Lateral and anterior-posterior mandibular position discrimination by normal subjects

This study examined and compared lateral and anterior-posterior (A-P) mandibular position discrimination for a group of twenty normal subjects (mean age = 26 years). A specially designed and constructed sliding scale required subjects to position their mandible precisely in the horizontal plane and to try to discriminate differences in the control of their mandibular position. The results revealed that subjects are more sensitive in detecting changes in the lateral positioning of their mandible than in the A-P positions. Subjects' difference limen (DL) values (threshold of discrimination between two positions) in detecting changes in mandibular position to the right of centre was 1.59 mm, and to left of centre was 1.41 mm. Subjects' DL values obtained with the mandible forward, and back of, the reference position were 1.39 and 2.61 mm respectively.