence of dentures. Thus questionnaire data can be used for information and screening about some well-defined oral conditions.