Joint mobility was assessed in each member of an epidemiological sample of 96 girls and 97 boys, 17 years old, and graded by means of the hypermobility score of Beighton et al. Twenty two per cent of the girls and 3% of the boys could perform five or more of the nine manoeuvres. The prevalence of symptoms and signs of internal derangement in the temporomandibular joint was higher in adolescents with hypermobility of joints (score 35/9). In subjects with a high mobility score oral parafunctions (overuse) correlated more strongly with several signs and symptoms of craniomandibular disorder than in those with a low score.

Abstract— Correlations between craniomandibular disorders (CMD) symptoms and an inherited factor (general joint hypermobility) were studied in 193 adolescents (96 girls and 97 boys). They answered a questionnaire concerning CMD symptoms, oral parafunctions, head and jaw trauma and symptoms from other joints. Joint mobility was assessed by determining the Beighton score (0‐9). Twenty‐eight percent of the girls and 21% of the boys could perform four or more of the maneuvres. Twenty‐two percent of the girls and 3% of the boys were extremely hypermobile (score ≥5). Eighty‐nine percent were aware of some oral parafunction and the prevalences of oral habits were about the same in the two groups. Girls reported significantly more dysfunction symptoms than boys. No indication was found that oral parafunctions generally produced CMD but a systemic factor (joint hypermobility) seemed to play an important role when the masticatory system was exposed to local forces as in oral parafunction. This may be one explanation for the predominance of females among CMD patients.

The aim of this study was to obtain information about the quantitative distribution of salivary mutans streptococci and the relation to dental caries in children with contrasting levels of natural water fluoride. A total of 698 schoolchildren aged 12 yr were selected from areas with high (1.2 ppm) or low (0.1 ppm) fluoride concentration in the drinking water. They were all examined for the presence and number of mutans streptococci in saliva by a specially prepared plastic strip, the "Strip mutans" method, cultivated in a selective broth. Data on the caries experience were obtained from the dental records and from bite-wing radiographs. Mutans streptococci were identified in 82% of all children with no difference between the two areas. The number of mutans streptococci was however significantly (p less than 0.05) lower among the children from the high fluoride area than those from the low fluoride area. Children with no detectable or low levels (0-10 CFU) of mutans streptococci had less caries experience than children with moderate or high levels (11- greater than 500 CFU) in both areas investigated.