ANGLE OF MOUTH OPENING MEASUREMENT - RELIABILITY OF A TECHNIQUE FOR TEMPOROMANDIBULAR-JOINT MOBILITY ASSESSMENT

The maximal interincisal distance added to the vertical overlap is gen erally used as a measure for temporomandibular joint mobility. However , the length of the mandible also has an influence on this measure. Th e angle of mouth opening as a measure of temporomandibular joint mobil ity is independent of the length of the mandible. The aim of the study was to develop a mandibular goniometer to measure the angle of mouth opening and to test its reliability. Ten subjects, two males and eight females (mean age 28.1 years) participated in the study. The measurem ents were performed during four independent sessions of three measurem ents each. The results were analysed with ANOVA. Intraobserver variabi lity was found to be 2.0 degrees when the result of all the measuremen ts were analysed, and were found to be 1. 2 degrees when the mean valu e of the sessions were used for analysis. Based on the results of this study it can be concluded that the angle of mouth opening can be meas ured reliably.