Simplified technique to measure mandibular range of motion.

The validity and reliability of a simplified technique to measure mandibular range of motion was studied in 10 dentate subjects without symptoms. The simplified technique consisted of marking with a pencil the centric relation and maximum right, left, and protrusive positions and maximum opening. These markings were made on a tongue blade held against the maxillary anterior teeth with the mesioincisal embrasures between the mandibular central incisors used as a reference. Range of motion was also measured with a mandibular kinesiograph as the control. Each method was repeated five times on each subject by each of three investigators. Intraclass correlation coefficient demonstrated a moderate level of agreement between the two techniques and high inter-rater reliability for the three investigators for all positions except maximum left movement. These data support the hypothesis that this simplified technique is a valid and reliable way to measure mandibular range of motion.