Generalized joint laxity and its relation with oral habits and temporomandibular disorders in adolescent girls

A group of 248 girls, aged 15-16 years, were randomly selected and examined both clinically and by questionnaire with regard to the signs and symptoms of temporomandibular disorders (TMD), generalized joint laxity (GJL), rang e of mandibular opening, temporomandibular joint (TMJ) hypermobility and pr esence of oral parafunctions. The prevalence of GJL was 43% and that of TMJ hypermobility (TMJH) was 27.3%. A significant, albeit weak, correlation wa s found between the two. In the presence of joint click, both active and pa ssive opening were significantly larger. When either muscle or joint sensit ivity to palpation was present, the difference between the active and passi ve range of mouth opening increased significantly. The presence of reported clicks was negatively associated with GJL. This association was not valid in the presence of parafunction. Some of the signs and symptoms of TMD affe cted the range of mouth opening. In the presence of joint clicks, the mean active and passive mandibular opening were significantly larger. In the pre sence of joint and muscle sensitivity to palpation, the difference between passive and active mouth opening was larger. This was possibly because of t he effect of pain on the full active range of opening, which was invalid in the registration of the passive mandibular opening. GJL, when present, did not seem to jeopardize the health of the stomatognathic system as expresse d in the signs and symptoms of TMD. There was a negative association betwee n GJL and the presence of reported joint clicks and catch. When a parafunct ion was present in addition to GJL, this association was invalid but not re versed, as has been previously reported.