Registration and measurement of opening and closing jaw movements and rotational mandibular capacity by using the method of electronic axiography.

The aim of this study was to register and measure lower jaw movements, to analyse the measured length of opening and closing movements and to analyse the rotational mandibular capacity during the maximal opening of the mouth in the position of centric relation. Our objective was to determine the average values for each mandible and temporomandibular joint movement, as well as to determine the accuracy of electronic axiography, while diagnosing temporomandibular joint disorders. A statistical analysis was performed in order to evaluate whether significant differences between the length of the measured movements in asymptomatic and symptomatic subjects could be found. A symptomatic group consisted of 51 subjects with temporomandibular disorders. A control group consisted of 43 subjects without signs and symptoms of temporomandibular joint disorders. Each subject was registered by the GAMMA CADIAX system for registration of position and movement of the lower jaw, which consists of a conventional SAM axiograph, an electronic device for drawing curves by means of a computer. No significant differences were found between the groups of subjects for the measured variables. The results of the length of the mandibular and condyle movements, along with the rotational capacity of the mandible are important, in spite of unreliable indicators of temporomandibular joint function. Description analysis of a graphic recording of mandibular and TMJ movement remains an accurate evaluation method for the determination of TMJ dysfunction.