This study measured the amount of positional change in the terminal transverse horizontal axis of the mandible that results from altering undesirable neuromuscular influence. Centric relation records were made on 19 healthy subjects before and after deprogramming. The axis was located with a computerized axiograph, and the centric relation records were compared in vivo at the axis location. The positional change of the axis was quantified in three dimensions at an accuracy of ± 0.05 mm. The net amount of positional change was compared to scores from the temporomandibular joint scale to test for correlation with the potential for developing a temporomandibular disorder. The findings showed that the amount of positional change in the terminal transverse horizontal axis in 18 of 19 healthy patients after 12 hours of deprogramming was less than 0.5 mm and did not correlate with scores from the TMJ Scale. © 1992 The Editorial Council of The Journal of Prosthetic Dentistry.