Changes in condylar position using different types of splints with and without a chinstrap: a case-control study

The aim of this case-control study was to analyze and quantify if there is a different mechanical effect of stabilization and pivot splints with uni- or bilateral pivot of different heights and with and without an additional chinstrap, on the vertical, sagittal, and horizontal condyle position. A stabilization splint and splints with unilateral or bilateral posterior pivot support of 0.6 mm or 1.9 mm height were used with and without a chinstrap individually adjusted to 5N per side. Electronic-condylar-position-analysis was performed using an ultrasound-based jaw-tracking system with an accuracy of 0.1 mm. Manual guided central position served as the reference point. Participants were 40 functional, asymptomatic volunteers with a mean age of 33.9 years. Main effect splint design (stabilization, uni-, bilateral pivot) was not significant. Pivoting height was reported as significant (p < or = 0.02) in all axes. Use of the chinstrap was significant (p < or = 0.03) in the X- and Y- axis, but not significant in the Z-axis. A post-hoc test revealed that use of a chinstrap led to significantly (p = 0.003) less anterior and significantly (p = 0.002) more inferior condyle displacement. Results indicate that the use of pivot splints only in combination with a chinstrap lead to a distractive effect of the condyles.