Mandibular position at chin-point guided closure, intercuspation and final deglutition in asymptomatic and...

This study compared the mandibular position at chin-point guided jaw closure, intercuspation and final deglutition (position at the end of swallowing) in 159 asymptomatic subjects and 142 subjects with symptoms in the craniomandibular system. The symptomatic subjects were assigned to four groups showing an adapted centric posture, pain, luxation with reduction of the temporomandibular joint and pain with luxation and reduction. Computer equipment aided recording of hinge axis movements in three dimensions. While the three positions differed significantly in anterior-posterior direction on both sides and in inferior-superior direction on the right, a significant difference between asymptomatic and symptomatic subjects existed only in final deglutition on the left side and in the anterior-posterior location of the guided closure. Final deglutition did not coincide with the guided closure or the intercuspation in approximately 89%. A proportionally large standard deviation gave evidence against a strict relationship of the three positions in asymptomatic and symptomatic subjects. Because of this variability, final deglutition was not recommended for verification of centric relation or the intercuspal position.