[Functional state of the masticatory system in healthy individuals (control group) and in patients with temporomandibular joint disorders].

The functional status of the masticatory system was investigated in a sample of 68 self-defined controls without any treatment need and 82 craniomandibular disorder patients. Among the parameters investigated were measures of mandibular mobility, the presence of joint noises and palpation tenderness of 17 muscle and 3 TMJ sites. These data allowed for calculation of Fricton's Craniomandibular Index (CMI) and Helkimo's Clinical Dysfunction Index (Di). Several socalled signs of dysfunction were found in the normal control group: 38% of the joints had some kind of noise and several muscle sites were tender to palpation (splenius capitis muscle 50%, anterior masseter and temporal muscle 45%, insertion of the trapezius muscle 40%). In addition, according to Helkimo's Di. 90% of the controls would be classified as having mild to moderate dysfunction. The high prevalence of positive signs in the control sample calls for a less rigid definition of what is called a normal craniomandibular status and refutes the a priori establishment of a narrow set of criteria for normality. Some parameters showed a highly statistically significant difference among the control and patient group (p < .001): active range of motion, deviation upon opening, pain on mandibular movement, number of tender palpation points and the CMI and Di.